Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Bruce Layne]

I'm starting to use larger quantities of filament in a small but growing
3D print farm.  I'd love to find someplace where I could buy 10-100 kg
of filament per order and be assured of good quality and good pricing,
but I've been surprised that my initial investigations have been mostly
fruitless.  Maybe my search-fu is weak, but it looks like online sources
aren't much better than Amazon.

I did stumble across MakeShaper.com.  I recently placed an order for two
2.25kg reels of ABS filament.  With the discount code from their website
and free shipping, it was 1.62 cents per gram, probably the least
expensive filament I've purchased, and it prints like a dream.  It's the
only filament I've ever used that doesn't dribble when the nozzle is
preheated, but it prints very well without stringing or blobs.  It
doesn't have the styrene smell of other ABS filament when printing.  The
filament feeds reliably from the spool and the diameter in both reels is
always 1.74mm or 1.75mm - much higher tolerance than other brands.  The
84th part just finished of a 100 part order.  In 30 minutes, the part
will contract and separate from the glass plate.  I'll lift it from the
bed effortlessly, apply a few milliliters of glue juice (10 grams of
Elmer's XTreme glue stick dissolved in 500 ml of distilled water), I'll
spread the glue juice on the glass bed with a nylon bristle brush and
press Print Another Copy.  Easy peasey.  Having good filament is
important to reliable and trouble free 3D printing.  I'm sure bad
filament is the source of a lot of frustration and failed prints.

If anyone has a good source of quality 3D printing filament at a good
price, particularly TPU, I'd love to hear your suggestion.





On 8/19/20 11:34 PM, James Isaac wrote:
>
>> The white pla is not the same stuff as the black, by a hell of a long row
> of apple trees.  Where the black is a brittle as can be cold, the white
> is much more forgiving,  . . .
>
> Back in about 1977, I got told the black plastic was the first that was 
> recycled.
> The people doing the recycling needed a consistent colour in their product,
> and hid the recycling by changing the colour to black.
> The quantity of additives needed to mask the multiple colours of the source 
> plastic changed the properties of the plastic at the same time.
>
> Sounds as though the same thing is happening today.
>
> James Isaac.
>
>
> 
> From: Gene Heskett 
> Sent: August 19, 2020 10:47 PM
> To: emc-users@lists.sourceforge.net 
> Subject: Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse
>
> On Wednesday 19 August 2020 19:17:08 Gene Heskett wrote:
>
> Well, I'm back, hat in hand.
>
> The white pla is not the same stuff as the black, by a hell of a long row
> of apple trees.  Where the black is a brittle as can be cold, the white
> is much more forgiving, AND it sticks to the glass about 1000 times
> better, I just interrupted the job because I moved the glass trying to
> get the priming . . .
>
> ___
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> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>


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Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[James Isaac]

> The white pla is not the same stuff as the black, by a hell of a long row
of apple trees.  Where the black is a brittle as can be cold, the white
is much more forgiving,  . . .

Back in about 1977, I got told the black plastic was the first that was 
recycled.
The people doing the recycling needed a consistent colour in their product,
and hid the recycling by changing the colour to black.
The quantity of additives needed to mask the multiple colours of the source 
plastic changed the properties of the plastic at the same time.

Sounds as though the same thing is happening today.

James Isaac.



From: Gene Heskett 
Sent: August 19, 2020 10:47 PM
To: emc-users@lists.sourceforge.net 
Subject: Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

On Wednesday 19 August 2020 19:17:08 Gene Heskett wrote:

Well, I'm back, hat in hand.

The white pla is not the same stuff as the black, by a hell of a long row
of apple trees.  Where the black is a brittle as can be cold, the white
is much more forgiving, AND it sticks to the glass about 1000 times
better, I just interrupted the job because I moved the glass trying to
get the priming . . .

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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[John Dammeyer]

> From: dave engvall [mailto:dengv...@charter.net]
> Ah, John,
> In the words of way too many math professors, "It is obvious that ." .

Hear hear!

Having said that though I must admit I probably use more math than most.  About 
11 years ago I had to look up Airy Disk effect and then do the math to work out 
lamp positions.  

https://en.wikipedia.org/wiki/Airy_disk#Mathematical_formulation

I think if anything that came from it all it's that the math courses gave me 
the confidence to attempt a solution.  It was really cool when the end result 
matched the math.

John Dammeyer


> 
> On 8/19/20 7:12 PM, John Dammeyer wrote:
> > My computer science degree required 4 terms of calculus, 2 terms of linear 
> > algebra, 2 terms of differential equations, 4 terms of
> physics and 2 terms of statistics.  I think that was all of it.  I also took 
> a nuclear physics course that was quite interesting.  The diff
> equations were part of the electrical engineering minor.
> >
> > Didn't really do much with astronomy so I really don't quite get how they 
> > figured out the distance to the sun.  But I thought it was
> interesting as is the book 'sapiens'.
> > https://www.amazon.com/Sapiens-Humankind-Yuval-Noah-Harari/dp/0062316095
> >
> > Oh and I remember almost none of all that math.  Too long ago.
> >
> > John Dammeyer
> >
> >> -Original Message-
> >> From: Chris Albertson [mailto:albertson.ch...@gmail.com]
> >> Sent: August-19-20 6:59 PM
> >> To: Enhanced Machine Controller (EMC)
> >> Subject: Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors
> >>
> >> Yes,  If this is a theoretical discussion then at the end of all the chains
> >> of reasoning it all comes to "mutually observed event".   If this is just
> >> engineering then it comes down to "the delay is so fast no one cares".
> >> -
> >> My background is computer science.   Computer science is a mash-up of
> >> mathematical theory and practical engineering.  In some classes we did
> >> proofs and others we built stuff.   It is kind of fun to look both ways.
> >>
> >> A real disaster happened at TRW some years back where us poor working
> >> minions were required to do proofs on the stuff we were building.   Looking
> >> both ways at the same time did not work.
> >>
> >> On Wed, Aug 19, 2020 at 6:10 PM John Dammeyer 
> >> wrote:
> >>
> >>>
>  From: John Dammeyer [mailto:jo...@autoartisans.com]
>  I was just reading a few weeks ago in the book "Sapiens" that the early
> >>> explorers set up an experiment where they would observe an
>  astronomical event from both England and the South Pacific.  Something
> >>> about either time or position.
>  I think it was Cook who was exploring at that point.  I'll have to dig
> >>> through to see exactly what it was.
>  Still quite something to plan on observing something that will take you
> >>> a year or more before you are even there to do the observing.
> >>> Chapter 15, The marriage of science and empire.  James Cook was
> >>> commissioned to take astronomers and others to the pacific to be there in
> >>> 1769 to measure the duration of the transit that Venus makes across the
> >>> sun.  Apparently measured from different places on earth results in simple
> >>> trigonometry to determine the distance of the earth from the sun.
> >>>
> >>> Who knew.
> >>>
> >>> John
> >>>
> >>>
> >>>
> >>>
> >>> ___
> >>> Emc-users mailing list
> >>> Emc-users@lists.sourceforge.net
> >>> https://lists.sourceforge.net/lists/listinfo/emc-users
> >>>
> >>
> >> --
> >>
> >> Chris Albertson
> >> Redondo Beach, California
> >>
> >> ___
> >> Emc-users mailing list
> >> Emc-users@lists.sourceforge.net
> >> https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> 
> 
> 
> ___
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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[dave engvall]

Ah, John,
In the words of way too many math professors, "It is obvious that ." .

On 8/19/20 7:12 PM, John Dammeyer wrote:

My computer science degree required 4 terms of calculus, 2 terms of linear 
algebra, 2 terms of differential equations, 4 terms of physics and 2 terms of 
statistics.  I think that was all of it.  I also took a nuclear physics course 
that was quite interesting.  The diff equations were part of the electrical 
engineering minor.

Didn't really do much with astronomy so I really don't quite get how they 
figured out the distance to the sun.  But I thought it was interesting as is 
the book 'sapiens'.
https://www.amazon.com/Sapiens-Humankind-Yuval-Noah-Harari/dp/0062316095

Oh and I remember almost none of all that math.  Too long ago.

John Dammeyer


-Original Message-
From: Chris Albertson [mailto:albertson.ch...@gmail.com]
Sent: August-19-20 6:59 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

Yes,  If this is a theoretical discussion then at the end of all the chains
of reasoning it all comes to "mutually observed event".   If this is just
engineering then it comes down to "the delay is so fast no one cares".
-
My background is computer science.   Computer science is a mash-up of
mathematical theory and practical engineering.  In some classes we did
proofs and others we built stuff.   It is kind of fun to look both ways.

A real disaster happened at TRW some years back where us poor working
minions were required to do proofs on the stuff we were building.   Looking
both ways at the same time did not work.

On Wed, Aug 19, 2020 at 6:10 PM John Dammeyer 
wrote:




From: John Dammeyer [mailto:jo...@autoartisans.com]
I was just reading a few weeks ago in the book "Sapiens" that the early

explorers set up an experiment where they would observe an

astronomical event from both England and the South Pacific.  Something

about either time or position.

I think it was Cook who was exploring at that point.  I'll have to dig

through to see exactly what it was.

Still quite something to plan on observing something that will take you

a year or more before you are even there to do the observing.
Chapter 15, The marriage of science and empire.  James Cook was
commissioned to take astronomers and others to the pacific to be there in
1769 to measure the duration of the transit that Venus makes across the
sun.  Apparently measured from different places on earth results in simple
trigonometry to determine the distance of the earth from the sun.

Who knew.

John




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--

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Gregg Eshelman via Emc-users]

Could build a crossed gantry printer 
https://hackaday.com/2020/08/19/re-imagining-the-crossed-gantry-3d-printer/
Toolchanging between plastic extruder and milling tool for high surface 
precision with FDM printing 
https://hackaday.com/2020/08/18/e3d-teaches-additive-machines-how-to-subtract/
Using a sharpie marker to make support removal much easier 
https://hackaday.com/2020/05/27/improving-3d-printed-supports-with-a-marker/This
 person automated it but pause commands inserted in the right place would make 
it possible to scribble on top of the support then resume.






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Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Gene Heskett]

On Wednesday 19 August 2020 19:17:08 Gene Heskett wrote:

Well, I'm back, hat in hand.

The white pla is not the same stuff as the black, by a hell of a long row 
of apple trees.  Where the black is a brittle as can be cold, the white 
is much more forgiving, AND it sticks to the glass about 1000 times 
better, I just interrupted the job because I moved the glass trying to 
get the priming strip off, and it was stuck tight enough my pulling it 
moved the glass despite clothes pins front and rear, and it took cold 
running water and three trips to the edge burnisher with the putty knife 
and half an hour to get the last of the first .4mm back off the glass. 
So obviously I can drop the bed temp about 10C from my usual startup. 
And set the nozzle temp down a ways too.

Right now the glass is clean clean, barkeeper's friend clean and well 
rinsed.  What would you guys do to reduce adhesion to manageable levels?

An extra obvious layer of this purple stick school glue?  Or ???

So far with that stuff, more is less and vice-versa.  Bare glass I get 
the impression would be a forever stuck disaster.

Thanks.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Chris Albertson]

I was not suggesting a cycloidal drive for your application.   You need
something that can't be back driven and harmonic is best.   My comment was
that soon you will know more than the designer of this thing.   I did that
with printed drone chassis.   I made a bunch then broke them and made more.
   Plastic works well for prototypes and learning but in the end you can't
beat metal for things like gears and bearings.

For my toy car project, I started with printing the ball bearing units as a
disk with a hole in it.  They work for about 5 minutes.  Nest I made them
from mild steel and they work well.   In the final build, I buy real deep
groove bearings.  Same with my printed timing belts.  They work for
hours.   Then I deside to change something.  When the design a fixed I'll
buy real belts, real bearings and make the motor mounts with aluminum.

In my case, I need back drivable reduction systems that are ultra
compact for robots.  I don't need a huge strength because a large impact
spins the motor backward and with luck we recover that energy back to the
battery.

If you design from the start around cheap bearing you can save a pile of
cash.  608ZZ type can be bought for 14 cents each from China
ebay.com/itm/100PCS-608-ZZ-Skateboard-Bearings-Double-Shielded-8x22x7


Same for smaller ones
https://www.ebay.com/itm/100pcs-623ZZ-Ball-Bearing-3x10x4mm


The trick is to find the good deals on bearings and screws FIRST, then do
the design.

On Wed, Aug 19, 2020 at 4:19 PM Gene Heskett  wrote:

> On Wednesday 19 August 2020 17:52:39 Chris Albertson wrote:
>
> > I suspect that in the end you will need to design your own reduction
> > drive from a clean sheet of paper using what you learn from building
> > this.  I think I'd make the gear teeth larger so that small printing
> > errors don't matter.
> >
> That also reduces the gear ratio. But I don't have that math handy other
> than to note I counted splines and decided it was a 30/1, but I am
> observing more than that I think.
>
> I've made the second new flexgear at the same scale is the other, and
> according to my measurements to get full mesh, I need a wave bearing of
> 74.23mm so since I've lost the scale references for that part, but have
> made several bigger, too big in fact, I switched PLA spools for some
> white that I can write notes on, and reset the printer for a scale of
> 80.00 per mm, a std I can do math from, and its made the cap, with
> prelim measurements indicating it will be about 74.10mm so I'm already
> pretty close.  The carrier I had in it, which is a hair too small, is
> 73.51, and a caliper stretching it to fit 100% at the apex's says I need
> 74.23.  I should be able to assemble and test this one around 21:00.
> That 74.23 is a 2 point measurement, but this carrier has 6 bearings, 3
> on each end. With the other 4 touching, 74.10 might be enough.
>
> I'm trying to conjure up a scheme to mount a good size rotron fan  on the
> top frame bar to come on and blow down on the plate to speed up the
> glass cooling at the end of the job.  The cooldown is a significant part
> of the production time for smaller parts like the bearing carrier
>
> > My plan with my plastic printed milling machine parts is to do a
> > boot-strap where I use the plastic machine to make metal parts.   You
> > might have to do that same, use the plastic reduction units to make a
> > better one in metal.
> >
> > I'm wanting to try to make one of there using rubber timing belts as
> > gear teeth.   There are some belt profiles that mesh with themselves
>
> Not without a cyclic velocity 

Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[John Dammeyer]

My computer science degree required 4 terms of calculus, 2 terms of linear 
algebra, 2 terms of differential equations, 4 terms of physics and 2 terms of 
statistics.  I think that was all of it.  I also took a nuclear physics course 
that was quite interesting.  The diff equations were part of the electrical 
engineering minor.  

Didn't really do much with astronomy so I really don't quite get how they 
figured out the distance to the sun.  But I thought it was interesting as is 
the book 'sapiens'.
https://www.amazon.com/Sapiens-Humankind-Yuval-Noah-Harari/dp/0062316095

Oh and I remember almost none of all that math.  Too long ago.

John Dammeyer

> -Original Message-
> From: Chris Albertson [mailto:albertson.ch...@gmail.com]
> Sent: August-19-20 6:59 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors
> 
> Yes,  If this is a theoretical discussion then at the end of all the chains
> of reasoning it all comes to "mutually observed event".   If this is just
> engineering then it comes down to "the delay is so fast no one cares".
> -
> My background is computer science.   Computer science is a mash-up of
> mathematical theory and practical engineering.  In some classes we did
> proofs and others we built stuff.   It is kind of fun to look both ways.
> 
> A real disaster happened at TRW some years back where us poor working
> minions were required to do proofs on the stuff we were building.   Looking
> both ways at the same time did not work.
> 
> On Wed, Aug 19, 2020 at 6:10 PM John Dammeyer 
> wrote:
> 
> >
> >
> > > From: John Dammeyer [mailto:jo...@autoartisans.com]
> > > I was just reading a few weeks ago in the book "Sapiens" that the early
> > explorers set up an experiment where they would observe an
> > > astronomical event from both England and the South Pacific.  Something
> > about either time or position.
> > >
> > > I think it was Cook who was exploring at that point.  I'll have to dig
> > through to see exactly what it was.
> > >
> > > Still quite something to plan on observing something that will take you
> > a year or more before you are even there to do the observing.
> > >
> >
> > Chapter 15, The marriage of science and empire.  James Cook was
> > commissioned to take astronomers and others to the pacific to be there in
> > 1769 to measure the duration of the transit that Venus makes across the
> > sun.  Apparently measured from different places on earth results in simple
> > trigonometry to determine the distance of the earth from the sun.
> >
> > Who knew.
> >
> > John
> >
> >
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> 
> 
> --
> 
> Chris Albertson
> Redondo Beach, California
> 
> ___
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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[Chris Albertson]

Yes,  If this is a theoretical discussion then at the end of all the chains
of reasoning it all comes to "mutually observed event".   If this is just
engineering then it comes down to "the delay is so fast no one cares".

My background is computer science.   Computer science is a mash-up of
mathematical theory and practical engineering.  In some classes we did
proofs and others we built stuff.   It is kind of fun to look both ways.

A real disaster happened at TRW some years back where us poor working
minions were required to do proofs on the stuff we were building.   Looking
both ways at the same time did not work.

On Wed, Aug 19, 2020 at 6:10 PM John Dammeyer 
wrote:

>
>
> > From: John Dammeyer [mailto:jo...@autoartisans.com]
> > I was just reading a few weeks ago in the book "Sapiens" that the early
> explorers set up an experiment where they would observe an
> > astronomical event from both England and the South Pacific.  Something
> about either time or position.
> >
> > I think it was Cook who was exploring at that point.  I'll have to dig
> through to see exactly what it was.
> >
> > Still quite something to plan on observing something that will take you
> a year or more before you are even there to do the observing.
> >
>
> Chapter 15, The marriage of science and empire.  James Cook was
> commissioned to take astronomers and others to the pacific to be there in
> 1769 to measure the duration of the transit that Venus makes across the
> sun.  Apparently measured from different places on earth results in simple
> trigonometry to determine the distance of the earth from the sun.
>
> Who knew.
>
> John
>
>
>
>
> ___
> Emc-users mailing list
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>


-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] OT: Anyone tried these auto lube units?

[Leonardo Marsaglia]

Thank you guys for all the replies :)

I'll give them a try and see how it goes.

El mié., 19 ago. 2020 a las 9:54, Todd Zuercher ()
escribió:

> I think I'd prefer a model with a pressure guage (but you could always add
> one in-line after the pump).  And for Linuxcnc I'd prefer one without the
> timer features and do the timing control in Linuxcnc.
>
> Todd Zuercher
> P. Graham Dunn Inc.
> 630 Henry Street
> Dalton, Ohio 44618
> Phone:  (330)828-2105ext. 2031
>
> -Original Message-
> From: Leonardo Marsaglia 
> Sent: Tuesday, August 18, 2020 7:06 PM
> To: Enhanced Machine Controller (EMC) 
> Subject: [Emc-users] OT: Anyone tried these auto lube units?
>
> [EXTERNAL EMAIL] Be sure links are safe.
>
> Hello guys,
>
> I'm about to purchase some automatic lube units for a copying lathe I'm
> retrofitting with LCNC and for the router project (which is alive again
> finally).
>
> I'm planning to use an auto lube unit like this:
>
>
> https://www.ebay.com/itm/CNC-Electromagnetic-Lubricant-Pump-Automatic-Lubricating-Oil-Pump-220V-HTS02-2L/184283971779?hash=item2ae82e40c3:g:TCMAAOSwiI1eYgJZ
>
>
> Do you have any experience with these? Should I try something a little
> more expensive just to play it safe?
>
> Thanks as always!
>
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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[John Dammeyer]

> From: John Dammeyer [mailto:jo...@autoartisans.com]
> I was just reading a few weeks ago in the book "Sapiens" that the early 
> explorers set up an experiment where they would observe an
> astronomical event from both England and the South Pacific.  Something about 
> either time or position.
> 
> I think it was Cook who was exploring at that point.  I'll have to dig 
> through to see exactly what it was.
> 
> Still quite something to plan on observing something that will take you a 
> year or more before you are even there to do the observing.
> 

Chapter 15, The marriage of science and empire.  James Cook was commissioned to 
take astronomers and others to the pacific to be there in 1769 to measure the 
duration of the transit that Venus makes across the sun.  Apparently measured 
from different places on earth results in simple trigonometry to determine the 
distance of the earth from the sun.

Who knew.

John




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Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Gene Heskett]

On Wednesday 19 August 2020 17:52:39 Chris Albertson wrote:

> I suspect that in the end you will need to design your own reduction
> drive from a clean sheet of paper using what you learn from building
> this.  I think I'd make the gear teeth larger so that small printing
> errors don't matter.
>
That also reduces the gear ratio. But I don't have that math handy other 
than to note I counted splines and decided it was a 30/1, but I am 
observing more than that I think.

I've made the second new flexgear at the same scale is the other, and 
according to my measurements to get full mesh, I need a wave bearing of 
74.23mm so since I've lost the scale references for that part, but have 
made several bigger, too big in fact, I switched PLA spools for some 
white that I can write notes on, and reset the printer for a scale of 
80.00 per mm, a std I can do math from, and its made the cap, with 
prelim measurements indicating it will be about 74.10mm so I'm already 
pretty close.  The carrier I had in it, which is a hair too small, is 
73.51, and a caliper stretching it to fit 100% at the apex's says I need 
74.23.  I should be able to assemble and test this one around 21:00.
That 74.23 is a 2 point measurement, but this carrier has 6 bearings, 3 
on each end. With the other 4 touching, 74.10 might be enough.

I'm trying to conjure up a scheme to mount a good size rotron fan  on the 
top frame bar to come on and blow down on the plate to speed up the 
glass cooling at the end of the job.  The cooldown is a significant part 
of the production time for smaller parts like the bearing carrier 

> My plan with my plastic printed milling machine parts is to do a
> boot-strap where I use the plastic machine to make metal parts.   You
> might have to do that same, use the plastic reduction units to make a
> better one in metal.
>
> I'm wanting to try to make one of there using rubber timing belts as
> gear teeth.   There are some belt profiles that mesh with themselves

Not without a cyclic velocity variation to deal with.  One of the secrets 
to the splined design is very constant velocity because the "teeth" are 
all carrying load as they slide down the mateing side ramps of the saw 
tooth spline format.  Thats primarily the reason I chose this project.  
Cycloid's share that but with all those bearings, bearing costs will eat 
your lunch.

Thanks Chris.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Chris Albertson]

I suspect that in the end you will need to design your own reduction drive
from a clean sheet of paper using what you learn from building this.  I
think I'd make the gear teeth larger so that small printing errors don't
matter.

My plan with my plastic printed milling machine parts is to do a boot-strap
where I use the plastic machine to make metal parts.   You might have to do
that same, use the plastic reduction units to make a better one in metal.

I'm wanting to try to make one of there using rubber timing belts as gear
teeth.   There are some belt profiles that mesh with themselves

On Wed, Aug 19, 2020 at 11:37 AM Gene Heskett  wrote:

> On Wednesday 19 August 2020 12:09:05 Gene Heskett wrote:
>
> > On Wednesday 19 August 2020 10:25:14 Greg Bernard wrote:
> > > Most hardware stores carry silicone grease for o-rings in the
> > > plumbing section. I'd be willing to bet it would work just fine for
> > > your purpose.
> >
> > Thats similar to DC-4, and I have some of that but its 60 yo.
> > "Borrowed" it while building titan ones up in SD in '60. But as a
> > lubricant, not to good, -0 surface tension. So I didn't think of it.
> >
> > Its running on a thin film of Lymans Super Moly barrel grease, seems
> > happy but its young yet. Running nicely at noon yet, at about 15 rpm
> > out, sounds like maybe 1000 revs in. Can't stop it by hand. More
> > making.
> >
> > Looked at printers, thought I'd found one in the Saphire, till I read
> > the reviews, zero support, crappily made, 9 reviews, all complaining.
> > Thumbs down.
> >
> But the cyclic noise seemed to be getting worse, like the tips of the
> splines were starting to drag again. So I took it apart, and found
> something else that bothers me, in addition to the motor mount screw
> back out an making a slight mark on the carrier, all 3 of the bearing
> carriers I have printed are .2mm non symmetrical, as in one center
> bearing runs .2mm farther from the shaft than the other. This is causing
> the whole cup to wobble and it can be seen and felt in the output
> flange.  Greased the inside of the cup. Went to garage and got a dial
> and found that on an inch dial, only around a thou difference. Put a
> bigger stator ring in it about .3mm bigger, just enough to make the
> bolts drag going back in. Back to running till? At max divisor and about
> 250 kilohertz steps. This gave it a just detectable backlash.  Way more
> than that in the BS-1's worm at best setting. Which may be where this
> one is going if I don't destroy it first  And I'm trying to find the
> weakest link here.  Another thing of note, at .5 amps a coil, the
> current mapping of these tb6560's sucks dead toads thru soda straws, the
> microstepping is nowhere linear. And makes the iron complain
> vocipherously.
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[John Dammeyer]

I was just reading a few weeks ago in the book "Sapiens" that the early 
explorers set up an experiment where they would observe an astronomical event 
from both England and the South Pacific.  Something about either time or 
position.

I think it was Cook who was exploring at that point.  I'll have to dig through 
to see exactly what it was.

Still quite something to plan on observing something that will take you a year 
or more before you are even there to do the observing.

John Dammeyer

> -Original Message-
> From: Chris Albertson [mailto:albertson.ch...@gmail.com]
> Sent: August-19-20 2:09 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors
> 
> I think the question was intended to be more theoretical and asks about
> "exactly" synchronizing commands. The LinuxCNC/SPI solution is not
> that.  SPI works only because it is so fast that the error in
> synchronization is tiny and goes unnoticed.
> 
> Here is a harder problem. Let's say I am in North America and by buddy
> lives in Europe and we want to each run clocks and we want them to stay in
> phase at a high level of accuracy.   To make matters worse assume this is
> the mid-1800s and the radio is not yet invented.  They actually solved this
> problem.  The solution was "mutually observed events" and we use this same
> solution today to keep widely dispersed machines in sync.   In the old
> days, they would observe one of Jupiter's moons from both America and
> Europe and assume they both say the moon transit the planet at the same
> time.  Orchestras use a conductor waving a stick who is "mutually
> observed" by all musicians.Same with a CAN bus, you could, if needed
> use a high priority "clock tick" message that all nodes see at the same
> time.
> 
> But in real-life.   We accept "close enough" and just us a SPI signal that
> is fast enough that no one notices the error.
> 
> On Tue, Aug 18, 2020 at 8:08 PM Frank Tkalcevic 
> wrote:
> 
> > > You subject line says RS485/CAN which are dramatically different from the
> > SPI based synchronous clocked serial interfaces.  Even RS485 and CAN are
> > dramatically different.
> >
> > Thanks for the replies...
> >
> > The question was around slower RS485/CAN.  I'm seeing a lot of actuators
> > (motor/gearbox/driver combinations) that are driven by CAN bus (MIT
> > cheetah).
> >
> > Brute speed seems to be a common solution, which I'm guessing protocols
> > like
> > EtherCAT rely on.
> >
> > Given the CAN bus speed limits - 1MHz, it doesn't seem possible to
> > send/receive messages to many motors at a typical LinuxCNC 1kHz rate.  Is
> > there some kind of "smarts" that let these control systems work smoothly at
> > lower update rates?
> >
> >
> >
> >
> >
> >
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> 
> 
> --
> 
> Chris Albertson
> Redondo Beach, California
> 
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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[John Dammeyer]

> -Original Message-
> From: N [mailto:nicklas.karlsso...@gmail.com]
> Sent: August-19-20 1:46 PM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors
> 
> > The usual technical solution for exact synchronization where commands must
> > go over a shared media is to time-tag the commands with the time when the
> > command is to be executed then send the commend in advance of that time.
> >  On a fast bus like CAN you only have to send the command a few
> > milliseconds in advance.  But on a slow channel such as a radio link to a
> > rover on Mars, they send commands hours or a day in advance.
> 
> In CANopen over a CAN bus standard method a sync message is used for this 
> purpose. Periodic PDOs are sent anywhere within
> communication period and started to be used then sync message is received, 
> usually COB-ID 0x80 but may be configured to other.
> 
> > On CAN you can take advantage of the fact that all devices read the bus at
> > the same time.  Each reader decides what information it wants to read and
> > ignore the rest so a time-sync heartbeat could be implemented if the nodes
> > all needed to be time synchonized.  So on CAN if it were needed I'd invent
> > a protocol that did something like this:  "motor A, On the mark, you are to
> > move to X", "motor B, On the mark, you are to move to Y", "MARK".
> 
> Sync is used for this purpose. The fact that all devices read the bus at the 
> same time may have some advantages, no crossing of
> messages may have some advantages then things should be agreed upon.
> 
> > For a robot on Mars, I would send a table of instructions where the first
> > column is the time to execute and the second column is the instruction
> > itself.   I would send the table then have the rover read it back to me to
> > verify. Then at some later time, the wheels would move and so on.
> 
> Read something in the CANopen about receive FIFO but are uncertain about 
> possibility to verify if properly received, guess simplest
> would be if receiver make complain if expected message not received in time 
> so it could be resent and in such case some missing
> messages could be expect without loss of any functionality. It will also work 
> for coordinated motion but add some delay but if path is
> known beforehand this is not a problem. FIFO will work for CNC path but EDM 
> will be worse.
> 
> Nnicklas Karlsson

CAN is a broadcast network using the "one to many" model and the associated 
high level protocols understand this.  I've been paid well to solve the "roll 
your own" protocols that don't quite understand the concept.

So a CANopen SDO message is a request for information from a specific node # 
that is contained in the identifier.   If the target node  doesn't respond in a 
particular amount of time the sender can ask again or mark that node as 
possibly having a problem.  That's an even higher level application issue.

At the lowest level the sender may well have had the message ACK'd by a node.  
Just perhaps not the node in question.  That's why you never ever ever send 
'toggle' messages over CAN bus.

The PDO messages are configured by the end user to contain a number of 
different Object Dictionary entries.  These are also launch and forget.  
There's no hand shaking involved in these.  So although you might send a PDO 
with XYZ and A values (16 bits each) the XY and A might well have received it 
but the Z missed it.

That can happen in that noisy environment mentioned previously where Z has gone 
into what is called the Error Passive State.  At this point if noise corrupts a 
message for Z but not for the others then it can't mark it with an ERROR FLAG 
and so the message won't be resent.  Now Z is out of sync with the rest.

Many years ago in collaboration with one of the semiconductor manufacturers I 
designed and we built what was called a CAN Bus Message Marker.  It used a 
custom CAN engine inside an FPGA to listen for particular IDs and then mark 
those messages n times with an ERROR flag.  It was a deterministic method of 
moving a single CAN receiver and/or transmitter into Error Warning, Error 
Passive and Bus Off.

The point of the tool was to verify that the supplier of the CAN based 
equipment was handling low level CAN errors correctly.  That was in 1995.

John Dammeyer




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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[Chris Albertson]

I think the question was intended to be more theoretical and asks about
"exactly" synchronizing commands. The LinuxCNC/SPI solution is not
that.  SPI works only because it is so fast that the error in
synchronization is tiny and goes unnoticed.

Here is a harder problem. Let's say I am in North America and by buddy
lives in Europe and we want to each run clocks and we want them to stay in
phase at a high level of accuracy.   To make matters worse assume this is
the mid-1800s and the radio is not yet invented.  They actually solved this
problem.  The solution was "mutually observed events" and we use this same
solution today to keep widely dispersed machines in sync.   In the old
days, they would observe one of Jupiter's moons from both America and
Europe and assume they both say the moon transit the planet at the same
time.  Orchestras use a conductor waving a stick who is "mutually
observed" by all musicians.Same with a CAN bus, you could, if needed
use a high priority "clock tick" message that all nodes see at the same
time.

But in real-life.   We accept "close enough" and just us a SPI signal that
is fast enough that no one notices the error.

On Tue, Aug 18, 2020 at 8:08 PM Frank Tkalcevic 
wrote:

> > You subject line says RS485/CAN which are dramatically different from the
> SPI based synchronous clocked serial interfaces.  Even RS485 and CAN are
> dramatically different.
>
> Thanks for the replies...
>
> The question was around slower RS485/CAN.  I'm seeing a lot of actuators
> (motor/gearbox/driver combinations) that are driven by CAN bus (MIT
> cheetah).
>
> Brute speed seems to be a common solution, which I'm guessing protocols
> like
> EtherCAT rely on.
>
> Given the CAN bus speed limits - 1MHz, it doesn't seem possible to
> send/receive messages to many motors at a typical LinuxCNC 1kHz rate.  Is
> there some kind of "smarts" that let these control systems work smoothly at
> lower update rates?
>
>
>
>
>
>
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>


-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

Quite often used a lot lower speed than maximum on CAN bus, in some cases cable 
is long and while in other cases an ordinary cable not optimized for maximum 
speed is used. Sometimes only slow communication is needed so possibility to 
reduce speed to accomodate these case are good.

> Yes, that works in your case where the cable is short.   But what if this
> were a CAN bus in a very noisy environment. So noisy that only slow speed
> could work.   Image an electric car and you want to keep the from and rear
> traction motors "balanced" so they don't work in opposition and you care
> about 0.1% gains in efficiency.   These are 120 horsepower three-phase
> motors working at 400 volts DC.  Your CAN bus is slow.  Your bos is nuts
> and demands you solution have a 50 year design lifetime in an
> automotive environment.   Tesla engineers solves this problem.
> 
> Now image you are given the same problem, Ok smaller moters, but this time
> the "cable" has to reach to Mars and has a 14 minute speed of light delay.
> And the environment is even worse than "automotive".   JPL engineers seem
> to have solved this. (They could be the same engineers.  Both places are
> within commute distance of my house and people here swap jobs every few
> years.)
> 
> Here is one of by favorite "synchronized motors" videos.  "Atlas is a 28
> degree of freedom machine.   All 28 motors are well synced
> https://youtu.be/knoOXBLFQ-s?t=42
> 
> Here is another.  They built by mear mortals at a much lower cost.  They
> use motors from quadcopter drones and some CNC'd metal parts. These are 12
> "axis" machines, with three motors and three rotary encoders per leg.
> These are "Open Source" so you can download the design files.
>  https://youtu.be/G6fMV1UPzkg?t=86
> 
> SO motor syncing is possible and is done.  The machine tool use case is
> actually easy compared to other things
> 
> 
> 
> 
> 
> On Tue, Aug 18, 2020 at 5:41 PM Gene Heskett  wrote:
> 
> > On Tuesday 18 August 2020 18:58:01 Frank Tkalcevic wrote:
> >
> > > An off topic question, not directly LinuxCNC related...
> > >
> > > How are motors on a serial bus controlled and synchronised?
> > >
> > > My only real control experience is with LinuxCNC with Mesa and
> > > parallel port hardware where commands and feedback and precisely
> > > timed.  Sending commands and receiving feedback over a serial link I
> > > would expect to cause synchronising problems, and the bandwidth would
> > > reduce the update rate.
> > >
> > > How are these issues handled?  I tried googling this, but didn't find
> > > much -  I wasn't sure what to search for.
> > >
> > By running the serial connection at many megabaud speeds. With spi, I am
> > issueing 32 bit command words with the pi's gpio's, writing to the 7i90
> > at 40 megabaud, and reading the 7i90's replies at 25 megabaud.  With a
> > transmission line only an inch long, its bulletproof.
> >
> > > Thanks,
> > > Frank
> > >
> > >
> > >
> > >
> > >
> > >
> > > ___
> > > Emc-users mailing list
> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> >
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > If we desire respect for the law, we must first make the law respectable.
> >  - Louis D. Brandeis
> > Genes Web page 
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
> 
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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> The usual technical solution for exact synchronization where commands must
> go over a shared media is to time-tag the commands with the time when the
> command is to be executed then send the commend in advance of that time.
>  On a fast bus like CAN you only have to send the command a few
> milliseconds in advance.  But on a slow channel such as a radio link to a
> rover on Mars, they send commands hours or a day in advance.

In CANopen over a CAN bus standard method a sync message is used for this 
purpose. Periodic PDOs are sent anywhere within communication period and 
started to be used then sync message is received, usually COB-ID 0x80 but may 
be configured to other.

> On CAN you can take advantage of the fact that all devices read the bus at
> the same time.  Each reader decides what information it wants to read and
> ignore the rest so a time-sync heartbeat could be implemented if the nodes
> all needed to be time synchonized.  So on CAN if it were needed I'd invent
> a protocol that did something like this:  "motor A, On the mark, you are to
> move to X", "motor B, On the mark, you are to move to Y", "MARK".

Sync is used for this purpose. The fact that all devices read the bus at the 
same time may have some advantages, no crossing of messages may have some 
advantages then things should be agreed upon.

> For a robot on Mars, I would send a table of instructions where the first
> column is the time to execute and the second column is the instruction
> itself.   I would send the table then have the rover read it back to me to
> verify. Then at some later time, the wheels would move and so on.

Read something in the CANopen about receive FIFO but are uncertain about 
possibility to verify if properly received, guess simplest would be if receiver 
make complain if expected message not received in time so it could be resent 
and in such case some missing messages could be expect without loss of any 
functionality. It will also work for coordinated motion but add some delay but 
if path is known beforehand this is not a problem. FIFO will work for CNC path 
but EDM will be worse.

Nnicklas Karlsson


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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[Chris Albertson]

Yes, that works in your case where the cable is short.   But what if this
were a CAN bus in a very noisy environment. So noisy that only slow speed
could work.   Image an electric car and you want to keep the from and rear
traction motors "balanced" so they don't work in opposition and you care
about 0.1% gains in efficiency.   These are 120 horsepower three-phase
motors working at 400 volts DC.  Your CAN bus is slow.  Your bos is nuts
and demands you solution have a 50 year design lifetime in an
automotive environment.   Tesla engineers solves this problem.

Now image you are given the same problem, Ok smaller moters, but this time
the "cable" has to reach to Mars and has a 14 minute speed of light delay.
And the environment is even worse than "automotive".   JPL engineers seem
to have solved this. (They could be the same engineers.  Both places are
within commute distance of my house and people here swap jobs every few
years.)

Here is one of by favorite "synchronized motors" videos.  "Atlas is a 28
degree of freedom machine.   All 28 motors are well synced
https://youtu.be/knoOXBLFQ-s?t=42

Here is another.  They built by mear mortals at a much lower cost.  They
use motors from quadcopter drones and some CNC'd metal parts. These are 12
"axis" machines, with three motors and three rotary encoders per leg.
These are "Open Source" so you can download the design files.
 https://youtu.be/G6fMV1UPzkg?t=86

SO motor syncing is possible and is done.  The machine tool use case is
actually easy compared to other things





On Tue, Aug 18, 2020 at 5:41 PM Gene Heskett  wrote:

> On Tuesday 18 August 2020 18:58:01 Frank Tkalcevic wrote:
>
> > An off topic question, not directly LinuxCNC related...
> >
> > How are motors on a serial bus controlled and synchronised?
> >
> > My only real control experience is with LinuxCNC with Mesa and
> > parallel port hardware where commands and feedback and precisely
> > timed.  Sending commands and receiving feedback over a serial link I
> > would expect to cause synchronising problems, and the bandwidth would
> > reduce the update rate.
> >
> > How are these issues handled?  I tried googling this, but didn't find
> > much -  I wasn't sure what to search for.
> >
> By running the serial connection at many megabaud speeds. With spi, I am
> issueing 32 bit command words with the pi's gpio's, writing to the 7i90
> at 40 megabaud, and reading the 7i90's replies at 25 megabaud.  With a
> transmission line only an inch long, its bulletproof.
>
> > Thanks,
> > Frank
> >
> >
> >
> >
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>


-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> Have a read on the manuals for the Yaskawa Legend 01  or 04
> 
> It uses serial at 9600 !!! to command the drive.  (RS232 serial, or
> ethernet interface)
> The trick it uses is to send only new, relevant data, and not fixed packets

Good enough for configuration but not coordinated movement in real time. Most 
drives have digital inputs for on/off, reverse/forward and analog input for 
speed. Guess you need an extra module/card to get a CAN interface.


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[Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[Roland Jollivet]

Have a read on the manuals for the Yaskawa Legend 01  or 04

It uses serial at 9600 !!! to command the drive.  (RS232 serial, or
ethernet interface)
The trick it uses is to send only new, relevant data, and not fixed packets

Roland


On Wed, 19 Aug 2020 at 01:31, Frank Tkalcevic 
wrote:

> An off topic question, not directly LinuxCNC related...
>
> How are motors on a serial bus controlled and synchronised?
>
> My only real control experience is with LinuxCNC with Mesa and parallel
> port hardware where commands and feedback and precisely timed.  Sending
> commands and receiving feedback over a serial link I would expect to cause
> synchronising problems, and the bandwidth would reduce the update rate.
>
> How are these issues handled?  I tried googling this, but didn't find much
> -  I wasn't sure what to search for.
>
> Thanks,
> Frank
>
>
>
>
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[Chris Albertson]

The usual technical solution for exact synchronization where commands must
go over a shared media is to time-tag the commands with the time when the
command is to be executed then send the commend in advance of that time.
 On a fast bus like CAN you only have to send the command a few
milliseconds in advance.  But on a slow channel such as a radio link to a
rover on Mars, they send commands hours or a day in advance.

You can also use implied time tags where commands are sent in blocks and
the rule is to execute everything in a block at the start of (say) the next
time interval.Audio and video that is streamed over the Internet work
like that.   The audio and video are sent in "frames" and there is an
agreed frame rate and it all gets resynced by the display device.

On CAN you can take advantage of the fact that all devices read the bus at
the same time.  Each reader decides what information it wants to read and
ignore the rest so a time-sync heartbeat could be implemented if the nodes
all needed to be time synchonized.  So on CAN if it were needed I'd invent
a protocol that did something like this:  "motor A, On the mark, you are to
move to X", "motor B, On the mark, you are to move to Y", "MARK".

For a robot on Mars, I would send a table of instructions where the first
column is the time to execute and the second column is the instruction
itself.   I would send the table then have the rover read it back to me to
verify. Then at some later time, the wheels would move and so on.





On Tue, Aug 18, 2020 at 4:31 PM Frank Tkalcevic 
wrote:

> An off topic question, not directly LinuxCNC related...
>
> How are motors on a serial bus controlled and synchronised?
>
> My only real control experience is with LinuxCNC with Mesa and parallel
> port hardware where commands and feedback and precisely timed.  Sending
> commands and receiving feedback over a serial link I would expect to cause
> synchronising problems, and the bandwidth would reduce the update rate.
>
> How are these issues handled?  I tried googling this, but didn't find much
> -  I wasn't sure what to search for.
>
> Thanks,
> Frank
>
>
>
>
>
>
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-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] OT: Synchronised motion using RS485/CAN bus motors

[N]

> > From: Frank Tkalcevic [mailto:fr...@franksworkshop.com.au]
> > > You subject line says RS485/CAN which are dramatically different from the
> > SPI based synchronous clocked serial interfaces.  Even RS485 and CAN are
> > dramatically different.
> > 
> > Thanks for the replies...
> > 
> > The question was around slower RS485/CAN.  I'm seeing a lot of actuators
> > (motor/gearbox/driver combinations) that are driven by CAN bus (MIT
> > cheetah).
> > 
> > Brute speed seems to be a common solution, which I'm guessing protocols like
> > EtherCAT rely on.
> > 
> > Given the CAN bus speed limits - 1MHz, it doesn't seem possible to
> > send/receive messages to many motors at a typical LinuxCNC 1kHz rate.  Is
> > there some kind of "smarts" that let these control systems work smoothly at
> > lower update rates?
> > 
> Most CAN based Step or Servo motors can operate in position or speed mode.  
> In speed mode you can also set torque values.   They work well for say pick 
> and place or tool changers etc.  And anything else where you might want 
> precision motion or torque control.
> 
> Generally the motors come in two flavours supporting either J1939 or CANopen. 
>  Recall I mentioned that CAN messages have 11 bit IDs and up to 8 data bytes. 
>  To set up or control a motor you send Service Data Object messages (SDO) 
> writing to the device object dictionary (OD).  You get information back by 
> reading from the OD.
> 
> When working with CAN bus it's handy to have some sort of dongle for 
> receiving and sending messages.  Once such device is a CANUSB from Lawicel I 
> Sweden.
> www.canusb.com

And an application to read/write the dictionary using an .eds or .dcf file.


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Re: [Emc-users] What cables between 7i44 and 7i70/7i71

[Leonardo Marsaglia]

I bought CAT 5 cables to Mesa when I ordered the boards. If I'm not
mistaken CAT 6 is a good option too recommended by Mesa.

They work flawlessly.

Leonardo Marsaglia

El mié., 19 ago. 2020 15:39, Viesturs Lācis 
escribió:

> Hello!
>
> Just a quick question about requirements for cables between 7i44 and
> 7i70 or 7i71 boards. Are there any special requirements or can I use
> usual CAT5 LAN cables? Is there anything special about pinout? I
> recall that there are "normal" LAN cables and there are "crossover"
> cables...
>
> Viesturs
>
>
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Re: [Emc-users] What cables between 7i44 and 7i70/7i71

[Peter C. Wallace]

On Wed, 19 Aug 2020, Viesturs L?cis wrote:


Date: Wed, 19 Aug 2020 21:36:55 +0300
From: "[UTF-8] Viesturs L?cis" 
Reply-To: "Enhanced Machine Controller (EMC)"

To: "Enhanced Machine Controller (EMC)" 
Subject: [Emc-users] What cables between 7i44 and 7i70/7i71

Hello!

Just a quick question about requirements for cables between 7i44 and
7i70 or 7i71 boards. Are there any special requirements or can I use
usual CAT5 LAN cables? Is there anything special about pinout? I
recall that there are "normal" LAN cables and there are "crossover"
cables...

Viesturs





Standard straight through CAT5 cable are fine
crossover cables will not work



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Peter Wallace
Mesa Electronics

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Re: [Emc-users] 7i73 Lagging jog key

[Peter C. Wallace]

On Wed, 19 Aug 2020, Thaddeus Waldner wrote:


Date: Wed, 19 Aug 2020 13:04:54 -0500
From: Thaddeus Waldner 
Reply-To: "Enhanced Machine Controller (EMC)"

To: "Enhanced Machine Controller (EMC)" 
Subject: Re: [Emc-users] 7i73 Lagging jog key

Can someone define a good way to test the keypad scan signals? I put a scope on 
a circuit and it appears that the signals stands out clearly from the noise. I 
don??t know what the switch thresholds are so the noise could still be enough 
to cause issues. Setting the scope trigger voltage to about 1/3 of the scan 
voltage causes it to trigger on noise.

Should I be doing anything to condition the keypad lines? Pullup resistors are 
internal, so I connected them directly to the 7i73.


Could unused pins be an issue?



No additional components should be needed

Are the keycodes actually delayed?

The keypad scanning/debouncing adds about 30 ms delay to make and break
but nothing like 100/300 ms

If keycodes are delayed, it does suggest a noise issue in the keypad signals
but its not really clear if this is the case

Can you try with just the 7I73 a single switch
and no additions connections to eliminate ground bumping noise issues








On Aug 7, 2020, at 1:34 PM, Gene Heskett  wrote:

On Friday 07 August 2020 14:07:04 Thaddeus Waldner wrote:


I finally got to do a little troubleshooting and here??s what I found:

Key response on the keypad is never as fast as the on-screen UI but it
is consistent. I??m guessing there??s about a 100-300 ms delay but
that??s just a guess. Could this delay be due to the fact that this is
a scanning keypad? What is the scan rate on

Once the inverter starts, I get a LOT of noise on the SmartSerial
lines. The noise voltage is around 4v  as measured from the 7i73
ground but it spikes to higher than that. Frequency is about 40khz but
it??s not consistent.


Check the invertor for a ground that does not go directly to that single 
bolt or buss bar I preach about. If its connected to that bolt, lift it 
and see if its still grounded someplace else, and isolate it from that 
unwanted ground. Then hook it back up to the common bolt.  The static 
ground line to the invertors PSU should go only to this bolt. The static 
ground in the power cord should go to this bolt.  But only once if there 
are more than one power cord.


In rare cases, the moving parts of the machine, such as the table and Z 
sled or knee should be jumpered to the machine frame, and that frame 
connected to this common bolt. Well oiled moving ways are not that great 
an ohmic connection if actively moving on a film of oil.



The noise on the 5v power supply line to the 7i73 is minimal. The 7i73
and all its connected switches are grounded only through the board??s
connection to the 7i96 board.

Would a shielded ethernet cable help?


You could try it, but I'd have doubts. Shielding only grounded at one 
end. Both make a ground loop you don't need or want.




IHTH.


On Jul 31, 2020, at 9:17 AM, andy pugh  wrote:

On Fri, 31 Jul 2020 at 15:15, Peter C. Wallace  

wrote:

Also even with default sserial error management you could only have
10 servo thread cycles (10 ms with a 1 ms servo thread) of delay
due to failed transactions before a sserial error popup would
occur.


Maybe noise on the keyboard itself? Is the keycode pin a single
clean transition?

--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
?? George Fitch, Atlanta Constitution Newspaper, 1912


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Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page >


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Mesa Electronics

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Re: [Emc-users] 7i73 Lagging jog key

[Gene Heskett]

On Wednesday 19 August 2020 14:04:54 Thaddeus Waldner wrote:

> Can someone define a good way to test the keypad scan signals? I put a
> scope on a circuit and it appears that the signals stands out clearly
> from the noise. I don’t know what the switch thresholds are so the
> noise could still be enough to cause issues. Setting the scope trigger
> voltage to about 1/3 of the scan voltage causes it to trigger on
> noise.
>
> Should I be doing anything to condition the keypad lines? Pullup
> resistors are internal, so I  connected them directly to the 7i73.
>
> Could unused pins be an issue?

Only if a lot of wire is attached. But I'd suspect ground loops from a 
lack of single point grounding is the real problem.

> > On Aug 7, 2020, at 1:34 PM, Gene Heskett 
> > wrote:
> >
> > On Friday 07 August 2020 14:07:04 Thaddeus Waldner wrote:
> >> I finally got to do a little troubleshooting and here’s what I
> >> found:
> >>
> >> Key response on the keypad is never as fast as the on-screen UI but
> >> it is consistent. I’m guessing there’s about a 100-300 ms delay but
> >> that’s just a guess. Could this delay be due to the fact that this
> >> is a scanning keypad? What is the scan rate on
> >>
> >> Once the inverter starts, I get a LOT of noise on the SmartSerial
> >> lines. The noise voltage is around 4v  as measured from the 7i73
> >> ground but it spikes to higher than that. Frequency is about 40khz
> >> but it’s not consistent.
> >
> > Check the invertor for a ground that does not go directly to that
> > single bolt or buss bar I preach about. If its connected to that
> > bolt, lift it and see if its still grounded someplace else, and
> > isolate it from that unwanted ground. Then hook it back up to the
> > common bolt.  The static ground line to the invertors PSU should go
> > only to this bolt. The static ground in the power cord should go to
> > this bolt.  But only once if there are more than one power cord.
> >
> > In rare cases, the moving parts of the machine, such as the table
> > and Z sled or knee should be jumpered to the machine frame, and that
> > frame connected to this common bolt. Well oiled moving ways are not
> > that great an ohmic connection if actively moving on a film of oil.
> >
> >> The noise on the 5v power supply line to the 7i73 is minimal. The
> >> 7i73 and all its connected switches are grounded only through the
> >> board’s connection to the 7i96 board.
> >>
> >> Would a shielded ethernet cable help?
> >
> > You could try it, but I'd have doubts. Shielding only grounded at
> > one end. Both make a ground loop you don't need or want.
> >
> >
> > IHTH.
> >
> >>> On Jul 31, 2020, at 9:17 AM, andy pugh  wrote:
> >>>
> >>> On Fri, 31 Jul 2020 at 15:15, Peter C. Wallace 
> >
> > wrote:
>  Also even with default sserial error management you could only
>  have 10 servo thread cycles (10 ms with a 1 ms servo thread) of
>  delay due to failed transactions before a sserial error popup
>  would occur.
> >>>
> >>> Maybe noise on the keyboard itself? Is the keycode pin a single
> >>> clean transition?
> >>>
> >>> --
> >>> atp
> >>> "A motorcycle is a bicycle with a pandemonium attachment and is
> >>> designed for the especial use of mechanical geniuses, daredevils
> >>> and lunatics."
> >>> — George Fitch, Atlanta Constitution Newspaper, 1912
> >>>
> >>>
> >>> ___
> >>> Emc-users mailing list
> >>> Emc-users@lists.sourceforge.net
> >>> https://lists.sourceforge.net/lists/listinfo/emc-users
> >>
> >> ___
> >> Emc-users mailing list
> >> Emc-users@lists.sourceforge.net
> >> 
> >> https://lists.sourceforge.net/lists/listinfo/emc-users
> >> 
> >
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> > soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > If we desire respect for the law, we must first make the law
> > respectable. - Louis D. Brandeis
> > Genes Web page  > >
> >
> >
> > ___
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> > Emc-users@lists.sourceforge.net
> > 
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> > 
>
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Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 

[Emc-users] What cables between 7i44 and 7i70/7i71

[Viesturs Lācis]

Hello!

Just a quick question about requirements for cables between 7i44 and
7i70 or 7i71 boards. Are there any special requirements or can I use
usual CAT5 LAN cables? Is there anything special about pinout? I
recall that there are "normal" LAN cables and there are "crossover"
cables...

Viesturs


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Re: [Emc-users] 7i73 Lagging jog key

[Chris Albertson]

I wonder if there is some aggressive switch de-bounce happening.   Without
looking at your hal file, I'd bet there is a software debounce.   If so it
has to wait until it sees a steady-state on the pin for some period of
time.  Any random noise above some threshold would re-set the waiting time.

Two ways to address that.   (1) do hardware debounce with an RC circuit.
and (2) clean up the noise issue.  YOu would like for noise to be one full
order of magnitude below the signal.   This is a reasonable goal is ANY
system like this and should be easy to achieve.

On my do-to list, to design simple hardware debounce PCB that uses some RC
filters and a Schmitt trigger.

On Wed, Aug 19, 2020 at 11:07 AM Thaddeus Waldner 
wrote:

> Can someone define a good way to test the keypad scan signals? I put a
> scope on a circuit and it appears that the signals stands out clearly from
> the noise. I don’t know what the switch thresholds are so the noise could
> still be enough to cause issues. Setting the scope trigger voltage to about
> 1/3 of the scan voltage causes it to trigger on noise.
>
> Should I be doing anything to condition the keypad lines? Pullup resistors
> are internal, so I  connected them directly to the 7i73.
>
> Could unused pins be an issue?
>
>
> > On Aug 7, 2020, at 1:34 PM, Gene Heskett  wrote:
> >
> > On Friday 07 August 2020 14:07:04 Thaddeus Waldner wrote:
> >
> >> I finally got to do a little troubleshooting and here’s what I found:
> >>
> >> Key response on the keypad is never as fast as the on-screen UI but it
> >> is consistent. I’m guessing there’s about a 100-300 ms delay but
> >> that’s just a guess. Could this delay be due to the fact that this is
> >> a scanning keypad? What is the scan rate on
> >>
> >> Once the inverter starts, I get a LOT of noise on the SmartSerial
> >> lines. The noise voltage is around 4v  as measured from the 7i73
> >> ground but it spikes to higher than that. Frequency is about 40khz but
> >> it’s not consistent.
> >
> > Check the invertor for a ground that does not go directly to that single
> > bolt or buss bar I preach about. If its connected to that bolt, lift it
> > and see if its still grounded someplace else, and isolate it from that
> > unwanted ground. Then hook it back up to the common bolt.  The static
> > ground line to the invertors PSU should go only to this bolt. The static
> > ground in the power cord should go to this bolt.  But only once if there
> > are more than one power cord.
> >
> > In rare cases, the moving parts of the machine, such as the table and Z
> > sled or knee should be jumpered to the machine frame, and that frame
> > connected to this common bolt. Well oiled moving ways are not that great
> > an ohmic connection if actively moving on a film of oil.
> >
> >> The noise on the 5v power supply line to the 7i73 is minimal. The 7i73
> >> and all its connected switches are grounded only through the board’s
> >> connection to the 7i96 board.
> >>
> >> Would a shielded ethernet cable help?
> >
> > You could try it, but I'd have doubts. Shielding only grounded at one
> > end. Both make a ground loop you don't need or want.
> >>
> >
> > IHTH.
> >
> >>> On Jul 31, 2020, at 9:17 AM, andy pugh  wrote:
> >>>
> >>> On Fri, 31 Jul 2020 at 15:15, Peter C. Wallace 
> > wrote:
>  Also even with default sserial error management you could only have
>  10 servo thread cycles (10 ms with a 1 ms servo thread) of delay
>  due to failed transactions before a sserial error popup would
>  occur.
> >>>
> >>> Maybe noise on the keyboard itself? Is the keycode pin a single
> >>> clean transition?
> >>>
> >>> --
> >>> atp
> >>> "A motorcycle is a bicycle with a pandemonium attachment and is
> >>> designed for the especial use of mechanical geniuses, daredevils and
> >>> lunatics."
> >>> — George Fitch, Atlanta Constitution Newspaper, 1912
> >>>
> >>>
> >>> ___
> >>> Emc-users mailing list
> >>> Emc-users@lists.sourceforge.net
> >>> https://lists.sourceforge.net/lists/listinfo/emc-users
> >>
> >> ___
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> >> Emc-users@lists.sourceforge.net  >
> >> https://lists.sourceforge.net/lists/listinfo/emc-users <
> https://lists.sourceforge.net/lists/listinfo/emc-users>
> >
> >
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> > soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > If we desire respect for the law, we must first make the law respectable.
> > - Louis D. Brandeis
> > Genes Web page  http://geneslinuxbox.net:6309/gene>>
> >
> >
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> > https://lists.sourceforge.net/lists/listinfo/emc-users <
> 

Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Gene Heskett]

On Wednesday 19 August 2020 12:09:05 Gene Heskett wrote:

> On Wednesday 19 August 2020 10:25:14 Greg Bernard wrote:
> > Most hardware stores carry silicone grease for o-rings in the
> > plumbing section. I'd be willing to bet it would work just fine for
> > your purpose.
>
> Thats similar to DC-4, and I have some of that but its 60 yo.
> "Borrowed" it while building titan ones up in SD in '60. But as a
> lubricant, not to good, -0 surface tension. So I didn't think of it.
>
> Its running on a thin film of Lymans Super Moly barrel grease, seems
> happy but its young yet. Running nicely at noon yet, at about 15 rpm
> out, sounds like maybe 1000 revs in. Can't stop it by hand. More
> making.
>
> Looked at printers, thought I'd found one in the Saphire, till I read
> the reviews, zero support, crappily made, 9 reviews, all complaining.
> Thumbs down.
>
But the cyclic noise seemed to be getting worse, like the tips of the 
splines were starting to drag again. So I took it apart, and found 
something else that bothers me, in addition to the motor mount screw 
back out an making a slight mark on the carrier, all 3 of the bearing 
carriers I have printed are .2mm non symmetrical, as in one center 
bearing runs .2mm farther from the shaft than the other. This is causing 
the whole cup to wobble and it can be seen and felt in the output 
flange.  Greased the inside of the cup. Went to garage and got a dial 
and found that on an inch dial, only around a thou difference. Put a 
bigger stator ring in it about .3mm bigger, just enough to make the 
bolts drag going back in. Back to running till? At max divisor and about 
250 kilohertz steps. This gave it a just detectable backlash.  Way more 
than that in the BS-1's worm at best setting. Which may be where this 
one is going if I don't destroy it first  And I'm trying to find the 
weakest link here.  Another thing of note, at .5 amps a coil, the 
current mapping of these tb6560's sucks dead toads thru soda straws, the 
microstepping is nowhere linear. And makes the iron complain 
vocipherously.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] 7i73 Lagging jog key

[andy pugh]

On Wed, 19 Aug 2020 at 19:07, Thaddeus Waldner  wrote:

> Could unused pins be an issue?

I have seen unused pins charge up and carry a signal into the next pin
in the multiplexer, in multiplexed ADC.
But whether that might be a problem here would need PCWs expertise.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] 7i73 Lagging jog key

[Thaddeus Waldner]

Can someone define a good way to test the keypad scan signals? I put a scope on 
a circuit and it appears that the signals stands out clearly from the noise. I 
don’t know what the switch thresholds are so the noise could still be enough to 
cause issues. Setting the scope trigger voltage to about 1/3 of the scan 
voltage causes it to trigger on noise.

Should I be doing anything to condition the keypad lines? Pullup resistors are 
internal, so I  connected them directly to the 7i73.

Could unused pins be an issue?


> On Aug 7, 2020, at 1:34 PM, Gene Heskett  wrote:
> 
> On Friday 07 August 2020 14:07:04 Thaddeus Waldner wrote:
> 
>> I finally got to do a little troubleshooting and here’s what I found:
>> 
>> Key response on the keypad is never as fast as the on-screen UI but it
>> is consistent. I’m guessing there’s about a 100-300 ms delay but
>> that’s just a guess. Could this delay be due to the fact that this is
>> a scanning keypad? What is the scan rate on
>> 
>> Once the inverter starts, I get a LOT of noise on the SmartSerial
>> lines. The noise voltage is around 4v  as measured from the 7i73
>> ground but it spikes to higher than that. Frequency is about 40khz but
>> it’s not consistent.
> 
> Check the invertor for a ground that does not go directly to that single 
> bolt or buss bar I preach about. If its connected to that bolt, lift it 
> and see if its still grounded someplace else, and isolate it from that 
> unwanted ground. Then hook it back up to the common bolt.  The static 
> ground line to the invertors PSU should go only to this bolt. The static 
> ground in the power cord should go to this bolt.  But only once if there 
> are more than one power cord.
> 
> In rare cases, the moving parts of the machine, such as the table and Z 
> sled or knee should be jumpered to the machine frame, and that frame 
> connected to this common bolt. Well oiled moving ways are not that great 
> an ohmic connection if actively moving on a film of oil.
> 
>> The noise on the 5v power supply line to the 7i73 is minimal. The 7i73
>> and all its connected switches are grounded only through the board’s
>> connection to the 7i96 board.
>> 
>> Would a shielded ethernet cable help?
> 
> You could try it, but I'd have doubts. Shielding only grounded at one 
> end. Both make a ground loop you don't need or want.
>> 
> 
> IHTH.
> 
>>> On Jul 31, 2020, at 9:17 AM, andy pugh  wrote:
>>> 
>>> On Fri, 31 Jul 2020 at 15:15, Peter C. Wallace  
> wrote:
 Also even with default sserial error management you could only have
 10 servo thread cycles (10 ms with a 1 ms servo thread) of delay
 due to failed transactions before a sserial error popup would
 occur.
>>> 
>>> Maybe noise on the keyboard itself? Is the keycode pin a single
>>> clean transition?
>>> 
>>> --
>>> atp
>>> "A motorcycle is a bicycle with a pandemonium attachment and is
>>> designed for the especial use of mechanical geniuses, daredevils and
>>> lunatics."
>>> — George Fitch, Atlanta Constitution Newspaper, 1912
>>> 
>>> 
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>> 
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>> 
> 
> 
> Cheers, Gene Heskett
> -- 
> "There are four boxes to be used in defense of liberty:
> soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
> - Louis D. Brandeis
> Genes Web page  >
> 
> 
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Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Gene Heskett]

On Wednesday 19 August 2020 10:25:14 Greg Bernard wrote:

> Most hardware stores carry silicone grease for o-rings in the plumbing
> section. I'd be willing to bet it would work just fine for your
> purpose.
>
Thats similar to DC-4, and I have some of that but its 60 yo. "Borrowed" 
it while building titan ones up in SD in '60. But as a lubricant, not to 
good, -0 surface tension. So I didn't think of it.

Its running on a thin film of Lymans Super Moly barrel grease, seems 
happy but its young yet. Running nicely at noon yet, at about 15 rpm 
out, sounds like maybe 1000 revs in. Can't stop it by hand. More making.

Looked at printers, thought I'd found one in the Saphire, till I read the 
reviews, zero support, crappily made, 9 reviews, all complaining. Thumbs 
down.

> On Wed, Aug 19, 2020, 5:02 AM Gene Heskett  
wrote:
> > On Wednesday 19 August 2020 00:19:40 Gene Heskett wrote:
> > > On Tuesday 18 August 2020 20:30:45 Gene Heskett wrote:
> > > > On Tuesday 18 August 2020 18:50:22 Frank Tkalcevic wrote:
> > > > > > the middle of a now thicker and nuch denser 6 wall build. 
> > > > > > cura settings are for 6 line walls, 15 ipm and 30 ipm.
> > > > >
> > > > > 6 line walls/perimeters is a large number.   My default
> > > > > setting is 2. Less perimeters also prints a lot faster.  If
> > > > > the part is weak, you can always increase it later, but it
> > > > > sounds like you are still having issue with the extrusion flow
> > > > > rate.
> > > >
> > > > The 2 I broke already were made before I calibrated it and found
> > > > it set for about 18mm of pla for a 100mm move. At 6, its buckets
> > > > sturdier, but the bearing bottom was 35.5mm and I killed a
> > > > bearing putting it together.  So I've scaled it down a wee bit
> > > > and will make another for the 3rd one if this one fits better.
> > >
> > > I picked the smallest bearing carrier I had assembled, stuck on
> > > that motor, and picked the smallest internal spline ring. Bolted
> > > it all up. Its been running at about 400 rpm input, and a turn
> > > every 4 seconds for output for longer than the other 2 together.
> > > But its crackling and stalling, too it apart, flexgear is good,
> > > but I think it doesn't have quite enough hop over clearance.  The
> > > next on on the printer should be a few thou smaller. This will
> > > also get me into it far enough to refresh that lumpy bearing.
> > >
> > > But I need some sleep while the next one is finishing.
> >
> > It has, it fits perfectly in a new main bearing, and the smaller
> > wave carrier I used before is in it, along with the stator ring. Its
> > running quieter at about 6 rpm.  Dry, but I was looking at my
> > cooking oil, thaws at 75F coconut and wondering.  Now they are
> > telling me the si stuff I ordered, won't be here before Nov 7th.  I
> > think that belongs in the WTF category... Another one started, this
> > ones running and I'm going back to bed.
> >
> > > > Thanks Frank.
> > > >
> > > > Cheers, Gene Heskett
> > >
> > > Cheers, Gene Heskett
> >
> > Cheers, Gene Heskett
> > --
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > If we desire respect for the law, we must first make the law
> > respectable. - Louis D. Brandeis
> > Genes Web page 
> >
> >
> > ___
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> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
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Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Gene Heskett]

On Wednesday 19 August 2020 01:53:13 Gregg Eshelman via Emc-users wrote:

> More perimeters = more strength in FDM printing. For rigid plastics
> like PLA that also increases stiffness. Several years ago, Benelli was
> designing a new auto loading shotgun and they had a problem with part
> of the bolt breaking. They made it thicker serveral times, they tried
> different metals, they tried different hardening treatments but the
> part would always eventually break. Then they applied some better
> analysis techniques to find how the part was trying to flex when the
> gun was fired and made a bolt with that part thinner than the first
> one which broke. Allowing the part to flex stopped it from breaking,
> and the lighter weight increased the cycling speed to the point where
> some trick shooters were able to break longstanding records like how
> many clay targets they could hand toss into the air and shoot before
> any hit the ground. So rather than tying to make the part ever
> stronger, and thus less flexible, you need to see what can be altered
> in the 3D model to make the area where it breaks more flexible.
>
The 6 layer wall part is still running.  The problem is the concentration 
of the flex at the base of the wall.  There is a filet at the junction 
of wall and disk, and it was breaking at the exact top of the filet. 
Going from 3 to 6 on that wall thickness did increase the stiffness 
some, but getting the wave bearing the right size to remove the roughly 
2x needed flex seems to have been the fix.

Makeing all parts at the same printer scale gets a flexure so excess 
theres 3mm of air between the spline teeth midway between the bearings 
and with that much flex its bound to break in 5 minutes or less.

The first one I assembled yesterday had a fraction of a mm too big a butt 
end and I beat the bearing up getting it inserted, made another by 
changing the scale down from a calculated 80.79 down by .14 to 80.65, 
(In terms of scale per mm in merlin) which also increased the wave about 
5 thou, enough that I am not hearing a crackling sound as the splines 
hop over each other.  But that was the only internal spline I had that 
still fits in the bodies which were made first after calibrating the 
extruder feed. So I have another flexgear in process and will make a 3rd 
one that size.  Then I'll make another bearing carrier and adjust it to 
be the same as the one thats working. Then measure the internal spline 
and adjust to make 2 more that size which does fit the bodies and motor 
caps both of which have a surrounding flange to hide the spline when 
they come together at assembly. And that should do it.

And I am tempted drill for a lube hole thru the spline face to allow some 
lube to be inserted with a hypo needle or such. I just need to find a 
plastic compatible lube on this side of the big pond.  Everybody has it, 
but when you order it, it has to come from some goat herders shack in 
Ulan Bator, by donkey cart. In the meantime, I am tempted to try some 
barrel grease I have that made for molycoating rifle barrel bores, its 
about 95% molysulfide, it should stay where I put it with a q-tip.  What 
it will do to the PLA is TBD.

I believe I am fighting with a variation of the cartographers copyright 
scheme.  An error was detectable in a copyright violation copy by 
looking for a town that only the original map drawer knows is fake.  And 
this error, purposely designed to fail, was this guys copyright 
detector.  Its a very old ploy, and holds up in court 100% of the time.

Neither the tpu, nor the micro-swiss hot end kit appeared yesterday. My 
personal curse for living in a technological vacuum. Long distance 
shopping.

So I took it apart and smeared some of that on the tips of the teeth, and 
found another potential wear site. Where the bearings are rolling on the 
inside face is worn noticeably smoother. The bearings are rolling 
smoothly but I am wondering if I should have colored that area with some 
of that moly grease now just to slow that wear. That did help with the 
torque multiply, as it cannor now be stalled by hand despite running at 
this driver lowest, not much heating, current.

These drivers respond instantly to the changes in the dip switch 
settings, so I contemplating the removal of the dip switch to gain 
access to the pads for current control for linuxcnc to put max current 
to the motor if its running, idling back to minimum current for holding 
when stopped.

Can I get an only when moving that axis signal out of motion? And do it 
without losing a step? I have a oneshot in mind, trigger on leading 
edge, but send the step so its done on the falling edge, giving a couple 
u-secs for the current to rise?  Sneaky but it might work.  Our goal is 
to make sneaky work reliably isn't it?  Or should I junk these and get a 
tb6600 that incorporates that. Except it doesn't.

> On Tuesday, August 18, 2020, 5:23:58 PM MDT, Frank Tkalcevic 
 wrote:
>  > the middle of a now 

Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Greg Bernard]

Most hardware stores carry silicone grease for o-rings in the plumbing
section. I'd be willing to bet it would work just fine for your purpose.

On Wed, Aug 19, 2020, 5:02 AM Gene Heskett  wrote:

> On Wednesday 19 August 2020 00:19:40 Gene Heskett wrote:
>
> > On Tuesday 18 August 2020 20:30:45 Gene Heskett wrote:
> > > On Tuesday 18 August 2020 18:50:22 Frank Tkalcevic wrote:
> > > > > the middle of a now thicker and nuch denser 6 wall build.  cura
> > > > > settings are for 6 line walls, 15 ipm and 30 ipm.
> > > >
> > > > 6 line walls/perimeters is a large number.   My default setting is
> > > > 2. Less perimeters also prints a lot faster.  If the part is weak,
> > > > you can always increase it later, but it sounds like you are still
> > > > having issue with the extrusion flow rate.
> > >
> > > The 2 I broke already were made before I calibrated it and found it
> > > set for about 18mm of pla for a 100mm move. At 6, its buckets
> > > sturdier, but the bearing bottom was 35.5mm and I killed a bearing
> > > putting it together.  So I've scaled it down a wee bit and will make
> > > another for the 3rd one if this one fits better.
> >
> > I picked the smallest bearing carrier I had assembled, stuck on that
> > motor, and picked the smallest internal spline ring. Bolted it all up.
> > Its been running at about 400 rpm input, and a turn every 4 seconds
> > for output for longer than the other 2 together. But its crackling and
> > stalling, too it apart, flexgear is good, but I think it doesn't have
> > quite enough hop over clearance.  The next on on the printer should be
> > a few thou smaller. This will also get me into it far enough to
> > refresh that lumpy bearing.
> >
> > But I need some sleep while the next one is finishing.
>
> It has, it fits perfectly in a new main bearing, and the smaller wave
> carrier I used before is in it, along with the stator ring. Its running
> quieter at about 6 rpm.  Dry, but I was looking at my cooking oil, thaws
> at 75F coconut and wondering.  Now they are telling me the si stuff I
> ordered, won't be here before Nov 7th.  I think that belongs in the WTF
> category... Another one started, this ones running and I'm going back to
> bed.
>
> > > Thanks Frank.
> > >
> > > Cheers, Gene Heskett
> >
> > Cheers, Gene Heskett
>
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
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> https://lists.sourceforge.net/lists/listinfo/emc-users
>

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Re: [Emc-users] OT: Anyone tried these auto lube units?

[Todd Zuercher]

I think I'd prefer a model with a pressure guage (but you could always add one 
in-line after the pump).  And for Linuxcnc I'd prefer one without the timer 
features and do the timing control in Linuxcnc.

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Leonardo Marsaglia  
Sent: Tuesday, August 18, 2020 7:06 PM
To: Enhanced Machine Controller (EMC) 
Subject: [Emc-users] OT: Anyone tried these auto lube units?

[EXTERNAL EMAIL] Be sure links are safe.

Hello guys,

I'm about to purchase some automatic lube units for a copying lathe I'm 
retrofitting with LCNC and for the router project (which is alive again 
finally).

I'm planning to use an auto lube unit like this:

https://www.ebay.com/itm/CNC-Electromagnetic-Lubricant-Pump-Automatic-Lubricating-Oil-Pump-220V-HTS02-2L/184283971779?hash=item2ae82e40c3:g:TCMAAOSwiI1eYgJZ


Do you have any experience with these? Should I try something a little more 
expensive just to play it safe?

Thanks as always!

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Re: [Emc-users] found a harmonic drive set of .stl's on thingiverse

[Gene Heskett]

On Wednesday 19 August 2020 00:19:40 Gene Heskett wrote:

> On Tuesday 18 August 2020 20:30:45 Gene Heskett wrote:
> > On Tuesday 18 August 2020 18:50:22 Frank Tkalcevic wrote:
> > > > the middle of a now thicker and nuch denser 6 wall build.  cura
> > > > settings are for 6 line walls, 15 ipm and 30 ipm.
> > >
> > > 6 line walls/perimeters is a large number.   My default setting is
> > > 2. Less perimeters also prints a lot faster.  If the part is weak,
> > > you can always increase it later, but it sounds like you are still
> > > having issue with the extrusion flow rate.
> >
> > The 2 I broke already were made before I calibrated it and found it
> > set for about 18mm of pla for a 100mm move. At 6, its buckets
> > sturdier, but the bearing bottom was 35.5mm and I killed a bearing
> > putting it together.  So I've scaled it down a wee bit and will make
> > another for the 3rd one if this one fits better.
>
> I picked the smallest bearing carrier I had assembled, stuck on that
> motor, and picked the smallest internal spline ring. Bolted it all up.
> Its been running at about 400 rpm input, and a turn every 4 seconds
> for output for longer than the other 2 together. But its crackling and
> stalling, too it apart, flexgear is good, but I think it doesn't have
> quite enough hop over clearance.  The next on on the printer should be
> a few thou smaller. This will also get me into it far enough to
> refresh that lumpy bearing.
>
> But I need some sleep while the next one is finishing.

It has, it fits perfectly in a new main bearing, and the smaller wave 
carrier I used before is in it, along with the stator ring. Its running 
quieter at about 6 rpm.  Dry, but I was looking at my cooking oil, thaws 
at 75F coconut and wondering.  Now they are telling me the si stuff I 
ordered, won't be here before Nov 7th.  I think that belongs in the WTF 
category... Another one started, this ones running and I'm going back to 
bed.

> > Thanks Frank.
> >
> > Cheers, Gene Heskett
>
> Cheers, Gene Heskett


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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