Re: [Emc-users] Servo reduction for gantry machine

[Gregg Eshelman via Emc-users]

With a physical connection between the two sides, the gantry cannot get out of 
square, aside from a serious mechanical problem. It also frees up a motor 
driver for other use or eliminates the need for one driver.
The software is also simpler because it doesn't need to be able to ensure that 
the gantry is homed square. One switch per axis, or two if you want a limit 
switch at both ends.
I just don't see the point in making the electronics and electrical system more 
complex when there's no need for it.

On Saturday, April 27, 2019, 9:04:46 AM MDT, Leonardo Marsaglia 
 wrote:  
 >
> With any rack or rack-like drive a gantry can have zero racking problems
> by connecting the drive on both sides with a shaft.

Gregg, sounds you don't trust too much on having two motors driving the
gantry. I've seen too many machines working this way but I would like to
hear your opinion about that matter. I have zero experience with gantries
so I like to hear all the opinions. I have to say I do like more the two
motors approach but I would like to know what do you think about it.  
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[Emc-users] RE. bluing scraping

[Marshland Engineering]

Thanks for the tip. I still have some Permatex left (30 years old) I'd like to
try your option. While you are at the art shop, get some leaded white oil
paint. Add this to EP gearbox oil and it makes for a good lube when thread
forming.

I ended up brazing carbide tips to a flattened bit of tube with a wooden
handle. As I was new to scraping, I ended up making several of them and each
has its own use. There is enough Youtube clips on scraping but I do have a
good CD with the process discussed. If anyone wants, I can try and shrink it
for emailing. 

Cheers Wallace. 



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Re: [Emc-users] bluing scraping

[andy pugh]

On Sat, 27 Apr 2019 at 13:31, TJoseph Powderly  wrote:

> Winsor Newton Winton Oil 1414538 Prussian Blue 37ml
>
> It's an oil paint in a tube
> (think Van Gogh's Starry Night )

I have used Windsor and Newton "Yellow Ochre" as an anti-flux to avoid
solder tinning the decorative parts of a brass radiator.


-- 
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, 1916


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Re: [Emc-users] Servo reduction for gantry machine

[Leonardo Marsaglia]

>
> Any rack you make, even if machined perfectly will have some backlash.   It
> is unavoidable.Belts have zero backlash if you use the belt the way it
> was designed -- the belt moves


I said rack because I didn't know how to call it but the idea is to make
the rack in wich the belt can travel. In a certain way it's a rack, but not
engaged against a pinion, instead I'm thinking about the ServoBelt system.
But not gluing a belt to use it as the rack, I think it's a lot better (at
least for me) to machine the teeths in aluminum and mount them in tandem as
normal racks.

If I were building this I'd use either V-track or round rails.   Chips can
> not build up on a V or a round.  Then pull the carage with a long belt.  IF
> you do you calculatins right (or ask for help) belt streach is a
> none-issue.


I'm thinking about using round rails as you suggest. I'm almost conviced to
use linear ball bearings but I'm also wondering how these could work:
http://www.nationalbronze.com/News/self-lube-bushings-what-are-the-options/

I suspect the torque needed to move the gantry with those bronze bushings
would be a lot more but I don't know if the benefits justify them. I like
them because of the increase in rigidity and also because I guess they are
less prone to damage because of dust and grit. But I've never used them so
I can't tell how they behave. Anyway, since I'm decided to use round rails
I can try them anytime I want.

El sáb., 27 abr. 2019 a las 14:37, Chris Albertson (<
albertson.ch...@gmail.com>) escribió:

> Any rack you make, even if machined perfectly will have some backlash.   It
> is unavoidable.Belts have zero backlash if you use the belt the way it
> was designed -- the belt moves
>
> If you want to use a belt, contact the sale engineers at
> https://www.sdp-si.com/ or at least read the technical article on their
> web
> site.  They have a lot of good engineering advice and real data  SDP/SI is
> *the* place to buy this kind of stuff.
>
> If I were building this I'd use either V-track or round rails.   Chips can
> not build up on a V or a round.  Then pull the carage with a long belt.  IF
> you do you calculatins right (or ask for help) belt streach is a
> none-issue.
>
> But does it matter?   Maybe for wood cutting a 1mm tolerance is OK?
>
>
>
> On Sat, Apr 27, 2019 at 8:08 AM Leonardo Marsaglia 
> wrote:
>
> > >
> > > Cutting your own racks, while doable is a heck of lot of work for the
> > > lengths you are talking about, even if you make it in short sections.
> If
> > > your time is worth even a fraction of minimum wage you would be better
> > > off using off the shelf rack and pinions.
> >
> >
> > I know it sounds like a pain in the ass but I can get some really nice
> and
> > squared 6061 aluminum profiles to make the racks. And I'm planning to
> mount
> > them on the turret of the Mazak and use a fly cutter on a shaft between
> > centers to machine the racks in a serial way. That way I can make them
> in a
> > easy way. I already have the jig to mount them so it's only a matter of
> > program the job and start to cut. I need to make some holes and registers
> > to mount the racks but still I think it's not that big deal.
> >
> > It's just that gluing the belt sounds cheap and/or not at all a secure
> > option for me. But it's just the way I see it.
> >
> > El sáb., 27 abr. 2019 a las 12:01, Leonardo Marsaglia (<
> > ldmarsag...@gmail.com>) escribió:
> >
> > > With any rack or rack-like drive a gantry can have zero racking
> problems
> > >> by connecting the drive on both sides with a shaft.
> > >
> > >
> > > Gregg, sounds you don't trust too much on having two motors driving the
> > > gantry. I've seen too many machines working this way but I would like
> to
> > > hear your opinion about that matter. I have zero experience with
> gantries
> > > so I like to hear all the opinions. I have to say I do like more the
> two
> > > motors approach but I would like to know what do you think about it.
> > >
> > > El mié., 24 abr. 2019 a las 11:16, Les Newell (<
> > les.new...@fastmail.co.uk>)
> > > escribió:
> > >
> > >>
> > >> > 10m, 35mm width T5 for $60
> > >> >
> > >>
> >
> https://www.aliexpress.com/item/10Meters-T5-open-ended-timing-belt-T5-30-W-30mm-T5-timing-belt-polyurethane-with-steel/2051875939.html
> > >>
> > >>
> > >> That's a good price. Two of those would do both sides of a 4M machine.
> > >> That is steel cored which is stiffer than Kevlar. Pity one reel isn't
> > >> quite enough to do a 2.4m machine. Of course it would be enough for a
> > >> 'tank track' style mechanism. Must...resist...temptation...
> > >>
> > >> Les
> > >>
> > >>
> > >>
> > >> ___
> > >> 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
> > 

Re: [Emc-users] Servo reduction for gantry machine

[Chris Albertson]

Any rack you make, even if machined perfectly will have some backlash.   It
is unavoidable.Belts have zero backlash if you use the belt the way it
was designed -- the belt moves

If you want to use a belt, contact the sale engineers at
https://www.sdp-si.com/ or at least read the technical article on their web
site.  They have a lot of good engineering advice and real data  SDP/SI is
*the* place to buy this kind of stuff.

If I were building this I'd use either V-track or round rails.   Chips can
not build up on a V or a round.  Then pull the carage with a long belt.  IF
you do you calculatins right (or ask for help) belt streach is a
none-issue.

But does it matter?   Maybe for wood cutting a 1mm tolerance is OK?



On Sat, Apr 27, 2019 at 8:08 AM Leonardo Marsaglia 
wrote:

> >
> > Cutting your own racks, while doable is a heck of lot of work for the
> > lengths you are talking about, even if you make it in short sections. If
> > your time is worth even a fraction of minimum wage you would be better
> > off using off the shelf rack and pinions.
>
>
> I know it sounds like a pain in the ass but I can get some really nice and
> squared 6061 aluminum profiles to make the racks. And I'm planning to mount
> them on the turret of the Mazak and use a fly cutter on a shaft between
> centers to machine the racks in a serial way. That way I can make them in a
> easy way. I already have the jig to mount them so it's only a matter of
> program the job and start to cut. I need to make some holes and registers
> to mount the racks but still I think it's not that big deal.
>
> It's just that gluing the belt sounds cheap and/or not at all a secure
> option for me. But it's just the way I see it.
>
> El sáb., 27 abr. 2019 a las 12:01, Leonardo Marsaglia (<
> ldmarsag...@gmail.com>) escribió:
>
> > With any rack or rack-like drive a gantry can have zero racking problems
> >> by connecting the drive on both sides with a shaft.
> >
> >
> > Gregg, sounds you don't trust too much on having two motors driving the
> > gantry. I've seen too many machines working this way but I would like to
> > hear your opinion about that matter. I have zero experience with gantries
> > so I like to hear all the opinions. I have to say I do like more the two
> > motors approach but I would like to know what do you think about it.
> >
> > El mié., 24 abr. 2019 a las 11:16, Les Newell (<
> les.new...@fastmail.co.uk>)
> > escribió:
> >
> >>
> >> > 10m, 35mm width T5 for $60
> >> >
> >>
> https://www.aliexpress.com/item/10Meters-T5-open-ended-timing-belt-T5-30-W-30mm-T5-timing-belt-polyurethane-with-steel/2051875939.html
> >>
> >>
> >> That's a good price. Two of those would do both sides of a 4M machine.
> >> That is steel cored which is stiffer than Kevlar. Pity one reel isn't
> >> quite enough to do a 2.4m machine. Of course it would be enough for a
> >> 'tank track' style mechanism. Must...resist...temptation...
> >>
> >> Les
> >>
> >>
> >>
> >> ___
> >> 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
>


-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] bluing scraping

[Gene Heskett]

On Saturday 27 April 2019 08:29:59 TJoseph Powderly wrote:

> I'm in the boonies and need to scrape somethings flat.
>
> Permatex prussian blue is hard to get.
>
> But when googling,I always hit upon
> Winsor Newton Winton Oil 1414538 Prussian Blue 37ml
>
> It's an oil paint in a tube
> (think Van Gogh's Starry Night )
>
> I found some at a local book store that has art supplies,
> It works great!
>
> a box of black nitrile gloves,
> and a 50x80cm slab of grey granite from a kitchen remodeler shop,
> ( a real deal, very flat and was a cut off , cost me 300Baht so about
> 10$ ) and I got real scraping!
>
> I had tried several home brews that failed
> (lip stick, and magic marker with vaseline goop)
>
> This stuff is really easy to see.
> the granite plate charges and stays for many imprints.
>
> hope this helps someone
>
> tomp

Thanks TomP, I have asked at NAPA stores here, and got that raised 
eyebrow treatment like I was speaking Navajo or Swabili...

Good to know, msg marked FFR.

Most of my stuff is well worn in ( or out :), or too finely finished, so 
stiction is a much bigger problem than it is when things are properly 
scraped so an oil film has a place to hide.

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)
Genes Web page 



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Re: [Emc-users] Servo reduction for gantry machine

[Leonardo Marsaglia]

>
> Cutting your own racks, while doable is a heck of lot of work for the
> lengths you are talking about, even if you make it in short sections. If
> your time is worth even a fraction of minimum wage you would be better
> off using off the shelf rack and pinions.


I know it sounds like a pain in the ass but I can get some really nice and
squared 6061 aluminum profiles to make the racks. And I'm planning to mount
them on the turret of the Mazak and use a fly cutter on a shaft between
centers to machine the racks in a serial way. That way I can make them in a
easy way. I already have the jig to mount them so it's only a matter of
program the job and start to cut. I need to make some holes and registers
to mount the racks but still I think it's not that big deal.

It's just that gluing the belt sounds cheap and/or not at all a secure
option for me. But it's just the way I see it.

El sáb., 27 abr. 2019 a las 12:01, Leonardo Marsaglia (<
ldmarsag...@gmail.com>) escribió:

> With any rack or rack-like drive a gantry can have zero racking problems
>> by connecting the drive on both sides with a shaft.
>
>
> Gregg, sounds you don't trust too much on having two motors driving the
> gantry. I've seen too many machines working this way but I would like to
> hear your opinion about that matter. I have zero experience with gantries
> so I like to hear all the opinions. I have to say I do like more the two
> motors approach but I would like to know what do you think about it.
>
> El mié., 24 abr. 2019 a las 11:16, Les Newell ()
> escribió:
>
>>
>> > 10m, 35mm width T5 for $60
>> >
>> https://www.aliexpress.com/item/10Meters-T5-open-ended-timing-belt-T5-30-W-30mm-T5-timing-belt-polyurethane-with-steel/2051875939.html
>>
>>
>> That's a good price. Two of those would do both sides of a 4M machine.
>> That is steel cored which is stiffer than Kevlar. Pity one reel isn't
>> quite enough to do a 2.4m machine. Of course it would be enough for a
>> 'tank track' style mechanism. Must...resist...temptation...
>>
>> Les
>>
>>
>>
>> ___
>> Emc-users mailing list
>> Emc-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/emc-users
>>
>

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Re: [Emc-users] Servo reduction for gantry machine

[Leonardo Marsaglia]

>
> With any rack or rack-like drive a gantry can have zero racking problems
> by connecting the drive on both sides with a shaft.


Gregg, sounds you don't trust too much on having two motors driving the
gantry. I've seen too many machines working this way but I would like to
hear your opinion about that matter. I have zero experience with gantries
so I like to hear all the opinions. I have to say I do like more the two
motors approach but I would like to know what do you think about it.

El mié., 24 abr. 2019 a las 11:16, Les Newell ()
escribió:

>
> > 10m, 35mm width T5 for $60
> >
> https://www.aliexpress.com/item/10Meters-T5-open-ended-timing-belt-T5-30-W-30mm-T5-timing-belt-polyurethane-with-steel/2051875939.html
>
>
> That's a good price. Two of those would do both sides of a 4M machine.
> That is steel cored which is stiffer than Kevlar. Pity one reel isn't
> quite enough to do a 2.4m machine. Of course it would be enough for a
> 'tank track' style mechanism. Must...resist...temptation...
>
> Les
>
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
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>

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Re: [Emc-users] bluing scraping

[Marcus Bowman]

On 27 Apr 2019, at 13:29, TJoseph Powderly wrote:

> 
> Winsor Newton Winton Oil 1414538 Prussian Blue 37ml
> 
> This stuff is really easy to see.
> the granite plate charges and stays for many imprints.
> 
> hope this helps someone
> 
Thanks for that. I have some 'genuine' blue, but it is really messy. I also got 
a new Sandvick scraper last week, so I'm dying to try the Winsor & Newton. I 
use their Indian Ink on clock dials, sometimes. Pity our local art shop closed 
down. Amazon will have to do.

Marcus




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[Emc-users] bluing scraping

[TJoseph Powderly]

I'm in the boonies and need to scrape somethings flat.

Permatex prussian blue is hard to get.

But when googling,I always hit upon
Winsor Newton Winton Oil 1414538 Prussian Blue 37ml

It's an oil paint in a tube
(think Van Gogh's Starry Night )

I found some at a local book store that has art supplies,
It works great!

a box of black nitrile gloves,
and a 50x80cm slab of grey granite from a kitchen remodeler shop,
( a real deal, very flat and was a cut off , cost me 300Baht so about 10$ )
and I got real scraping!

I had tried several home brews that failed
(lip stick, and magic marker with vaseline goop)

This stuff is really easy to see.
the granite plate charges and stays for many imprints.

hope this helps someone

tomp

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