Re: [Emc-users] Need to select a timing belt type and size

[Gene Heskett]

On Sunday 18 February 2018 18:53:59 Chris Albertson wrote:

> Question:  What would be the preferred timing belt for a new design?
>
> Here is the application.  I'm making a z-axis control for a Harbor
> Freight mini mill (Sieg X2).   In this design a 5/8 diameter, 0.200
> pitch ball screw is fixed and the nut spins.  The nut is driven by a
> timing belt "about" 50 teeth and the motor has an about 25 tooth
> pulley.   I'm thinking a 400 in/oz. NEMA 23 stepper should work.   
> Assuming the 2:1 reduction each 1.8 degree step lifts the head 0.0005
> inches.  By 1/4 stepping I get 0.000125 per pulse.
>
> When looking for a good design for the mini mill I was looking for a
> good place to put the ball screw.  This design places it very close to
> the dove tail, almost touching it.  Maybe 0.1 inch in front of the
> dovetail.  The ball screw goes right where the current rack it the
> original design.  I will have to remove the rack to fit the screw.
>
> So I need to select a belt type and size.   My initial guess at this a
> the GT2, 3mm pitch and 9mm wide.
>
> Some one else used a XL type 3/8 wide and 0.2 pitch but I'm reading
> that XL is not the best for new designs as GT2 has a much improved
> both profile that eliminates backlash.
>
> I started to calculate torque and load on the belt then thought "Why
> bother?" the actual force is going to be whatever the motor can do as
> I'll set the acceleration limits until it start skipping steps then
> back up by about 30% or so.   I might go with a NEMA 34 1100 in/oz
> motor if I need to.  So I might choose a belt that can handle whatever
> the 1100 in/oz motor can do.   Just looking to double check GT2, 3mm
> pitch and 9mm wide is reasonable.
>
> So I guess the best way to ask the question is what kind of belts are
> working well with motors in the 400 to 1100 in/oz. range.
>
> If there is any interest I'm modeling this in Fusion 360.  and can
> share the CAD files

Its been a while since I did my micromill, but ISTR I used the XL belt 
and its quite tight. Like you, I spin the nuts, doubled nook bronze 
ones, and my backlash stays below 3 thou. the screw is in front of the 
post by about 1/2 the distance between the post and the edge of the 
gearbox cover, which has been turned 90 degrees to get that clearance. 
the motor is an 8 wire good for a bit over 300 oz/in.  Works well.  you 
can see pix of it on my web page in the sig. The counter springing has 
been reworked a bit but the rest of the pix are still valid.

Not a cad artist, so what you see came straight out of my head, quite a 
few years ago now. I write my own gcode.

-- 
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 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] non-contact position sensors, surprisingly good performance.

[Andy Pugh]

> On 17 Feb 2018, at 15:26, Peter Blodow  wrote:
> 
> 
>> Am 16.02.2018 um 06:32 schrieb Chris Albert
>> 
>> I think this thread size os used for those very thin rings used for
>> electrical  jacks and toggle switches.  The ring nuts are only 2mm thick so
>> they need an ultra fine pitch.
> ...which usually is 0.75

Another way is to use a very large thread angle. 
This one is metric on diameter, 80 degree thread angle and TPI pitch. 

https://en.m.wikipedia.org/wiki/Panzergewinde


--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] non-contact position sensors, surprisingly good performance.

[Gene Heskett]

On Friday 16 February 2018 06:16:00 Chris Albertson wrote:

> If you are bending a screw the speed does not matter it is the
> acceleration.  That is measured in meters per second squared (or
> whatever the Imperial equivalent is?  feet per second per second?)
>
> I think a typical low performance mill like most of us have might have
> go a 2m/s^2  A very high performance one might do 20m/s^2
>
> If the mill can do about 10m/S^2 then the force on the ball screw is
> equal to the weight of the table and whatever is bolted down to it.  
> Remember what Newton said "f=ma".
>
> Which happens first the ball nut breaks or the screw bends is
> determined by the length of the screw from motor to nut.
>
> Gene when you used the motor in a design where there was a very large
> static load, where the motor had to hold the weight of large vertical
> moving head  you'd expect poor movement compared to a horizontal axis.

That I have figured out finally Chris, its moving close to 100 ipm with a 
32 to 42 pulley set in the z on my Sheldon but its noisy as can be in 
the 7 to 20 ipm box. Its noise telegraphs up the keyboard shelf mounted 
on its mounting bracket. I'd had to put a 1/4" high fence around the 
edge to keep other stuff from vibrating off including the keyboard 
itself. Its also running an a few more volts than it was on the mill 
with its heavy head. 7 more volts IIRC. X is slow, but if I ever get off 
my duff and make a thin vibration damper, I think that would bring it up 
to 60 ipm. Its a nema 24, 8 wire, wired parallel and getting all a 2m542 
can give it at around 43 volts. Neither motor is best match, but what I 
had, or could get in the crowded area behind the new apron.

> On Fri, Feb 16, 2018 at 12:54 AM, Gene Heskett  
wrote:
> > On Friday 16 February 2018 02:20:40 jeremy youngs wrote:
> > > Chris, I think you are spot on . Nema 34 1600 oz in. And
> > > automation direct 110v drives.
> >
> > I have one of those motors. On the Z of my mill, with a 60 volt psu,
> > very poor performance. 27 ipm or stall lifting the head on the
> > G0704. Its now on the sheldons Z and while noisy, is also about 4x
> > faster.
> >
> > > I had y at 300 ipm 9×42 table. It was a very cheap
> > > ballscrew and I had it cobbled together now that the Machine is 3
> > > axis and spindle functional I will be able to make some belt and
> > > pulley mounts and resolve some issues.
> > > --
> > >  Check out the vibrant tech community on one of the
> > > world's most engaging tech sites, Slashdot.org!
> > > http://sdm.link/slashdot
> > > ___
> > > 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)
> > Genes Web page 
> >
> > 
> > --
> > Check out the vibrant tech community on one of the world's most
> > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > 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)
Genes Web page 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Chinese "C7" ball screws

[Chris Albertson]

Yes they are used in aircraft, but are also very commonly used in machine
tools to move an X, Y or Z axis.   In this case I'm moving the Z axis of a
Harbor Freight Mini Mill.

If you have never seen one, they are much like a normal lead screw except
there are ball bearings between the screw threads and the nut.  This
reduces friction considerably but most importantly ball screws can have
zero or nearly zero backlash.   A ball screw is very efficient.  It
typically converts 95% of the applied torque to thrust

On Tue, Feb 27, 2018 at 8:05 PM, Frank Tkalcevic <
fr...@franksworkshop.com.au> wrote:

> That ebay ad says "Ball screws are used in aircraft and missiles".  What
> are
> you building?
>
>
>
> -Original Message-
> From: Chris Albertson [mailto:albertson.ch...@gmail.com]
> Sent: Wednesday, 28 February 2018 8:34 AM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] Chinese "C7" ball screws
>
> On Tue, Feb 27, 2018 at 11:49 AM, Cecil Thomas 
> wrote:
>
> > Chris,
> > Could you post the link to the Ebay listing where you bought the ball
> > screw?
> > I  have  a couple of applications that might benefit from them.
> >
>
> Here it is once more.   One difference I find is the physical size of the
> nut.   It is larger than the kind that use 15/16 threads.  These nuts have
> a 48mm diameter flange mount with some not parallel (wedge taper) flats
> milled into the 48mm diameter.
>
> www.ebay.com/itm/Ball-Screw-SFU1605
>  1605-Ballscrew-End-Machi
> ned-with-Single-Ballnut-CNC/182984365566?epid=28012153006&
> hash=item2a9ab7d5f
> e:m:mF8BMRqxbajGNo71dHrdHQw>
>
> The above vendor maintains stock in the US so for met the shipping was just
> a few days.
>
>
> > Also, what is the diameter of the nut?
> >
> >
> > Cecil
> >
> > At 01:47 PM 2/26/2018, Chris Albertson wrote:
> >
> >> Anyone use these no-brand ball screws in a machine tool?
> >>
> >> I could not resisted the price.  $27 with free shipping for a 16mm
> >> diameter by 550mm long ball screw and nut.
> >>
> >> What I am wondering now is if anyone has first hand experience with this
> >> product in a real machine.Mine is a 16mm diameter by 5mm lead screws
> >> 550mm total length with an SFU1605 ball nut.
> >>
> >>
> >
> > 
> > --
> > Check out the vibrant tech community on one of the world's most
> > engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
>
>
>
> --
>
> Chris Albertson
> Redondo Beach, California
> 
> 
> --
> Check out the vibrant tech community on one of the world's most engaging
> tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
> 
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>



-- 

Chris Albertson
Redondo Beach, California
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Chinese "C7" ball screws

[Frank Tkalcevic]

That ebay ad says "Ball screws are used in aircraft and missiles".  What are
you building?



-Original Message-
From: Chris Albertson [mailto:albertson.ch...@gmail.com] 
Sent: Wednesday, 28 February 2018 8:34 AM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Chinese "C7" ball screws

On Tue, Feb 27, 2018 at 11:49 AM, Cecil Thomas 
wrote:

> Chris,
> Could you post the link to the Ebay listing where you bought the ball 
> screw?
> I  have  a couple of applications that might benefit from them.
>

Here it is once more.   One difference I find is the physical size of the
nut.   It is larger than the kind that use 15/16 threads.  These nuts have
a 48mm diameter flange mount with some not parallel (wedge taper) flats
milled into the 48mm diameter.

www.ebay.com/itm/Ball-Screw-SFU1605


The above vendor maintains stock in the US so for met the shipping was just
a few days.


> Also, what is the diameter of the nut?
>
>
> Cecil
>
> At 01:47 PM 2/26/2018, Chris Albertson wrote:
>
>> Anyone use these no-brand ball screws in a machine tool?
>>
>> I could not resisted the price.  $27 with free shipping for a 16mm 
>> diameter by 550mm long ball screw and nut.
>>
>> What I am wondering now is if anyone has first hand experience with this
>> product in a real machine.Mine is a 16mm diameter by 5mm lead screws
>> 550mm total length with an SFU1605 ball nut.
>>
>>
>
> 
> --
> Check out the vibrant tech community on one of the world's most 
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot 
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>



-- 

Chris Albertson
Redondo Beach, California

--
Check out the vibrant tech community on one of the world's most engaging
tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users


--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] non-contact position sensors, surprisingly good performance.

[Gene Heskett]

On Tuesday 20 February 2018 12:53:08 John Alexander Stewart wrote:

> Hi Gene;
>
> Regarding the DM1182 - Ok - I see what it is you are doing. Very
> interesting - I've been out of the loop for a year or two and getting
> back into it.
>
> John.

And I'm just now catching up, been in the shop for a few days while they 
filtered a gallon or so of heperin thru my kidneys. The sore knee turned 
into the whole leg, and the ultrasound yelped about a nice sized blood 
clot fairly close to the groin. Still sore, which I'm told will be a 
week or more getting back to normal.  And they blamed it on too long 
sitting in this chair! So I am supposed to get a fitbit, and let it yelp 
at me every so often. So I did, then discovered it only runs on winderz 
or Macs.  Its all packed up, never powered up, get my money back until 
its private, and runs on linux.

-- 
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 

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] non-contact position sensors, surprisingly good performance.

[John Alexander Stewart]

Hi Gene;

Regarding the DM1182 - Ok - I see what it is you are doing. Very
interesting - I've been out of the loop for a year or two and getting back
into it.

John.
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Chinese "C7" ball screws

[Chris Albertson]

On Tue, Feb 27, 2018 at 11:49 AM, Cecil Thomas 
wrote:

> Chris,
> Could you post the link to the Ebay listing where you bought the ball
> screw?
> I  have  a couple of applications that might benefit from them.
>

Here it is once more.   One difference I find is the physical size of the
nut.   It is larger than the kind that use 15/16 threads.  These nuts have
a 48mm diameter flange mount with some not parallel (wedge taper) flats
milled into the 48mm diameter.

www.ebay.com/itm/Ball-Screw-SFU1605


The above vendor maintains stock in the US so for met the shipping was just
a few days.


> Also, what is the diameter of the nut?
>
>
> Cecil
>
> At 01:47 PM 2/26/2018, Chris Albertson wrote:
>
>> Anyone use these no-brand ball screws in a machine tool?
>>
>> I could not resisted the price.  $27 with free shipping for a 16mm
>> diameter
>> by 550mm long ball screw and nut.
>>
>> What I am wondering now is if anyone has first hand experience with this
>> product in a real machine.Mine is a 16mm diameter by 5mm lead screws
>> 550mm total length with an SFU1605 ball nut.
>>
>>
>
> 
> --
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>



-- 

Chris Albertson
Redondo Beach, California
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] Isocpus

[jeremy youngs]

Hello all,
I recently replaced my mother board, added a video card, and a parallel
card, Dell optiplex 620 4 mb ram. It's been quite a while since I last ran
a latency test , but I don't remember it being this horrible as I'm seeing
a Max interval of 1020092 and butter of 25572 on the servo thread. And a
base thread of 51566 and 26703 respectively.  In reading this
http://wiki.linuxcnc.org/cgi-bin/wiki.pl?The_Isolcpus_Boot_Parameter_And_GRUB2
It says rtai 3.14 doesn't need isocpus
My grub screen says I'm running 3,4 I updated this machine last month. So
my question is , is there nothing I can do for this?
--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Chinese "C7" ball screws

[andy pugh]

On 27 February 2018 at 19:49, Cecil Thomas  wrote:
> Chris,
> Could you post the link to the Ebay listing where you bought the ball screw?

Just search for "SFU1605"

-- 
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

--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Chinese "C7" ball screws

[Cecil Thomas]

Chris,
Could you post the link to the Ebay listing where you bought the ball screw?
I  have  a couple of applications that might benefit from them.

Also, what is the diameter of the nut?


Cecil

At 01:47 PM 2/26/2018, Chris Albertson wrote:

Anyone use these no-brand ball screws in a machine tool?

I could not resisted the price.  $27 with free shipping for a 16mm diameter
by 550mm long ball screw and nut.

What I am wondering now is if anyone has first hand experience with this
product in a real machine.Mine is a 16mm diameter by 5mm lead screws
550mm total length with an SFU1605 ball nut.




--
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users