[Emc-users] 7/8" R8 collet

[Gene Heskett]

I just found, for 7/8" R8 collet, made in Korea (doesn't claim N or S) 
says .0005 TIR, better than most for this project, so now I can keep 3 
of them preloaded. Just under $8/copy.

I don't know if they are fibbing, or actually trying to take away some of 
that business from the Chinese.  We'll see when they show up next Friday 
I guess.

-- 
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] looking for M5mm x .8 5mm long screws

[melamy]

you can find 6mm long in three different types of socket heads at 
www.boltdepot.com

best regards, Steve Thatcher


-Original Message-
>From: Gene Heskett 
>Sent: Mar 31, 2018 12:32 PM
>To: emc-users@lists.sourceforge.net
>Subject: [Emc-users] looking for M5mm x .8 5mm long screws
>
>And I don't seem to find any shorter than 10mm.
>
>5mm long would be a great plenty. This is to be installed in the side of 
>a 7/8" diameter slug, with about 1/2 the head buried in the slug, and 
>the other half to stick up into a cutout the same width as the head of 
>the screw, purpose to lock the slug into the R8, which itself is keyed 
>into the spindle. With short threads, and a dot of green thread locker, 
>it ought to hold more torque that my spindle can muster up. If I machine 
>it right, for a snug fit in the slot cut in the R8 to just clear the bit 
>of screw head sticking out, the should not be enough slop to dislodge 
>the screw.
>
>But where can I find such short 5mm socket head screws?  Need a full box.
>
>Net searchs show 10mm and up, too long.
>
>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)
>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

--
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] looking for M5mm x .8 5mm long screws

[Gene Heskett]

On Saturday 31 March 2018 19:26:53 Chris Albertson wrote:

> Gene,
>
> "MonsterBolts" on eBay has M5x.8 at 6mm long in grade 12.9 alloy steel
>  Only 1mm longer than you wanted  About $8 for a box or 50.  see item
> 112016494139
> I've been buying hardware and these guys seem to always have what I
> want.
>
Duly noted.  Thanks.

> On Sat, Mar 31, 2018 at 3:58 PM, Gene Heskett  
wrote:
> > On Saturday 31 March 2018 15:43:41 Kenneth Lerman wrote:
> >> https://www.mcmaster.com/#standard-socket-head-screws/=1c7nzv5
> >>
> >> McMaster has them -- stainless only.
> >>
> >> Ken
> >
> > Stainless=too soft.  Darn it.
> >
> >> On Sat, Mar 31, 2018 at 3:32 PM, Gene Heskett
> >> 
> >
> > wrote:
> >> > And I don't seem to find any shorter than 10mm.
> >> >
> >> > 5mm long would be a great plenty. This is to be installed in the
> >> > side of a 7/8" diameter slug, with about 1/2 the head buried in
> >> > the slug, and the other half to stick up into a cutout the same
> >> > width as the head of the screw, purpose to lock the slug into the
> >> > R8, which itself is keyed into the spindle. With short threads,
> >> > and a dot of green thread locker, it ought to hold more torque
> >> > that my spindle can muster up. If I machine it right, for a snug
> >> > fit in the slot cut in the R8 to just clear the bit of screw head
> >> > sticking out, the should not be enough slop to dislodge the
> >> > screw.
> >> >
> >> > But where can I find such short 5mm socket head screws?  Need a
> >> > full box.
> >> >
> >> > Net searchs show 10mm and up, too long.
> >> >
> >> > 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)
> >> > 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
> >>
> >> ---
> >>---  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] looking for M5mm x .8 5mm long screws

[Gene Heskett]

On Saturday 31 March 2018 16:00:36 Greg Bernard wrote:

> I always check good old McMaster-Carr first:
> https://www.mcmaster.com/#standard-socket-head-screws/=1c7o6zf
>
I did too, struck out, nothing smaller in socket-head metric than 
6mm.8x12mm long.

> On Sat, Mar 31, 2018 at 2:32 PM, Gene Heskett  
wrote:
> > And I don't seem to find any shorter than 10mm.
> >
> > 5mm long would be a great plenty. This is to be installed in the
> > side of a 7/8" diameter slug, with about 1/2 the head buried in the
> > slug, and the other half to stick up into a cutout the same width as
> > the head of the screw, purpose to lock the slug into the R8, which
> > itself is keyed into the spindle. With short threads, and a dot of
> > green thread locker, it ought to hold more torque that my spindle
> > can muster up. If I machine it right, for a snug fit in the slot cut
> > in the R8 to just clear the bit of screw head sticking out, the
> > should not be enough slop to dislodge the screw.
> >
> > But where can I find such short 5mm socket head screws?  Need a full
> > box.
> >
> > Net searchs show 10mm and up, too long.
> >
> > 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)
> > 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] looking for M5mm x .8 5mm long screws

[Gene Heskett]

On Saturday 31 March 2018 15:55:22 andy pugh wrote:

> On 31 March 2018 at 20:32, Gene Heskett  wrote:
> > And I don't seem to find any shorter than 10mm.
> >
> > 5mm long would be a great plenty.
>
> Can you use 6 long?
> https://www.ebay.com/itm/112016494139
> He list 5mm long but is out of stock.
> Lots exist in China.
>
> But it seems a bit odd to use a screw shorter than it is wide.

The threaded part of the screw is only to hold it in the recess, with 
about 1/2 the head sticking out to key into a cutout in the lip of a 
7/8" R-8 collet. I might even have to trim it a bit to clear the shank 
of a large tap as it goes by. I'll take some pix and put them up once I 
have enough stuff to "go into production".


-- 
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] looking for M5mm x .8 5mm long screws

[Gene Heskett]

On Saturday 31 March 2018 15:52:53 Ken Strauss wrote:

> I assume that you want SHCS? I'm not sure about 5mm but M5-0.8x6 is
> readily available:
> https://www.fastenal.com/products/fasteners/sockets/socket-cap-screws?
>term=s
> ocket+head=~%7Ccategoryl1:%2260%20Fasteners%22%7C~%20~%7Ccategor
>yl2:%2
> 2600039%20Sockets%22%7C~%20~%7Ccategoryl3:%22600040%20Socket%20Cap%20S
>crews%
> 22%7C~%20~%7Csattr05:%5E6mm$%7C~%20~%7Csattr04:%5E%22M5%20-%200.8%22$%
>7C~
>
>
> A M5 dog point set screw might be more suitable though:
> https://www.fastenal.com/products/details/90294?term=set+screw=~%7Cc
>ategor
> yl1:%2260%20Fasteners%22%7C~%20~%7Ccategoryl2:%22600047%20Set%20Sc
>rews%2
> 2%7C~%20~%7Ccategoryl3:%22600049%20Socket%20Set%20Screws%22%7C~%20~%7C
>sattr0
> 4:%5E%22M5%20-%200.8%22$%7C~%20~%7Csattr05:%5E5mm$%7C~%20~%7Csattr05:%
>5E6mm$ %7C~
>
This will be using about 1/2 the head height as a key to fit a pocket 
ground into the lip of a 7/8" R8 collet. Point is immaterial.

> > -Original Message-
> > From: Gene Heskett [mailto:ghesk...@shentel.net]
> > Sent: Saturday, March 31, 2018 3:32 PM
> > To: emc-users@lists.sourceforge.net
> > Subject: [Emc-users] looking for M5mm x .8 5mm long screws
> >
> > And I don't seem to find any shorter than 10mm.
> >
> > 5mm long would be a great plenty. This is to be installed in the
> > side of a
>
> 7/8"
>
> > diameter slug, with about 1/2 the head buried in the slug, and the
> > other
>
> half
>
> > to stick up into a cutout the same width as the head of the screw,
> > purpose
>
> to
>
> > lock the slug into the R8, which itself is keyed into the spindle.
> > With
>
> short
>
> > threads, and a dot of green thread locker, it ought to hold more
> > torque
>
> that
>
> > my spindle can muster up. If I machine it right, for a snug fit in
> > the
>
> slot cut in
>
> > the R8 to just clear the bit of screw head sticking out, the should
> > not be enough slop to dislodge the screw.
> >
> > But where can I find such short 5mm socket head screws?  Need a full
> > box.
> >
> > Net searchs show 10mm and up, too long.
> >
> > 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)
> > 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
>
> --
> 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] looking for M5mm x .8 5mm long screws

[Chris Albertson]

Gene,

"MonsterBolts" on eBay has M5x.8 at 6mm long in grade 12.9 alloy steel
 Only 1mm longer than you wanted  About $8 for a box or 50.  see item
112016494139
I've been buying hardware and these guys seem to always have what I want.

On Sat, Mar 31, 2018 at 3:58 PM, Gene Heskett  wrote:
> On Saturday 31 March 2018 15:43:41 Kenneth Lerman wrote:
>
>> https://www.mcmaster.com/#standard-socket-head-screws/=1c7nzv5
>>
>> McMaster has them -- stainless only.
>>
>> Ken
>>
> Stainless=too soft.  Darn it.
>
>> On Sat, Mar 31, 2018 at 3:32 PM, Gene Heskett 
> wrote:
>> > And I don't seem to find any shorter than 10mm.
>> >
>> > 5mm long would be a great plenty. This is to be installed in the
>> > side of a 7/8" diameter slug, with about 1/2 the head buried in the
>> > slug, and the other half to stick up into a cutout the same width as
>> > the head of the screw, purpose to lock the slug into the R8, which
>> > itself is keyed into the spindle. With short threads, and a dot of
>> > green thread locker, it ought to hold more torque that my spindle
>> > can muster up. If I machine it right, for a snug fit in the slot cut
>> > in the R8 to just clear the bit of screw head sticking out, the
>> > should not be enough slop to dislodge the screw.
>> >
>> > But where can I find such short 5mm socket head screws?  Need a full
>> > box.
>> >
>> > Net searchs show 10mm and up, too long.
>> >
>> > 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)
>> > 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
>>
>> --
>> 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



-- 

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] looking for M5mm x .8 5mm long screws

[Gene Heskett]

On Saturday 31 March 2018 15:51:19 Martin Dobbins wrote:

> Hi Gene,
>
>
> McMaster Carr carry a wide variety of M5 screws in various lengths. 
> 6mm is the shortest I could find on a quick search.
>
>
> https://www.mcmaster.com/#standard-flat-head-screws/=1c7o3c3
>
Wrong screw type, need socket head, 6mm was smallest they could show me. 
But I did find them (4mm.7-6mm long) at Grainger, $6.75/50 pack, bought 
3. I have quite a tap collection.
>
> Martin

Thanks Martin.
>
>
>
> And I don't seem to find any shorter than 10mm.
>
> 5mm long would be a great plenty. This is to be installed in the side
> of a 7/8" diameter slug, with about 1/2 the head buried in the slug,
> and the other half to stick up into a cutout the same width as the
> head of the screw, purpose to lock the slug into the R8, which itself
> is keyed into the spindle. With short threads, and a dot of green
> thread locker, it ought to hold more torque that my spindle can muster
> up. If I machine it right, for a snug fit in the slot cut in the R8 to
> just clear the bit of screw head sticking out, the should not be
> enough slop to dislodge the screw.
>
> But where can I find such short 5mm socket head screws?  Need a full
> box.
>
> Net searchs show 10mm and up, too long.
>
> 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)
> Genes Web page 
> Gene's Web pages
> geneslinuxbox.net
> Welcome to Gene's web pages. Here you will find some of the things
> that make me tick, and that help keep me out of the bars. That is me &
> the missus, Dee (Elladene) I self timed on Easter Sunday 2004 as we
> were leaving for services.
>
>
>
>
> --
> 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



-- 
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] looking for M5mm x .8 5mm long screws

[Gene Heskett]

On Saturday 31 March 2018 15:45:25 Mark Johnsen wrote:

> Gene,
>
> Mcmaster has 6mm long M5 screws:
> https://www.mcmaster.com/#socket-cap-screws/=1c7nxzi
> MSCDIrect also has 6mm:  https://tinyurl.com/yas6ujlh
> Not sure that link will work.
>
> I was surprised they didn't have 5mm.
>
> Mark
>
How about 4's?  I'll look, but it seems that good enough if a hard 10-9 
screw.

Aha, found them in 50 packs at Grainger, s/b here the 4th.

Thanks guys.

> On Sat, Mar 31, 2018 at 12:32 PM, Gene Heskett  
wrote:
> > And I don't seem to find any shorter than 10mm.
> >
> >
> > But where can I find such short 5mm socket head screws?  Need a full
> > box.
> >
> > Net searchs show 10mm and up, too long.
>
> --
> 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] looking for M5mm x .8 5mm long screws

[Gene Heskett]

On Saturday 31 March 2018 15:43:41 Kenneth Lerman wrote:

> https://www.mcmaster.com/#standard-socket-head-screws/=1c7nzv5
>
> McMaster has them -- stainless only.
>
> Ken
>
Stainless=too soft.  Darn it.

> On Sat, Mar 31, 2018 at 3:32 PM, Gene Heskett  
wrote:
> > And I don't seem to find any shorter than 10mm.
> >
> > 5mm long would be a great plenty. This is to be installed in the
> > side of a 7/8" diameter slug, with about 1/2 the head buried in the
> > slug, and the other half to stick up into a cutout the same width as
> > the head of the screw, purpose to lock the slug into the R8, which
> > itself is keyed into the spindle. With short threads, and a dot of
> > green thread locker, it ought to hold more torque that my spindle
> > can muster up. If I machine it right, for a snug fit in the slot cut
> > in the R8 to just clear the bit of screw head sticking out, the
> > should not be enough slop to dislodge the screw.
> >
> > But where can I find such short 5mm socket head screws?  Need a full
> > box.
> >
> > Net searchs show 10mm and up, too long.
> >
> > 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)
> > 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
>
> --
> 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] looking for M5mm x .8 5mm long screws

[Gene Heskett]

On Saturday 31 March 2018 15:32:02 Gene Heskett wrote:

> And I don't seem to find any shorter than 10mm.
>
> 5mm long would be a great plenty. This is to be installed in the side
> of a 7/8" diameter slug, with about 1/2 the head buried in the slug,
> and the other half to stick up into a cutout the same width as the
> head of the screw, purpose to lock the slug into the R8, which itself
> is keyed into the spindle. With short threads, and a dot of green
> thread locker, it ought to hold more torque that my spindle can muster
> up. If I machine it right, for a snug fit in the slot cut in the R8 to
> just clear the bit of screw head sticking out, the should not be
> enough slop to dislodge the screw.
>
> But where can I find such short 5mm socket head screws?  Need a full
> box.
>
> Net searchs show 10mm and up, too long.
>
> Thanks.

In looking over my limited screw supply, it seems a M4x.7 socket head cap 
screw is a great plenty for the key since the whole head of it will 
effectively be the key.

-- 
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] looking for M5mm x .8 5mm long screws

[Martin Dobbins]

Hi Gene,


McMaster Carr carry a wide variety of M5 screws in various lengths.  6mm is the 
shortest I could find on a quick search.


https://www.mcmaster.com/#standard-flat-head-screws/=1c7o3c3


Martin




And I don't seem to find any shorter than 10mm.

5mm long would be a great plenty. This is to be installed in the side of
a 7/8" diameter slug, with about 1/2 the head buried in the slug, and
the other half to stick up into a cutout the same width as the head of
the screw, purpose to lock the slug into the R8, which itself is keyed
into the spindle. With short threads, and a dot of green thread locker,
it ought to hold more torque that my spindle can muster up. If I machine
it right, for a snug fit in the slot cut in the R8 to just clear the bit
of screw head sticking out, the should not be enough slop to dislodge
the screw.

But where can I find such short 5mm socket head screws?  Need a full box.

Net searchs show 10mm and up, too long.

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)
Genes Web page 
Gene's Web pages
geneslinuxbox.net
Welcome to Gene's web pages. Here you will find some of the things that make me 
tick, and that help keep me out of the bars. That is me & the missus, Dee 
(Elladene) I self timed on Easter Sunday 2004 as we were leaving for services.




--
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] looking for M5mm x .8 5mm long screws

[Chris Albertson]

On Sat, Mar 31, 2018 at 12:43 PM, Kenneth Lerman 
wrote:

> https://www.mcmaster.com/#standard-socket-head-screws/=1c7nzv5
>
> McMaster has them -- stainless only.
>


Makes sense as there is no point in making a short screw in alloy steel,
the softer stainless would give full strength of the engaged threads.

You can also buy the short screws on eBay.   I've been stocking up lately
on M3 to M6 sizes buying them when I see exceptional values.  In some cases
I don't see the seller is making money  For example I have a set of M3, 4,
5, 6, 8 taps I paid $1.75 with free shipping.  Maybe a mistake but I got
them and they work fine.  eBay is good for hardware but it takes hours of
hunting.

-- 

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] looking for M5mm x .8 5mm long screws

[Kenneth Lerman]

https://www.mcmaster.com/#standard-socket-head-screws/=1c7nzv5

McMaster has them -- stainless only.

Ken


On Sat, Mar 31, 2018 at 3:32 PM, Gene Heskett  wrote:

> And I don't seem to find any shorter than 10mm.
>
> 5mm long would be a great plenty. This is to be installed in the side of
> a 7/8" diameter slug, with about 1/2 the head buried in the slug, and
> the other half to stick up into a cutout the same width as the head of
> the screw, purpose to lock the slug into the R8, which itself is keyed
> into the spindle. With short threads, and a dot of green thread locker,
> it ought to hold more torque that my spindle can muster up. If I machine
> it right, for a snug fit in the slot cut in the R8 to just clear the bit
> of screw head sticking out, the should not be enough slop to dislodge
> the screw.
>
> But where can I find such short 5mm socket head screws?  Need a full box.
>
> Net searchs show 10mm and up, too long.
>
> 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)
> 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
>
--
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] looking for M5mm x .8 5mm long screws

[Mark Johnsen]

Gene,

Mcmaster has 6mm long M5 screws:
https://www.mcmaster.com/#socket-cap-screws/=1c7nxzi
MSCDIrect also has 6mm:  https://tinyurl.com/yas6ujlh
Not sure that link will work.

I was surprised they didn't have 5mm.

Mark


On Sat, Mar 31, 2018 at 12:32 PM, Gene Heskett  wrote:

> And I don't seem to find any shorter than 10mm.
>
>
> But where can I find such short 5mm socket head screws?  Need a full box.
>
> Net searchs show 10mm and up, too long.
>
>
--
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] looking for M5mm x .8 5mm long screws

[Greg Bernard]

I always check good old McMaster-Carr first:
https://www.mcmaster.com/#standard-socket-head-screws/=1c7o6zf

On Sat, Mar 31, 2018 at 2:32 PM, Gene Heskett  wrote:

> And I don't seem to find any shorter than 10mm.
>
> 5mm long would be a great plenty. This is to be installed in the side of
> a 7/8" diameter slug, with about 1/2 the head buried in the slug, and
> the other half to stick up into a cutout the same width as the head of
> the screw, purpose to lock the slug into the R8, which itself is keyed
> into the spindle. With short threads, and a dot of green thread locker,
> it ought to hold more torque that my spindle can muster up. If I machine
> it right, for a snug fit in the slot cut in the R8 to just clear the bit
> of screw head sticking out, the should not be enough slop to dislodge
> the screw.
>
> But where can I find such short 5mm socket head screws?  Need a full box.
>
> Net searchs show 10mm and up, too long.
>
> 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)
> 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
>



-- 
"Anyone who believes exponential growth can go on forever in a finite world
is either a madman or an economist."
-Kenneth Boulding, economist
Corporations are NOT people and money is NOT speech!
--
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] looking for M5mm x .8 5mm long screws

[andy pugh]

On 31 March 2018 at 20:32, Gene Heskett  wrote:
> And I don't seem to find any shorter than 10mm.

> 5mm long would be a great plenty.

Can you use 6 long?
https://www.ebay.com/itm/112016494139
He list 5mm long but is out of stock.
Lots exist in China.

But it seems a bit odd to use a screw shorter than it is wide.


-- 
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] looking for M5mm x .8 5mm long screws

[Ken Strauss]

I assume that you want SHCS? I'm not sure about 5mm but M5-0.8x6 is readily
available:
https://www.fastenal.com/products/fasteners/sockets/socket-cap-screws?term=s
ocket+head=~%7Ccategoryl1:%2260%20Fasteners%22%7C~%20~%7Ccategoryl2:%2
2600039%20Sockets%22%7C~%20~%7Ccategoryl3:%22600040%20Socket%20Cap%20Screws%
22%7C~%20~%7Csattr05:%5E6mm$%7C~%20~%7Csattr04:%5E%22M5%20-%200.8%22$%7C~


A M5 dog point set screw might be more suitable though:
https://www.fastenal.com/products/details/90294?term=set+screw=~%7Ccategor
yl1:%2260%20Fasteners%22%7C~%20~%7Ccategoryl2:%22600047%20Set%20Screws%2
2%7C~%20~%7Ccategoryl3:%22600049%20Socket%20Set%20Screws%22%7C~%20~%7Csattr0
4:%5E%22M5%20-%200.8%22$%7C~%20~%7Csattr05:%5E5mm$%7C~%20~%7Csattr05:%5E6mm$
%7C~


> -Original Message-
> From: Gene Heskett [mailto:ghesk...@shentel.net]
> Sent: Saturday, March 31, 2018 3:32 PM
> To: emc-users@lists.sourceforge.net
> Subject: [Emc-users] looking for M5mm x .8 5mm long screws
>
> And I don't seem to find any shorter than 10mm.
>
> 5mm long would be a great plenty. This is to be installed in the side of a
7/8"
> diameter slug, with about 1/2 the head buried in the slug, and the other
half
> to stick up into a cutout the same width as the head of the screw, purpose
to
> lock the slug into the R8, which itself is keyed into the spindle. With
short
> threads, and a dot of green thread locker, it ought to hold more torque
that
> my spindle can muster up. If I machine it right, for a snug fit in the
slot cut in
> the R8 to just clear the bit of screw head sticking out, the should not be
> enough slop to dislodge the screw.
>
> But where can I find such short 5mm socket head screws?  Need a full box.
>
> Net searchs show 10mm and up, too long.
>
> 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)
> 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



--
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] looking for M5mm x .8 5mm long screws

[Gene Heskett]

And I don't seem to find any shorter than 10mm.

5mm long would be a great plenty. This is to be installed in the side of 
a 7/8" diameter slug, with about 1/2 the head buried in the slug, and 
the other half to stick up into a cutout the same width as the head of 
the screw, purpose to lock the slug into the R8, which itself is keyed 
into the spindle. With short threads, and a dot of green thread locker, 
it ought to hold more torque that my spindle can muster up. If I machine 
it right, for a snug fit in the slot cut in the R8 to just clear the bit 
of screw head sticking out, the should not be enough slop to dislodge 
the screw.

But where can I find such short 5mm socket head screws?  Need a full box.

Net searchs show 10mm and up, too long.

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)
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] Making a steper pulse generator, would like comments

[Gene Heskett]

On Saturday 31 March 2018 11:52:01 Chris Albertson wrote:

> On Fri, Mar 30, 2018 at 8:20 PM, Gene Heskett  
wrote:
> > On Friday 30 March 2018 20:34:52 Chris Albertson wrote:
> >
> >
> > Just one question? Can you build this for less than you can buy it
> > from Mesa?  Or Pico? If you time is worth a buck an hour, its a slim
> > chance of yes. Very slim. Otherwise get it from a supplier that
> > supports us.
>
> The arm is not going to use MK or LCNC.   I'm using that on the
> machine tools
> but this arm needs more flexibility than offered by any of the machine
> tool controllers.   This is the high level control software I'll use
> if you are interested:
> https://moveit.ros.org/documentation/concepts/
> This pulse generator will be part of the blue box called "robot
> controllers"
>
> The trouble with Mesa in this case is that I'd have to write a whole
> bunch of FPGA code to make it into what they call a "joint trajectory
> action server"
>
> I thought about using G-code for the robots but they need to do things
> like notice you have set a beer can on the table then plan motion
> around the can. This has to happen in real time, you can't code the
> motion in advance
>
> There is not much to build.  A need to buy an ARM-M based board and
> than add a buffer chip to convert 3.3 volts to 5 volt TTL.  Cot should
> be <$20 total but if one of these works I can build it for under $5
> .ebay.com/itm/STM32F103C8T6
> opment-Board-Module-For-Arduino/162247218933?epid=532038167=item25
>c6b016f5:g:ZXMAAOSwA3dYCJJd>
>
>
> Back to steps per second.   If the carriage moves at 90ipm, that is 38
> mm/sec, with a 5mm screw that means 8 turns per second.   or  1600
> full steps per second but perhaps you are doing 1/4 steps so it is
> 6400 steps/second.   Your machine with software steps is doing about
> 8X slower? with no more then 800 steps/second.   It looks like there
> is no need for more than 10K steps per second and half that might
> work.

I think its running 1/8 step. But my hand isn't anywhere near the good 
book on that.  That machine also threw a drive fault, so got rebooted 
when amanda screamed about a read-only drive this morning. I've a 60GB 
SSD to put in it if its not the cable, which IIRC is red=trouble after 
some time, copper and that bright red insulation dye do not tolerate 
each other at all well. If the data cable is red, and a tail on the log 
blows up when its touched, that dye has struck again.  Its beat me to a 
pulp for the last 40 years starting with the J.A.Pan Co 2 way radio 
microphone cables back in the early 70's. Use any other color but red 
for a sata data cable.

> About jitter, if 3% of the period reduces torque and the fastest rate
> is 10KHz then only 3 uSec of jitter can be tolerated.
>
Since it regularly tolerates more than that with the speed limits 
configured, I should have emphasized "bleeding edge" speeds. 10 ipm 
isn't bleeding edge by any definition. 70+, maybe but its out of torque 
from low motor voltage long before it gets up to that speed. I also have 
homemade dampers on the rear shaft which on that machine helps a lot. 
Right now, running latency-histogram on that machine, with a 25 us base 
thread, the max deviation in about a ten minute run is -8.0 us to 
+8.5us, but those wide times were maybe once in that 10 minutes. It 
might exceed 3 us once a minute.
 
> > How  many motors in your arm? The 7i90HD at less than $70, + 3 
> > 7i42TA's at about 45$ ea, about $200, can handle 8 steppers.  And
> > have plenty of gpio left to do lots of other things. Limited only by
> > your imagination.
> >
> > --
> > 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] Making a steper pulse generator, would like comments

[Chris Albertson]

OK so here is what is required.  The "joint action server" gets messages
for up to 6 axis.  The messages contain the velocities for each joint.
Realistically it will not get more than abut 20 of these per second.
Other types of messages are per joint acceleration limits and
transformation matrixes.   But this pulse generator lives at the "far end"
of the chain and will only see the velocity commands.   If there are more
than 6-axis then two controlers are used.

Yes, it does seem like if I used an Ethernet based Mesa card I could just
send the right data down the cable.   I assume the protocol is documented.
I will download the user manual tonight.

I like the idea of using commodity hardware, things like develoment boards
because they are made in huge quantities and sell for under about $15.
Arduino clones, ARM boards and even these:
STM32F103C8T6-ARM-STM32


The higher level planning is done on much more powerful machine.  I'm using
an 18-core Intel Xeon.

As a separate issue the server sends back the state of the joints.  It can
do this any way it likes including open loop, that is just sending back
where it "thinks" the stepper is based on counting steps.  Or there could
be sensors in the joints or even accelerometers and gyros.

On Sat, Mar 31, 2018 at 9:06 AM, andy pugh  wrote:

> On 31 March 2018 at 16:52, Chris Albertson 
> wrote:
>
> > The trouble with Mesa in this case is that I'd have to write a whole
> bunch
> > of FPGA code to make it into what they call a "joint trajectory action
> > server"
> >
> > I thought about using G-code for the robots but they need to do things
> like
> > notice you have set a beer can on the table then plan motion around the
> can.
> > This has to happen in real time, you can't code the motion in advance
>
> Motion commands do not have to come from G-code. You can send
> canonical motion commands independently from motion, or you can simply
> set the step-generator input pin to the required position (in
> engineering units)
> The Mesa step-generators have built-in acceleration and velocity limits.
> halcmd setp hm2_5i25.0.stepgen.00.position 123.456
> But you don't even need to use LinuxCNC at all, you can just write the
> required positions directly to PCI registers or transfer them down an
> ethernet cable.
>
> And then there is Mesa's own motion controller.
> http://store.mesanet.com/index.php?route=product/
> product=65_id=163
> Free with any FPGA card (according to that page)
>
> This was just posted to the forums, might be relevant:
> https://forum.linuxcnc.org/49-basic-configuration/34295-
> rdl2-arduino-command-line-stepper-testing-utility#108162
>
> --
> 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
>



-- 

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] Making a steper pulse generator, would like comments (jitter)

[Nicklas SB Karlsson]

I did something similar two years ago. 32 bit value with 16 bits for encoder 
style pulse counter and 16 bits for decimal is what I should chose. Position 
values.

With encoder style I think of an encoder timer which usually overflow and then 
number of overflows is counted for longer motion. This will allow for an 
arbitrary long motion but put a limit on how often value is checked.

Decimal point is needed to avoid jitter which will happen even at constant 
speed then number of pulses per second is close to update frequency. For 
example will an update frequency of 1kHz and a pulse frequency around 1.5kHz 
produce a lot of jitter but decimal point to place signal within period will 
remove this. I should have the formula to remove this jitter if you want it?

I also implemented averaging of receive time which will allow high jitter on 
received times with low jitter on pulses if number of receive times i high for 
the average.

It would be possible to use receive FIFO to allow more than one period jitter 
or sending several positions each time provided positions is known before hand 
so any feedback would be delayed in this case.


I used Micro controller with DMA feeding comparator register. More than one 
timer period between each pulse require some special handling. By this method 
flanks will be placed with micro controller clock so it should be both cheap 
and good method but might be a little bit tricky to avoid errors, there are 
"hard" real time demands on some updates but but Micro controller usually have 
good support for this.


Regards Nicklas Karlsson



On Fri, 30 Mar 2018 17:34:52 -0700
Chris Albertson  wrote:

> I'm making a stepper motor pulse generator for my own use but others
> might find it useful.  To help make sure it is useful to others I'm
> asking what specs it would need to have  to make in "interesting" to
> you.
> 
> Here is what it does...   You send it via a serial link a point in 6
> or 7 axis (x,y,z,a,b,c) and a time.  The pulse generator will step all
> the motors such that they all get to the given point at the specified
> time and the movement is along a straight line (in joint space).   The
> units are "steps".  Also you can send it one point and then while the
> motors are moving you send it the next point and it will go from one
> to the next without stopping.  This way the serial link timing need
> not be perfect.  As long as the next point is sent in time, the timing
> is near perfect.
> 
> In my use case all of the move commands are sent at a given rate.  say
> maybe 50 points per second.   The output pulses are "standard TTL"
> five volts and maybe about 20 ma source/sink
> 
> Whatever sends the commands does all the inverse kinematics, real
> world to joint space transform, acceleration control and so on.All
> this thing does is handle the real-time pulse generation so no hard
> real time work must be done by the sender.my target cost is "dirt
> cheap".
> 
> Now for the survey questions:
> 
> 1) what is the fastest pulse rate you would reasonably use.  The
> DM542T driver I'm using for testing is spec'd to 200KHz but I can't
> imagine anyone actually getting close to that.  What's a real number?
> 
> 2) How much jitter in the pulse timing is acceptable?  Yes i know it
> depends on the speed.
> 
> 3) Are people using balanced signals on the step and direction pins.
> I kind of doubt it but want to be sure.
> 
> 
> I don't know if something like this could be used with MK, if so t
> could offload all of the hard real-time requirements.I need this
> for a robot arm
> 
> -- 
> 
> 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] Making a steper pulse generator, would like comments

[andy pugh]

On 31 March 2018 at 16:52, Chris Albertson  wrote:

> The trouble with Mesa in this case is that I'd have to write a whole bunch
> of FPGA code to make it into what they call a "joint trajectory action
> server"
>
> I thought about using G-code for the robots but they need to do things like
> notice you have set a beer can on the table then plan motion around the can.
> This has to happen in real time, you can't code the motion in advance

Motion commands do not have to come from G-code. You can send
canonical motion commands independently from motion, or you can simply
set the step-generator input pin to the required position (in
engineering units)
The Mesa step-generators have built-in acceleration and velocity limits.
halcmd setp hm2_5i25.0.stepgen.00.position 123.456
But you don't even need to use LinuxCNC at all, you can just write the
required positions directly to PCI registers or transfer them down an
ethernet cable.

And then there is Mesa's own motion controller.
http://store.mesanet.com/index.php?route=product/product=65_id=163
Free with any FPGA card (according to that page)

This was just posted to the forums, might be relevant:
https://forum.linuxcnc.org/49-basic-configuration/34295-rdl2-arduino-command-line-stepper-testing-utility#108162

-- 
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] Making a steper pulse generator, would like comments

[Chris Albertson]

On Fri, Mar 30, 2018 at 8:20 PM, Gene Heskett  wrote:
> On Friday 30 March 2018 20:34:52 Chris Albertson wrote:
>

> Just one question? Can you build this for less than you can buy it from
> Mesa?  Or Pico? If you time is worth a buck an hour, its a slim chance
> of yes. Very slim. Otherwise get it from a supplier that supports us.

The arm is not going to use MK or LCNC.   I'm using that on the machine
tools
but this arm needs more flexibility than offered by any of the machine tool
controllers.   This is the high level control software I'll use if you are
interested:
https://moveit.ros.org/documentation/concepts/
This pulse generator will be part of the blue box called "robot controllers"

The trouble with Mesa in this case is that I'd have to write a whole bunch
of FPGA code to make it into what they call a "joint trajectory action
server"

I thought about using G-code for the robots but they need to do things like
notice you have set a beer can on the table then plan motion around the can.
This has to happen in real time, you can't code the motion in advance

There is not much to build.  A need to buy an ARM-M based board and than
add a buffer chip to convert 3.3 volts to 5 volt TTL.  Cot should be <$20
total but if one of these works I can build it for under $5
.ebay.com/itm/STM32F103C8T6



Back to steps per second.   If the carriage moves at 90ipm, that is 38
mm/sec, with a 5mm screw that means 8 turns per second.   or  1600 full
steps per second but perhaps you are doing 1/4 steps so it is 6400
steps/second.   Your machine with software steps is doing about 8X slower?
 with no more then 800 steps/second.   It looks like there is no need for
more than 10K steps per second and half that might work.

About jitter, if 3% of the period reduces torque and the fastest rate is
10KHz then only 3 uSec of jitter can be tolerated.





> How  many motors in your arm? The 7i90HD at less than $70, + 3  7i42TA's
> at about 45$ ea, about $200, can handle 8 steppers.  And have plenty of
> gpio left to do lots of other things. Limited only by your imagination.
>
> --
> 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



-- 

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] controlling a 6 or 7 axis arm?

[theman whosoldtheworld]

no ... if use lcnc you have a quite good motion planner, more then one
kinematics to load to make your robot arm ... for 7 axis robot you can add
1 axis to pumakins if the axis is calculated  for limit acceleration
... there are some realtime component that can help you to make these
features ... joint rate is limited from ini file ... best off all is to
study the integrator manuals ...

regards
bkt

2018-03-24 0:20 GMT+01:00 Chris Albertson :

> So if I read correctly.  Using MK/LCNC will not get me acceleration limited
> moves, joint rate limits or any kind of motion planning unless I'm using
> trivial IK?
>
>
> --
>
> 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] Making a steper pulse generator, would like comments

[Gene Heskett]

On Saturday 31 March 2018 02:16:36 Marcus Bowman wrote:

> On 31 Mar 2018, at 04:20, Gene Heskett wrote:
> > Just one question? Can you build this for less than you can buy it
> > from Mesa?  Or Pico? If you time is worth a buck an hour, its a slim
> > chance of yes. Very slim. Otherwise get it from a supplier that
> > supports us.
>
> +1 for that.
> I'm all for avoiding reinventing the wheel.
>
> Marcus

So am I Marcus, since we do have a really long menu/choice. Pico's 
pwm-servo driver is a heck of a pm-dc spindle motor driver for up to 
around 2 hp motors, does my 1's without a problem. And Mesa has a 
plethora of reasonably priced fpga cards. The only Achilles Heel of 
those is the 3.3 volt innards. The 5i25 can tolerate 5 volt i/o, because 
it needs the std par-port bob to make its outside world connections, but 
the 7i90HD needs the 7i42TA's to protect it from the 5 volt world and 
its noises. They effectively are the circuit protection bobs. However, 
with the 7i42TA's you also get a 10,000% easier wire-up as it has the 
usually green stick the wire in the hole and tighten the screw 
connection strips. That right there makes those aux cards worthwhile. 
All you need to do is smash up some short 50 wire scsi-ii ribbon cables 
to make the interconnections. I think my longest 50 pin cable is 5.5". I 
stack mounted mine so all 4 cards are still pretty compact. With the 26 
pin to the pi needing the pi turned over in order to face pin 1 to pin 
1, and a video card fan under the pi, my 26 pin cable is under an inch 
long.  And I've overclocked the pi from 700 to 800 mhz w/o any 
instability or over heating.

> --
> 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] Making a steper pulse generator, would like comments

[Marcus Bowman]

On 31 Mar 2018, at 04:20, Gene Heskett wrote:

> 
> Just one question? Can you build this for less than you can buy it from 
> Mesa?  Or Pico? If you time is worth a buck an hour, its a slim chance 
> of yes. Very slim. Otherwise get it from a supplier that supports us.

+1 for that.
I'm all for avoiding reinventing the wheel.

Marcus

--
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