Re: [Emc-users] Lathe update

[Gene Heskett]

On Saturday 22 March 2014 20:49:47 Cecil Thomas did opine:

> Gene,
> I also have a home brew encoder disk and interrupter set up on a 9x20
> jet with a treadmill motor and an M60 controller.  I also have a
> similar setup on a Monarch 10EE with a 3.5 hp 350 VDC drive motor.
> I was having a random problem cutting threads on both machines. The
> thread was losing its pickup occasionally and wiping the previous
> thread.  This was an intermittent problem and it took a while to find
> the culprit.
> After watching a scope much more than I enjoyed I found that I was
> getting an occasional noise spike on the index interrupter which was
> of course the cause of the problem.
> My fix was to decouple the Vcc on every interrupter with a 1mf cap
> and I also snaked a length of "chinese fingercuff" braid over the
> outside of all the cables (grounded at the power supply end).  I also
> ran a #6 bare copper from the motor frame to the control box chasis
> ground.  I don't know if these attempts completely removed the noise
> spikes but I do know that I haven't wiped a thread since I did it.
> 
> If I ever do another backfit I WILL use differential interrupters or
> packaged differential encoders.  There is a lot of really nasty QRM
> associated with DC motors, DC motor controllers and relays.
> 

Thanks for the reply Cecil, but I've already been checking with a scope, 
plus I'm using a C1G breakout with has a tally led in every I/O line. The 
opto's I use are buffered, cmos output, and pull very hard to whatever rail 
they should be switched to at the instant. So noise is not a problem as 
even the ground rail is isolated from the lathe frame in the way its 
mounted.

When it happens, the lines involved simply go high & stay there.  I'll go 
get it off tomorrow, and open a drawer & lay a board on it for a work table 
so I can sit and fiddle with my rework station, which has tips down to 
1/32" in diameter.  When I carved it, the traces were only like 7 or 8 mils 
wide, and its been patched to add small pots in series with the leds so I 
can adjust the relative timing a bit.  Because of that, one could say its 
been hacked quite a bit from what I drew up in eagle about 3 or 4 years 
ago.  Throw in that the rat shack board i used only has 1 oz copper on it, 
its trouble. 1 oz stuff is damned fragile.  Sort of like asking if concrete 
will crack.  Wrong question, not if, but when, because it will... ;-)

When it did it to me this afternoon, I had already been on my feet pushing 
my bad back for an hour too long, so that was the straw that stopped me for 
the day.  Getting old is not for wimps, and I'll be 80 in October.  But I'm 
not built to just sit in a rocker till I stop, gotta be doing something.

I'll find it, possibly related to it being a double sided board with no 
plated thru holes, so it has to be soldered on both sides where a hole is 
used to get to the other side.  I may have missed at least one.

Cheers, Gene
-- 
"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 


--
Learn Graph Databases - Download FREE O'Reilly Book
"Graph Databases" is the definitive new guide to graph databases and their
applications. Written by three acclaimed leaders in the field,
this first edition is now available. Download your free book today!
http://p.sf.net/sfu/13534_NeoTech
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] Lathe update

[Cecil Thomas]

Gene,
I also have a home brew encoder disk and interrupter set up on a 9x20 
jet with a treadmill motor and an M60 controller.  I also have a 
similar setup on a Monarch 10EE with a 3.5 hp 350 VDC drive motor.
I was having a random problem cutting threads on both machines. The 
thread was losing its pickup occasionally and wiping the previous 
thread.  This was an intermittent problem and it took a while to find 
the culprit.
After watching a scope much more than I enjoyed I found that I was 
getting an occasional noise spike on the index interrupter which was 
of course the cause of the problem.
My fix was to decouple the Vcc on every interrupter with a 1mf cap 
and I also snaked a length of "chinese fingercuff" braid over the 
outside of all the cables (grounded at the power supply end).  I also 
ran a #6 bare copper from the motor frame to the control box chasis 
ground.  I don't know if these attempts completely removed the noise 
spikes but I do know that I haven't wiped a thread since I did it.

If I ever do another backfit I WILL use differential interrupters or 
packaged differential encoders.  There is a lot of really nasty QRM 
associated with DC motors, DC motor controllers and relays.


--
Learn Graph Databases - Download FREE O'Reilly Book
"Graph Databases" is the definitive new guide to graph databases and their
applications. Written by three acclaimed leaders in the field,
this first edition is now available. Download your free book today!
http://p.sf.net/sfu/13534_NeoTech
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] Lathe update

[Gene Heskett]

Putting it back together, making room for the 3/8" higher motor as I go, I 
am exercising just the spindle, and it slowed about 25%, and the rpms gui 
faded to zero.  And of course one of the neighbor frogs was a witness to my 
clay feet.  OHOH, he still thinks I can walk on water.

My encoders pcb, didn't get a coat of varnish, so it is by now turning red 
from copper oxide.  Looked it over with a strong glass, can't see a bad 
joint but 2 of the three interrupters are coming and going independently 
and do not seem to be sensitive to flexing the board.

My back is about ~30~, so its the end of the day for me.  I had an MRI done 
on it 2 weeks ago, and if I was the vet, looking at a million dollar race 
horse, I'd still take me out back of the barn & put me down. My spinal cord 
is being pinched in 4 places, and is not a lot of fun anymore.

To PCW, I zeroed out the lincurve settings and I do not think I will need 
them at all in the final setup once I arrive at a proper scale setting for 
the pwmgen.  So I can shorten my .hal file by at least 30 lines.

So the SPINx1 is doing exactly what its supposed to do.  I like stuff that 
Just Works(TM) and this is certainly doing a good job.  Thank you very much 
Peter for a great and inexpensive product.
 
Cheers, Gene
-- 
"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 


--
Learn Graph Databases - Download FREE O'Reilly Book
"Graph Databases" is the definitive new guide to graph databases and their
applications. Written by three acclaimed leaders in the field,
this first edition is now available. Download your free book today!
http://p.sf.net/sfu/13534_NeoTech
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] "Slow" G code (sam sokolik)

[Mark Wendt]

On Fri, Mar 21, 2014 at 12:32 PM, Bertho Stultiens wrote:

> On 03/21/2014 05:05 PM, sam sokolik wrote:
> > heh - isn't that how we all dress?
>
> That depends on how many lumps still hang together on my coat. It has
> some signs of wear and tear.
>

You do realize a pocket protector and slide rule are required items of
haute couture with that getup.

>
> --
> Greetings Bertho
>

Cheers,
Mark
--
Learn Graph Databases - Download FREE O'Reilly Book
"Graph Databases" is the definitive new guide to graph databases and their
applications. Written by three acclaimed leaders in the field,
this first edition is now available. Download your free book today!
http://p.sf.net/sfu/13534_NeoTech
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users