Thanks for all the responses. I now know what the source of the vibration I
hear during a G33 can be attributed to.
First a correction. I said something yesterday that was incorrect and
misleading. The oscillation I was seeing in the velocity waveform (also in the
DDT of the position informat
> On Sep 10, 2015, at 4:50 PM, Chris Radek wrote:
> Can you say again what problem you are
> trying to solve? Maybe I missed something. I don't want to guess.
Well, basically it was to get rid of the vibration or sound that G33 makes
(very different from the smooth quiet G1’s) which we believ
If you have an AC current pickup transformer and a scope around, it is
really easy to see what is going on with the motor. Put one motor lead
through the transformer, put a burden resistor across the transformer and
put the scope across the resistor. This will show you the current flow of
the motor
On Thu, Sep 10, 2015, at 04:24 PM, Tom Easterday wrote:
>
> > On Sep 10, 2015, at 1:58 PM, John Kasunich wrote:
> >
> … ultimately pointed to the issue>...
>
> It was a good suggestion to forget about G33 and run the spindle my itself.
> Even at max rpm (3000) we still have the same noisy sp
On Thursday 10 September 2015 11:47:04 Tom Easterday wrote:
> > On Sep 10, 2015, at 11:34 AM, Gene Heskett
> > wrote: I have not encountered anything even remotely resembling that
> > on my lathe with its 200 edge/turn A/B/Z homemade encoder.
> >
> > If it was jerking at 50 revs, thats more than
On Thu, Sep 10, 2015 at 04:24:33PM -0400, Tom Easterday wrote:
>
> A question: We would like to perhaps smooth the velocity input
> that the trajectory planner uses for G33 commands. What signal
> does it use for the velocity in spindle coordinated motion? It
Spindle-sync motion is a position
> On Sep 10, 2015, at 1:58 PM, John Kasunich wrote:
>
…...
It was a good suggestion to forget about G33 and run the spindle my itself.
Even at max rpm (3000) we still have the same noisy spindle-speed-in signal.
So to make a long story short, the source of the variation in the
spindle-spee
> On Sep 10, 2015, at 12:17 PM, sam sokolik wrote:
>
> could we see the gcode you are running?
G8
G53 G0 X0
G53 G0 Z0
M6 T3 G43
# = 0.700
# = [#/2]
# = 0.025
# = [# + #]
# = 0.000
# = 0.25
# = 0.010
# = 0.002
# = 28
# = 30
# = [# - #]
# = 100
# = 3.142
; The surface is the circumference o
The scope pictures need some accompanying explanation from the
original poster.
My guess would be that each cycle of the spindle-revs sawtooth is
one pass of the G33 cycle.
The falling edge of the sawtooth happens when the spindle hits the
index before the pass. Axis speed prior to that point is
On 09/10/2015 10:00 AM, Tom Easterday wrote:
> Sorry, that was the plot when using G1 (smooth). Here is the plot using G33,
> notice all the noise on the joint velocity command:
> http://bgp.nu/~tom/pub/noise-velocity-G33.png
> -Tom
>
>
Why is the command jumping all over the place? It appears
On Thu, 10 Sep 2015, Tom Easterday wrote:
Date: Thu, 10 Sep 2015 12:07:31 -0400
From: Tom Easterday
Reply-To: "Enhanced Machine Controller (EMC)"
To: "Enhanced Machine Controller (EMC)"
Subject: Re: [Emc-users] G33 and motion-spindle-speed-in,
motion-spindle-revs
could we see the gcode you are running?
On 9/10/2015 11:07 AM, Tom Easterday wrote:
> I also wonder if all the noise in the commanded velocity using G33 could be a
> result of the new trajectory planner (being better at lots of little moves)
> send lots of commands in response to the changes of
I also wonder if all the noise in the commanded velocity using G33 could be a
result of the new trajectory planner (being better at lots of little moves)
send lots of commands in response to the changes of position at low speed…?
-Tom
---
> On Sep 10, 2015, at 11:34 AM, Gene Heskett wrote:
> I have not encountered anything even remotely resembling that on my lathe
> with its 200 edge/turn A/B/Z homemade encoder.
>
> If it was jerking at 50 revs, thats more than 1 second per turn and the
> speed changes would be extremely visibl
anced Machine Controller (EMC)"
> > Subject: Re: [Emc-users] G33 and
> > motion-spindle-speed-in,
> > motion-spindle-revs (2.7.0-pre7)
> >
> > The encoder is fed into a Mesa 7i85s/5i25 running Hostmot2 encoder
> > module. I donÿÿt see any other output I cou
> On Sep 10, 2015, at 10:36 AM, Peter C. Wallace wrote:
> Looks like you spindle simply cannot keep accurate speed control at the very
> low speed you are turning (50 RPM?) I suspect if you really need accurate 50
> RPM speeds a VFD is not going to do it without a large gear reduction
Yes, the
Sorry, that was the plot when using G1 (smooth). Here is the plot using G33,
notice all the noise on the joint velocity command:
http://bgp.nu/~tom/pub/noise-velocity-G33.png
-Tom
> On Sep 10, 2015, at 10:07 AM, Tom Easterday wrote:
> The Halscope plot which I mean to post with the first messa
On Thu, 10 Sep 2015, Tom Easterday wrote:
Date: Thu, 10 Sep 2015 10:07:59 -0400
From: Tom Easterday
Reply-To: "Enhanced Machine Controller (EMC)"
To: "Enhanced Machine Controller (EMC)"
Subject: Re: [Emc-users] G33 and motion-spindle-speed-in,
motion-spindle-re
The encoder is fed into a Mesa 7i85s/5i25 running Hostmot2 encoder module. I
don’t see any other output I could use…
The Halscope plot which I mean to post with the first message is here:
http://bgp.nu/~tom/pub/noise-velocity.png
-Tom
> On Sep 10, 2015, at 7:18 AM, andy pugh wrote:
>
> On 10
On 10 September 2015 at 02:53, Tom Easterday wrote:
> believe there really is a small variation in the spindle but not sure why or
> how to deal with it so that
Does your encoder counter offer a position-interpolated output? That
might be smoother.
--
atp
If you can't fix it, you don't own it.
We were having a problem running a G33 command to do knurling (using a cutting
tool, not knurling tool) on the Emco lathe today. It is essentially a very
small TPI thread (on the order of 0.68 TPI run with a very slow spindle speed).
It turned out that I had the acceleration set too high in th
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