Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: TheSniper on December 20, 2013, 09:48:27 AM
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All,
I have a new setup. (I have previous machines that work under Mach). This is a router table with 2 drives driving the X axis.(the A one is slaved)
Controller is a PDMX122, Geko 203V and Vexta Geared Motors.(PK296 series)
The PC is a Pentium 3Ghz stripped down to bare bones configuration.
and I am registered Mach3 user too :)
All is functional. and typically the machine behaves properly.
Sometimes (pretty frequently) the motors could be any of the axis. X Y or Z (X has a slave axis)
the motors stall. The best way I can describe it is . ITs as if the velocity is set to high. (but its not)
I can tune the motors to say 300ipm range and they operate smoothly.
The problem seems to only occur on first start of any direction on any axis. One their running I can stop and start. many times their after.
Another way of getting them to stall reliably. is to perform an "Axis Calibration" this will almost always cause the motors to stall.
Example.
Run first test... Motors stall for about a second then proceed as normal.
Run second test. Same results.
Run same test but jog motors any direction. just before hand... no stalling.
Using the above example. I have even adjusted the motor tuning down from say 250 to as low as 20. all with the same results.
My apologies If I have not explained my symptoms correctly.
One last injection. I have ran a sample g code file with as much as 12K lines of code. and ran with out a hiccup.
BUT... the actual first movement stalled. my solution. re home. Re jog... then re run the g code file.
-S
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Have you tried reducing the acceleration a bit, sounds like your tuning is just on the edge and that can be acceleration as well as velocity.
Hood
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As already mentioed. I have reduced both velocity and acceleration to turtle speed. And the results are precisly the same. Funny thing when i reduce both of them to say 5 each ( crazy slow) same stall but only at startup snd only once per go.
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Dont think you mentioned Velocity ;)
Try increasing the pulse width and Dir as well, probably wont help but ... well give it a go.
If you attach your xml I will see if I can find an issue with it.
Hood
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I have minimized the Acceleration and velocity to what I believe too slow to even test with. But here is my current XLM for the Machine.
Things to remember. I have cut a file with +/- 11,685 Lines of code (to be exact :) )... running at about 200ipm with no missed steps.
But did on the first launch.. So I re homed& zeroed and then re ran the file. worked flawlessly the second go around.
So put another way. seems the first attempt (very first) is when the problem shows it self.
According to what I have read the steppers should be Step Pulse set @ 2 and Dir pulse left @ 0
here is the XML http://www.trickinteriors.com/MechMate-Mach3/MechMate.xml (http://www.trickinteriors.com/MechMate-Mach3/MechMate.xml) file.
(This is a new machine I have ran it for about 2 hours +/-)
Just to be sure I was clear. The so called stall's only happen at the "First movement" if its going to stall at all. In the case its going to... the first thing you hear is the stall... for about a second once recovered... it does not miss a beat. The only other scenario. Is it does not stall at first movement. and again does not miss a beat.
One thing I don't quite understand.... Say It reliably stall's when set @ 200ipm. and I do an axis calibration.... Upon first movement. I get the stall and then the calibration goes to completion with out a hiccup their after... So I set the Speed and Accel to 20 and 5.... I re run the Axis Calibration... Same stall same results.
I know Im prob talking out of my ars... but seems to me the motor is trying to start up if full speed mode. Like you mentioned earlier. But if this was the case.
then why does it almost reliably stall under an axis test when the setting are real low. Also under other conditions. Only at the first move... but then never their after?
Thanks In Advance!
S-
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Not sure where you read that regards the Pulse widths but whatever :)
Try reducing your kernel to 25KHz, you have it at 60KHz and your motor tuning only requires 19KHz.
I would also uncheck A as angular on General config page, it shouldnt matter really as it is slaved but maybe there is something there, especially as you say it is just the first move.
Hood
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Sam,
The Gecko G203Vs have an axis auto current reduction feature. It activates after about 1 second of axis inactivity, if I read the manual correctly. It is supposed to reduce current on standby to 70%, but some versions reduce current to 0%.
Could your problem be related to this feature? From your description, it sounds suspicious to me, especially since you say it happens with any axis.
John Champlain
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I'll give all these changes a shot this afternoon I have to goto wk this morning. but only for half a day! :)
@Hood: In the Gecko Manual under troubleshooting is where I found the pulse widths info apparently the 203V are different from most of the other drives?. I have tried lowering the kernel speed to 25KHz as well as many other speeds. But Im glad to try again :).
@Picengraver: Sounds like a possibility. Ill have to look into that.
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All,
After trying many changes
1:Kernel speed I tried 25000KHz, and a few others all with exactely the same results (currently @ 25000KHz though)
2: Tried lowering the motor Velocity & Acceleration to say 10 and 10, Same results. But I can Jog all day at 250/20 with not one missed beat.
3: Played around with different Step Pulse and Dir pulse. Current setting @ 2us and 0 respectivly.
4: Tried a fresh install of Mach.
5: Switched my Parallel port from EPP to ECP
6: Set the Process "Mach" to realtime in the process manager
All with not any noticeable change in my hunt for the problem.
I cannot seem to wrap my head around the problem. Like I said in an earlier post. I ran a test file with around 10K lines of code. all with no missed beats/steps. But had their been one it would have been upon first move.
If I had to make a claim. in regards to "can you reliably reproduce the problem?
I would have to answer "No" But I can get close.
1: When it occurs its always when the software is in control. NEVER under a MANUAL jog does it fail.
2: typically the absolute first movement is when it will rear its ugly head
ie if the routine has 1 or 5000 lines of code it will be the first line that has movement. never afterwards.
3: I prefer to use one of the Mach blue or Hoss etc screen sets. when I do a auto Zero touch off.
it will crash during the line under the Z- button Script
"Code "G1 Z1.0 F2" 'put the Z retract height you want here"
interesting enough it also fails to retract the desired 1" but goes to about 1.5 or 2" but never 1"
Perhaps I can take a few videos and upload so the problem can be seen and heard. at the same time.
In regards to Johns suggestion I was unable to prove/disprove the motors sleeping. As Gecko is closed for the holiday and I was un able to find any iNet related issues.
-Still mystified...
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Does the skipping happen if only a single axis is used and connected?
" when starting from any spot along the axis?
To find the culprit i would keep things as simple as possible as that eliminates causes.
Since it's rather repeatable as only the first move, see if one axis skips when the motor is not driving ( ie; remove the motor coupling)
an axis. Then do checkout in a logical way.
RICH
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Rich,
Skipping or what ever you want to call it. It only happens at the sign of a first movement. from then on no skips what so ever.
This can happen on any of the axis's at any place. I have not ascertained a certain location. As I do not feel its a mechanical problem
in any way, In fact I can just remove the steppers thus eliminating any mechanical issues. (which Im 99.9 % confident its not)
Repeat the skipping never never happens after the first movement at any location... "never" / "never has"
I should have added that when I do a pulse test. I get "every time" "Pulsing too fast" at the beginning of every test.. no matter what speed I choose.
then it clears up. and will run smoothly even at 100MHz. but just like the motors. only at the beginning. of each test segment.
Im starting to think its the PC. this is the third pc I read in another post/thread of someone having similar issues. And, the problem entirely went away after the third PC was introduced. perhaps Im just in need of the 4th pc!?...
Curious all. What do you think of the SmoothStepper possibility? seems to me it would solve any parallel port issue. Im just afraid Ill trade off my current dillema for another unknown problem.
-S
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So try with PDMX bypassed, that leaves the drive PC and one motor unconnected to the axis, that eliminates the mechanical issues and also
a possible power supply issue.
I didn't see anything where you could jumper on the drive as I can on the 201's, but, with only one motor feed from the power supply and max torque
available even at 70% reduction should not have an issue. If your velocity is 100 use an acceleration of 10, 60 vel - 6 accel.
If it's a signal issue you need trace it at each interface and compare.
I have no firm answer for you so KISS applies, process of elimination / test!
RICH
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So try with PDMX bypassed, that leaves the drive PC and one motor unconnected to the axis, that eliminates the mechanical issues and also
a possible power supply issue.
Rich, Im not sure what you mean by bypassing the PDMX. If I do that how will I drive the motor?
Im on track with your earlier suggestions.
What I've done so far.
1: I disconnected all other motors and tried one all by it self. (Same results)
2: I built tried 2 other PC's this would make my 6th pc. Same results.
3: I need to swap parallel ports I have 2 of them One on board one an add on card. and try. (pending)
4: I can reliably reproduce this. Lets try with the Z axis.
Let me say this pre hand I can JOG the Z axis all day long and it hums like a well oiled sewing machine.
However I noticed. from the MDI I can say Zero the Z axis. and then issue a from Z0.0 G0 Z1.0 and it will proceed Upwards 1"
same if I tell it G0 Z-1.0 or even G1 Z1.0 or G1 Z-1.0. all moves are perfection....I have tried this dozens of times.
Now say from the offsets page. I try and Zero the Z axis. Im using Hoss's Blue screen. lets assume the Z is reading +3.0 the Z travels downward.
touches the touch plate. and zeros the DRO. then back off a slight bit and still zero'd the DRO. next move is the upward to the pre set/ desired height default is 1" (above the work) ... Right as the motor starts to move upward. and I do mean the instant. the DRO changes from 0.00 to some negative number lets say -.3256 at virtually the same time the motor makes its weird noise. then proceeds upwards to what ever the DRO reversed to plus the 1" so in my example final height? 1.3256...? go figure.... The DRO flashes so quickly I never noticed it. also while Im distracted from the motor noise.
All this sounds like a different problem. But in truth I could care less if the motor huffed and puffed and cried a pool of tears. so long as it does its job. perhaps the noise is negligible and my problem is not with the motors after all? I see/hear the motors whine. all while the expected travel distance isnt what I expect. perhaps the changing DRO is the culprit.?
Ideas?
I have 2 XML files for the same machine 1 is at 25000Hz and the other at 60000Hz both have the same anomolies.
but run fine otherwise.
whats appropriate?
Should I upload the files and create a link or post the file contents here.
MechMate25000Hz file
http://www.trickinteriors.com/MechMate-Mach3/MechMate25000Hz.xml (http://www.trickinteriors.com/MechMate-Mach3/MechMate25000Hz.xml)
MechMate60000Hz file
http://www.trickinteriors.com/MechMate-Mach3/MechMate60000Hz.xml (http://www.trickinteriors.com/MechMate-Mach3/MechMate60000Hz.xml)
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bypassing the PDMX
I was thinking that you run the cable direcly from the drive to the stepper using the PP. That would eliminate the
BOB. Good grief you can't have 6 bum pc's!
Stay away from using offsets or some screen other than the standard Mach Mill screen and state which Mach version your using.
I don't know what the Hoss screen does as compared to the standard one.
The intent is to just start at a rock basic system and if the problem goes away then adding a component or move may pinpoint.
I have no answer for you and just suggest testing unless someone chimes in with a solution based on similar experience.
PITA it is and if it makes you feel any better we all had something which took more time to solve than we wish to say.
RICH
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@Rich: I was not aware I could bypass the BoB...
I suppose I can google or do a search. and go from their.
Yes, I agree 6 pc's? and all with the same symptoms? not likely. But hey, I have had worse luck! :)
BTW thanks for all the ideas thus far. I have another machine. that suffers no problems. 1 out of 2 aint bad eh?
-Sam
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I had a similar issue once that drove me crazy. Machine had worked perfectly for months and suddenly with no changes it started randomly stalling. After going though everything (as I am sure you have) I checked my bios settings, somehow during a reboot the parallel port got switched to standard mode. I switched it back to enhanced mode and it's been fine ever since.
Something to check.
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I had a similar issue once that drove me crazy. Machine had worked perfectly for months and suddenly with no changes it started randomly stalling. After going though everything (as I am sure you have) I checked my bios settings, somehow during a reboot the parallel port got switched to standard mode. I switched it back to enhanced mode and it's been fine ever since.
Something to check.
Thanks for the follow up.
Wow, I wish I were that lucky... My problem is just that, a problem... Ill keep beating it till one of us "it or me" gives in. :) I have btw tried changing my Port from one mode to the other and in my case? no change. :/ Glad to hear your back up and running though!
-S
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All,
I am happy to report... I have resolved my So called motor stall on first event.
If you read the entire thread. though their are very few entries I hope I documented all I have tried and not tried.
One thing of interest and funny thing its probably the first thing I could have looked at.
is the version Im running. According to the help about screen I was on 3.043.00
I though??? heck, Ill try a beta if ones available. After looking I seen the current version is at 3.043.062
and I decide to read the change log. WHOA! lots O' changes... (thanks for the fixes Art :) ) I re-installed the updated version and low and behold.
no stalling at first run. Heck even the Zero Z script runs ... Though I tweaked it to suit my needs. Im glad to post what I changed.
Other things I changed to test for the problem pre-updating the software.
1: I changed the parallel cables to the shortest ones I could find.
2: I created a profile with everything turned off except say one axis. absolute minimum setup.
3: My next step was going to bypass the BOB... (thanks to RICH's suggestion)
So, As of now.
1: Im back to my first PC! Geez that was pain full X 6!!! (5 spares in the bank-O'-matic tho.)
2: I'm locked on 60000Hz... Ill have to continue on with my tests. But as of now that particular issue is "SLAM DUNKED!"
3: Gecko 203V's set at 250, 50, 2us, 0 and Active High. just like the documentation says to set it at.
Thanks to you all. Im most grateful for your suggestions and time you gave me :)
-S
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Glad you got her fixed.
Took a while, but, state which Mach version
, rang a bell and sometimes bells skip and takes few tries to hear it ring. ;)
RICH
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All versions from 3.43.000 to 3.43.028 are rather buggy. Lots of changes and additions were made in these versions to support the MSM screenset