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Author Topic: Mill problem?? Having a crazy jitter  (Read 3179 times)

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Mill problem?? Having a crazy jitter
« on: March 07, 2017, 11:49:12 PM »
Hey guys take a look at this video. this machines been up and going for years. I can jog all day long without a problem. I just noticed today after trying to cut a programmed piece that my X axis jumps when crossing a specific spot. I doubt is in the ball screw cause i can jog past it fine its only on a coded move. I tried lowering my motor velocity even though i run super conservative and have twice the size motors as anyone with this mill, that didn't help. I have my shuttle at .004 IS is that okay? it's worked for two years now??

https://youtu.be/C3zLL86YSX4

Any thoughts? Thanks Zach

Offline Tweakie.CNC

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Re: Mill problem?? Having a crazy jitter
« Reply #1 on: March 08, 2017, 02:44:05 AM »
Interesting.

The obvious question I suppose is - does it still do this with the Shuttle (and any other USB devices) disconnected ?

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Mill problem?? Having a crazy jitter
« Reply #2 on: March 08, 2017, 03:12:20 PM »
I dont have a pendent or any usb devices. I jog with my key board. my mouse and keyboard are usb.....
Re: Mill problem?? Having a crazy jitter
« Reply #3 on: March 08, 2017, 05:12:49 PM »
I also really need this piece cut today. but I now know it is for sure only x that need a move command.tried .08-.01-.004-.001 shuttle accel. no different. changed all sorts of motor parameters still nothing. all wires are pristine, no bends or breaks. can not get it to do this wile jogging for the life of me..  Right now Im ganna try to swap the driver with Y and see if Y does it.......Please help Im screwed here
Re: Mill problem?? Having a crazy jitter
« Reply #4 on: March 08, 2017, 11:08:37 PM »
Alright super weird. I swapped the power/Motor Plug and Breakout plug with Y axis Driver. I then Move Y with MIDI and it jumped!!!! So Okay Its a driver.. NO!!! WTF I take that driver out, put a smaller driver used for A on Z, and took Z's driver and put it on X. button it all up ready to have a super late night cutting my piece, Zero it all in. Do a test move and F**King X jiumps again!!!! When doing this I am using my Z's output on breakout board as X( Just swapped in ports and pins). So that means its not a driver. its not a bad output on breakout. Its not wiring. Its not machine.... Dude this has to me some software issue??????


AHHHHHHHHHHHH!!!!!!!!   LOL

Re: Mill problem?? Having a crazy jitter
« Reply #5 on: March 09, 2017, 12:57:44 AM »
https://www.youtube.com/watch?v=ZhtkO7j0j_Y


updated video found new issue will O scope pc and breakout outputs tomorrow..

Offline Tweakie.CNC

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Re: Mill problem?? Having a crazy jitter
« Reply #6 on: March 09, 2017, 05:47:40 AM »
From your earlier posts I assume you are still using the RnR USB motion controller. From another member’s tests it has been shown that the Direction signal from this board is not persistent but is resent following a break in the Step signal train. Your stepper glitch is indicating such a break in the data stream and that could explain it running backwards slightly then correcting itself.
This is not a Mach3 problem per say but your PC could be interrupting the data stream by carrying out other tasks as may be associated with power saving features (allowing USB devices to power down, screensaver, hard drive power down, etc., etc.). It could also be associated with electrical noise spikes etc. Fitting clip-on ferrites at each end of the USB cable between the PC and the RnR may help.
What bugs me is that this glitch is happening in more or less the same place and that I just can’t explain or understand but I will keep digging.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Mill problem?? Having a crazy jitter
« Reply #7 on: March 09, 2017, 03:09:57 PM »
Hey thanks for the response,

I am currently not using that RnR motion controller. When I first tried to use that controller any kind of manual movement was very laggy. So I got a standard breakout board from stepper online. It's a standard db25 serial Breakout. but I am almost to the shop I will take some scope pics when I get there
Re: Mill problem?? Having a crazy jitter
« Reply #8 on: March 09, 2017, 05:10:07 PM »
Okay I cant really get a clear view of whats happening on my scope. I can see the pulse but not a drastic change.

Im Sure its some software setting or error now....... I can open Mach 3 home all Axis' then move X manually. It sounds fine. If i input a command is sounds funky and clunks, If I go to Ports and Pins Swap X and Y So Mach thinks its moving X but really now is moving Y. Y then makes the funny sound. So that right there shows its gatta be the software. By changing the port it is using a different pin on the DB25 connector/ different input on breakout/ different stepper driver and different motor but some how does the same thing??? So that means for some reason mach 3 is outputting a funky signal only for what it thinks Is X.

That means im now lost.....
I posted my settings maybe its something weird i have in there
Re: Mill problem?? Having a crazy jitter
« Reply #9 on: March 09, 2017, 05:55:56 PM »
I at least know whats happening......Okay the Pulse does not change at all.. that's why i couldn't see it on my scope. Its the carrier frequency that's changing on X. If i type a G01 command so its slower i can see the frequency changes. you can see in the two pictures one has evenly spaced pulses. the other has a gap this gap changes all the time. its like the carrier freq for X isn't stable. the freq counter on O scope also wiggs out and cant find a stable frequency... its also its not the computer since it'll change to what ever pin is set as X.
 
So what could be causing that???  2nd pic is on page 2

I tried a fresh download, didn't help..
« Last Edit: March 09, 2017, 05:59:50 PM by nissan20det »