Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: guynamedbathgate on April 08, 2007, 11:47:52 AM

Title: Roatary/stepper stalling
Post by: guynamedbathgate on April 08, 2007, 11:47:52 AM

OK I am just getting around to using this cnc rotary table I built. it uses a stepper motor currently set up for half stepping. the rest of my mill is outfitted with servo drives. my problem is. for one my stepper motor sounds like it could run smoother but all my attempts to tune it have yeilded little results. anyhow. when Im running a program say doing some rotary slotting, when ever the stepper is running and another axis on the table starts to move I get a jerk out of the stepper. or if the feed rate is set pretty fast The motor will stall all together. If I over ride the feed rate and slow it down it improves someone and I can keep it from stalling. but I would like to fix it all together if I could. Is it just that steppers arnt ment to run very fast or what. what kind of max rpm should I expect out of a stepper motor. anyone else have this problem

Title: Re: Roatary/stepper stalling
Post by: Hood on April 08, 2007, 12:02:01 PM

What drive are you using? what size stepper? ratio? Steps?
Can you run the stepper at full rapids on its own?
Never had a fourth axis so might not be much help but do use steppers on my mill.
Hood

Title: Re: Roatary/stepper stalling
Post by: guynamedbathgate on April 08, 2007, 12:29:51 PM

its a gecko 210 stepper drive

the motor is a nema 34  762 0z 3amp wired in parrallel
step angle 1.8

Ive tried to reproduce the problem while jogging but it runs smooth as can be. only when running an actual program do I get a problem.
kinda strange. but Ive had a problem like this before until I finally got a faster processor computor and have had no trouble. but that had to do with my servo's. steppers, well Im lost with them.

Title: Re: Roatary/stepper stalling
Post by: guynamedbathgate on April 08, 2007, 12:33:29 PM

also how smooth should my stepper run. If I just run it at a rapid I can here it kinda skipping every few rotations. its kinda hard to check if Im losing steps on a rotary table though since I have no way to home it and no encoder.

Title: Re: Roatary/stepper stalling
Post by: Chaoticone on April 08, 2007, 02:25:08 PM

Hey GNB,
    Your stepper should run very smooth. Try turning down your accel and vel. in motor tuning and see if it sounds smoother. Sounds kinda like a noise issue to me. Also, post your code for us to see and notice if when it messes up while running code is it trying to move two axis at once at the same feed rate? One way to check and see if it is skipping steps would be to put a mark on the table and command a move equal to one rev. and see if the marks line back up.


Brett

Title: Re: Roatary/stepper stalling
Post by: guynamedbathgate on April 08, 2007, 06:46:47 PM

yeah Iv played with the velocity alot and no matter what I do I get a skipping noise (is all I can describe it as) itl be a nice humm with small breaks in it. Ive tride setting a block up on the rotary table to indicate off of and i dont seem to be losing steps. as for when it stalls you got it right basicaly when I have the mill feeding into the work as it is spinning when the mill reaches depth the table keeps spinning while the Xaxis moves left than right to clean out the slot. its when the x axis tries to move when the motor stalls. If its a noise problem it doesnt seem to affect the rest of my set up. but again Im not sure how easily steppers are affected by noise. my servos run great.
will post the code.

Title: Re: Roatary/stepper stalling
Post by: guynamedbathgate on April 08, 2007, 06:53:17 PM

here is the basic program. I havent really cleaned it up yet so bare with the lack of line numbers. was just trying to test it first.
G90 G94 G64 (SETUP PARAMETERS)
M6 T4 (TOOL4)
M08 (COOLANT)
M03 (SPINDLE ON)
G00 X0 Y0 Z.2
G00 X-.625
G00 Z0
G91 G01(INCRIMENTAL)
G01 Z-.05 A360 F20 (SLOT RUN)
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.0125 A360 F20
G01 A360 F20 (BOTTOM OF SLOT)
G01 X.01 A90 (WIDEN SLOT)
G01 A360
G01 X-.02 A180
G01 A360
G01 X.01 A90
G00 Z.3125 (RETURN TO 0)
G90 (ABSOLUTE)
Z.2 (SAFEZ)
G00 X-1.125
G00 Z0
G91 G01(INCRIMENTAL)
G01 Z-.05 A360 F20 (SLOT RUN)
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.0125 A360 F20
G01 A360 F20 (BOTTOM OF SLOT)
G01 X.01 A90 (WIDEN SLOT)
G01 A360
G01 X-.02 A180
G01 A360
G01 X.01 A90
G00 Z.3125 (RETURN TO 0)
G90 (ABSOLUTE)
Z.2 (SAFEZ)
G00 X-1.625
G00 Z0
G91 G01(INCRIMENTAL)
G01 Z-.05 A360 F20 (SLOT RUN)
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.0125 A360 F20
G01 A360 F20 (BOTTOM OF SLOT)
G01 X.01 A90 (WIDEN SLOT)
G01 A360
G01 X-.02 A180
G01 A360
G01 X.01 A90
G00 Z.3125 (RETURN TO 0)
G90 (ABSOLUTE)
Z.2 (SAFEZ)
G00 X-2.125
G00 Z0
G91 G01(INCRIMENTAL)
G01 Z-.05 A360 F20 (SLOT RUN)
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.0125 A360 F20
G01 A360 F20 (BOTTOM OF SLOT)
G01 X.01 A90 (WIDEN SLOT)
G01 A360
G01 X-.02 A180
G01 A360
G01 X.01 A90
G00 Z.3125 (RETURN TO 0)
G90 (ABSOLUTE)
G00Z.2 (SAFEZ)
G00 X-2.625
G00 Z0
G91 G01(INCRIMENTAL)
G01 Z-.05 A360 F20 (SLOT RUN)
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.05 A360 F20
G01 Z-.0125 A360 F20
G01 A360 F20 (BOTTOM OF SLOT)
G01 X.01 A90 (WIDEN SLOT)
G01 A360
G01 X-1 A7200 F20
G01 A360
G01 X.01 A90
G00 Z.3125
G90 (ABSOLUTE)
M9 M5 (COOLANT AND SPINDLE OFRF)
G00 Z.2
X0 Y0 Z.2
M30


woo a bit long for a post . but heh
chris

Title: Re: Roatary/stepper stalling
Post by: guynamedbathgate on April 09, 2007, 03:30:12 PM

here is an update on what I found.
Im begining to think that there may be a problem with the motor itself. Its just making this funny ticking noise while it runs and nothing I have tried really changes it much. except I tried changing the kernel speed of the computor down to 25000 hz and it seems to be a less frequent tick. but it still ticks non the less. Ive tried running in Full, Half ,5 , and 10 microsteps and none of that affects the noise coming from the motor. also I found that when Im running the below program the motor will hesitate just slightly between lines of code. even though its in CV mode it slows slightly like its going to change directions. If I slow the feedrate down to say 10 it will not stall. and by 10 I mean Inches per minute not degrees per minute. I am using the "use diameter for feedrate setting" from the toolpath screen. was also curiouse what the "A rotations enabled" check box does?

Title: Re: Roatary/stepper stalling
Post by: Brian Barker on April 10, 2007, 09:14:35 AM

Please post you XML and i will check to see if there is a problem

Thanks
Brian

Title: Re: Roatary/stepper stalling
Post by: guynamedbathgate on April 10, 2007, 11:09:42 AM

sure

Title: Re: Roatary/stepper stalling
Post by: Brian Barker on April 11, 2007, 08:12:53 PM

You need to redo your motor tuning settings. You have the X axis set to a MaxVel of 100 IPM and you can't get to that speed at 25KHz. You can only get to 75IPM, so the Calcs that Mach3 was doing was based on the 100IPM and not the 75 that it can do max...

If you tune your motors you should be good to go

thanks
Brian

Title: Re: Roatary/stepper stalling
Post by: guynamedbathgate on April 12, 2007, 06:09:36 AM

Im affaid thats not the problem.
everyonce in a while my computor locks up because I click on to many things at once and when I reboot it, mach for some reason revert back to 25khz. I just switch it back to 45khz and Im done with it. I must have accidently posted my xml when it was in this state. but I can assure you im running at 45khz and that isnt the problem. my computor isnt internet accesable so I have to copy file to a flash drive to post them and move them around. so that what happened there. sorry

Title: Re: Roatary/stepper stalling
Post by: Brian Barker on April 12, 2007, 11:53:47 AM

Could you please post one that you know is good ?

If you do that I will test it again

Title: Re: Roatary/stepper stalling
Post by: guynamedbathgate on April 12, 2007, 07:58:22 PM

sorry here it is

Title: Re: Roatary/stepper stalling
Post by: Graham Waterworth on April 13, 2007, 04:13:57 AM

Hi Chris,

try this modified version of your code, and let me know what happens, also have a look at the comment at the end of your code.

Graham.

G90 G94 G64 (SETUP PARAMETERS)
M6 T4 (TOOL4)
M08 (COOLANT)
M03 (SPINDLE ON)
G00 X0 Y0 Z.2
G00 X-.625
G00 Z0
G91 G01(INCRIMENTAL)
G01 Z-.05 F20
A360(SLOT RUN)
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.0125
A360
G01 X.01 (WIDEN SLOT)
G01 A360
G01 X-.02
G01 A360
G01 X.01
G00 Z.3125 (RETURN TO 0)
G90 (ABSOLUTE)
Z.2 (SAFEZ)
G00 X-1.125
G00 Z0
G91 G01(INCRIMENTAL)
G01 Z-.05
A360(SLOT RUN)
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.0125
A360
G01 X.01 (WIDEN SLOT)
G01 A360
G01 X-.02
G01 A360
G01 X.01
G00 Z.3125 (RETURN TO 0)
G90 (ABSOLUTE)
Z.2 (SAFEZ)
G00 X-1.625
G00 Z0
G91 G01(INCRIMENTAL)
G01 Z-.05
A360 (SLOT RUN)
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.0125
A360
G01 X.01  (WIDEN SLOT)
G01 A360
G01 X-.02
G01 A360
G01 X.01
G00 Z.3125 (RETURN TO 0)
G90 (ABSOLUTE)
Z.2 (SAFEZ)
G00 X-2.125
G00 Z0
G91 G01(INCRIMENTAL)
G01 Z-.05
A360 (SLOT RUN)
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.0125
A360
G01 X.01  (WIDEN SLOT)
G01 A360
G01 X-.02
G01 A360
G01 X.01
G00 Z.3125 (RETURN TO 0)
G90 (ABSOLUTE)
G00Z.2 (SAFEZ)
G00 X-2.625
G00 Z0
G91 G01(INCRIMENTAL)
G01 Z-.05
A360 (SLOT RUN)
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.05
A360
G01 Z-.0125
A360
G01 X.01  (WIDEN SLOT)
G01 A360

(this bit below looks wrong to me)
(its going to scroll through)
(the job)

G01 X-1 A7200 F20
G01 A360
G01 X.01
G00 Z.3125
G90 (ABSOLUTE)
M9 M5 (COOLANT AND SPINDLE OFRF)
G00 Z.2
X0 Y0 Z.2
M30

Title: Re: Roatary/stepper stalling
Post by: Brian Barker on April 14, 2007, 09:28:09 PM

I have tested it here and it still looks good... Try the following and tell me if you miss steps

From X0.0 A0.0
G00 X.1 A180

and

From X0.0 A0.0
G00 X3 A.1

Do you have a problem?

Thanks
Brian