Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Haik on July 05, 2007, 06:01:48 PM
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Hi Forum,
I need some help getting Feedrate speed out of my setup... when a gCode line with only "A" on it runs all is fine and "A" is as fast as "F" is set, but lines with "A" and another axis like "X" "Y" and/or "Z" the feedrate drops to around 1.2 IPM which is like sooo very slow!
My setup is:
-Mach3 w/ G100
-4th Axis Motor Tuning settings: Steps[500], Velocity[2500] yes it's cranked!, Acceleration[1000]
-Tangential control[OFF]
-Settings page Rotation Diameters: A[+0.0001]
-Settings page Axis Ihibits[OFF] for all 6 axis'
-General Config Angular Properties [CHECKED/on] for A, B,and C
-ToolPath Configuation Use diameter For Feedrate[CHECKED/on]
My snippet of gCode is:
f50000 (cranked and still slow on A w/XYorZ)
x0 y0 z0
z-.187 (moves fast)
y2 (moves fast)
y0 (moves fast)
x2 a90 (moves SLOW!!!)
z.2 (moves fast)
x-.5 y0 (moves fast)
z-.187 (moves fast)
x0 y0 a90 (moves SLOW!!!)
x2 a180 (moves SLOW!!!)
...etc........etc.......
Also to rule out software/firmware woes I've tried different versions of Mach3, different versions of Mach3 G100 Plugin, and different version of G100 Plugin Firmware... all perform with same problem persisting.
Any help is h-u-g-e-l-y appreciated!!!
-Haik
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For what I understood from the video:
Settings page Rotation Diameters: A[+0.0001
should be the diameter of the block being milled. Did you try with, say, 100 mm ?
Gianni
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Thanks for the reply!... Yes, I did try a diameter, my units are 'inches' and I tried a variety of diameters from .5"-20" all having no effect. The .0001 diameter is supposed to Mach to use the 'Z' value for calculating rotational feedrate, but that had no effect either.
-Haik
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Hey Haik,
Do you have your a axis steps per set to = 1degree or 1 rotation?
Brett
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This I don't know... where in Mach do I find/make this setting???
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It is in config, motor tuning, steps per. Did you do the math for one rotation or one degree?
Brett
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Well... It's set to 500 steps: My turntable is geared at 90:1 and stepper pulleys are 1:1
The thing is I get 90 degrees of rotation when I do A90... I do think this area of my setup needs investigation. How can I test both approaches or can I ???
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Haik,
Are you single stepping, microstepping, servos? How many pulses does it take to make the motor turn 1 round?
Brett
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I'm using stepper motors and I have G203v (10 microstep) drivers on all axis, but on XY and Z the steps are set to 4000 steps and the screws are 2 TPI. So I'm "microstepping" and there are 2000 step pulses per turn.
On A the steps are currently set to 500, so I believe I'm set to "steps per degree" (as in 500 steps p/deg, 4 deg p/crank rot, 1:1 pulleys, 90:1 table gearing, 180,000 steps for 360 deg). It seems that 180,000 steps p/360 degrees is radically high, maybe I should be full-stepping (div by 10) and then the step relationship between XYZ and A will be closer?
I hope this is the info your asking for... and "Thanks" for helping!!!
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Yup, that is what I was wanting to know. :) I can't remember for sure but I'm certain I have seen this come up before. Can you try tuning your motor to Stepr per rev. and see how it does? It sounds like it is right as is though. Hmmmmmmmmm. Can you post your XML? I don't have a 4th axis but will look at it and see if I can find anything to cause this.
Brett
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Here's my XML... Thanks!!!
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Hi Brett:
I have his Gcode and am runnign a test here as well..
Art
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Thanks Art.
Brett
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Hi, Halk
Edit:-------------Halk this file below doesn't have any blended moves, I'll post one Later today ---------------!!
In my experience with 4th axis (using P-port hear) think your using G-rex, Anyway the limiting factor is the 4th axis speed for blended moves.
Pump it up as fast as you can in Vel. and Accel., Without losing steps, With 10 Micro-steps it's allot of steps compared to you other axis's.
I am using a sherline rotary table some 144,072 steps 360 deg. 1 full turn, ( set at 1 deg. 400.2 steps) 10 micro-step also vel 2500 accl 500.
A 1, 1/2, 5, 10 selectable cont. would speed it up using the 1 or 1/2 mode would speed it up.
Once you factor in the rotational Dia., I think you'll find it's OK, What's your planed use.
Try below file, 2.0 inch A dia. F25 may want to set it up or over ride speed
Thanks, Chip
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Will do on topping-out the Vel and Accl... I've already expeienced stalling and on a 4-stack/1300oz-in NEMA 34 @ 80vdc I gotta say it sounds ugly. :-(
GREAT NEWS is Art made a change for me that fixed the "crawling" problem I was having. 4 Axis code now runs as fast as my steppers allow! I do need to use high F values, but I've heard of others having to do that and since that's such a small thing... "no problem."
Also... My "THANKS" Bret, Gianni, and you for helping me out!
Oh, by the way... I'm making balusters and other turned parts. In my pic you might notice I have Perske spindles (on VFD, RPMs/Frequency controlled by Mach3), 1 verticle and 1 horizontal. G100 and 5 G203V's round out the control.
And Art, again, THANK YOU!!!
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Good deal Haik, I'm glad you are sorted.
Brett
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Hi, Halk
Glad your working now what did it take to fix it. ?
Give this file a try, Got side-tracked today.
Thanks, Chip
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It was a problem with How the G100 was getting the velocity and how Mach3 likes to have the velocity.... It is nothing that he could have fixed but it should be good to go now :)
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Thanks, Brian
Chip
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Yes, it's as Brian explained... for almost a week I tried everything before contacting Art. Nothing I tried ever put a dent in the problem... but Art stuck to it and found the problem and fixed it. I'll bet many users will benefit with this fix in place!
-Haik