Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: cmnewcomer on May 28, 2008, 08:21:09 PM
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I just finished converting an Enco tabletop mill to CNC and have gotten the x/y axis working fairly good but I have been unable to save the recommended Step Pulse setting. I'm using Nema 34 steppers (4 wire type from Homeshopcnc) and Gecko 201s and it's my understanding that the Step Pulse should be set to 2. When I enter this setting and save it appears to work but when I return to the setup screen the value is 1. Any feedback would be greatly appreciated.
Best Regards.
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Rich,
OK, I've tried that and a dozen other things but it just won't persist. The only reason I decided to set it is that I lost some steps when drawing circles at 60ipm. Was more curious if that would solve the missed steps more than anything. I'll never need to drive this thing that fast which is a good thing. When I run it up to 50ipm doing circles it's right on. I never expected the accuracy I'm getting out of this old thing so I'm pleased.
Thanks again for the feedback.
Best Regards.
Carl
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Hi Carl,
I to are having the same problems and are specifically loosing steps on the A axis and I cannot change the step pulses, they are currently at zero and even if I do a restart they return to zero. I'm using a Grex also .
My Kernel speed is 100kHz and in the Grex config I have selected 32kHs for all the axiii. If I select higher settings in the Grex the max vel and acc decreases so I have left them as is.
Axis Step/unit Vel Accell
X 50.5102 15000 1250 Servo with a G320
y 39.2857 15000 1500 Stepper with a G203
A 5.55555555 15000 1500 Stepper with G203
My X and Y axis do not loose steps only my A. I have reduce feed rates to 5000mm/min and gone as high as 15000mm/min. The A axis looses steps to the tune of 5-10 degs when I have the knife removed meaning no load.
This is geting frustratiing. May be the cause is the Grex, but like your post says I wished to adjust these pulse setings and they do not change.
Thought anyone??
Jason
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If you are talking about the Step Pulse settings on the Motor Tuning window -
1. You must have the same settings for all axis - although the step can be different to the dir.
2. You must "change" both windows (you need not actually change them, but you need to highlight the window and type in the value you want to keep on BOTH step and dir windows.
3. The "Save Axis settings button" should now be highlighted. Click this and your settings will be saved.
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Thanks for the quick response.
Yes I have tried what you have suggested and still no change. It keep resetting to zero. This may have something to do with the Grex???
Jason
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Jason, I can't remember for sure but I think if using the G100 those aren't setable. Been a long time since I had mine hooked up.
Brett
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Thanks Brett,
I did find a short reference to it being set to 0 in the set guide.
The Grex is starting to frustrate me with it's lack of ability to deal with lots of short steps in the Gcode and also the fact tha I can only get my machine to run smooth with feed rates of 2000mm/min. I am also convinced that my A axis loosing it's setps over a large file size is also due to the Grex.
Thanks again for your help
Jason
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I have noticed the same issue with the step pulse value, if you enter the value you want , choose save setting and then close the motor tuning dialouge box it will save your setting but each time you open the motor tuning dialouge box that value will drop by one . I have it set at 11 and each time I open motor tuning it drops by one to 10 , 9 , 8 and so on , you just need to make sure you type in the value you want and click save axis setting every time you open motor tuning.
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How far does it drop if you keep going in without resetting it?
Hood
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it keeps dropping until it hits 2 on the machine I use daily
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I just spent a bit of time playing with mach 3 , The value will keep dropping until it hits 2 , but if you save the value you want and then open the ports and pins dialouge box it seems to break the cycle of dropping by one and stays on the last value before ports and pins was opened. Not sure why but it seems to work
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I think 5 is the max you should set it to but not 100% sure as mine is always at zero so its not a setting I pay particular attention to. What to try however is setting it to the figure you wish then go to the config menu and choose the save settings option and see if that solves the problem.
Hood
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mine needs to be at 11 or 12 for the spindle motor to spin up to the correct speed, at a value of 5 I cant get the output to my VFD over aprox 3 volts, needs 10 for full rpm (1725). I am not sure exactly what the value I am changing is but a few months ago when i was going thru the VFD setup someone here mentioned trying a much higher value.
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Panaceabeachbum, Have you tried setting to Sherline mode in Ports and Pins, on port set up page? Would be interesting to see if it fixes the problem.
Brett
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I will try that , config menu and choose the save settings option does not break the cycle , the only thing that seems to break the cycle is opening the ports and pins dialouge after motor tuning.
The earlier version of mach 2.5 or so did not have this issue , it started when I upgraded to a more recent version , its not really a problem once you figure out how to stop it , just a little glitch as the original poster pointed out