Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: mad_dog096 on April 13, 2009, 10:43:00 PM

Title: z axis problems
Post by: mad_dog096 on April 13, 2009, 10:43:00 PM
Hay guys,
 i am new to this form and new to the Mach3 controler and i am having some problems with my machine. here is some specs of my machine

computer: amd 500+ processer, 1GB of ram. and all i have installed on there is mach3 cut2d and turbocad. (nothing else no internet or anything)

the machine has: Gecko G540, 24v 8A powersupply, 3 nema 23 495 oz-in motors from keling.

here is my problem.
  i go to cut out my project and what happens is i set my z zero as close as i can to the material then zero everything out, i hit run and it goes trough its paces. then when it come to the z axis going down for the next pass it just simple stops, mach still keeps everything going, it calculates it going down, numbers move but the z axis doesn't. the x and y axis keep on moving but the z wont, then when i stop the machine and tell it to go to z zero its always way above the material.
what can i do to fix this, any suggestions out there.
Title: Re: z axis problems
Post by: lemo on April 13, 2009, 10:59:57 PM
Check the motor tuning section and do not forget to select the axis before adjusting parameters as one can easily mess up the x axis as it is the default... Mach3 is currently not the most intuitive piece of software.

Run the z axis manual with the highest jog speed and make sure that it does not stall. When it stops and rattles and hums then the motor tuning parameters are set incorrectly. Every machine is different so there are no settings I could give you.

Don;t be afraid to set the acceleration to high. The steppers will stop moving while cursing you out with the sound of a hornets nest if settings are to high. For short test you cannot ruin anything. Just don;t let them sit and scream while you go and have a beer.

So... try to tune the motors. Looks like you have a clean little machine. All should work well.

Title: Re: z axis problems
Post by: mad_dog096 on April 13, 2009, 11:19:52 PM
thx lemo,

 i will give that a try tomrrow and see if that helps. i have a buddy coming over tomorow to help me out with it, but he doesnt know much whats going on with it eiter, so more info the marrier.
thx again and i will post what happens
Title: Re: z axis problems
Post by: lemo on April 14, 2009, 08:05:34 AM
Include the description of noise and all sorts of observations. The matter is complex enough that a behavior meaningless to you might be the key to the root of the problem for someone else. Also go to the geck drive website and read the essay about steppers. There are a few critical issues with stepper motors like mid band resonance and things alike which at first sound esoteric but then once manifested and observed in your own machine become a very real and understandable. The size of the machine does not really mater, all the principles are alive and kicking in a gantry crane to lift containers or your small router. So go, try to adjust and then let us know how things go.

Another hint.... if you calibrate your machine, then do not calibrate the amount of steps with a caliper for starters. Calibrate the amount of steps with the maximum distance you can move. If you calibrate that within an inch only or a couple, then the slight error you will have multiply along the larger distance. If you calibrate over a few feet and you are off maybe 5/1000th then you will have a fraction of that error within smaller distances. However, checking for accuracy with a caliper or dial is useful, just not really for the initial calibration.

Good luck