WHen i move the z axis up 10mm is wizzes moves a little and stops. it works fine at 1mm movements.
i have included a youtube link for a video of it in action.
im using skr 1.3 2209 drivers.
Try lowering your feed rate
how do i do that? does it have to be done in the firmware?
My guess is that your Z Max Speed is too high. It doesn’t get to full speed on short moves, but starts to miss steps on longer moves. Acceleration may also benefit from tuning.
Before changing firmware or configuration, I’d do a series of gcode G01 command tests moving Z up and down the max distance you ever expect them to move (50+ mm?) to ensure you get to full speed depending on your acceleration setting. Then run the test at various speeds to see where you are not in danger of missing steps. e.g.:
G01 Z0 F60
G01 Z50 F60
The number after Z is the desired Z end position (assuming you’re using absolute coordinates), the number after the F (feedrate) is the desired speed in mm/minute. Be sure to use a G01 (or G1) for this test. G00 (or G0) is for “rapid” moves and doesn’t officially support the F parameter.
Repeat the test, adjusting the feedrate to where you go as fast as possible without losing steps, then reduce by 5-10% for your permanent setting.
You can set the max speed in the firmware, or store it in the eeprom.
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thanks for that, when looking at the eeprom setting in repetier i noticed the steps being well out so after setting them up the z moves lovely now
Another parameter to look at in such cases is the acceleration rate, if available. That implies the deceleration as well, of course, an often overlooked source of long head scratching sessions. The fact that short distances made less problems than longer ones speaks for this, also your description of the error.
I used EMC2 (now LinuxCNC) on my first home-build CNC machine (Phlatprinter) many years ago. Their recommended commissioning strategy back then was to tune acceleration first on each axis by slowly increasing it (with a known moderate-to-slow feedrate) until you started to lose steps, then back off 10% (or whatever safety margin you chose). Once acceleration was dialed in you slowly ramped up feedrate to the point of losing steps and backed it off to your desired safety margin. That method got me to an operational set of parameters pretty quickly, without a lot of bouncing back and forth.
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That is a really good process and I used something similar, except I get a little panicky with high accelerations, so I drop them quite a bit lower, like 50%. I just enjoy the machine more that way.
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Btdt. But beware of LinuxCNC rounding off edges and corners deliberately, at least in earlier (>5 years old) versions. Squeaking the acceleration made that invisible at least, but it is still there. That is / was Linux-CNC-specific, though.
And the machine enjoys its jobs more likely too… 