Z axis issues

I jog all the motors in each direction. X and Y seem to be working. I go up on the Z and it just turns so so slow and I tell it to go up 100mm and it goes up about twenty. I used the Josef Prusa MM per step online tool and set the lead screw 2267.718321038048 steps per mm value and changed it in the firmware. I am running Repetier on my 2011 MBP. What I'm curious about is why is the motor so slow to go up and inaccurate and why when I home the machine the motors move at a lightning speed. Thanks for your time.


Here is the link to the video of this in action.

[www.youtube.com]

why don't know why it it inacrute but i know the speed problem can be fixed by changing the move speed on the host software

It's actually part of the same problem -- your steps per mm are way out of calibration. I had the same problem when I was setting up the machine I just built (marlin firmware). In the firmware, one of the options is mm per minute so if the steps/mm are way off, then the movement speed will be way off as well since it thinks a millimeter is much less rotation than it actually is. Calibrate the steps per mm and you'll solve both problems.

I'm having the same problem with the latest Repetier firmware from github. I have a newly built MendelMax (M8 Z rods) with Megatronics 2.0 electronics. X and Y move fine, but raising Z by 10 mm turns the motors only about 1/3 turn, at really low speed.

And yes, the Z steps are most definetely correct: #define ZAXIS_STEPS_PER_MM 2560.0

Z homing works fine, and moves much faster than the regular move command.

Solved already! The firmware was using a Z-step value of about 90 (as well as slightly incorrect X and Y step values) from EEPROM even though I had never written anything to EEPROM. Strange... So, for anyone having issues, remember to check the EEPROM settings with M205.

edit: Oh, the settings are automatically stored to EEPROM when the firmware first runs and there's a special parameter you have to use if you want to (ever) override the EEPROM setting with the ones from Configuration.h. Haven't used Repetier before this so I had missed that...

Edited 1 time(s). Last edit at 03/08/2013 07:24PM by ttsalo.