Motors not turning [solved]

Hello!

I'm having an issue with getting the motors to make a full rotation.

I have the Prusa design connected to the RAMPS 1.4 and Arduino boards running Sprinter firmware and I'm using the Pronterface.
Currently I have the steps/mm set to 80 (and I have tried practically everything from 64 to 200 but found the calculation to get 80). My stepper drivers have 2 pots and I have fully adjusted both with very little change.

The main response I am getting is either low or high volume vibration or it seems to bounce back and forth with no real movement. I did get it to move a little the other day but it was very loud and rough.

Any ideas would be awesome!

Edited 1 time(s). Last edit at 09/15/2013 05:52PM by minktheshrink.

What is the status of your endstops? This is a common issue when first getting a printer to work. In not too sure about sprinter, but with marlin, you can check the endstop status with the M119 command

This sounds like the same issue I had when I built my printer. I has misinterpreted the meaning of the number and letters for the stepper motor connectors. You need to make sure you have read the stepper wiring page from top to bottom.

One pair will be connected to 1A and 1B of the connector and the other pair will be connected between 2A and 2B.

I recommend the v-ref method for tuning your pots. If you have motors that are rated for 1.x amps, then you usually target 0.4v. If your motors are rated for 0.5 amps, then you will target something slightly under 0.2v. Read up on v-ref. Properly tuned pots will prevent the motors from running scalding hot and prevent skipped steps. Some will say it's OK for them to run scalding hot, but I know that this kind of heat breaks stuff down over time and effects the flow of electricity.

Thanks for the speedy reply. I checked the resistance on my motors to make sure i have each pair wires correctly and they do spin easily when powered. I've also checked the vref and got it to a reading of .477 but they are still sitting and vibrating.

I've done a ton of reading and searching but can't seem to get this worked out. I even added a microsecond delay and that isn't helping either.

Also with endstops I was originally have issues with the motors responding one way but after reversing the polarity in the firmware it has been responding both ways. I bought them in a mostly complete machine on eBay and the machine was working when I bought it.

Do all motors just sit still and twitch back and forth? If another motor (axis) is working OK try moving that motor to the working driver and see if it still works. If it does, try putting the motors back and swapping the driver boards instead.

All the motors do vibrate or twitch. I did have them moving very rough at one time but after trying to fine tune they are just vibrating/twitching again.

Thanks to everyone!

I double double checked my wiring and apparently my y and z axes weren't paired correctly somehow. My x axis was wired correctly but was acting up too!