Questions about the stepper motors
December 17, 2007 04:21AM
I got my stepper motors wired up over the weekend and had a couple of questions:

Firstly, the instructions have a different pin combination for the X motor that is the opposite of the pins for the Y and Z. Why? Whatever the issue is, wouldn't it be better solved in software which would let all the motors be inter-changeable?

Secondly, once I got everything wired up, I tested the motors and found that the Z motor always turns in the same direction, both when its supposed to be going forwards and backwards. I doubt this is supposed to happen (and if it is why?) so how would I go about troubleshooting this?

I've swapped the Y and Z motors over and its always the motor connected to the Z controller board (version 1.2.1) so its most likely the controller board itself. Its getting late so I'll go over the board tomorrow more thoroughly but I can't see any obvious blobs of additional solder or anything but I'd like to know where I should be focusing my efforts?
Re: Questions about the stepper motors
December 17, 2007 04:52AM
Hi Reece,

... best way for adjusting driving direction should be an inverter and an jumper for selecting 'normal' or 'inverted' direction ...

And for your Z-motor: - look if the DIR-signal changes polarity in CW or CCW mode.

If not, then trace the conections - if yes, then it's something wrong with the adressing of motor-coils ...

Re: Questions about the stepper motors
December 17, 2007 01:37PM
viktor... this is on the Universal Controller boards. unfortunately, they do not have any of the 'standard' stepper driver features. no direction pin, etc. they take all commands via serial.

reece: i'm not sure what to tell you. it may be the firmware, or it may be a solder bridge somewhere. what you're dealing with now is one of the reasons i created the 2nd generation electronics, because the boards are a PITA to work with.
Re: Questions about the stepper motors
December 17, 2007 02:20PM
... ah, got the point ...

When it's possible to perform single steps, then you can measure the voltage of every output-pin (or the coil-polarity) per step and draw a stepping-matrix.

So you can check whether the coil-driving works in the right mode or if two coils are bridged ...

Re: Questions about the stepper motors
December 18, 2007 12:53AM
I did a quick test to make sure it wasn't the firmware by swapping the Y and Z PICs and the issue stayed with the board. It has now changed though to the motor only going counterclockwise and only when you drag the slider (in the software) to the left.

Hopefully thats going to make it easier to figure out whats going on.

Edit: Found the problem. Faulty wiring connections for one of the endstops. Swapping the opto-endstop didn't fix the problem but swapping out the 3-pin header->wire->3 pin header did.

I'll redo the connections and retest it.

Edited 2 time(s). Last edit at 12/18/2007 03:34AM by reece.arnott.
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