Z-Axis doesn't run

I have a Techzone lasercut Mendel. I have everything assembled and am at the point of getting everything running. But I can't get the Z-axis to work. I am using a recent compile of repsnapper under Ubuntu 10.10. X and Y axes work fine, but the Z axis just buzzes. It will turn a bit if I remove the belt but it seems like it's fighting itself.
So what I have done to test where the problem is: I swapped the wiring for the Y and Z axis (I swapped the cables where they plug into the main-board, so this swaps the cable, the stepper driver and the stepper motor). When I do this, then the Z-motor (which is plugged into the Y-axis connector) works fine. And now the Y motor (which is plugged into the Z axis connector) buzzes and doesn't move. So I know that there's nothing wrong with the cable, the stepper-driver board, or the stepper motor.
So this led me to think that the main board was bad, so I asked Techzone to replace the board, but the new one does exactly the same thing. So now I'm thinking that the problem has to be something in the repsnapper software. I can't find anything in the configuration that would address this. Does anyone have any suggestion for what I might try? Or a suggestion for different software that is known to work with the Techzone electronics? I had been told that repsnapper was the best software for this electronics set, so that is why I was using it.

I'm not familiar with your electronics, but is the current setting for the Z-Stepper set correctly? If there isn't enough current then the motor won't turn if it has a heavy load (as with the Z-axis). There should be some trim-pots somewhere on your board that you can adjust.

JB

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Check out my blog: AdventuresIn3-DPrinting

You need to adjust the trimpot in the stepper controller board that's connected to the Z axis. If you turn it clockwise while it's buzzing, the motor should eventually start. Note that it goes completely around so it's difficult to tell where the minimum and the maximum position is. I suggest checking the Techzone wiki. In my experience when I was using that electronics, I had them at around 50%.

If that doesn't work, I suggest disconnecting the belt from the z stepper motor and see if you can make it turn while adjusting the trimpot.

Well, I know that the current setting is OK because the cable/driver/motor combo works fine when it's plugged into the Y-axis connector.

I have been looking for a forum like this that is specific to the Techzone but haven't found it. Do you have a URL by any chance?

Thanks.

Is it wired back to front by some chance I have come across this on another forum where some parts were wired incorrectly

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Experimenting in 3D in New Zealand

Re: wiring: As I said, when I try swapping the Y and Z axis wiring, I'm swapping everything. The entire combination of cable, stepper-driver and stepper motor works when plugged into the Y-axis, so if it were a wiring problem, it would still fail when plugged into another axis, but it doesn't, so I know there's no wiring problem. That is why I went to the trouble of replacing the circuit board, but even that didn't fix it. So I'm assuming it's something wrong with the software. Or at least with the copy of software I'm running. That's why I was asking for suggestions about other software that anyone knew to work well with the Techzone electronics.

The Y and Z axes are not the same: the steps per mm is much higher in the Z than in the Y and the torque needed to move them are also different. Thus, you're not comparing apples to apples when you switch the wiring because the sw and firmware is doing different things to each axis. This is why I suggested that you adjust the trimpot on the z controller board and/or remove the load from the motor by removing the belt. Buzzing usually indicates that your trimpots need adjustment.

Have you changed the max z speed in the printer settings in repsnapper? Set it to a conservative number like 50 to start with. I think this is the default.

Edited 1 time(s). Last edit at 06/24/2011 03:40AM by brnrd.

Woo Hoo! That was the problem. The software defaults to the Z speed running from 50 min to 150 max. I changed it to 40 min to 50 max and now my Z-axis moves just fine!

Thanks!