Rumba Board problem

[ex-egll]

Hi, my machine had been happily printing, but the next time I did an ABL the Z-Axis would only move in an up direction.

I went to the menu on the LCD to try to to move the Z-Axis that way, and again it would only go up.

I swapped 2 motor plugs around on the Rumba so the X axis controlled the Z motor and vice versa. When I commanded the X-axis to move, the Z-Axis moved, so it seems the motors are OK. When I commanded the Z Axis to move the X-Axis moved in one direction only.

I put the motor plugs back in their original locations, and swapped the X and Z motor driver boards. The X axis worked, the Z only moved one way, so it looks as though the driver boards are OK.

I reloaded the firmware, but that made no difference.

To my mind this suggests an issue with the main board. Next thought was to move the Z-Axis driver board and motors plug to either the E1 or E2 position on the Rumba.

My questions are:

How do I (or can I) remap the Z axis to E1 or E2?

Is there anything else I should try?

Thanks

[ex-egll]

A bit of an update, all bad news!

After a little more testing the Z motor refused to move in either direction (but still worked if I switched the X and Z motor plugs). I also noticed that the first time I commanded the Z axis to move after powering on the system, there would be a quick "clunk" form the Z motors, any further commands would result in nothing until the power was recycled. I also noticed a Z Stop hit or similar message on the LCD, this could well have been there all along and I just didn't see it. Investigation showed that a wire had indeed come of the Z axis stop switch. The wire was re-attached, and although the message no longer appeared there was no change in the behaviour of the motors This was probably the reason the motors only worked in one direction initially, but why has the motor totally stopped now?

Frustrating

[Mjolinor]

I think you need to try again here. You will not get a reply as long as people are confused. Most 3d printers do not have any servos on unless you have auto bed levelling in which case you may have one.

If you don't know what things are called on your printer then take some pictures and draw some arrows on it or find a link to a picture of the things you are talking about.

[ex-egll]

Mojolinor, point taken! I had a seniors moment there. I had been working on the CNC machine for a few days, this machine does have servos. I guess servos were in my mind when I really meant steppers.

I have been reading though the pins.h files and have found the entries for the motor assignments so I will try moving the Z axis motors from the Z to E1 positions later.

[Mjolinor]

Does the Z axis move up irrespective of you selecting up or down or is it moving up and not moving when you select down? If it is the former then your direction signal (pin 8 on the driver board) is not getting a signal from the micro.

Measure the voltage on pin 8 when you go up and measure it when you go down. Those two should be different voltages.

[ex-egll]

Hi, If I put a scope on the direction pin it shows a change in state depending on which direction is commanded. I am fairly confident that the original problem was caused by the bad connection on the Z axis limit switch. The X and Y axis can both be made to act the same way by activating their limit switches.

[Mjolinor]

Use M119 to test your end stop status.

[ex-egll]

Some times I hate electronics!

The end stops checked out fine with M119.

I had not had time to do any more work on the system until this evening, I switched it on to do some probing with the scope on the ENA pin and lo and behold the system worked flawlessly. I guess the gremlins were a week early for Halloween.

Thanks for the replies.