Geeetech

After plenty of searching, I can't find a solution to my specific problem. Also, I'm not sure which forum to post. If you need to move this, I understand.

My printer was working fine. I've made a few things with it in the couple of weeks it's been up and running. I got confident enough with it to try installing the 3DTouch sensor. Everything seemed to go well. I wired it up, checked and installed the firmware for GT2560 A+, and ran the Gcode test in the instructions. Looking good!

The problem came when I hit the home button. X and Y homed as usual. When the extruder centered for Z, only the right side Z motor was running. I tested a couple more times, shutting down and restarting each time. Still nothing. So then I swapped the Z plugs on the main board. This time the left side didn't work. The socket is clean. No debris anywhere.

I'm guessing it's something in the firmware, but I have no idea where to look. I used the instructions downloaded from the product page for the Gt2560 A+ board. I only ended up checking against the list of things to change. I didn't have to change anything listed. It was already done. I used the Marlin-PI3_Pro_B_3DTouch (A+) firmware found here on the forum.

Can someone please point me in a direction?

Hello.


I am convinced that your problem is not directly related to the functioning of the new sensor.

For me, these are two different issues that coincided at the same time.

In the printer's electronic system, the Z axis motors are connected in parallel.
This way you can be sure that the electronics are working properly.
Failures may be found in connections to stepper motors.

Ok, now it's different.

I tried again this morning and only the right Z motor worked. I removed both plugs, checked them and the sockets for anything unusual and then swapped them to test. Neither motor worked.

So I swapped them back and tested again. Neither motor works. Z axis is completely dead.

???

If the driver blew, they both would have gone out at the same time, right? You say connections to stepper motors, what exactly should I look for? Everything looks fine.

Hi.


Yes. If the stepper motor controller module was damaged, none of the connected motors should work.

I suggest to check the quality of connections, starting from the socket in the controller board.
Check if there is no cold solder, if the terminals on the wires are well clamped, if there is no loose space somewhere.

If you have a multimeter, you will be able to do it faster.

For testing, you can also connect another motor to the uncertain stepstick module.
Or, in turn, connect the Z axis motors to a working stepstick module for the test.

I think I found the problem.

I was initially focused on possible loose connections to the stepper motors and kept going in circles because nothing looked out of place. But then I noticed that the 2-wires that connect to the Z-MIN plug were loose. They were making intermittent connection with the pins and possibly causing random output. It turns out that the black Dupont female connectors included with the 3DTouch are for larger jumper pins. It really should have the white JST connector to fit the smaller style jumper pins, like the other plugs in that row.

So I removed the leads from the black housings, crimped them a bit with pliers, and plugged them back in to test.

And it works fine now! I still need to play around with the calibration, but the printer works as it should. I'm going to cannibalize a JST from an old computer fan or something so I don't have bare wires connecting to the board.

Thanks for the heads-up on checking the connections!