Z Axis Issue

Hi, RoBo 3D team.

I just printed off my first PLA cube.

However, I had a devil of a time getting Repetier working. I gave up on Linux because it was getting some gobbledy gook back from the printer, but I will try again, having finally got it to work with Windows 7 on my ThinkPad X200 Tablet (I had to try using "Home All" to get it "reset" so that I could do the manual control steps in the instructions, after many reboots since it was Windows ).

There is a serious problem, though, and, having received the unit assembled, I need some direction for troubleshooting. Whenever the z-axis is homed, the extruder head drops right onto the platform and the z-axis screws keep turning while the nuts drop out of the carriage "T" bars. When it finally stops, I have to carefully turn the screws to get the bolts back up into the bars and then recalibrate the extruder head distance.

When I adjust the z-axis stopper screw, I can hear the switch clicking, and I can see that it physically worked as it was supposed to have done, but the printer seems to ignore the signal.

So, where should I look to see if this is something that I can fix? I can test voltages if that is needed; I ordered the assembled printer for convenience, not because I could not have put one together, myself.

Thanks in advance.

Peter E. Humphries

 

After more testing, it appears that the T bar on the right side is just not heavy enough to trigger the Z Axis switch during normal operation. When I home the Z Axis and push down on the right hand T bar with my finger, it works, but without the extra weight, hitting the spring on the switch seems to be enough to prop up the T bar while the nut screws out.

I added a weight (a plumbing pipe connection over the threaded rod), and it appears to have been enough to make it trigger the switch.

Sincerely,

Peter E. Humphries

 

As per this thread, my Z-axis switch was mounted the wrong way around (the design changed, I take it from the pictures in the manual).

I turned my Z-axis switch around, and it was improved, but it still threw the nuts because the switch is stiff enough to lift the carriage when it first makes contact. Once the other side has dropped a bit more, the switch is thrown. So, I put the weight back on, as pictured, above, and it has been working like a charm, since.