Nozzle not heating, and can't remove 'set screw' for heating rod


#1

Hi all -

I had a pretty bad clog on a print a few days ago, and the plastic wrapped around the nozzle and the bottom of the aluminum block.

I’ve taken it apart, cleaned it all, and re-assembled, but now the heating rod is not heating up.

I viewed the tutorial videos on YouTube, and am trying to remove the heating rod and temperature sensor to check for open circuit, broken wire, or other issues, however the ‘set screw’ won’t come out - the one that faces the bottom of the aluminum heating block, next to the nozzle, which holds the heating rod in place.

I think plastic got all into the set screw location during the clog, so it’s really stuck in there. I’m a pretty strong guy, and it’s not coming out of there with the allen wrench. I’m pushing as hard as I dare - any more and I’m afraid I’ll just strip it. The person in the video, by comparison, seemed to be able to use almost fingertip pressure to get the screw out and remove the heating element.

Any ideas on how I can get that screw out?

Should I just order a replacement block/heating element/temperature sensor from Dobot?

Thanks,
Aaron


#2

Here’s a video of it with the nozzle off. Note that there doesn’t seem to be any damage or shorts with the power or temperature wires, and the screen is showing about 30 degrees - everything seems to be hooked up correctly and fine - but it doesn’t heat up.

https://photos.app.goo.gl/gxqCJjpa9ctyD5ms6


#3

Update:
I soaked the aluminum block in acetone overnight and was able to get the screw out and remove the heating element, so that’s cool.

I can confirm - the problem is that the heating element is not getting hot. I plugged it all back in, but with the heating rod out of the aluminum block, and when I turned the Mooz back on and used the screen to turn on the nozzle heating, the heating rod did not get hot at all. I could hold it in my hand for well over a minute, and it should have gotten hot almost immediately.

I got out a multimeter, and tested the pins where the four black wires connect to the board under the top plastic cap. The left two pins read 12V, whether the heating is turned on or not, and the right two pins read 1.5mV, again, no change when I turn on tip heating with the screen. I would have thought that when I turn on nozzle pre-heating on the touch screen, something would change in that circuit.

What other information can I give you to help diagnose this?


#4

Hello? Dobot support? I feel I gave a good amount of detail and tried fixing this on my own.

Right now my 3D printing head is useless, really need help figuring it out.


#5

My suggestion is that you better buy one to replace:喜悦:


#6

It is not listed on the Dobot store site. Is there a spec so I can get a replacement that will fit?