Loud noise from Z motor while Leveling (UMO+)

[pa_tanhuanco 0]

Hi All,

Just encountered this problem today.

My prints are really bad today, the first layer not adhering to the build plate. As I had to reset, and bring it to 'Auto home' after every failed attempt - suddenly in one of my attempts there's a loud, alarming noise when leveling the plate. Happened twice already, and I took a video of it. (see youtube link).

 

In this video I tried hitting the Auto-home multiple times, until it encounters the problem.

What could have caused this? and How to fix it?

The sound is very alarming!!!

Appreciate your feedback and help!

Thanks!

Regards,

Patrick

[gr5 2,268]

Most likely your stepper driver is too hot. Check the fan underneath and make sure it's spinning properly. Consider using air conditioning to cool the whole room maybe? Or just put a desk fan such that it blows under the printer (maybe tilt the printer 20 degrees - it prints fine in any orientation including upside down).

That sound can be caused by too little current (even though it sounds like too much to your ears maybe) and also by too much current. Most likely too little. Most likely a temperature issue like I said. You can test by swapping the driver chip among 2 axes - oh wait - this is umo+? There is no fan. On the UMO+ and UM2 this is a very common problem - especially with the z driver. It gets too hot. So remove the bottom cover - that might be enough airflow but try blowing some air under there. Also it's recommended to lower the Z driver current to 1000ma. I think they lowered it in the UM2 firmware but probably forgot in UMO+. I think you can control the current manually from the front panel - I forget - too many versions out there! Some versions you can, some you can't. If you do adjust the current you have to do a SAVE or else the value resets on power cycle.

[neotko 1,417]

Please can you zoom on the z endstop? It seems like it passes it and misses to touch it properly. It might be just bad alignment.

Please zoom on the z endstop and do that again.

Edited June 16, 2016 by Guest

[pa_tanhuanco 0]

Many thanks @gr5. Since I've printed successively, and weather here now is extremely hot and humid, that could be one of the potential causes of the problem. Will take note of your suggestions in case it happens again.

[pa_tanhuanco 0]

Thank you @neotko! You're right, it didn't touch or overshot the z-endstop at one point. And it barely touches it every time. Its part of the wood that's a bit further out. Will find a way to adjust it so that it touches properly.

Many thanks.

[neotko 1,417]

That z endstop seems wrong. Looks like a z endstop that umo (not umo+) uses on the bottom z. The umo+ endstop (top one) it's a bit larger.

I say this because one of my umo+ assembled it using the endstops kit from ultimaker and that kit has 2 black endstops, one shorter and one larger. Te sorter one (looks like yours) gived me the same error of missing to contact the wood. The fix for me was using the good endstop. I'll show you a photo of the shorter one and the correct one. If that's so I would contact me dealer so they change that peace.

[neotko 1,417]

This is how the endstop should look. Much larger.

[pa_tanhuanco 0]

That z endstop seems wrong. Looks like a z endstop that umo (not umo+) uses on the bottom z. The umo+ endstop (top one) it's a bit larger.

I say this because one of my umo+ assembled it using the endstops kit from ultimaker and that kit has 2 black endstops, one shorter and one larger. Te sorter one (looks like yours) gived me the same error of missing to contact the wood. The fix for me was using the good endstop. I'll show you a photo of the shorter one and the correct one. If that's so I would contact me dealer so they change that peace.

 

Ohhh I see! Although, I got all short ones in the UMO+ kit I bought.

Might try to find parts locally. I bought my UMO+ while at UK and just shipped it home after my studies.

[neotko 1,417]

Oh. Maybe you could print some stuff to fix. Maybe this? https://www.youmagine.com/designs/ultimaker-1-heated-bed-z-stop

[pa_tanhuanco 0]

Great! Thanks!

[gr5 2,268]

Or just take a tiny piece of wood and glue it on the top of the existing wood post. Use wood glue.

[neotko 1,417]

Since the problem it's that it 'slips' that endstop if I remember correctly it's thinner. If you unscrew it enough you could put a printed spacer so it's more 'inside' since the problem it's that it's too thin that it can slip.

[neotko 1,417]

Something like this:

https://www.dropbox.com/s/0lkdqxyt0nru7rf/endstop2mmscaper.stl?dl=0

[gr5 2,268]

You can either modify the endstop or you can modify the part that hits the endstop. I found modifying the part that hits the endstop easier.

[neotko 1,417]

I tend to avoid hard mods if posible so it keeps resell value.