UM 3 Ext Problems All Around

[durdevici 0]

Hey Guys,

I need help with UM 3 Ext. I've been playing around with UM 2+ for some time and never had any issues with it and always got what I wanted.

Now I have a chance to use the 3 Ext, but everything is going in a wrong direction. I got it brand new, I've set it up myself, calibrated it and loved it. I was so excited to print with PVA, in two colors, oh the opportunities that were awaiting ahead of us (me and the printer).

 

First print, I had to stop. I was printing a figurine that I had previously 3D scanned and printed a lot of times on UM 2+. It started of nicely for the first 30 minutes but than stopped printing the figurine but continued with PVA support. Image shows the holes where the model was supposed to be.

 

Than it printed just fine but at around 80% of the model it stopped printing the PVA support. You can see on the image that the head is all fudged up.

 

Than I had issues with PVA in general, sizzling and burning the BB head while printing. Combing through this forum I found a possible culprit - moisture in PVA filament itself. I'm yet to try a new one.

 

Than I've swapped the BB to another AA and started a new print yesterday (Before that I cleaned both heads AA and BB (hot and cold)). Two colors. After some 12 hours I've noticed that I'll be running out of filament. I paused the print, changed it and resumed. Of course, it didn't work. It started scrapping the head against the model and I stopped it immediately.

 

Finally, re-calibrated the plate and started a new print. And than, this happened. It "exploded". Was it printing too fast? I haven't had one successful print with this printer.

 

 

 

Does anybody have any idea what might be the problem?

Thank you all a lot!
  

[pbackx 11]

I can't really explain everything, but these look like extrusion issues. What you can try:

* Clean the heads using hot and cold pull method

* Check the temperatures at which you are printing. Maybe increase them a bit?

* If printing PVA is making popping/hissing noises, it's probably because the PVA has absorbed too much moisture. Try to dry it on the build plate, or with another technique.

 

Keep in mind: PVA is a very difficult material. You have to keep it in a bag as much as possible and not expose it to air for too long. On my UM3 I have the same problem as your 2nd print: when there's not much support to print and there's a lot of retraction, it will just clog up the nozzle. The only workaround I have found is to try to increase the amount of support material that is printed. For instance, enable a prime tower.

 

What is the other (green) material? I haven't had any issues with PLA at all. It's just PVA that is giving me headaches.