Print Head Hitting Print

[snickers 0]

Hello!

I'm trying to make a print of a Paul McCartney statue and I'm running into problems with the print head hitting the print. I've tried 4 prints with varying settings, and with all of them the printer makes it to near the top of the legs before hitting the right leg repeatedly. After a few dozen whacks of the print head, the leg breaks off either at the ankle or the foot causing it to wobble around for the print.

Here is the file I'm trying to print:

http://mpl.pm/3D_Printable_Paul

And here is a picture of the print with the gap where it broke:

http://i.imgur.com/sqY25qp.jpg

I'm printing with T-Glase Taulman at 224° on an Ultimaker 2 and I've tried re-leveling the print bed with no luck.

I've also tried a print with my fan off, at 30% and at 100%. I'm running Normal quality with the speed reduced to 20 for my latest try, but I've also tried just the normal print settings. I also tried enabling z-hop to see if that might bring the print head up enough so that it wouldn't strike the side of the leg - again with no success.

Any ideas??

Thanks!

Chris

 

[pm_dude 27]

What version of Cura are you using? If you are using Cura...

Since version 14.12 I noticed it changed some behavior in the way it starts the new layer. This causes the Z step to occur during a long traveling from end of layer A toward beginning of layer B. In previous versions the layer B would start very close to where the layer A ended.

This could be the cause of the leg getting knocked out.

 

[snickers 0]

Hmm... that's very interesting... I can see in the layer view that the extruder is traveling from the outside of the left leg to the outside of the right leg...

I'm running the latest - 15.02.1

The print looks very clean and I don't see any bulges on the leg that keeps getting hit. Do you have any ideas how I might be able to fix that behavior?

Thanks!

 

[gr5 2,230]

This is a common problem for overhangs. I call it "raised edges". There's much discussion. The basic fix to reduce raised edges on overhangs like this is to use more fan.

But this leg looks like it should be much stronger! I suspect you have bad layer adhesion and should be printing a bit hotter. If you destroy the part later does it break easily along layer lines? If so you aren't printing hot enough. This part should be unbreakable in Taulman Bridge. It should bend in a complete circle and still not break.

So:

More fan, more heat.

 

[gr5 2,230]

Another solution is to put in a temporary support between the 2 legs that you cut out and file down later. Also it would help to use a heated chamber as the shrinkage is problematic with Taulman Bridge. The support would connect the legs and keep you from getting raised edges (that can get hit by the print head).

 

[pm_dude 27]

Thats TGlase. is it warping as much?

 

[pm_dude 27]

You can try with Cura 14.09 or 14.07 version to see

 

[yellowshark 153]

Couple of things. Whilst it has quite a high temp. range, Taulman state the optimum temp. to be 235-240c. On one of the T-glase web pages Taulman talk about raising the nozzle 2mm for travel; the default in Cura (if that is what you are using) is 0.075; I am not suggesting that is right, just noting a huge difference.

 

[BrookeWinslow 0]

Hello,

I know this thread hasn't been active in years, but I am learning how to use Taulman Bridge filament and am experiencing very similar problems that you describe higher up in the print. I have many thin diameter branching pieces to my print and they tend to get hit by the print head as they warp, causing burned parts of the print, printing in empty air, messy printing, etc. I will try lowering the printing temp and using some fan to see if there is an improvement, as was suggested in the thread.

Since this topic started, have there been any new strategies you've learned to decrease the warping higher up in the print?

Thank you!

Brooke