Hot end keeps hitting part and knocking it loose

[TruckerGeek]

I have been trying to print out the PEEK fan shroud. I have tried three time to print it out--the first two just going through the process in the documentation. The third I followed the settings recommended in the document below. The result is shown below.

http://forum.seemecnc.com/viewtopic.php ... oud#p89408

It appears that when attempting to bridge the gap on the fan openings (as the hole starts to get smaller), the materials kind of sticks up and the print head catches it and knocks the part loose.

Here are all three of them together.

This is the first one I tried. On the left side, top of the fan opening, it appears as the opening was coming back together something went wrong and the extruded material seems higher than the rest of the piece. I am speculating the print head caught this raised section and knocked the part off the bed.

This is the second attempt and it looks very similar.

I am using the settings straight out of the box, or as in the documentation. I was able to print the calibration box that MatterControl loads up by default. It has some minor glitches, but nothing like this.

I ran through the calibration procedure, but it is possible with my eyes that I did not get everything exactly right. If you think that could be it, I will definitely go back through the calibration process and see if I can get it more exact.

Any thoughts would be appreciated.

[Qdeathstar]

It sure does look like you are extruding under temp.

Perhaps you could verify your temps with a meter? If the temps aren't the problem, you could make some abs juice with a bit of abs filament and some acetone and see if that helps keep the print down...

[Polygonhell]

Your probably slightly overextruding, It's somewhat difficult to see from the images you posted.
The extra plastic gets pushed around by the nozzle, and it will later hit a high spot.
Your better off slightly under extruding as a starting point.
It could also be belts not being tight, as the head changes direction the mechanics cause the head to drop slightly.
Or could just be bad adhesion to the bed as the previous poster mentioned.