Deep Z Axis Scar / Deformity in Prints - Possible Causes? See Picture

[protechtrader]

Hello,

Somehow I started getting this large scar/cavern in my prints and I wanted to ask what the possible causes are of something like this. The picture below is of a 20mm cube showing the scar on the top side of the pic and the other side is on the bottom which I guess printed okay. The Scars on on every print in the same spot. What types of issues could cause this?




DSCN0275.jpg

[wirlybird]

Are you indicating that the lower part of the print is ok but at a certain height then that deep groove starts to show? Or is the scar from the bottom to top of the print on just one side?

If so that may be a mechanical issue. I would look for something hanging up like a wire. Any recent changes to the gantry or extruders etc.?

[Sebastian Finke]

If you're using Makerware/Makerbot Desktop then it could be the seam i.e. the point where each begins and ends (which in Makerware/Makerbot Desktop is in exactly the same place leaving a witness each time). Give us a bit more info like slicer, material, speeds, etc

[protechtrader]

Are you indicating that the lower part of the print is ok but at a certain height then that deep groove starts to show? Or is the scar from the bottom to top of the print on just one side?

If so that may be a mechanical issue. I would look for something hanging up like a wire. Any recent changes to the gantry or extruders etc.?

It is from top to bottom on the one side.

I think it is mechanical as even though there wasn't any intentional changes I had the belts off as I cleaned out the printer, the bars and extruder. I lightly lubed the X Y Z bars and pillow bearings with a drop of oil each and reassembled. Somehow causing this, but I am not sure how yet. I verified screws seem good, belts seem good, operation seems as smooth as it has been before, so not sure were I caused this issue yet.

Thanks for your reply.

[protechtrader]

If you're using Makerware/Makerbot Desktop then it could be the seam i.e. the point where each begins and ends (which in Makerware/Makerbot Desktop is in exactly the same place leaving a witness each time). Give us a bit more info like slicer, material, speeds, etc

I was currently using Matter Control even though I think I have most major slicers installed. I did not try another as I am under the impression it is a mechanical issue (see my last post as it happened after some disassembly, cleaning, and reassembly)

It was Matter Control, ABS, 40mm/sec

[wirlybird]

It is from top to bottom on the one side.

I think it is mechanical as even though there wasn't any intentional changes I had the belts off as I cleaned out the printer, the bars and extruder. I lightly lubed the X Y Z bars and pillow bearings with a drop of oil each and reassembled. Somehow causing this, but I am not sure how yet. I verified screws seem good, belts seem good, operation seems as smooth as it has been before, so not sure were I caused this issue yet.

Thanks for your reply.

One quick thought is to see where the belt tensioners on each side belt are, they should be in the middle of the belt and line up with the gantry when it is half way from the back to the front as you look down.

[Sebastian Finke]

Can you replicate the effect with other slicers?

[curious aardvark]

print looks like it was extruded too hot, but that's just an observation, wouldn't cause that.

Can we just say that taking the belts of for no good reason, is a bad idea :-)

It's not something I ever plan to do unless one breaks.