Bottom parts curved

Printed with 0.0.3 software and 0.0.2 firmware, light filling and no support.

No problem with raft bond, but as you can see on pictures, the top of the parts is always flat, but bottom is slightly curved (0.35mm at the bottom angles for a 5x5cm cube). The result is not geometrically correct and makes it difficult to produce parts that fit together.

The parts all show the same deformations whatever the print area on the bed.

I guess that is an ABS characteristic, and in this case maybe using PC-ABS can solve this?

Otherwise, how to get around this problem?

Thanks for your advice

how long did you wait before you took the parts off the platform? Was everything completely cooled down to room temperature? Rafal told me that this helps to avoid this.

Since then I have not printed anything with a wide flat bottom yet to test it.

But it could also be the flex of the perfboard… I could imagine that the ABS pulls the perfboard away from the aluminum platform a little…especially since we mostly print in the center area.


yes I always expect at least 20-30 minutes after the end of the print


ok I’ll try again and wait longer to see if that changes anything


Try another one and wait an hour. Let us know if it fixes it. If not, then I think it is the perfboard flexing. When I took it off for cleaning I was surprised how soft it is. It also bulges a lot near the attachment screws. I personally think the perfboard should be a lot more rigid. I have used some radio shack perfboard in the past that was thinner but more rigid than the one used here.

One workaround that I did in the early days with my UP (when I was fighting with general adhesion issues) was to add a mm or two in the design and then sand the part down on my belt sander to the final specification/flatness.

Not the most elegant solution… but at least you have a usable part.

You could aslo try to enclose the build area. That might help, too!


Thanks for your help ! I followed your advice and things are going much better.

Martin, why have you deleted your answer ? Anyway thank you all for helping me to solve this problem.

I’ll post pictures this afternoon.


At time when I posted my answer I saw that Andre wrote same answer as me so I deleted mine, seems it was exactly in time of your next post :slight_smile:

Ah ok Martin, so it was perfect synchronization :wink:

Well, here’s the picture of improvement.

On the left, the previous print.

On the right, the same impression (same settings) but until one hour before removing the piece of cold bed.

It is much better even if there is a slight deformation of the bottom (under 0.2 mm - and the top is perfect), but that will not really affect the accuracy to match several parts.

Thanks again.