I am a newby to 3d printing generally and am getting an odd quality issue with a fan shroud I have modelled on my X1Carbon.
The issue I am having is that the filaments are not binding in a few features (images attached below) generally the print is Ok, but it would be nice to be able to clean this area up.
From the reading I have done I understand that the shape of this part may be challenging in ABS due to shrinkage as the part cools, indeed I did observe a little lifting of the model during the print.
Could this be down to bed adhesion? Would a brim help? Settings were the standard ABS suggestions with support turned on, on a freshly cleaned Engineering plate with glue stick.
Appreciate the thought! I assumed that this had not bonded as it printed, not really thought about it being a cracking while cooling issue, will try for sure!
Next thing I intend to try is pre heating the bed a little longer to warm the chamber. I’ll note improvements for the sake of the next person with similar issues.
I’m assuming this has the supports removed as it looks like that area would be off the plate. Could be a combination of too fast and/or flex in the supports. Could you post the preview with supports in place? My first thought would be to show down the wall speed.
I have a fairly long history of printing ABS on glass.
It is my practice to turn the bed on to about 45 C and let it stabilize while I do everything else - which can take a while while I slice it, transfer the sliced file, etc. Maybe even go back to the CAD tools and RE design it Yet AGAIN (-:
Then I glue up the plate with disappearing purple and print.
BTW, treseme (spelling ?) hair spray works well with ABS on glass plates, so well that it can pull up chips of glass as it cools.
sometime pu
It looks like your rings are not bonding to the supports properly causing the straight segments on the curves. Could be that it’s printing too fast in those areas and the bead of filament is also shrinking and pulling the arcs into straight lines.
I ran this again last night in PLA, with the outer wall speed reduced by about 10% and it has printed nicely. Last night’s print was a slightly updated model with thicker ribs in the plane in which it went stringy… so much for change one thing at a time to isolate what went wrong…
Great stuff Duane, Kinda what I was driving at but much better expressed.
Is this more likely speed and shrinkage than 1st layer bonding issue? I also wondered if I had the material insufficiently dry, I have a “ebox” heated dryer and gave the spool 8 hours in there before printing, but I live in a very humid part of Australia. (room is rarely below about 70%, although I have my AMS consistently at 30%, aiming for improvements here too)
Ok I think I’m getting closer to the nub of the thing. Experimenting with a variation of this model in PLA again, only this time I did not reduce the wall speed and while it did not separate quite the same way as the ABS did, it did distort, straightening the segments in the way that the ABS did. (I have to confirm some changes to the model against the parts it’s being produced for, hence running it in the cheaper PLA)
I’m in Perth so humidity is very low in summer, but I’ve found that ABS isn’t as bad as I was made to believe wrt to absorbing moisture. It seems to just get a bit wispy like PETG, but it still prints fine.
Are you printing at 0.2mm layers? if so maybe try using adaptive layer height and adjust the layers at the interface between support and part, smaller like 0.1mm. Maybe then it will stick better to the supports. I don’t think you can set the interface layer small than the layer height.
