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paulsroom 2 years, 7 months ago.
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I prefer to print models without support whenever possible; but given that 3D printing enables the features of models to be printed in mid-air (with support), it extends the capability significantly. But I wonder how much the support material affects the surface finish which would otherwise not be the case with a model that needs no support.
I printed another dodecahedron frame of the model I printed the other day. I have now additionally secured the PEI bed so that it doesn’t move during printing. All the model and support filament adhered to the bed. I used PLA with a setting of normal, 20% fill and a brim (raft) of 3.
On my previous print the bed moved and the support material encroached into the model area, causing a very pronounced stepped surface in places. My intended use for the dodecahedron is to stick printed panels on every side, so internal surface imperfections will be covered. But I wanted to try and get a clean print.
The design of how the support material is attached to the main model works as intended – I broke it off easily. The base pentagon, the top pentagon and the upper five upper pentagons have all been printed cleanly with sharp edges. But the underside of the top two struts of the lower five group of pentagons have surface faults due to the support material effectively forming part of the model. Even a sanding of these surfaces would not restore the sharp edges as elsewhere. The top pentagon (parallel to the base) which also had support material attached, has not shown the same problem.
@paulsroom You are using ABS or PLA. These materials warp upward when printed at low to the horizontal angles. XT is the best I have found at not doing that but it will if the included angle of the in-print feature is acute enough. I am guessing before your bed was stable the print head was hitting the upward warped areas and that is what was moving the print bed.
Printing with PLA on a cold surface helps. Using XT helps more. You will never get completely away from it, though.
I operate two Betas and four Production Robox.
I am the US/Canada Technical Support engineer for the Robox.
See my 3D Hub site at https://www.3dhubs.com/phoenix/hubs/ben@bhudson I’ve used PLA for this dodecahedron. Frankly it did seem to me that there are so many triangles making up this model from bottom to top, that I wasn’t entirely surprised to experience this problem. It makes no difference to my end use, so it was really just another try without the bed slipping. It seems to me that in fact printing corner pieces and struts to fit them, is far a far more efficient use of the filament anyway. It’s faster, uses less material and the overall size can be increased or decreased simply by changing the length of the struts.
I naturally want to get the best out of the Robox, so almost every print is an experiment. Despite everything I have found that PLA performs better than ABS at the start - less pull offs.
I am taking all your advice and suggestions on board and am very grateful for your time. I’ve ordered the GeckoTek plate (you can see their latest response in my post on Sticky bed) and I will order some XT filament.
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