Uneven shrinkage or non-sticking?
Bought and assembled Prusa CORE One. Fantastic machine!
Produced test piece of wing for race car in PETG, using default settings. This has internally stiffened wing profile, with one closed side.
Closed side is flat and was used to position the test piece on the heat bed.
After printing and cooling down, the trailing edge of the wing was found to be much shorter in height than the remainder of the wing profile. The closed side curves off the heat bed. The open side (printed last) is perfectly straight. See pictures.
Is this a case of the tapered trailing edge of the wing shrinking more the the rest, or did the model fail to stick to the heat bed?
Understandibly I cannot change the shape of the wing profile.
Any ideas?
RE: Uneven shrinkage or non-sticking?
Its a really common problem with 3d printing. Called 'warping' , hundreds of posts and threads about it as well as hundreds of youtube videos.
You can use brims, mouse ears, thermal chambers etc etc. I suggest you use google and do some research.
Essentially plastic shrinks as it cools. Different amounts of plastic shrink at different rates. Some plastics shrink more than others.
RE: Uneven shrinkage or non-sticking?
Trailing edges on wings are diffcult since they are so thin like to warp and lift off the bed due to very uneven shrinkage, try making some brim locally "mouse ear" as mentioned above. Sometimes Ive had so much warping that it bent up my print sheet. Be sure the chamber reaches its target temp.
Im actually also working on a wing for my car at the moment, the goal is to have rods through it and a lay a skin of glass fibre or carbon on it. That profile looks more like an airplane profile though 🙂
RE: Uneven shrinkage or non-sticking?
Thanks for tips. Will try to improve my knowledge of printing these parts.
Made wing for car before, from woven glass + epoxy, based on spars, ribs, foam cores. Hope to simplify by 3D printing, only using spars.
Wing has moderate profile to adjust aero balance only.
RE: Uneven shrinkage or non-sticking?
MSHD wing profile, 1600mmx250mm is the plan. Im doing some fine adjustments to make it easier to produce with a slightly thicker rear tail, and designing the wing internal structure at the moment 🙂 I also got some lift of the tail but solved it with a regular brim added in the slicer.
