Printing large hanging area without (or minimal) supports
Hello
I need to print many identical gears (see attached photos). Currently I'm using supports for the large area at the bottom and i print the gears in a same position as presented in pictures below. I need suggestions how to minimize required supports. I'm using Prusa Mini with Creality PETG filament.
RE:
Good question. I actually just experimented with the technique listed below in the Prusa blog post
https://blog.prusa3d.com/practical-uses-of-color-change-in-prusaslicer_59563/ "Inserting supports for flexible filaments"
I tried it with PETG as a support material and PLA as the printing material. I had a 0.2 mm distance between the support and the printed object. I'll attach my project file if you want to take a look.
Take note of which material you're using as a support, as some filaments stick well to others but not vice versa. See this link. For example, PLA doesn't stick well to PETG, but PETG sticks well to PLA. So I haven't tried, but in theory it wouldn't be possible to have the support material be PLA and the printing material be PETG.
EDIT: I'm having trouble attaching a file, but it's really as simple as it seems. Give it a try on a small test piece first if you're uncertain.
RE: Printing large hanging area without (or minimal) supports
@UjinDesign, how will this dual material suggestion work on the Mini that does not have a multi filament feed with this gear that has material below the supported part? You will have to swap materials manually in each layer.
@jacksee, is the gear your design? Could it be modified or split into two parts, one with the taller center section and one with the rest of the gear. You could then glue them together, although PETG does not glue the best. I have made several parts with ASA where I split them to have two pieces with flat bottoms and glued them with Acetone.
Regards,
Mark
RE: Printing large hanging area without (or minimal) supports
@UjinDesign, how will this dual material suggestion work on the Mini that does not have a multi filament feed with this gear that has material below the supported part? You will have to swap materials manually in each layer.
Hi Mark! I did this technique on my MK4 without an MMU. I just printed the support-object first. Then I started printing the desired object, paused the print right before it was going to start with the overhanged layer, placed the support-object on the printbed, and then continued the print. I'll attach some images of what it looked like.
RE: Printing large hanging area without (or minimal) supports
@UjinDesign, how will this dual material suggestion work on the Mini that does not have a multi filament feed with this gear that has material below the supported part? You will have to swap materials manually in each layer.
Hi Mark! I did this technique on my MK4 without an MMU. I just printed the support-object first. Then I started printing the desired object, paused the print right before it was going to start with the overhanged layer, placed the support-object on the printbed, and then continued the print. I'll attach some images of what it looked like.
Thanks for the explanation. With this gear having a center cylinder, it should be pretty easy to put the support object back on the bed accurately.
I had never thought of this idea.
Regards,
Mark
RE:
@UjinDesign Thank you for the input. This is a very clever trick and it would be perfect for "mass production" situation like mine. However it requires attention to pause the print in the right moment. Unfortutnetly it would be impossible for me to do this. It takes about 5h to print this gear due to high fill parametr and during the week I just setup my printer in the morning and get my gear when I'm back from work. And yes @mark this gear is my design and connot be split because of mechanical stregth requriement. I print these gears as a side job for a building maintance company.