can someone with 3d modelling experience help me out? i have an STL of a keycap that is 20mm in diameter and i want to make it 24mm without changing the part of the keycap that fits into the switch. is there like a program for this... or a tutorial that would help?
i tried using meshmixer to do this but i could only figure out global transforms for the whole model.
in openscad (which lets you import an .stl) I would use a difference() with a cube to cut the stem out, then scale the remainder by 20% in x (and y?) and then union back the intersection between the cutting cube and the original model, which should be just the stem.
although, i'd note that if you are 3D printing a keycap there are some stem models that are better to use than what one sees on injection molded parts. so you might want to replace it altogether.
OK! i will do that ! thank you for the detailed answer :)
im a little confused by your second paragraph though, what do you mean? (this is my first time doing this kinda project) is there like an optimal stem that i should find ?
here is an example of me splitting up an STL for an LPX profile keycap which has a choc switch stem:
https://github.com/wolfwood/printed-keycap-mods/blob/738607ae7a4a48b24030c2fea899623cefc17bdb/LPX/LPX.scad#L3-L23
the LPX module imports the STL and manually repositions it to sit on the origin.
LPX_legs "selects" the stem using a cube.
LPX_shell removes the stem using a cube with identical dimensions.
in LPX/MX.scad I take the LPX_shell and stick on a printing-friendly MX-compatible stem from rsheldiii's fantastic keycap generator https://github.com/rsheldiii/KeyV2
https://github.com/wolfwood/printed-keycap-mods/blob/develop/LPX/MX.scad#L36-L42
is your keycap for an MX switch (cross shaped stem?) or a kailh box switch (cross with a box)?
to get a nice top surface on a keycap it would be ideal to print it at a 90° y rotation (with the layer lines running the same direction as your finger), but then the stem would need to be completely supported. as a compromise, its best to print with a 45° rotation on the y axis so the stem only needs to be supported at the base, and the resolution is still finer on the top.
a "normal" MX stem is round, but it ends up with very thin areas where the corners of the cross cutout approach the edge of the cylinder. its also a bit janky to print at 45°. so rsheldiii's KeyV2 uses a shape that fills the available space above the switch stem completely, with long cut outs for the cross. I've also seen ppl use a shape made of rectangles like a # with the inner square removed. this is easier to print (but it won't fit a box switch). my code additionally cuts the edges that the stem will be supported on at a 45° angle so its easier to support (not standing on a corner).
the LPX keycaps were designed with 3D printing in mind and their choc stems also have a 45° chamfer. i got a lot of the ideas in my 3D printed keycap library from the recommendations made by the designer of LPX, which i link to here: https://github.com/wolfwood/printed-keycap-mods/tree/738607ae7a4a48b24030c2fea899623cefc17bdb#print-keycaps-that-feel-great
oh my !! thanks so much!! i can follow the scad operations and the general idea of how to do it. i really appreciate the examples!
my switches are MX and I'm printing keycaps for a fight stick. however i dont have control of the 3d printer so i don't know if it's possible for me to print at angles... is that something that i do with the base model?
you can do orientation in the software producing the STL and ask for it to be printed as-is, or you can do additional orientation in the slicer prior to printing. its very handy to be able to rotate and mirror prints without needing to generate a new STL.
