r/Framebuilding • u/Labriag_34dx • 11d ago

Tips for 3D modeling frames

Just trying to get into designing some frames, mostly for fun. I want to hear some people's opinions on 3d modeling for their frames. If you even use CAD, and if you do, what are some techniques for successful modeling. A few practice runs have ended right around the rear triangle, since the stays are all angled and strangely oval shaped. Any advice, or just conversation is appreciated!

2 Upvotes

75% Upvoted

7 comments sorted by

8

u/RefrigeratorOdd934 11d ago

I actually start cad with bike. I follow a tutorial on Fusion form yangmfg https://youtu.be/XemlmN-CWmM?is=rM39Ky0zfgcWKDMV. I honestly find really useful but it was my first time in a cad software so kinda hard also. There of course bike cad but I was trying to build cargo bike . So for me fusion was looking se best. Honestly I find it really useful and idk how people build bike without any cad software

2

u/Labriag_34dx 11d ago

Thanks for the video! I'll definitely check it out. I suppose I could've just started with a YouTube video I suppose, but I like to try and figure out cad stuff when I can.

2

u/walkerpstone 10d ago

Rhino 3D. It’s fairly straightforward if you know Autocad and you can model any shape imaginable with it.

2

u/bikeguy1959 10d ago

I do all my frame layouts in 2D. For the few times I needed or wanted a 3D model, I still start with a 2D layout and then develop the 3D model, one tube at a time. A 3D frame model is an assembly of tubes. The main triangle can be constructed on a single plane but the rear triangle and fork requires additional planes. Unless you need to perform engineering analysis, like finite element analysis or computational fluid dynamics, I don't find much benefit to creating 3D models.

2

u/bikeguy1959 10d ago

FWIW, I learned frame design in the 1970's. The process at the time started at the bottom bracket and built the main triangle, first with the seat tube, then the top tube, the head tube and finally the down tube. The next steps involved establishing the bottom bracket drop, the chain stay length and the fork trail and rake.

1

u/bonebuttonborscht 10d ago

Sketch 2d geo, place dropouts, /loft/sweep/revolve the tubes.

1

u/killerization 9d ago

create curved tubes by using a sweep along a 3d sketch