Page 1 of 1

3D Modeling a Skateboard Mold

Posted: 08 Jan 2020 15:52
by deepdish
For the past month or so, I have been teaching myself 3D modeling in order to design my own skateboard molds.

I have no prior experience with any kind of modeling, but am gaining a more proficient understanding of the program.
As for program, I am running Rhino 3D - a solid 3D program primarily used for manufacturing.

I was wondering if anyone has any tips on how to start a skateboard mold build from scratch.
From my baseline knowledge, I believe it will begin with a lot of control point curves, layers, lofting, and sweeping.
Once I have my desired specs, what is the best way to start?

Any information on this would be greatly appreciated.
I will post more updates as I progress - thanks in advance!

Re: 3D Modeling a Skateboard Mold

Posted: 11 Jan 2020 09:58
by Beau
Nice! First, check out SK8CAD-MOLD: https://www.opensourceboards.com/CAD/SK8CAD-MOLD.html - this tool may be able to save you some time.

If you still would like to make the mold from scratch, Rhino is definitely good (I've used it in the past). I currently use Fusion 360, because it is free for hobbyists and small businesses, and has CAM built in. It works similarly to Rhino, and I break mold design down into a few basic steps:

1) Draw the concave on the front plane and extrude it the kick-to-kick distance, minus 2 x the transition distance (refer to the key in the SK8CAD-MOLD link I posted above for clarification on these terms).
2) Draw the kicktail from the side view, and position it so that the beginning of the kick is offset from the end of the concave by the transition distance. You can do one kick and mirror if they're symmetrical, or do both kicks independently if not. Extrude the kicks.
3) Once you have your kicks and concave, separated by gaps, you create a loft between the two faces separated by the gap. Depending on what software you use, you may need to create guide curves in the side plane.

Lastly, if you are making a two-sided mold, you need to make sure the top mold and bottom mold faces' curves are offset by the thickness of the number of decks you'll be pressing. For example, if your board's concave radius is 20" and you're pressing two decks at once, the other mold would have to have a concave radius of 20" + 2 x (7/16") = 20.875" (and technically, one of the boards on the mold would have a concave radius of 20.4375").

I realize this description is extremely oversimplified, and I've been thinking of creating a video tutorial about this that someone could simply follow step by step. I'll post here if/when it's live on YouTube (or you can subscribe to Open Source Skateboards on YouTube to find out right away).

Hope this helped at least a little bit for now!

Re: 3D Modeling a Skateboard Mold

Posted: 11 Jan 2020 22:18
by Beau
Just realized I do have a video showing a sped-up summary of the process (though this board has wheel wells and rocker, so there were some extra steps added in): https://youtu.be/NNpS8pYuV_A?t=214