And just a few words on the CNC moulds.
The
CNC is a shapeoko XL, just under $3k landed including buying the spindle (in my case a Makita Laminate Trim Router). Can machine foams, wood, plastic (things like nylon, acetal etc), even engraves aluminium, and can cut aluminium too, but you have to take it pretty slow. I do some engraved rowmark and aluminium labels, as well as some plastic parts for work with it (they were too cheap to buy an engraver, but not too cheap to pay someone else to do it??). ->
carbide3d.com/shapeoko/The
CAM software I used is Autodesk Fusion360. Available free for non-commercial use. Use this to tell the shapeoko how to cut stuff. Shapeoko does come with software to make some simple 2D stuff, but once you get into 3D parts you need something with a bit more capability, and Fusion360 has a pretty decent following in the hobbyist arena. I can make the files public for people to view if they are interested (benefits of cloud based software I guess...).
The
Material is Necuron 651. It was just under $400 for a 1500x500x50mm board. Its basically a polyurethane modelling board, fairly widely used in the industry. I ended up using a full board for the moulds for Fangy, however there were a few mistakes made etc, ideally next time I'd probably use less than half a board. Or at least use the 25mm thick board.
Main advantages are that it is dimensionally stable and machines really nicely without any dust. Alternatives are to use something like wood or mdf, but MDF is allegedly hard on machine tooling, and the worst thing is the amount of dust produced when machining, and it isn't particularly dimensionally stable.
necumer.com/index.php/en/products/board-materials/modelling/necuron-651It wouldn't be a really big step to sand, paint with high-build, sand, polish, and then pull composite parts out of moulds made from Necuron. Although they don't particularly recommend doing mass production with something like Necuron 651 (may only last a few parts). The next step up Necuron 702 is specifically designed for tooling for laminates, but its about double the price, and not justified considering what Fangy was after. However, it really isn't that expensive if you think about it, you could probably build tooling for composite fins for less than $100-200 bucks per fin worth of tooling (not including labour).
necumer.com/index.php/en/products/board-materials/tooling/necuron-702 The entire process took way too long, but not too bad considering it was the first project of this type I've attempted. Probably about 32 hours total, about 16 hours of machining time total and the same amount of time doing the CAM. Second time around I think I could easily half the programming time, and probably the machining time as well (take out the one major screwup binning a part after about 4 hours of work
). A lot of time was spent roughing out material, which was a pretty inefficient way to doing things in hindsight.
If anyone is curious on other parts of the process in making the moulds happy to share. End of the day its pretty cool that for not too much money you can buy "tools" (i won't say toys) like these.
Very interesting Ross, I lasted 10 minutes of the video. When I put a fillet on this fin the other day I thought I would leave the excess bog at the back and sanded it up as part of the fillet. Do you think think this will act as a cut out or part there of without cutting into the fin and weakening it.
