Random: 3d print or cnc/fiberglass car parts?

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The whole reason I built an MPCNC was because I figured I could model, slice, mill, glue, and fiberglass over some foam to make parts for my kit car interior (maybe exterior if I get nuts). I’ve done a lot of really neat things since then (building skills, earning cash for upgrades, general falling-down-the-rabbit-hole stuff), but no other progress on the original goal. Then a month or so ago, I see the story about that guy and his kid 3d printing and skinning a Lamborghini replica.

I think the foam would be easier to fine-tune/shape after coming off the CNC and before making the final part, and if I commit to some “less-than-crazy” amount of finishing paths on the CNC it shouldn’t take TOO long. BUT…would it be “better” to build a large 3d printer out of an MPCNC? Is this one of those “Hey, a good use case” moments?

I’m not terribly familiar with either process, so the advantages/drawbacks of both are not obvious to me, especially relative to each other. I am smart enough to admit I’m kinda dumb, though, so I’ll listen attentively to any experience y’all can share.

A friend of mine (who actually buys a lot of the stuff I make, and thus helps to fund my R&D, lol) is fixing the interior of his truck and I suggested we do something really unique with his dashboard. He wins (if it works), I get experience. So maybe I can experiment with that? Not sure if the opportunity helps with this post, but thought I throw it out there.

Thanks in advance.

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3D printing is an additive process, so everything from the bottom up needs to be printed. The most common nozzle sizes are 0.4mm, and can make layers 0.2mm tall. Going a little bigger isn’t so hard, but going way bigger is. The farther you get from the normal, the more expensive it will get and the more skill you will need. The plastic can be formed afterward, but it is much harder than foam.

You can go just about as fast as you want in foam, in contrast. You are also subtracting material, so you may have to remove less than you have to add in a printer.

I suggest you try to make some shape to understand the challenges. You can start with something like a cylinder, but a roman column might show more issues, or a taco, or some words. Pretty soon, you’ll get the knowledge to help you design the parts to be manufacturable.

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Thanks. The Roman column sounds like a good idea. Maybe I can turn it into a pedestal or something for a side table. Then it’s useful, too.

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Something like a gauge pod would be a good test. I think you will find with either method you chose, the CAD will be the hardest part. If you can do the CAD the manufacturing is pretty easy relatively.

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