SketchUp for CNC prototyping

Alex Jenyon

I've got some product protoypes I would like to get made, probably on a CNC milling machine, since the runs will be in the 1-10 range. I'm thinking that a specialist CNC protoyping company will probably be the way to go, something like 'First Cut' (http://www.firstcut.eu/gb)

I don't have any experience with this kind of thing at all (I normally paint pretty pictures ), so I thought I would ask here for some advice. I don't have any pics to post (these are prototypes, after all), but examples of the kind of things I have in mind would be 1)an aluminium belt-buckle, all straight geometric shapes (no curved surfaces) and 2)a shaped shoulder pad, probably to be made from some kind of rubber

From the company website:

@unknownuser said:

At First Cut, we accept native Solidworks (.sldprt) and ProE (.prt) files as well as files from other CAD systems output in IGES (.igs), STEP (.stp), Parasolid (.x_t or .x_b), ACIS (.sat) and AutoCAD (.ipt and .dwg, 3D only) format.

What would be the recommended workflow, particularly if anyone has used 'First Cut' themselves?
Can I get away with modelling in SketchUp (which I know very well) and using an exporter?
What about the organic shapes - I'm capable of modelling them in SU, but would they work well for CNC milling?
If it's not recommended to use SU for this sort of thing, is there are cheap-ish Mac alternative to Solidworks/Shark/etc.?

I thought there would be a lot of info hanging around about this sort of thing, but a search didn't turn up anything. Apologies if I'm going over old ground.

Thanks for the help

AJ

jpatrick

Alex - a lot of this is going to be a learning experience. Every shop does things a little different than others. A lot depends on the material(s), the scale, and the complexity; it depends on what and how you want it made.

But the most simple and obvious start point is to export a 3D DWG of your model from SketchUp, email it to them, and then get them to review the file with you.

Alex Jenyon

Thanks for the reply. I guess just 'giving it a go' isn't a bad idea. I just wondered if anyone had used SU for this sort of thing before, and whether there were any major schoolboy errors I should try to avoid...

Cheers!

AJ

thomthom

@jpatrick said:

What about the organic shapes - I'm capable of modelling them in SU, but would they work well for CNC milling?

Undercuts can be a problem. Depend on how many axis the milling machine has. If it only has two then you can't do any undercut - you'd have to split the shape into smaller parts with no undercut and assemble later on. Maybe the company can do this for you.
But there are also machine with more axis - so it's not just a top-down operation. I've not had any experience with these though.

thomthom

Have you looked into 3D printing for your prototyping?

Alex Jenyon

I had looked into it, but the materials used for 3D printing tended to be quite fragile/brittle, as far as I could tell. CNC milling from real materials (i.e. aluminium) seemed the way to go, although more expensive.

I also couldn't find anyone capable of printing semi-flexible 3D models (i.e. hard rubber), instead of solid resin. Is this because it is impossible?

Thanks for the help

AJ