Prototype #4: Finally something half decent

Sure thing!

The tolerance on the machine is between 0.3 & 0.5mm, depending on material and how hard you’re pushing it. The overall work area is 750mm x 530mm.

Here are some gore shots after milling the battery holders

This design uses v-wheels for linear motion which is fine if you have this many of them, but the next one will be based on MGN or HGR rail for additional stiffness. Oh, and this one uses lead screws (there are also belt versions of this design, but I would avoid belts with a CNC as the torque requirement is a lot higher than a 3D printer. Dialling in a belt CNC is possible, but harder than a screw or rack&pinion system)


iiuc you machined each layer before gluing them together right? The alignment was achieved with those tabs, cool… did it work well?
Were the truck holes done by the router only for the top layer?

Yeah, I stacked all the sheets and screwed them together to keep them aligned. In the middle I left tabs on either side with a couple of scews to keep everything together during the lamination. It worked really well.
Because you cut the profile before adding the curve you do need to make it a bit larger to accommodate for the shift between layers at the ends (you get a staircase effect), so afterwards you’ll have to do another pass with a palm router or something to smooth the sides.

Yes, the CNC only put holes in the top sheet. Because the layers shift a bit during lamination you cannot do it beforehand (well, you could probably get away with it, but I didn’t want to risk it).

Actually, in retrospect you can mill the holes undersized and drill them out properly after lamination. This would also ensure that the direction of the holes is perpendicular to the board, which is a lot harder to do by hand (read: it sucked)

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Tbh, I would prefer to do it as you did, just on the top sheet. Having the CNC available, I would machine some wood guides and just use them to drill them out properly after lamination.

Do you know if it would be possible to machine the contours after lamination? Like fixing it somehow on the machine and then treat it as an horizontal block. Of course the machine would be drilling on air outside of the nose and tail on the first layers but does this even makes sense?

Sure, you could do that: If you can support it properly and make sure the curved material matches what you have in CAD, you could make a 3D contour operation that will machine along the curvature of the wood. This is definitely a lot harder to do and you also increase the chance of the spindle crashing into the material if something doesn’t line up.

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Yeah, probably machine them separately like you did is a better approach.

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