Making a cam from plastic

How much plastic can be used to make a cam? can glue sveral sheets together to make sturdy cause .07" terribly thin.

In our very first (admittedly pretty bad) iteration of our NbN robot, we cut a total of 6 identical nautilus cam shapes from the single legal plastic sheet, and then bolted them together to make two cams that were three layers thick. Depending on the size of the required cam, you might be able to get a few more layers (though I think 3 is enough, we never experienced any breaking/warping problems with the cams). Probably the biggest concern would be making sure you’re using a precise tool to cut the polycarb the same each time, because each layer needs to be almost exactly the same shape in order to get the full benefits of the multi-layer cams.

You might try roughly cutting out the shape of each cam, then clamping the rough-cut cams into a stack, then drilling out a few screw-sized holes including a hole to represent the pivot point. Then screw the stack together. After that, you can use a band saw or something similar to cut the entire stack so it has the same shape and dimension. If the band saw blade tilted a little, you can remove any final discrepencies by sanding. Also consider polishing the edge of the cam when finished.

I am not sure how large of a cam you need but would it be legal to cut a cam shape our of a gear?

That would be legal, since it’s already a VEX part.

If you wanted to cut a cam from a gear you would probably be better off using the Vex cam in the advanced motion kit:

Depends what you need it for. More than likely the OP needs a larger one than that.

I meant to emphasize that if OP would cut a cam from the largest gear, the 84 tooth, (s)he would probably be better using a standard cam because you can only get a relatively small cam from the 84 tooth. The resultant cam would probably not be much bigger than the Vex cam, and it would be imperfect.

If you have access to it, a laser cutter is useful too. That’s what we used last year (pretty sure…) and it got us what we needed.