Cost for camshaft prototype or very short run

[Reaper1]

I like the idea of splines. You can build the entire cam as a "stack"...bearing, lobe, spacer, lobe, bearing...etc. You could choose to make it so the splines are asymmetric so that you can't spline the lobes "off timing".

Or, cut down the bearing surfaces and find a needle bearing that will work. Expense is my worry here, but it saves from having to make the bearing surfaces.

In order to pull off the set screw idea I think the shaft would have to be through-drilled so the screw can engage both sides of the lobe, so the other side of the screw would actually go into the other side of the lobe and act like a drive pin. Of course the hole would have to be countersunk and beveled.

Ooohh...how about could you "dovetail" or "christmas tree" the base of a prototype lobe and have it slide into a receiving slot on the cam that has been machined? This is how jet engine blades are held into their hubs. There are a multitude of ways that the blades are captured so they don't fall out.

[acannell]

I like the idea of splines. You can build the entire cam as a "stack"...bearing, lobe, spacer, lobe, bearing...etc. You could choose to make it so the splines are asymmetric so that you can't spline the lobes "off timing".

Or, cut down the bearing surfaces and find a needle bearing that will work. Expense is my worry here, but it saves from having to make the bearing surfaces.

In order to pull off the set screw idea I think the shaft would have to be through-drilled so the screw can engage both sides of the lobe, so the other side of the screw would actually go into the other side of the lobe and act like a drive pin. Of course the hole would have to be countersunk and beveled.

Ooohh...how about could you "dovetail" or "christmas tree" the base of a prototype lobe and have it slide into a receiving slot on the cam that has been machined? This is how jet engine blades are held into their hubs. There are a multitude of ways that the blades are captured so they don't fall out.

Anything besides a circle is much more difficult to make precision. Needle bearings still need a precision bearing surface to ride on, no free lunch there.