How hard is it to CNC this?

[Random Dude]

Originally Posted by sanddrag

I was wondering how hard it would be to CNC this. Would I make it to size on the manual lathe first and then have the CNC mill do all the rest? Just to give an idea of the size, the OD is about 2.5 inches and the part is about 1 inch deep. I have a guy who will make the program in MasterCAM and I will set up the machine. I know this can be done (as I have seen way more complex stuff than this) but I don't know how hard it would be. The space between the six protrusions is .134 which is pretty small. Is a 1/8" end mill that is at least 1 inch long a common thing? Thanks.

EDIT: Forgot attatchment, added now.

Hmm.. this looks an awful lot like the hubs for the skyway wheels, just with a hub & keyway attached...

If thats what there intended purpose is, why not just machine a plate to mount to the existing hubs?

[sanddrag]

Originally Posted by Random Dude

Hmm.. this looks an awful lot like the hubs for the skyway wheels, just with a hub & keyway attached...

If thats what there intended purpose is, why not just machine a plate to mount to the existing hubs?

It is very similar to the skyway wheels but it is actually for different wheels for a different project. They are just a plain bore through plastic, no pre-existing keyway. That's what these hubs are for. I had thought about a plate that clamps the wheel (http://chiefdelphi.com/forums/showthread.php?t=26215) but have determined that since I have the resources to do a full-blown CNCed hub, I will go with that. It is kind of dificult to explain but the center section of my wheel connecting the spokes to the hub is is very thin width, only .125 at the most. Putting just bolts through that thin of plastic will not be enough to drive the wheel reliably, so the two sides of the hub would have to clamp together to drive the wheel and I'm not so sure of that because in its application, it really cannot afford to slip no matter what. This design I have shown in this thread will fully engage the wheel and fills in all the voids in the hub area which makes it very strong. Basically with this, the plastic cannot flex anywhere because it would be running into aluminum, which is contacting the next section of plastic, and so on.

EDIT: I attatched a picture of the wheel's hub area. These void spaces are present on both sides of the wheel. One of these hubs will go on each side. The "thin plastic area" I talked about above is in these cutouts or void areas in the wheel. These cutouts have a bottom to them, and so do the ones on the other side. See, the whole wheel hub is about 2 inches thick and the cutouts are .95 deep on each side. That's why I want to fill up those spaces with the aluminum hub.

[Bob92]

you can actually do it on a vertical mill if you have the 1/8th inch long endmill. But you must lathe it down first and then put it in an indexing head. Then if you have the time you can rotate the piece while lowering the endmill after each rotation. Then make all the other cuts you must.

[Joel Glidden]

Another option would be to make it in seven pieces instead of one. I would make the "orange wedges" seperate pieces that attach to the hub with machine screws - 10-32, perhaps.