At the Maximum, Suggestions How to Mill

[csdisme]

I have a X2 that I have converted to CNC and I need to make a part that is right at the limits of the machines capability. I need to do some perimeter milling, drill a number of holes, and bore 3 holes also.

The first problem is securing the work to the table, and the second is the order that I should do the milling.

I have inserted a picture of the piece I need to mill below. Any suggestions would be greatly appreciated.

Thanks in advance

[John Welden]

You could drill the small holes first and then screw it down to a fixture an do the rest.

[rustamd]

I think i would want to mill flat sides first, that way there is something to indicate off of

[Cartierusm]

what do you mean at the limits of the machine, can you machine this piece at one time? I mean what is the size of the piece and what is the travel of the machine?

What I would do it is clamp it ontop of another piece and drill dowel holes in holes that are going to be there anyway. Make sure to make the bottom piece longer so to clamp that too. So clamp the first base down (jig) and then ontop of that clamp the workpiece. Drill the dowel holes for the size of the press fit, go through both sections. Make sure to stop before drilling into your table. Then remove the workpiece and press in the dowels. Then on a drill press drill out the dowel holes, they will be more than accuarte enough since the existing hole is almost the size of the hole already. I've done it a ton of times like this and it's better than milling becasue if the dowel gets stuck as your test fitting it's much easier to manipulate to get the dowel out, just use a center punch on the underside. I would use 1/4" dowels, for me from grainger I have to mill a pocket that's about .25-.251" for a press fit and .253-.254 for a push fit. Since it's cnc you can mill the pocket too and just make sure you don't mill the larger hole further than the work piece. I would use 2 dowels and a screw hole so you can bolt the piece on to the jig.

Now that's if your going to make a lot of parts. If you only need to make one then just figure out how to line up where holes are going with the T slots in the table and then clamp the work piece in place drill or mill the hole, then slide a T nut under the piece and find it with a bolt, bolt it down and do the rest.