WCD milling pockets for bearing blocks

[Peck]

Originally Posted by Gray Adams

All of our mills have a massive piece of aluminum with 2 rows 1/2-13 for bolting vices and other clamps too without dialing them in. It's really convenient, but it looks expensive to buy a piece of aluminum that big and ground flat.

The material itself is only half the price of something like that. The other half is the holes. making it flat is a few simple facing operations on a cnc mill.

[Cory]

Originally Posted by Peck

The material itself is only half the price of something like that. The other half is the holes. making it flat is a few simple facing operations on a cnc mill.

I guess it depends on how precise you want it to be, and the layout of your machine, but I wouldn't want a base plate that's not ground flat.

Most machines have a substantially larger table than travel of the machine. Unless you have a large fly cutter you can't machine the entire surface in one shot.

As soon as you clamp or bolt the plate to the table to take a cut and flatten it out you're introducing/relieving stress as you clamp/cut/unclamp. As long as you're clamping it you will never truly get it flat while milling it.

If you clamp it and machine it flat and leave it in place and never remove it, it will be flat, at least as long as your machine is perfectly leveled at the time you cut it, and it never changes level after that.

In all likelihood the last method is probably good enough, especially if your machine is older/worn out.