Quote:
Originally Posted by sanddrag
Although I'm not Cory, we usually put a good size tooling plate (just 6061 plate, about .75" thick or so) in a vise and face mill it to level it out. Then we run a program to drill and tap that fixture plate with our hole locations for our gearbox plate. Then we clamp 1/4" plate to that with little C clamps, then we drill the 1/4" plate only barely through, using the same XY part zero offset. Then we remove the clamps, bolt down the plate, and do all the pocketing and cut the outside profile.
|
We do what Dave said, with modifications. If the plate is small enough to be clamped in a vise (less than 17" for our vises), we'll clamp the plate in the vise, drill and tap all the holes in it, then load up a fixture plate and drill and tap through a subset of the holes drilled in the actual part in the first operation.
Another alternative that works well for smaller (roughly the size of our drive gearboxes) is to do everything in one operation, in a vise, and leave tabs connecting the part to the stock when contouring the outside. After you're done you can cut the tabs and sand them flush with the outer contour. If you're careful and you follow the sanding with scotchbrite you can blend the contours very well.