Questions on using a moving gantry style mini-mill...

[JAZZCNC]

I had seen onion skinning used on the woodworking forums but how do you go about cleaning it off on a job like this or is it easier than i think?

The part breaks out easy. Often it breaks out clean but even if the 0.1 skin is left on in places it just snaps off clean. Then quick whip round edge with De-bur tool and done.

Rough and finish - large and small makes sense, would use the same process for shapes like the large oval or just use the large tool staring to finish?

Depends on Job really. If could get away with using same tool then I would but if Got to use small tool then it pays to use large tool to hog away material quickly then finish with small tool at full depth.
Often people try to avoid tool change and use same small tool but this fasle economy in several ways.?
Large tool will do it in fraction of time and with much less wear which more than offsets the tool change time. The small amount of material left also means the smaller tool is much less likely to break and also wear is less.

All it means is you have to think a little differently when you Cam the part and order the toolpaths are generated when large amount of tools are used.
Instead of having a operation which roughs then finishes in same toolpath before going to next area meaning lots tool changes. ie: Pocket operation then profile operation.
Instead you just have each operation do the roughing with large tool then create a separate set of operations for the finish passes with small tool.
This way when post processed all the Roughing passes are done before the Finish passes so only one tool change for all operations.

Hope that makes sense.?