09-27-2012, 07:19 AM
(09-27-2012, 07:10 AM)stevec Wrote: This is probably machining heresy and/or suicidal but I have shaped rounded ends on rectangular parts by drilling a hole in the centre of the end for a pivot pin which is held in the mill vise. Feed the vise toward the end mill and turn the part with your other hand. Take small cuts and DO NOT CLIMB CUT! Start at the apex of the corner you want to round off so as not to cut too deep as you're arcing the part into the side of the endmill. once the radius is done to your liking back off and flip the part over for the other side, If the part isn't long enough to be safely held by hand , hold it with vise grip pliers the added landth gives mechanical advantage and better control.
A better pivot pin would be one threaded for a lock nut to keep the part from lifting.
For large radii I rough cut excess metal off on the bandsaw to reduce milling time.
Steve,
That's a commonly used technique and certainly not heresy. Another tip is to add stops so you don't overshoot your arc.
Now that you mention using your bandsaw to cut off the excess, that's what I did with the small wrenches I made. Then I hand filed the OD radius at the business end of the wrench.
Ed