04-20-2013, 02:43 PM
My ex-Snap-On man, ex-Mac man and ex- Cornwell man, who now rebuilds automatic tranmissions, is in the process of building a sleeper street car. It will be powered by a fuel injected all aluminum small block and some highly modified auto transmission, disc brakes on all 4 wheels and various other changes to the original GM design. He bought an aftermarket front disc brake kit, to replace the original drum brakes, that uses a standard 70-80 era GM front caliper. the kit really on consist of 2 brackets and some misc hardware. The kit requires one of the original mounting bosses to be trimmed down 1/2". As this is a fairly common conversion, one of the crew has the rudimentary jig to hold the spindle in the mill. Once in position on the mill, the jig allows the spindle to be trued up, so the boss ends up on the same plane as the other 2 mounting bosses.
With a 1/2" carbide end mill, I just took a series of .050" cuts to trim the boss down to the required height. I went slow to avoid any chatter and to make sure the jig held together, I would have made the jig differently (or better), if it was mine. From start to finish about an hour, plus a 1/2 hour clean up.
1 - the jig in the mill
2 - modified one vs the original one
3 - an other view of the difference
4 - checking out the left side, still in the jig and bracket fitted
5 - the right side with the bracket fitted
With a 1/2" carbide end mill, I just took a series of .050" cuts to trim the boss down to the required height. I went slow to avoid any chatter and to make sure the jig held together, I would have made the jig differently (or better), if it was mine. From start to finish about an hour, plus a 1/2 hour clean up.
1 - the jig in the mill
2 - modified one vs the original one
3 - an other view of the difference
4 - checking out the left side, still in the jig and bracket fitted
5 - the right side with the bracket fitted
jack
