Well, I got the 10hp RPC all wired up but had the body sump drained of oil, due to that oil leak, so I couldn't test the RPC on the mill.
So I decided to see if the oil leak was from one of the allen cap screws holding this small casting over the transmission arm...
I could see that the lower cap screw was full of oil right into the threaded hole and surmised that that threaded hole went right through the casting and into the body sump. There appeared to be some remnants of a grey material on the threads of the cap screw. After cleaning all surfaces carefully, I applied a silicone gasket sealant to the threads of both cap screws and the casting contact areas. Impatient as I am, I went ahead and filled the body sump with oil, turned on the RPC and fired up the mill in low speed (4hp).
Yaaaaaaaaaaahhh... !!! No more oil leak...
I put the mill through it's paces and tried a .125" cut with a .500"x6" cutter in aluminium and it performed like a champ. I then tried a .250" cut and no problems. I don't remember the feeds and speeds, but chips were flying and it still left a nice finish, in spite of the cutter being mounted on a bent arbor.
I decided to take all of the spacers off the arbor to clean everything up and to try and rule out junk between the spacers as one of the reasons for the runout. The last two spacers were very difficult to remove from the arbor and key, but once I had them off I discovered that this arbor had been cut in two at one point and joined back together.... :yikes: I'm not sure what is in the joint, but the key bridges the joint and was stuck in pretty good.
Looks like I will be looking for a NMTB 50 taper 1" arbor in the near future.
So far so good...
Brian