- Joined
- Mar 20, 2014
- Messages
- 440
Today, I had a length of steel bar in the mill vise with the 1/2" thick edge facing up. I was using a small 3/4" fly cutter, with a 3/16" square HSS tool bit in it, and taking only light cuts of .010" per pass at the H-1 gear setting which was 670 RPM. Apparently, the grub screws holding the tool bit in the fly cutter slot were not tight enough (didn't check them before starting), and in the middle of the cut the tool bit slipped down and dug into the part. I heard kind of a " growling " sound, and saw that the fly cutter was not spinning, also, I'm pretty sure the spindle was not turning either. I immediately hit the E. Stop, which stopped the spindle motor. When I raised the quill the tool bit slid out of the flycutter, and when I re-set the E. Stop, the motor came on and the spindle started turning again as if nothing had happened. Of course, I turned it off, and decided to wait to hopefully here from some members much more experienced with these mills than I.
I'm hoping that someone will tell me that the "GROWLING" I heard was some kind of safety clutch or device to protect the gears from stripping. But, as I'm writing this, it occured to me that I'm really not all that sure if the spindle was stopped or spinning. There is only about an inch of spindle sticking below the quill, and in that quick second before I stopped everything, the spindle may have still been turning. That would mean that, either the fly cutter shaft was slipping in the collet, or the collet was slipping in the spindle (collet indexing pin removed).
Tomorrow I'll look closely for any signs of slipping in these parts, But for now, I welcome and appreciate any thoughts from all the knowledgeable members. Thanks, JR49
I'm hoping that someone will tell me that the "GROWLING" I heard was some kind of safety clutch or device to protect the gears from stripping. But, as I'm writing this, it occured to me that I'm really not all that sure if the spindle was stopped or spinning. There is only about an inch of spindle sticking below the quill, and in that quick second before I stopped everything, the spindle may have still been turning. That would mean that, either the fly cutter shaft was slipping in the collet, or the collet was slipping in the spindle (collet indexing pin removed).
Tomorrow I'll look closely for any signs of slipping in these parts, But for now, I welcome and appreciate any thoughts from all the knowledgeable members. Thanks, JR49