We have a Hansford/Davis Keyseater at work and we are getting a lot of chatter in the bottom of the keyway. Sort of a wavy surface probably3/4" between peaks and a couple of thou high. The keyway is 7/16 wide in a 1-3/4" bore. The material is 1045 steel. We tried the original broach, reground it, and bought a new one, getting the same chatter with all three. I checked the the machine and there doesn't seem to be any loose parts (the linkages inside seem tight with little slop) there is a little backlash in the drive gears but nothing I can do about it.
Any suggestions?? Our inspector is getting on my case about the chatter :-)