And indeed, I wish I had made this one with helical flutes. My machine was only a few weeks old at the time, and I needed the reamer and wanted to try out the rotary table anyway. I decided to go for a high probability of success and make straight flutes.
The problem with straight flutes, of course, is that the chips make absolutely no effort at moving out of the hole, even with coolant flowing through. I end up using essentially a peck drill with a pause to wipe the reamer off. I have to go slowly to gauge the small end of the hole anyway, so while it is a little frustrating, I can deal with it.
Chatter does get worse near the end of the cut when the flutes are fully engaged, but so far I have managed to control it.
I have considered making another one, and I would go ahead and try helical flutes this time. Hand dressing helical flutes is a bigger challenge, so I think I'd program the final sharpening pass using a stone in the high speed spindle and let the Tormach do that too.
I also need a tool to make an undercut in a part, and I had thought about putting two upcutting and two downcutting helical flutes on it to enable it to easily cut at the top and the bottom. Of course, straight flutes would do it, but where's the fun in that? I'll put it on the list of things to do...
Regards,
- Just Gary  |