.....and
Thing four: Proper hole size before reaming. Common mistake of leaving too much stock for the reamer to remove.
Thing five: Proper feeds/speeds. Changing them won't help much. Using the correct SFM and FPT will always give you a consistant hole size.
Thing six: The reamer will follow the hole. So if the hole has led off a bit the reamer will follow and ultimately give you a bad hole. Try running an end mill (or boring bar) thru the hole after drilling to 'straighten' up the hole.
And as HuFlungDung said, make sure your collet system is good. Put an indicator on the reamer to make sure it is running true. And use the lube! |