Got over to the shop today to make a bushing for the gear blanks I've made in previous days. The guy who's going to cut the gear teeth needed the bore to be 5/8", and the blanks are 20mm. I grabbed a piece of 1020 hot rolled steel, drilled, bored and reamed the 5/8", that same out so close that a .6250 pin just barely slips in. Perfect size!
Then I turned the O.D. to size. Coming down from just over 1", I left .040" for two final passes. I took the first, measured and took the second. I had about .0002"-.0003" of taper, presumably from deflection because I was using a somewhat worn negative rake insert. It worked out so perfect because the bushing has that "ground" feel to it slipping into the bores of the gear blanks. It pushes into each with virtually "zero" clearance! He wanted "no more than .001" or .002" of clearance, it's far less than that.
Another gratifying day of making chips! (Well, just a an hour or so really.)
![[Image: IMG_20140101_204623294_zpsgpi1swxi.jpg]](http://img.photobucket.com/albums/v466/kenm10759/Dads%20shop/IMG_20140101_204623294_zpsgpi1swxi.jpg)
Then I turned the O.D. to size. Coming down from just over 1", I left .040" for two final passes. I took the first, measured and took the second. I had about .0002"-.0003" of taper, presumably from deflection because I was using a somewhat worn negative rake insert. It worked out so perfect because the bushing has that "ground" feel to it slipping into the bores of the gear blanks. It pushes into each with virtually "zero" clearance! He wanted "no more than .001" or .002" of clearance, it's far less than that.
Another gratifying day of making chips! (Well, just a an hour or so really.)