07-13-2013, 03:16 PM
I made the pins this morning and tapped them in with a little ball pein hammer. Because I deburred/chamfered them by hand and don't have a collet stop, the depth they went to in the holes varied a little bit. Next time I'll find a way to make more consistent size pins.
![[Image: IMG_1900-r_zpsb6dfa2f5.jpg]](http://img.photobucket.com/albums/v466/kenm10759/Bike%20parts/Tiger800/IMG_1900-r_zpsb6dfa2f5.jpg)
Off back to my home where the bike lives, I found that the clearance on the backside wasn't quite enough. The square corner on the back of the tool where the boss for the 1/2" square drive is was hitting the bottom of the handlebar. :(
Back to the shop for a minor adjustment, I put the 3-jaw chuck back onto the lathe (collet chuck was on it from making the pins.) I put a dial test indicator on it and with .010" brass shim between the jaws and workpiece, I tapped it into true within .001" both radial and axial T.I.R.
Now I didn't have an exact radius in mind, I just knew it had to be at least a 1/8" radius. In my small supply of hand ground HSS and brazed carbide form tools, the closest I had measured about .160". Close enough. I did fudge it a little bit because I was wearing safety glasses that fit tight and fogged up (best excuse I could muster), so there is a little line in the part. Big deal.
But it fits the bike now! The pins engage, and I have just barely enough room for an oversized (IMO) 1/2" drive extension.
![[Image: IMG_1901-r_zps9e666130.jpg]](http://img.photobucket.com/albums/v466/kenm10759/Bike%20parts/Tiger800/IMG_1901-r_zps9e666130.jpg)
![[Image: IMG_1906-r_zps737352ec.jpg]](http://img.photobucket.com/albums/v466/kenm10759/Bike%20parts/Tiger800/IMG_1906-r_zps737352ec.jpg)
Prototype project a success. The next ones will be slightly different, offering just a little more clearance. Since the torque value for the headset bearing nut is a paltry 18 ft/lbs, I may offer these to interested buyers with a 3/8" square drive, though I'd need to make or buy a broach to make the hole easier to do. I have a surface grinder to make one, but no heat treating capabilities. Yet.
Off back to my home where the bike lives, I found that the clearance on the backside wasn't quite enough. The square corner on the back of the tool where the boss for the 1/2" square drive is was hitting the bottom of the handlebar. :(
Back to the shop for a minor adjustment, I put the 3-jaw chuck back onto the lathe (collet chuck was on it from making the pins.) I put a dial test indicator on it and with .010" brass shim between the jaws and workpiece, I tapped it into true within .001" both radial and axial T.I.R.
Now I didn't have an exact radius in mind, I just knew it had to be at least a 1/8" radius. In my small supply of hand ground HSS and brazed carbide form tools, the closest I had measured about .160". Close enough. I did fudge it a little bit because I was wearing safety glasses that fit tight and fogged up (best excuse I could muster), so there is a little line in the part. Big deal.
But it fits the bike now! The pins engage, and I have just barely enough room for an oversized (IMO) 1/2" drive extension.
Prototype project a success. The next ones will be slightly different, offering just a little more clearance. Since the torque value for the headset bearing nut is a paltry 18 ft/lbs, I may offer these to interested buyers with a 3/8" square drive, though I'd need to make or buy a broach to make the hole easier to do. I have a surface grinder to make one, but no heat treating capabilities. Yet.