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"Built Dam Strong!"

16 March 2014

You want to touch my knob, don't you?

I had a lot of fun making a shift knob! I had some really nice stainless round stock for a long while. With my friend's recently acquired lathe, I wanted to try it out! We were both rather skeptical of the machinability of the stainless, especially on a smaller lathe like the South Bend Heavy 10, but after some tweaking, we were both really happy with the results!

Here's my friend Dave getting things dialed in:


I really like this lathe. It works really well, especially with a VFD running the motor. It's nearly silent with the back gears disengaged. It can turn some really smooth cuts!
We actually had to set up the 4 jaw chuck and indicate the bar in. Neither of us had done that before. It went surprisingly well. Once we turned the bar down far enough, we got the three jaw chuck on and got to work tapering one end down:

This would have been easier had we had the taper attachment working, but it isn't and that's another story.

 Final pass complete:
 Look at how shiny that last pass was! That wasn't even with any polishing. Dave has a darn steady hand.

After the tapering was done, we tried parting the piece off at about 4", but the parting tool is honestly horrendously terrible. All we got was nasty chatter:
 Ew. So, we went medieval on things and lopped it off with a hack saw (while it was spinning, and no it isn't as dangerous as it sounds).

I missed some pictures in the processes, but we flipped the knob around and I chamfered the edge by hand then rounded it over with a file.

Then we got a wild hair up our butts and decided to try to knurl the end of the knob. I figured that if we boogered it up, we could just turn off the failed knurls and no one would be the wiser! heh

Here's Dave setting the knurling tool:
He had heard a tip that you set the knurls slightly off of perpendicular, so the knurls will "bite" better and have a better chance of following each other. If you look at he pic above closely, the rollers have a spiral groove pattern, which basically rubs the surface and pushes the material into the grooves. The bottom roller has the opposite pattern on it, and when the gears roll over the same surface, they create the classic diamond knurl pattern:
 We were shocked when we stopped the lathe and the pattern came out perfect! I'd only tried knurling a couple of times before without a huge amount of success. We didn't go too deep, as that can get pretty abrasive, but the patter really shows and gives a really satisfying texture on the top of the knob! AWESOME!

We flipped the knob around again and polished the thing up with some sandpaper. (I think it was 180 grit.)
 Notice the piece of paper wrapped around the knob. That keeps the teeth of the chuck jaws from digging in to the work, and in some cases, keeping the work from digging into the chuck jaws (though that is rare since they are hardened, usually).

 It's fairly large. It's about 1.5" diameter. The small end of the taper is about .750".
 It feels AMAZING. I'll try to weigh it some time, but it is pretty heavy.

The last thing left is to drill and thread it:
 I forgot the thread size, didn't have my tape set and want to be sure of what I am doing before I actually possibly ruin all the hard work and fun that went into this thing!

It's so awesome, kitty approves!
 My friend liked mine so much, he mad his own the next day:
Having access to a lathe is frickin' amazing!