Eccentric turning

[Clarifixer]

Here's a little gizmo I machined out of aluminum to mount a cycling computer on my recumbent trike. The upper part with the tube and flat side (the computer is strapped to it) is an eccentric turning--one piece. It is attached to the main plug with the two visible stainless flathead screws and the whole assembly inserted in the frame tube. A machined tapered pull-up "nut" and stainless cap screw inside secures it in place, like a bicycle bar stem bolt.

If you have never done eccentric turning, it's pretty unnerving to have a big bar of stock whipping around in the lathe with the tool only cutting on one side (cutus interruptus!) until you get down to a full diameter. I won't be doing THAT again, but the end product has bragging rights.

 

[jcouch1]

eccentric turning is quite anerving and interesting. we just did a litle eccentric turning at work for a safe door. we turned the pins to get the clearances right. does turn out some bragging rights

 

[Ign]

Nice work. Turned the crank for my single cylinder 4 stroke in school. Was a lot of fun. Never before or since seen a lathe throw chips so far w mild steel.

 

[Clarifixer]

Nice work. Turned the crank for my single cylinder 4 stroke in school. Was a lot of fun. Never before or since seen a lathe throw chips so far w mild steel.

Oh, man--mild steel. I was ready to head for the hills if anything got out of hand with wimpy aluminum.

 

[Ign]

Oh, man--mild steel. I was ready to head for the hills if anything got out of hand with wimpy aluminum.

It's not that bad, but the crank was long enough it needed a center. I milled a small Al block that slid over the crankcase bearing area and locked onto the flat, w a center-drilled eccentric hole. That made all the difference of course.

Here's a shot of the crank I found on my hard drive. It's one piece.

 

[Bigpigdave]

I always try to balance the unloaded side of the chuck. Makes for a more stable platform, try it sometime.
Good luck, Dave

 

[Clarifixer]

It's not that bad, but the crank was long enough it needed a center. I milled a small Al block that slid over the crankcase bearing area and locked onto the flat, w a center-drilled eccentric hole. That made all the difference of course.

Here's a shot of the crank I found on my hard drive. It's one piece.

Very creative and nicely done! How did it run when finished?

 

[A_Pmech]

Good work!

Eccentric turning and faceplate work is no big deal once you've done a bit of it. Obviously, you want to be a lot more careful. Especially when running jobs which could jam up if you put the carriage under the work.

 

[Ign]

Very creative and nicely done! How did it run when finished?

It ran fairly well, but my carb was the weak link. I didn't have a butterfly or any other way to regulate air, so I had to just regulate fuel w the needle. Of course a better carb could be constructed - it's only time LOL