Finished my first eccentric turn- Brass crankshaft

[Janderso]

This was a fun project. I learned about three different ways of offsetting the part in the lathe.
I did gain some confidence which is always a bonus.

 

[Nogoingback]

This was a fun project. I learned about three different ways of offsetting the part in the lathe.
I did gain some confidence which is always a bonus.

Would you like to tell us how you did the offsets?

 

[ch2co]

Yeah, like Nogo said, how?
I would think the vibration would be incredible
Very cool job though, well done. !

The Old Grumpy One

 

[Turner]

Neat looking piece, is there a TDC order for the rod journals?


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[Chewy]

Very, Very, Nice! Going to use it or just display it?

 

[Janderso]

This is just a piece that will serve as a paper weight. I wanted to try to figure out how to set up and turn an eccentric.
I cut a bevel in 10-24 cap screws. Used my mill and DRO to drill and tap the off set every 90 degrees.
I used 190 as the rpm. I didn’t want to go any faster than that. I used an insert style it off blade and a brazed carbide profile to clean up the edges. It was finicky work. Made a few mistakes in the finish but I wasn’t too worried about it.

 

[Janderso]

Neat looking piece, is there a TDC order for the rod journals?


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I should have made the rod journals like a typical four cylinder but I just turned them at 90 degree intervals as shown in the pic. I marked them 1-4 . Rolling it across a table is satisfying to see the mechanical action.

 

[Liljoebrshooter]

That looks really good. Now get to figuring out the connecting rods to fit.
Joe Hynes

 

[John281]

That's a cool part and your post is timely for me in that I plan to tackle a Sterling engine project soon and I'll have to make a crankshaft with multiple throws but not as complicated as what you've done. I'm still gathering materials and finding that brass is really expensive.

 

[Janderso]

Good old Youtube. You can find many examples on eccentric turning. The 4 jaw offset with an indicator was my first choice, then I saw one where he pinned the two ends accordingly.
I've thought a model steam engine. That looks like fun.
The grand kids are pretty young yet but I would love to spend some time with one of them in my shop learning together.
It's a great experience for our youth.