VW Logo Blank #5: Turning the Core

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This is the desired result.

 
After the centers are carefully located the blank is mounted on the lathe.

 
Next I mounted the end shown in my expanding jaw chuck and turned the piece to a cylinder of constant diameter.

 
That sounds easy, but it was not. More than once I thought I was done only to find I had a gradual taper from one end to the other. My use of external calipers was not accurate enough to get the job done. 
 
I ended up using a strip of Mylar (plastic about 0.004” thick) to measure the circumference. That got me closer but later on I found out that I still had a taper. Additionally, I had one area where I had gone a bit too deep. You can see the pencil mark in the picture below.

 
In the end I came pretty close. 
I knew this joint between the core and the outer circle of maple was going to be the hardest part of the project. I was right. On top of the accuracy challenges I had other issues as well… 
Been reading along, got to here, and have to say that is a Mother of a turning you are mounting to what appears to be a shopsmith mikey V. I do hope it has the double quill support bearing. What does that thing weigh?

Well seeing it on the TS I guess it isn't as big as it had appeared?
The finished piece is about 5 inches in diameter and 22 inches long. The final weight is 10.6 pounds. Before turning it was obviously heavier.
There was a bit of vibration when I started the turning. I was a bit cautious. I first turned the ShopSmith on and off to test the set up. I had trimmed the octagon well and most of the vibration was gone with first pass.
The biggest challenge on a wood lathe is getting a very uniform diameter on a long piece.Nice work on that piece!!

Cheers, Jim ........................ Variety is the spice of life...............Learn something new every day

Thanks Jim! It was a big challenge.This turning made me think about a 4 axis CNC.
What Jim said!

After getting it round, I'd beg/borrow/steal a metal lathe with a long bed to get zero taper.
That is just what I was thinking this morning! I know of a couple places where I could have taken it. It would have made life a lot easier.