This isn't going to work, new thread

[Hal Taft]

The old thread was getting so strung out, I was missing some of the responses. I wanted to respond properly to anyone who contributed, so I'm making a clean start.

This burl is a curse and a blessing. I've been able to solve two technical problems, lowering the RPMs on my lathe safely, and mounting that oddball burl in a way that I can almost turn it safely. But I also found that while solving the mechanical problems, I completely ignored the aesthetic issues. I am able to turn it, but I don't think I like the way it is coming out.

After reading all about variable speed options in old posts, and cursing myself for not getting the 3 phase motor, I figured out a mechanical solution that gives Rube Goldberg a bad name. I mounted a 12" wheel to The outboard end of the spindle, then set up the motor I use for my little Goodell-Pratt lathe to drive it. My guestimate is I'm getting about 100 RPM out of it, completely manageable with no vibration. But it does look a little like a Model T being pulled by a mule.

I got the turning started, more tales and pictures later.

[Richard Madison]

Cool setup Hal. Rube would be proud of you.

Years ago the 800 rpm minimum on the single tube Craftsman scared the crap out of me (trying to make a 11-3/4" diameter bowl). I hung an extra motor under the regular motor, used the latter as a jackshaft, and got the speed down to about 200. It wasn't smooth, but it was functional.

You are doing great. Motor gently and keep us posted.

[Bernie Weishapl]

Model T or not looks like it will work.

[Paul Atkins]

Mother of invention! Glad to see it. Are you standing on the backside of the lathe? The 1st picture looks like the tool rest is reversed.

[Hal Taft]

I solved the mounting issue, as I mentioned at the end of the old thread, with fitted wedges, and to hold the burl in its "cage", a pair of plastic coated aircraft cables, laced through drawbolts, tuned to matching frequencies like piano strings to get the same tension on each. As I was starting into the wood, I realised this thing could be a real finger-breaker. The one high side was almost invisible, so I put some blue tape on it so its position could be seen. The next challenge involved the cables. I ran them accross the branch ends, but it soon became obvious that I would be cutting away all the middle of the branch, and needed a better mounting plan. I re-routed the cables in a cross truss that didn't depend on the integrity of the branch for strength, and that worked very well. With all that weird wood flying around the opening I was making, I decided we need another edge designation ; WE for wild edge. This is the most challenging thing I've ever turned, every single movement of my hands and chisels has to be carefully planned. I have to know exactly where that blue tape is, exactly where my knuckles are, and where both the tip and shank of the chisel is, at all times. And I do not reach in to rake out the chips. Later, my disappointment with the way the form is taking shape.

[Jim Underwood]

I think I'd turn a tenon or a recess on that dude and mount it in a chuck or a glue chuck, so as to get all that "ganglia" out of the way...... It's quite the hazard isn't it?

Good luck and be careful.

[michael gallagher]

Is that a bungee cord connecting the motor to the lathe?

[Hal Taft]

Michael,
Its a drive belt made of interlocking tabs, I think it might be called "adjust-a-belt" or something like that, generally available.

[Hal Taft]

Jim,
The reason for all that junk was to preserve the complete outside of the burl, and only cut the entry hole. The surface of the object has a realy outstanding texture and I wanted to try to preserve it intact. After the fact, I'm not happy with the result, but it was an interesting technical challenge. I won the battle, but may have lost he war. More on that later.

[curtis rosche]

how come you mounted the burl that way, instead of having that branch be the bottom?

[Hal Taft]

Curtis,
save me some writing time, and read back in this thread and the previous 'This isn't going to work' thread.

Hal