How to model the mechanism of a Taylor Chuck?

This is one of those things that is entirely for curiosity (and some improvement in skills) than a practical purpose.

Looking at a Taylor chuck that came with some other tools I was quite interested by the conical scroll. I couldn't think how I would design it with all the power of CAD, never mind how someone worked out the form from just paper.

Could anyone here better at CAD and design in general show how to design such a conical scroll plate and matching jaws? I could make a scroll plate, I could make a thread but this is a weird mix between the two.

Well, if you decide to sell it, please let me know, as I've a 4 1/2" one with a damaged scroll.

It's been like that as long as I've had it, but previously I thought it was just badly mounted on a Myford backplate.
Now I've fitted it properly to a D1-4 mount, it's still off by a variable 10 thou+.
Seems a previous owner was a gorilla and damaged both the back and front of the scroll. There's a lump on the front which throws whichever jaw it contacts by several thou, so the error moves jaws as the scroll rotates.
Even the gear teeth on the back are cracked and chipped.

Annoyingly I recently missed on on ebay with external jaws only for about £25 & P+P, I've got normal jaws & 2 sets of specials, hence looking for a replacement body/scroll.

There's an interesting bit on them on Tony's site for anyone unfamiliar with the concept.

Bill

Edited By peak4 on 04/02/2019 20:08:26

Create a helical line that tapers then sweep a triangle along it. You can do it in AutoCad so I expect other CAD programs will have something similar.

Martin C

"Could anyone here better at CAD and design in general show how to design such a conical scroll plate and matching jaws? I could make a scroll plate,"

Solidworks has a Helix/Spiral tool to draw a spiral (not sure about other software). Then sketch the tooth shape and use the Sweep command to model the spiral tooth profile.

Paul.

Haven't seen one myself, but is it not just a coarse & very steeply tapered internal thread?

Martin.