Gallery, Projects and General > Project Logs

Lathe build project

<< < (5/8) > >>

NormanV:
Thanks Lyn

vtsteam:
Norman, you probably can do that, but if you think about it you'll likely use the same number of timing pulleys and the same sizes as you would change gears. And it might actually be a larger package overall in size, since gears mesh, while pulleys need to stand apart.

But certainly would be cleaner to change-- which is, I think, a great advantage.

vtsteam:
A threading system I've often thought about for a small lathe is the "master thread" type of spindle attachment.Basically you attach a threaded piece to the pulley end of the spindle, arrange a follower in it. Like an old style gramophone needle. That follower is on a rod that extends out to the carriage, and pushes it along (it is disengaged from the leadscrew). So whatever pitch thread the "master' has is duplicated on the work.

 I think they were used on the Unimat lathes. I've seen a fancier version on a larger lathe, and kept the picture for years -- don't remember where I got it from.....see below.

Fergus OMore:
Ned Westbury described an attachment in one of his small books -Lathe Accessories???

Again, I suspect that Prof Dennis Chaddock did something similar in his Quorn Book

Probably it all came out of from Holzapffel.

So it is not new but certainly interesting. I DID Maudsley and Holzapffel in 1946 as part of my studies which suggests -- ornamental turning too

Regards

N

vtsteam:
Timing Pulley type:

Norman, Knaell made a commercial set of toothed pulley types for the Taig lathe. Doesn't seem to be around any more, but pics of it still can be found and will maybe help you figure out a similar system.

Go here and click on the picture links:

http://www.cartertools.com/minimech.html


Thread Copying Type:

Deciphering the photo above that I attached -- it consists of:

1.) A long steel push rod that passes through a bushing on top of the headstock and one on top of the tailstock.
2.) Brass collar stops on that push rod at headstock and tailstock to limit its movement to the length of the "master screw" when resetting it.
3.) A follower toothed arm that sets in the master screw.
4.) A lathe tool holder attached to the pushrod.
5.) An adjustable vertical steel rod that serves as a rest and support on the topslide. I see a wingnut on the topslidethat retains a smooth plate. The end of the vertical rod slides along that plate with the topslide stationary, I believe. I think this rod sets the depth of cut. Not sure how pressure is applied to the lathe tool, but maybe it's just the weight of the attachment.

That's pretty much it.

Master screws could be made up on another lathe, and in some cases could be made from commercial threaded rod for the larger common sizes.

Navigation

[0] Message Index

[#] Next page

[*] Previous page