They buy then ready twisted off the shelf

When I was a lad (about 40 years ago now) there was an ex Admiralty engineer in my town (Tonbridge) who made these for customers models.

I was lucky to spend a little time in his workshop, and I am pretty sure he twisted square brass stock in his lathe. I don't recall him heating the brass, and it was all done in one operation. He would make long lengths of twisted brass of about 3/16 or 1/4 square stock.

John

I've seen the twists on 'wrought' iron gates produced simply cold twisted held in a vice. Whether it could be that simple with square brass stock I don't know. But to get even twists in orthopaedic wiring it was always important to traction the wire pairs while twisting.

Found this 2013 thread which is a bit of deja vu. A few familiar names:

http://www.model-engineer.co.uk/forums/postings.asp?th=79109

It also includes links to a 'routerlathe' as recently mentioned in an other thread.

Neil

Edited By Neil Wyatt on 01/02/2017 22:10:22

This is the method I used to twist some 3/16 square brass rod. This brass rod was bought from the Harrogate Show, and the seller said it was a grade that would probably break if I tried to twist it. But I had a go, and it worked fine, and the pitch comes out quite even.

I made the Barley Twist to upgrade the Wilesco Showmans Engine I bought for someone as a birthday gift in 2015. The Wilesco method was simply round brass rod with a coil spring slid over it to give a crude effect of Barley Twist.

Years ago when I used to make gates and railings I would use the same method to put a twist into a portion of 10mm steel square bar, later using an old lathe.

Edited By Lathejack on 01/02/2017 21:48:39

Some 45+ years ago I was shown how to make Oliver's this was done in a machine with two four jaw chucks spaced each end of a lathe bed if memory services me correct one was fixed and driven by a motor running about one rpm the other could be moved up and down the bed and locked in place .

For small square brass that were solid they were placed in a tube , the hollow ones were filled with a resin allowed to set twisted then the resin melted out . I think most of the ones we twisted were sent abroad

Thanks Paul.

I twisted the brass rod cold, I can't remember for sure how many turns, but I think it was maybe three and had no problems at all.

And thanks Nick, it seemed to turn out ok.

Edited By Lathejack on 01/02/2017 23:48:05

Edited By Lathejack on 01/02/2017 23:57:24

In ME or MEW there was once an article on making an simple Archimedean(?) drill using twisted steel as the 'thread' and making a nut by filing square holes in a series of stacked discs.

Neil

A further twist to this post, banisters were finished in this style of decoration in earlier times. I have a recollection of a woodworking article showing a lathe with a router mounted on the cross slide fitted with a milling cutter . Must have been created otherwise pre router!

Good point, wish I had thought of that 35 years ago when I first stated making them, particularly when the old lathe was put to use to twist them.

Maybe the brass twist I made for the Showmans engine would have looked better if done as you suggest.

Edited By Lathejack on 02/02/2017 21:03:02

With no care at all just tried it on a bit of (annealed) steel – so easy to twist I was surprised. But the twist is uneven: after three complete turns the bottom was more tightly turned than the top. What's the fix, reverse the rod at each turn??