How to make barley-sugar brass tubes

A simple question which (no doubt) has a complex answer:

How are the brass barley-sugar tubes used on showman's engines and galloping horses rides made?

My guess is that they are made by some sort of rotary swaging process closing down a round brass tube onto a twisted mandrel, which is then unscrewed and probably replaced by a plain steel tube to give strength. Is that correct - and if so, how is the exactly constant pitch 'thread' achieved as would be needed to do the unscrewing bit ?

And how to model makers make theirs? By twisting extruded square or hex brass rod, or how?

Cheers, Tim

They buy then ready twisted off the shelf

I was told full size ones were formed by pulling a chain thru a brass tube ?

How true I don't know

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 think I'd fill a square tube with lead and give it a twist. Blacksmiths seem to manage quite even ones in red hot steel so it should be possible with the right skill.

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.

Just for completeness, they are called 'Olivers' which may help if anyone wants to google for a technique.

Neil

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

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

mistake.

Edited By Michael-w on 01/02/2017 21:54:58

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

Nice one Lathejack! How hot did you get it?

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

.

That's a very good result Lathejack.

Nick

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

Crikey! I must try this... maybe on some cheapo well-annealed steel rather than costly brass though :D

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

Made up a bit of 1/4"(I think) square steel rod into a twist for the float guide/indicator in the fuel tank of a Dingo Scout Car. As far as brass goes, my brass supplier has racks of ornamental brass rod, including round, square, and hexagonal.

Ian S C

,

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!

When making wrought iron twists for gates and railings, you should twist the left hand ones one way and the right hand one the other way. This way they look much nicer and is the traditional way.

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