Barley Twist

Just wondering if it is possible to turn" barley twists " on brass to make the familiar canopy supports on a showmans engine

cheers,

Bob

I think the "tpi" would be far too great, certainly for spindle driven cutting but you may get away with driving the lead screw with a tool that has a shallow "D" shaped end and then give it all a good buff.

Any reason for not buying the twisted olivers? also in the larger sizes they are tube not cut from solid

Edited By JasonB on 27/01/2013 17:29:16

Hi Jason,

There was no particular reason ,just wondered how close you could get (or not )

I don't think the profile will look quite right, Barley twist can be done but that is not the same as a twisted square section, really depends on how much of a rivit counter is looking at the finished item.

J

I would twist square bar using vice and large adjustable spanner. Colin

On a lathe once you get beyond a certain 'courseness of thread' you reverse the drive as it were and apply the drive power (ie by hand) to the leadscrew and let the gears drive the chuck round. So the gear train you are powering is a reduction. More likely to be wanted for wood turning / routing though router lathes use bits of wire wrapped round things to do it.

Another technique is to use a milling machine and a universal dividing head to rotate the work as it is traversed under a suitably ball ended cutter.

Could make a jig up and keep pulling through by hand.

Bit of wood will do, as you pull the bar back the wood of course would have to have the rotation required. Any old hss cutter will do its only brass. Once got working edge the others get easier.

Barley twists as i know it are/were hammer forged.

I was told that the ones on the showmans traction engines, which are very thin, probably only 16G, were formed by pulling a length of chain thru brass tubing.

Can't see how these could be twisted being so thin or hammered

Back in my wood turning days, I used to make candle sticks with a hollow twist, mostly three bines, to do that, three helix are marked out along, and around the cylinder, then with the cylinder on V blocks, use the drill press to drill almost half way through the diameter, then the hard work starts cleaning out, and rounding the bines, at least the sold quite well at the local craft shop. Don't know if there are any hints in there. For wood there is a special lathe for forming a barley twist, haven't studied it, all strings and pullies. It is sold in a number of sizes for ornimental architecture work. Ian S C

here you go

barley twist lathe

ebay listing

The last sentence I wrote above should have said that it was brass tube that is available in barley twist, also in a great many other patterns.

The lathe I'm thinking of is made of four steel bars about 1.5M long and 30 mm dia. these are mounted parallel in a box form, and the top two form a guide for a router. The wooden cylinder that is being worked onis mounted between centers in the middle of the bed below the router. The center at the right hand end is turned by a hand crank, this has a pully on it with a string that is attached to the router, and as the crank is turned, the router is dragged along the bed. Its a whole lot cheaper, and simpler than the one on E-Bay. Ian S C

Ian, it's called a 'Routerlathe', made by Trend, they get snapped up very quickly on eBay and fetch relative fortunes compared to what they originally cost!

I've been looking for one for quite some time, but none ever become available within sane driving distance to me, and no one will post them due to their length (postal restrictions).

John

Edited By RJW on 02/02/2013 09:42:52

Funnily enough Geoff Theasby mentions a barley twist lathe in Club Chat and shows a pic of a (tiny) table made with it. Geoff - could you let us have a few details?

Neil

John [RJW]

Trend provides quite a detailed, downloadable manual for the RouterLathe.

Looks like it should be possible to build something very similar

MichaelG.

Problem with the trend lathe is the distance travelled is always the same.

We used to have barley twist lathes at the piano factory but these were modified simple wood lathes and had a series of cable wheels made from plywood of different diameters.

Most of the barley twist we did were the open type for spindles in high class kitchen furniture which was a side line we did as well as piano actions.

The lathes were to Taiwanese round bed wood lathes as brought into the UK by Poole Wood Equipment, since wound up.

A better version of the Router Lathe is the American Legacy ornamental mill, does far more intricate and complicated work.

I'll post a photo over the next day or so in my gallery.

I'm sure something like that could be made as an attachment for a millimg machine, or as a seperate machine. Ian S C

Years ago I started to make a routerlathe, but life got in the way and it never happened,
I took all the pulleys and cables off an old draughtsman's drawing table, those massive ones about 4 ft across with tilting table,
Not sure if I've still got all the pulleys somewhere or whether they got junked in the move!

If you can find one, possibly from an ex WD or machinery dealer etc, they have 3 alloy pulleys plus a larger one with a helical cut groove, the cable was under spring tension and the arrangement allowed the square to be pushed up and down the table and retain parallel travel,

It wouldn't be too difficult a task to use screw or fusee cutting methods to cut different grooves on something either to replace or slip over the original pulley to suit different helix pitches, and cable can be bought off the roll in various places!
You'd need to then rig up steel rods, a mounting for the router to be used, centres for the stock and a handle to wind it along!

John

Edited By RJW on 03/02/2013 09:45:53

Hi Stub Mandrel,

Sorry, I know very little more than I put in my column. Have a look at the club's website, or contact the club to get in touch with Peter Downes.

Regards

Geoff Theasby

Thanks Geoff,

My interest is purely theoretical at the moment, but it might help Bob if he follows this up.

Neil