copper af bar rolling or sheet

Hi everyone, can anyone suggest a way of rolling a foundation ring in copper approx 6 inch id x1/2" af or thicker that could be turned on the od ? i have not seen any ref to rolling rings, maybe it could be cast gun metal? First attempt is heading for scrap bin sadly. any ideas ? its for the 3 inch atkinson wagon.many thanks vic

Hi Vic,

Obtain some larger and longer section copper, then anneal, then roll in rollers. Most ME clubs have a large set of rollers.

You might need a few anneals and passes on the rollers. Silver solder the joint with high melting point silverflo 24 and Thessco F or Tenacity 4 after trimming the ends. Then maching to final size.

Or else get a slab of copper and machine the ring out of it. Ok very expensive but I know of many model engineers who have thick slabs of copper ( My 5"g terrier copper cap for the chimney was done this was by the very generous help of one model engineer providing an offcut of 3/4" copper slab).

What ever you do get it passed first by your club boiler inspector.

Cheers,

Julian

Assuming that the copper is rectangular or square section, it should be thoroughly annealed. It can then be shaped around a 6" mandrel, if you have one, or around a smaller mandrel but carefully so as not to overdo it. It will need annealing several times as soon as it starts to resist being formed.

It would be better to make it slightly undersize so that it can be hammered to make it grow to the correct size. If machining inside and out to size then the ends could be silver soldered together to prevent excess movement.

It is difficult to imagine that attempt No 1 is beyond redemption as copper is so easy to work when annealed.

Precision machinists should not read further but a suitable chuck body can be used as a former.

Brian

Edited By Brian Hutchings on 22/04/2017 07:19:37

You could do it in a press or even heavy bench vice using 3 pressure points and working along the length, best done as two half circles as 6" is a bit small and will close up around the press/vice.

This is the sort of thing

Quite controlable once you get the feel for it

Another option may be to make it out of a couple of rings cut oversize from 4 or 6mm material lightly rivited and then soldered into one piece with a high temp silver solder. Then turn to fit your tube and solder with a lower temp one.

hi Guys wow, thats some clever answers to try. I am very grateful for your answers, The three pin, is well worth a try, as for solid sheet, i did ask, even thickwall non ferrous tubes but alas nothing, have to keep a eye on ebay! The three pins ideas is very clever indeed! it looks like you are making a big stuart turner standard ! instead of a casting. thanks once again.vic