Ring stretchers

[Victoria]

Hi,
Just wondered if these are any good? Seems to cheap!
http://www.ebay.co.uk/itm/proops-jew...item19dad1c2c6
Thanks
Victoria

[Wallace]

Hi Victoria,

they leave lots of marks on the inside of the ring. Fine if you have some time to take the marks off, or have some leather that you can put inside the ring before you do use it.

kindest,

Wallace

[Dennis]

Hi,
Just wondered if these are any good? Seems to cheap!
http://www.ebay.co.uk/itm/proops-jew...item19dad1c2c6
Thanks
Victoria

Many years back I bought one of these out of curiosity. If you think about it a single hammer blow is short acting , quite feeble compared with a steady pull on a lever and likely to glance off onto the supporting hand. So you have to do lots of whacking. The process is very uncontrolled and there is little there that cannot be achieved by tapping on a ring mandrel (except the saving of any surface texture from blows).

When I finally bit the bullet and bought a proper upright ring stretcher, which easily did what it promised, it changed my approach to ring making. I now make my rings about three quarters of a size too small and gently stretch them to size, turning them over to avoid a taper and checking with my ring stick.This also makes them round and does not damage textures on the outer surface. Dennis.

[Wallace]

must admit Dennis, I do the same, although I still use my A-Z ring stick to help with sizing and shaping thinner rings.

I got myself one of the first mentioned when I started and really did not realise how much padding is needed and how much faffing about would happen and how many wasted items I would go through.

Cheap can be useful for practice. However, for rings really investing a little more will make so much difference.

[Victoria]

Thank you both. So to use this I would have to hit the ring with a raw hide hammer to stretch? In which case there's no difference between this and just using a mandrel!? I assumed it was some kind of cheap version of the one you posted Dennis...

That's really interesting that you stretch all rings...does this not stretch surface patterns and also any stone settings where the setting is in the band?

V

[caroleallen]

I've got one that I never use as well Victoria. I'd say save up for a proper one and it'll be money well spent. Like Dennis, I always make my rings a bit too small and size them up.

[Exsecratio]

So to use this I would have to hit the ring with a raw hide hammer to stretch?

Very similar effect to hammering in a nail (as in the things that hold wood together) the taper of the top pin forces the fingers apart as it is driven into the bottom section. Nice idea, terrible execution.

Hammer blows introduce momentary force, presses introduce applied force. Momentary force will allow more springing back of the job than applied force (the material has no time to realign it's structure when subject to hammer blows)

Couple of other things that may be a problem, the number of fingers (slots) is quite low so it's probably going to mark your Ring quite badly, the surface finish on the expanding part is rubbish (machining marks anybody?)

Looking at it, any Engineers here will think of internal mandrels used to turn the OD of tubes in a lathe, for that it would be great, for reforming a fine piece of hand crafted artwork made by an Artist here.....not a hope.

Has anybody here used Barnes Stretchers? don't know if they would work on Rings but they work well on cartridge cases and best of all they are free to make and don't deform stuff

best wishes

Dave

[art925]

Hi Victoria,
I also use the upright ring stretcher, I have never seen this version you post before. However, rather than hitting the ring stretcher with a hammer, could it not be positioned inside a large bench vice. As the handle is turned, will this not provide the constant gentle stretching effect as the upright?

Les

[Exsecratio]

Barnes Stretchers:



Used to bell case mouths on custom gun cartridges but should work well on rings as well.

The rubber should be a push fit in the ring and be around 2mm thicker than the width of the ring.

Tightening the bolts causes the rubber to expand (very evenly) and applies high force but low impact.

Dirt cheap to make pretty much throw away too

best wishes

Dave

ps: The design was by the late Frank C Barnes (all credit to him) many years ago when custom case dies were both expensive and hard to get hold of.

[Dennis]

Well the point about the real thing Dave, is

1. That it has quick release for removing the ring.
2. The ring travels down a calibrated column, so that you can see just how much yo have stretched so far.

Admittedly you also have to check with your standard ring stick as the marks on the column might not correspond. Making rings can be a nightmare, or a pleasure, depending on the sophistication of your method.