I am plannine on building a chandelier that will be 18" in diameter. The only mandrel I have is the horn of my anvil which I know is not the same thing. I know it can be done without the mandrel but what is the best way to go about it?

 

I do have a hossfeld (sp?) Iron bender but I would like to do this without it unless I absolutely have to. I'll post the plans I have drawn up if anyone is interested.

I would make up a ring like that cold, either hitting between the open jaws of a leg vice or bending the same way. correct the rind against a drawn circle. minute adjustments are much easier cold.

 I would not use heat unless you have a handy former, 

For a one off, I might simply make the jig out of plywood. It's not hard at all to cut a round with a simple radius jig and a jig saw. You can use that to make a metal ring if need be. Simply screw a piece of metal to the outside of your plywood jig and weld where they meet. I'll often "cheat" and try to find items roughly already the diameter I will need. I have a selection of odd size pipe lengths, rims etc to make things simple.

 

If that doesn't work, there are all sorts of other options. 1st I'd lay out the circle you want on a piece of plate. Then you can use a bending fork and "bump" the bend, checking it against the chalked ring to get it even and smooth. You can do the same thing with a hammer over a hollow like a large hardy hole, or two pieces of round stock. Best bet to to do small changes frequently vs big changes less often. The arches on my forge stand were done cold on the anvil over the hardy hole with a hammer. Stock is 1" x 1/2" It was a bit too heavy to do the bends with a bending fork easily. Distance across is roughly 24".

 

 

Think 30 gallon drums have 18" diams.

First thing I would do is go visit the scrapyard and find something close to that diameter and make the chandelier to fit that.  If it was off by half an inch would that be a major issue?  I design to what I have/can get, not some arbitrary value.  If you have to meet some spec you include time and cost of tooling up to be able to be exact. It raises the cost as does all tightening of tolerances  in metalworking.

Thanks for the replies, I'll probably play around with each idea till I figure which will work best for me. 

 

Mr Powers, the lamp is going to be going in my house and I'm more playing than anything, if it doesn't turn out then I'll either straighten everything out and try again or learn that I shouldn't have tried it yet and move on. This is more of an exorcise in drawing out, twisting and scrolling uniformly.

Do you have a "ski slope" tool for your anvil?   basically a chunk of steel with a stem for your hardy hole that has 2 (or more) differing slopes to it.  To use you heat your metal hot and then bridge it from the top of the slope tool to the anvil and then hit down on the section with clear air under it.  You can get quite nice circles with them with practice, I use them for trivets sometimes and that's bending the hard way!

I do not have one of those, but one get made soon.

If I were attempting this project, ... I'd probably wrap the steel about 1 & 1/4 turns around whatever I had, that was slightly smaller in diameter, than the intended size.

( Because it's much easier to "expand" a ring, ... than to "shrink" one. )

In my case, that would probably be a Brake Drum off a Semi-Tractor, ... ( about 17" OD ) ... that's waiting it's turn, to become a Dinner Bell.

 

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A semi brake drum makes a decent bell? I guess I'll have to add one more thing to the limited list of things they're good for.

I'd add suggestions for turning a ring but most of the better methods are well covered. Follow Ol' Smoothy's technique and turn it under sized, it IS much easier to expand a ring than shrink one.

Frosty The Lucky.

I'll try to get a picture of mine; nothing special about it. It was a scrap piece of torched out 2" plate that caught my eye at the scrapyard and had the two differing slops I wanted.  It would be neat to make one for the hardy that had 4 differing slopes.

Greetings Pancho, 

l am spoiled through years I have aquired and built many many tools .. First choice would be my ring roller .. 10 minutes work.. Second choice would be the Hosfeld ..  My personal favorite is my STS multi wonder tool ., I built this years ago to serve as a what many have said is my metal Shopsmith.. Eat your heart out TP made mostly from scrap yard parts.. Enclosed  a few pictures to give you an idea of what can be done if you set your mind to it. 

Forge on and make beautiful things

Jim

Jim, 

I don't know about TP, but I'm jealous... That's a good rig. Nice.

D

On 1/13/2016 at 2:16 PM, ThomasPowers said:

Do you have a "ski slope" tool for your anvil? 

I do not have any ski slope tools, but use the same technique with ordinary bottom tool cheese fullers set at right angles to the axis of the anvil. For tighter curves I have a chump of Ø100mm (Ø4") round with a hardy hole sized square welded on.

I have made up various sets of bending tools for the presses, two round bars on the base and a third round on the ram which bends the workpiece with the same basic principle. The twist was that I made up a few unbending tools as well. These comprise a single bar bottom tool and a twin bar top tool. The ring is held in the same place relative to the press table and the twin bars push on the inside surface of the ring. A lifesaver if you over bend something.

Another approach is to make up a former from another bit of flat (or whatever you have)...it does not have to be a complete circle just a short segment, and either pull or hammer your ring to fit that. For different projects I have used either the internal face or the external one.

Alan

actually I've had good success  making rings out of flat bar by putting an extra long piece and taking a small bend in slightly open vice jaws.   advance a little and bend some more repeat until you have a full circle.    keep and eye with a sector drawn on inside curve. on desired inside curve   The thing is that the each tiny bend is part of the circle.  the extra length permits you to bend near the ends.      So 18 inch diameter is roughly 56.5 inches circumference  I. start with 65.5 inch  flat bar  mark of 4.5 inches from each end and start bending at the first mark.  I'd expect that you would use nothing any heavier than 3/16 for the project and maybe 3 or four inches wide.  which would be really heavy. 

It is always the ends which are problematic when rolling anything around, even sheet metal. I tend to do the ends first while you can get at them and then roll the rest.

If you are using the workpiece directly as the lever and handle, as opposed to three roll benders or bending horns and forks, it is a good thing to really be aware of the "efficiency creep" advantage of the leverage when you are doing a series of little nips as you describe above. The centre section where you have the least leverage can fool you into over bending the end sections if using muscle memory to gauge the duration of the nip...I could tell you how I know... but a clue is that I mentioned having to invent an unbending tool in my previous post!

Alan

Alan Evans 

I know I'm 2 years late on this topic but I just joined here and I recently took on a chandelier project requiring 30" and 20" rings. I purchased angle rings from Midwest Metal Products and used them as a bending jig to bend 4" x 3/16" flat bar in to rings. Now I obviously had to heat them but I was able to bend them in only 2 heats per ring. I had about $80 in material but I needed to make 3 chandeliers. I easily made up for their cost and will keep the rings for future projects.