Mouth Piece Bending Jig

[txtwang]

Here's a few pictures of a bending jig I've been working on. It bends the mouth piece for a horse bit. The material it bends is 1/2", 1018 cold rolled mild steel bar. My intention is to make a jig that is easier to use.
Currently, the mouthpiece I'm using in the pictures is a throw away.
As it was at first, it took 3 hands, torch, clamps, wood blocks and hammers to bend the 1/2 stock. I have used this jig many times but it's always been an ordeal to use in the original configuration.
I have just added the parts that hold the top in place and am now getting ready to add the handles to bend the bottom section. I had hoped to use this in my 12 ton press but I don't believe my press is capable of this without heat so it will all be hand work.
I also want this jig to be able to bend different depths and widths etc, hence all the extra holes. I've made different sizes of posts to bend against. What I'm hoping for is to have the 1/2 " stock really hug the bending posts and be a tight bend. You can see where the bottom is completely away from the bottom posts.
I'm open to any and all suggestions ..even if it means having to completely redesign it...
Thanks
Jerry

[stan the toolfool]

the center bolt needs to be movable. you also need another fence on the right , looking at the first pic. . i would attach a piece of all thread to the center, silver bolt. and pull it back past the other 2. . Then you have 2 fences and the silver bolt on one side , and the black ones on the other. . Lay your red hot straight steel between them. then with an impact wrench turn the center , now sliding bolt until it hits the existing stop. the only piece that needs to move is the silver bolt, in the first picture it would move 3? inches from the bottom to the top.

[skibo]

Have you thought about a hydraulic press, and reconfigure your jig to work on a vertical plane instead of a horizontal one?
I have no idea the particular design in making a horse bit or what it involves, but hand cranking 1/2" cold rolled steel even though it's heated from my experience is tuff to do and keeping it corralled in the form. I'v personally never seen a horse bit out of the horse's mouth so to say, but you might try welding 3/4" key stock to both sides of the bit and use a hydraulic ram to do the work
Just my two cents worth!

[awright]

You haven't stated clearly the procedure you use to make the bends, but judging from the figures, it looks like you make a "U" bend in a short piece of stock, then put it in your jig and bend the legs out. This puts you in the position of working with short stubs on both legs, using levers built into your fixture to make the final two bends.

Consider the possibility of using a long piece of 1/2" bar stock and making each bend in succession from one end, giving you the mechanical advantage of having the long end of the bar stock as a lever for each of the three bends. Then use a cheater extension bar for the last bit of stock.

This approach would require three separate bending jigs but might save effort in the long run. I gather that you expect to be making many of these mouth pieces, so the extra jigs should not be a major cost factor.

I think you would benefit from heating the bar for each bend - perhaps with a pair of MAPP torches and a thermal retention cover plate to contain the heat and shield the hot bar from breezes - a small penalty to pay to keep the bend in the desired region of the bar.

Based upon my limited experience bending bar stock in an outdoor environment in the absence of a jig, having the MAPP torches clamped in place for optimal heating will avoid much juggling of flaring hot torches using all prehensile toes and elbows. I know that Bernz sells torch heads on hoses for use with remote tanks for under $100 at Home Depot. See if they are available in MAPP versions.

Each jig would have to have a large enough backing plate to have a deep scribe to show the stopping point for the bend.

Let us know what you work out.