made a bending die for my press. pics

[rdn2blazer]

so I made a bending die for my press to see if I could bend some 1/4 in cold rolled steel. well it will bend it easy but if I bend it too far it just breakes it. Im sure if I heated it up it would bend with a nice tite radius pretty well.

I think the corners at the 45 deg. of my "V" block does not help being rather sharp. if the corners were a smooth radius transition into the "V" the steel would not bite the corners and would want to slide into the "V" easier. I will have to buy a cheap V block and grind the corners. this is a good precision block I dont want to ruin. you can see the gough the block put on the steel in one of the pics.

I think it will work great for thinner stuff, and if I need to bend 1/4 in I will heat it up first.

 

[BadDog]

I made one a while back with some round stock. IIRC, 2 pieces of something like 3/4" about ~1" apart for the die, and a piece of 1/2 round welded to some other scrap for a press. That was just a one off tack-it-up-and-get-er-done rig, but it worked for the bends I needed, then got reallocated to something else.

I've got one now that will bend up to about 1/8", (like yours, it's too sharp for 1/4 w/o heat) and up to 20" wide, but no idea where the maximums cross.

 

[BadDog]

What the heck, I keep forgetting to get pics even though I've been asked a few times for them. So I went out in the rain to get them... don't you feel special?

The first shows the break in place and ready for use. Note the guides on the end that locate the ram blade. Also note the mods to the press itself in that I added "gibs" to the sliding cross bar. Second pic shows it from the side after I dropped one end down a bit so it would be more clear. Better description of the details is on the other thread linked below.

Description on older thread.

 

[rdn2blazer]

cool!, thanks Russ for the additional idea. that will be a future mod I will do for sure. did the gib help alot? I have to see how loose mine is.

 

[BadDog]

On mine the "gibs" helped a lot. Before it would take up the slack, and then invariably shift "the wrong way" as you started putting on the pressure, often forcing a reposition or damaging the part or tool. I had planned to make them adjustable, but it was getting late and I wanted to get a job done, so I decided to just "heavy tack" them in to avoid all the drilling, tapping, and pinning. A better design, other than making them adjustable, would be to make some using a low friction buy high density, low deformation poly lining like teflon or turcite. That way you could take out ALL slop with smooth movement. If I wind up buying turcite to put in the cross slide of my lathe, I may just zip those "gibs" off using the plasma and make some new guides...

Oh, and it's not clear from the pics, but the "blade" is 1/2 HRS(?) scrap I had lying around, and the business side is cut 45* to each side by nodding the head of the Bpt and running down the x-axis. There is also a small radius on the "edge" applied by "drawing" a file by hand.

 

[BadDog]

Oh, and one more thing. Makeshift "machinist jacks" can be used to hold the "blade" level as your pressing the brake. On a longer piece, when one side "gives way", it will want to cock sometimes. Generally it will sort of self level, but it puts a bind on. I'm thinking before I use it again I may take some threaded rod and make some permanent levelers.

 

[ntsqd]

snippage.....
.... and the business side is cut 45* to each side by nodding the head of the Bpt and running down the x-axis.

I use a 90* C'sink to chamfer stuff like that. Not as fast a cut, but I don't have to re-square the BPT head either. For what ever reason mine is a PITA to square, so I avoid moving it at all costs.

 

[BadDog]

It's a bit of a pain for sure, but not all that bad. But I can get 1/2 Carbide resharps for $3, way cheaper than a 90* CS big enough to run a job like that. This was ~40" of mild steel with ~3/8" flat including cutting through mill scale mixed with some rust. But I was sure pondering other options before taking the head out of tram...

 

[rdn2blazer]

I have several endmills in HSS and carbide that are 2 flute and 4 flute for this purpose, so I dont have to move the head. you can buy them or in a pinch you can sharpen a 2 or 4 flute up by hand on a grinder. as allways sharpening by hand is not easy but very doable.

 

[littlejimmythatcould]

That's cool idea. We have a big machine at work that basically does the same thing called the Accu Press. My buddies and I use it to make skid plates sometimes. Cleaning up your edges with a file or something before bending can help keep stuff from cracking. But not everyone has a Accu Press laying around, good thinking, I've always just used a press to make joggles in metal. Learn something everyday. Right on!

 

[tRustyK5]

Gotta remember the "8 times" rule when making die sets too. The throat of the lower die needs to be at least "8 times" the thickness you're trying to bend.

I've made all the die sets we use with our 90 ton Niagra, including one I use to bend 1" thick material 10" wide to 90 degrees. Bend radius is 1.25". I ended up having to heavily radius the upper edges of the lower die, then add some hardfacing and blend that smooth. I still get a few dent marks from the edges of the lower die, but overall the material goes into the die pretty smoothly.

Rene

 

[ntsqd]

I like the hardface idea. Wonder if that hardface arc rod I was given will work with the TIG after I knock the flux off. I've been told that some of the hardfacing alloying agents come from the flux itself, but I might just try it and see how it does.

 

[tRustyK5]

We use some stellite filler rod with TIG for some small hardfacing jobs. namely putting a very hard point on a set screw...

The rod I use for die sets is called "Hardernhelle". Completely unmachinable

Rene

 

[jekbrown]

man, I could really use a press. Yet another thing for the to-buy-from-HF list I guess.

j