Press Brake

Mememe! :-)

OK, here it is. It's very special in one aspect, and you'll like that!

As a pressure source, I used a 10 ton cylinder from a press set I bought

20 years ago when I made some body work on cars. The frame is welded out of flat stock (don't have the sized here, but can have a look if you want). There are two pairs of horizontal bars that either work as "table" or hold the "knives" (that V-shaped pieces). The very special thing about it is, that I am not using the conventinal prism bar (we call it that way. It's the bar with the V-groove the sheet metal is pressed into), but some special polyurethane rubber. I found that when I googled for something different and was so convinced that I built the press around it. The PU-bar is 300mm long, has a square section of about 40*40mm and a hole (diam about 15mm) in the center all the length through. That rubber is _very_ tuff. You nearly can't ruin it. You lay the metal on it and press it into the rubber with the "knives". The rubber gets compressed and wraps the sheet around the knives. You get _no_ scratches. You can have _any_ radius. You can have very short stickout. That rubber is so tuff, that you can even bend 5mm sheet on it with a bending radius of 1mm without hurting it.

I have no photos, but if you beg me, I'll make some. :-))

The rubber is from that company:

But their homepage doesn't speak english. :-(( The product is "Veith Eladur" and you should find a dealer selling that stuff. The bars are specially designed for bending, don't buy their PU-springs. :-)

If you need more information, feel free to ask!

Nick

Hi Nick

Ok Ok I am begging, that would be very handy, I guess the term used for you type of configuration would be Hydroforming, never thought about that, just shows.

My e mail is paulgy80atbtconnect.com.

Cheers in advance, thanks for the response

Paul

No, not quite hydroforming. The press looks normal, except the prism that is out of rubber. Hydroforming (also with rubber) has a sealed container. The process of the press brake is more like cutting (punching) on rubber or forming on rubber. Veith has that stuff to. But you can use normal PU with 45 to 60 Shore. Get their booklet, there are a lot of descriptions in (hoping that there exists a translation somewhere). There also might be others offering this, but as I don't know the propper terms, I can't help you finding them.

For the photos, I hop I'll find time tomorrow. Come back to me, if you are getting impatient (I sometimes even forget things). :-))

Nick

If you are in the UK,I have a nice little 8 ton Bronx manual pressbrake for sale.About 24" long. Mark.

You can find them here:

Also see my other posting for a brief description.

Nick

Thanks Nick - I accidentally destroyed your e-mail before reading it! --

Chris Edwards (in deepest Dorset) "....there *must* be an easier way!"

Nothing interesting in it. :-))

Nick

No, he wasn't referring to hydroforming, from what I can tell he was just talking about a piece of rubber :)

Hydroforming is where a fluid (gas/liquid) is applied to one surface of a blank (usually of aluminium) to form it against a mould. It's quite commonly used in the car industry usually on low production/lightweight models.

Imagine a press tool with only the female half, the blank laid on top and then a pressure chamber with an open bottom is clamped down on top, apply the pressure and the blank adopts the shape of the female half (like the end plate on a very malleable pressure vessel changing shape) Eventually the blank meets the female mould at all points and the expansion stops. The blank is then fully formed and can be removed from the press tool and the process repeated.

:-))

That's als done with "rubber". Looks exactly the same, but has the advantage that it doesn't require seals. So I would put rubber forming and hydroforming in the same corner (do you say that this way?).

Now to explosion forming in the home shop ...

Nick