Not another Metal brake :D

[Richard.]

I think we need to just let you get on with it now.
I’m sure you have enough ideas now and you’ll find Challenges with all of them because been completely honest none of them are the right tool for the job. A 600mm set of bench rollers for 1.5mm is neither that expensive or space invading. Certainly less space taken up than what all that under your press is gonna generate once/if you drag it out to knock up your big tool.
I’m 99% sure your tool isn’t going to bend your sheet in the fashion that you want it too. Every time I look at the drawing (it is a nice drawing by the way) I see another reason that would cause it to be a disaster. The biggest issue is transferring the pressure from that tiny central point into equal pressure over 600mm long which is challenging enough on a tool working on the machine bed but to extend that tool what looks to be 800mm to 1mtr down makes that challenge ten times more difficult. It won’t work unless that pressure applied is equal right across. Even 1mm which is way easier to bend I think you’ll struggle with that idea.
Hopefully you’ll try it and let us know eh.

 

[Richard.]

Yes, there are a fair few problems but it's still "only" 1.5mm sheet that would have to be bending 910mm of quarter inch thick benchtop with half a ton of flypress bolted to it.

I know which one I think will bend first...

It’s not a case of which one will bend first. It doesn’t work like that. My home made folder is made of 12mm solid bar braced up to the nuts. If I popped a lump of 2mm mild in it across its full length and gave it everything I could I can tell you that 12mm bar would look as sorry as the 2mm it was trying to bend. Seadogs point was one I overlooked but very valid.

 

[MattF]

Just try it. Make sure you post photo's of the carnage afterwards though.

 

[DAPPH]

Yeah I was thinking about putting a weight on that'll probably be more so for the next project. When I make a big one!

Make the counter weights so they can slide up & down on the mounting arms & be locked in place at the right positions ( mark the arms in numbered divisions ) it will make things a lot easier & quicker for different thicknesses

 

[KemppiFrog]

Little point Kim; The adjusting screws with the wing nuts that control the fore and aft pisition of the plate are back to front... Thay are to pressure it towards the fold line. At the moment, the only thing keeping the plate in place is the friction from clamping, seems to work though...

 

[KemppiFrog]

I know for a fact that at least half of the members on here know at least twice as much as I do about metalworking. That's a given so far as I am concerned. Rest assured.

I'm still convinced the idea has merit, my only worry at the moment is that I may have been thinking about "car panel thickness" when I said 1.5mm. 1.5mm might be a bit of a stretch but I will have to try it as a dare. Here's what I was thinking:

I am still 100% certain that's a goer for say 0.9mm, 1.5mm might be too much though I'd still have a crack at it! If those chunky "fork legs" are running through the table, through sections of fork guides (for example) it should hold the "frame" steady. I'd have as much gusset as required, remembering this is a concept, not a scale diagram. I still think it looks doable....

In this example, to make a 400mm diameter cylinder, I would need to stamp out a number of 15 degree bends only.

Surely that's not as impossible/impractical as everyone (?) seems to be suggesting? Even if 1.5mm might be a bit trickier than I had suggested.

In your drawing, the weak point is right under the flypress shaft. That bar to transmit the load to the rods at each side needs to be deeper in the middle, not at the sides. It will bend easily there.

 

[KemppiFrog]

Here is my little one. 500mm width and will bend 2mm to 135°. Though I mostly use it for 1 & 1.5mm. The plates are 12mm And the top one is stiffened with a bit of angle. The front edge is ground to 45° for over bends. The lower plate is welded to a bit of RSJ, so very stiff. The hinged part has a bit of angle welded to the edge on the hinge line. Hinges are 20mm in 16mm Plate.