Not another Metal brake :D

[Screwdriver]

Well you started it. I thought it was funny to start with when you made a challenge by saying I'm "not going to get much simpler than what I've drawn" (sic.) I genuinely thought you were pulling my leg so I suggested an absurd simplicity using levers only.

Anyhow. I accept the challenge and I am going to build this "monstrosity" out of sheer petulance.

It might be a while before I have sufficient floor space tho...

 

[Richard.]

It might be a while before you get it built and working too but hey you never mentioned time or complexity been a problem so I look forward to seeing the results.

 

[Screwdriver]

To bend 1.5mm 'medium' mild steel over a length of 600mm to an angle of about 30° you'll be looking at needing around 6-8 tonnes (more or not much less depending on die width and ratio).

Will that square frame take that?

I would say no if the drawing is anything like to scale.

The 'ram' will deflect the cross bar in the middle and those side arms will simply fold or wobble out of the way.

I remain confident. The length of the sheet is the key issue, however, the idea is merely to allow the material to fold completely around into a cylinder, something you "can't" usually do on a Flypress (yes I am familiar with the cantilevered tooling that hangs out the front. Not by 600mm tho!).

It's not a drawing, it is a concept. The idea is all about moving the press tool below the table to allow clearance for a fold. I think I'm onto a winner....

It wont need to bend 30 degrees. Like the example Gaz posts above, it just has to make a series of small deformations. The weight of a 600mm bar will actually help I suggest.

I am more confident that the drop arms will not fold, twist or buckle. I could run them in sections of the same sliding fork system they came from for example. The only tricky part will be making room to do it. I'm all fired up now

 

[Screwdriver]

It might be a while before you get it built and working too but hey you never mentioned time or complexity been a problem so I look forward to seeing the results.

Ha!

Perhaps you might care to indulge in a small wager?

 

[MattF]

Ha!

Perhaps you might care to indulge in a small wager?

It would be pointless. Your idea isn't feasible, realistically.

 

[Screwdriver]

It would be pointless. Your idea isn't feasible, realistically.

Bah! You've seen my workshop then

Let me go grab a piccy to show you the real "problem" with this design...

 

[MattF]

You mean problems other than weight of frame, flex etc.?

 

[Screwdriver]

You mean problems other than weight of frame, flex etc.?

I see that weight as a positive advantage. Clearly it is going to need a chunky bar if it's going to be a 600mm tool but I am thinking that will help rather than hinder. We'll see. I have a bit of 2 inch 2.5 inch round bar long enough but might be better off with a reinforced bit of angle (or maybe both!). Anyhow, these are mere engineering niceties. The real problem is this:

Not the machine itself, all the stuff that's under it and the general mess I laughingly refer to as my "workshop".

But for all you doubters and naysayers, here's something for you to consider before you pooh pooh it; that press tool that is fitted right now, in the above picture is way over 600mm. The longest V block at bottom is about 750mm. In fact I was worried I wouldn't be able to span the cast base but I measured it and it's 500mm.

So I am even more certain. Chop two holes either side of the base, run the drop links down through some sliding supports through the table and have a secondary table set up underneath. Looks like I should be able to roll up to 500mm diameter in that "top half" of the table.

Game on...

 

[Tinbasherdan]

Right, someone spent a good deal of time and money teaching me to bend metal, and if you won’t listen to the others, maybe you’ll pay attention to me. You’ve about as much chance forming a tube with that “concept” as I have of waking up tomorrow with a pair of wings.

1) you’re going to need a pair of hands just to position the material and hold it while the press is operated

2) i can’t be bothered doing the math to back it up, but just from experience I’ll tell you that any framework you make that’s light enough for you to handle will fold like a pretzel before you get any decent effect with the sheet

3) just get a set of rolls, they can be found at reasonable money and you won’t have to spend the next 3 weeks trying to dress out fold marks

 

[gaz1]

or be lazy use a lappost and a couple of wagon straps the old telegraph poles are thick

http://www.mig-welding.co.uk/forum/threads/half-round-of-3mm-steel.59633/#post-736291

i tried it with 3mm steel was hard work with them not advised to try it out, should be easier with 1.5mm steel

the lamp in my photos sometimes is what i used

 

[Richard.]

or be lazy use a lappost and a couple of wagon straps the old telegraph poles are thick

http://www.mig-welding.co.uk/forum/threads/half-round-of-3mm-steel.59633/#post-736291

i tried it with 3mm steel was hard work with them not advised to try it out, should be easier with 1.5mm steel

the lamp in my photos sometimes is what i used

I’ve done it with 1.5mm and ratchet straps round pipe. Once you get it nicely rapped round tight which as you know is no easy task it can be a decent job of it. Some good strong tacks before you remove those clamps are essential mind. You don’t want the thing letting go.

 

[Screwdriver]

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.

 

[gaz1]

on another note here round tubes can be used

large gas bottle 14"
mig welding bottle
lampost/ telegraph pole
soil stack plastic
steel tube

 

[Screwdriver]

I’ve done it with 1.5mm and ratchet straps round pipe. Once you get it nicely rapped round tight which as you know is no easy task it can be a decent job of it. Some good strong tacks before you remove those clamps are essential mind. You don’t want the thing letting go.

That is undoubtedly the best idea so far. I tried bending some builders stands in the flypress but ended up having to pull them with straps to finish off. There's a thread on that here somewhere.

 

[gaz1]

its better to have the 2 blades at top the one blade at bottom so can you go through the middle of that press ?

also you need the bar press to go through the table like in a press brake center push splaying out to the sides

 

[Richard.]

why don’t you force the sheet round a large pipe with a couple of ratchet straps and tack it shut. That’s the simplest crudest solution but will likely give better results that what you show there

 

[Screwdriver]

Right, someone spent a good deal of time and money teaching me to bend metal, and if you won’t listen to the others, maybe you’ll pay attention to me. You’ve about as much chance forming a tube with that “concept” as I have of waking up tomorrow with a pair of wings.

1) you’re going to need a pair of hands just to position the material and hold it while the press is operated

2) i can’t be bothered doing the math to back it up, but just from experience I’ll tell you that any framework you make that’s light enough for you to handle will fold like a pretzel before you get any decent effect with the sheet

3) just get a set of rolls, they can be found at reasonable money and you won’t have to spend the next 3 weeks trying to dress out fold marks

1. Yes that's always going to be the case though...
2. I am sure a pair of motorcycle fork legs (I just happen to have a few) would be strong enough as drop links. I **think** some gusseting (as shown) should stop them from folding in at the top. If those legs run through a bushing which is firmly connected to the table, that should stop the frame from twisting. The bottom bending blade can be as strong and thin as you like. Reinforced angle iron in the digram but could be a relatively deep blade, up to 400mm deep for a full size cylinder...
3. Can't. Unless you have some for me. But even if they were free, I'd still have to find somewhere to put them! (under the flypress perhaps )

I just want to knock up a bucket to make a simple forge body. None of my cylinders are empty and having emptied a couple, that in itself is quite a chore too. I may also want to make a furnace body and maybe even some cheap and cheerful flue pipe. None of those things need to look perfect.

 

[Screwdriver]

Well, I like shifting goalposts as much as the next person...

Istr there being mention that no bracing or side arm support would be required for a start - maybe I dreamed it.

0.9mm is so much less of a challenge, you can almost roll that by hand - 1.5mm might not sound like a lot more but it really is...

So, you're on to thinner metal with a much heavier construction than initially hinted - fancy making it into some sort of rolling tube design?

The aim is to bend a 600mm long cylinder out of 1.5mm mild steel. I was 100% sure it was a goer at the start but when I popped out to the shed, I discover the zintec sheet is 0.9/1.0mm hence the heebie jeebies. I still say its a goer. Now I'm down to 99% tho. (at 1.5mm).

Istr there being mention that no bracing or side arm support would be required for a start - maybe I dreamed it.

It's not a drawing, it is a concept. The idea is all about moving the press tool below the table to allow clearance for a fold.

 

[Seadog]

What about flexure of the bench top and the shelf? Unless they're very thick you'll have problems there too.

 

[Screwdriver]

What about flexure of the bench top and the shelf? Unless they're very thick you'll have problems there too.

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...