CwazyWabbit Posted September 18, 2011 Share Posted September 18, 2011 ok, 50x50x10mm lol, if that flexes then i will add bracing!, i think i got some old angle somewhere, god knows how much this will cost!! cheers Good man! Don't forget to post pictures of your results Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted September 19, 2011 Share Posted September 19, 2011 Not to discourage you but my box & pan folder weighs over a tonne and is rated at 4 foot wide x a little over 2mm thick. I don't think something weighing 50kg is going to give good results. I could be wrong, I've never built one. Rather than increasing the section width from 8 to 10 mm you'd be better off increasing the dimension of the sides of the angle section - 50mm is naff all! If you're buying steel and it is costed by mass (which it is), consider some unequal angle and use the long side for the vertical member (perpendicular to the sheet when you start bending) - its this 'bridge' which will dictate how good a bend you get, for the most part. You can also add structure within the back space of the angle. the taller you make it, the better, but its a trade-off between stiffness and capacity to bend small or awkward shapes. Alternatively, as suggested above, I got a manual press frame for 50 quid on ebay (cheap because it isn't covered in naff red paint...) - rated at 60 tonnes, 4 foot wide. I got a hydraulic bending machine for another 50 quid, stripped out the ram and powerpack and now I have a hydraulic press rated at 60 tonnes for 100 quid. Keep your eyes out for old stuff on ebay - its far better built than anything produced for domestic / light-commercial market now, and because people don't drool over it in cheap tool catalogues, they don't bid on it on ebay either. I think you need about 20 tonnes to bend a metre wide 2mm strip (roughly). Good luck. Al. Quote Link to comment Share on other sites More sharing options...
Landy-Novice Posted September 19, 2011 Author Share Posted September 19, 2011 you really know how to put someone off.... you lobed a spanner tool chest in the works!! had a look on ebay (dunno what im looking for) and its a dead duck........ got any pictures?? Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted September 20, 2011 Share Posted September 20, 2011 Don't take my word for it, give it a try. Just don't underestimate the numbers you're dealing with. Blame physics, not me. That's why all the cheap benders won't cope with 2mm sheet. If they could, they would! Pictures of what? Either cannibalise / build a press as per the couple of current threads on the subject, or spend some money on a machine. Personally though, I think you should try building one for minimal cost - you never know it might do what you want. Go as beefy as possible. It won't 'fail' as such (unless the welds don't hold), it'll probably do something, the things that suffer will be the radius of the bend wont be as tight as you might like and the axis of the bend will be an arc rather than a dead straight line as the frame bows while you're using it (more in the middle, hence the arc). Go on, give it a go! Al. Quote Link to comment Share on other sites More sharing options...
mickeyw Posted September 20, 2011 Share Posted September 20, 2011 I have this set that mount in the vice. Good for narrower pieces and copes surprisingly well with thicker stuff (vice and muscle dependant). If you still want to make something and don't know where to start, this guy on the bay sells plans for press brakes. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted September 20, 2011 Share Posted September 20, 2011 Using the same idea as mickeys small bender you could build a rectangular frame using old RSJ's from scrap yard/building demolition ..... get a stupidly large bottle jack, I believe you can purchase 50 tonne ones..... then make the 'V shaped' former using non webbed angle iron, to stop it splaying under pressure sit it between two upturned lengths of angle iron and weld everything to the face of one of the RSJ's..... for the 'blade' part use a thick lump of plate with the edge sharpened, run the ends in a slot created by more angle iron, weld some 'stuff' to the top edge of the blade so the bottle jack can sit on it. I bet that is all very confusing and I really should have drawn a picture ... oh well Quote Link to comment Share on other sites More sharing options...
Astro_Al Posted September 20, 2011 Share Posted September 20, 2011 Sounds like a winning formula C-W. Cheapest way to get something of sensible capacity. If in doubt with the welding, use the biggest bolts you can find instead / aswell. Al. Quote Link to comment Share on other sites More sharing options...
longlandy Posted September 20, 2011 Share Posted September 20, 2011 You dont need vees for the bottom tool on a press brake, I have a sedgewick plate bender(better than my modern one) than can do 100" of 16mm and the bottom tool is square side and adjustable gap for different thickness. Also using a 90deg piece of angle iron wont work too well as you cant go past 90 to take up material spring back. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted September 20, 2011 Share Posted September 20, 2011 You dont need vees for the bottom tool on a press brake, I have a sedgewick plate bender(better than my modern one) than can do 100" of 16mm and the bottom tool is square side and adjustable gap for different thickness. Also using a 90deg piece of angle iron wont work too well as you cant go past 90 to take up material spring back. Good point about spring back, I'd forgotten about that. Just for a bit of tool porn could you post a picture of your sedgewick plate bender? That must be a very hefty machine.... Quote Link to comment Share on other sites More sharing options...
longlandy Posted September 20, 2011 Share Posted September 20, 2011 I take some pictures tomorrow, memory permiting, ive got all sorts of stuff that can bend and do damage Quote Link to comment Share on other sites More sharing options...
ejparrott Posted September 21, 2011 Share Posted September 21, 2011 I have this set that mount in the vice. Good for narrower pieces and copes surprisingly well with thicker stuff (vice and muscle dependant). I like it...max capacity 2.5mm....I bet you need a better vice than most people have to bend a 4" wide strip of 2.5mm thick steel, not to mention the weight behind it to swing the handle! Quote Link to comment Share on other sites More sharing options...
Landy-Novice Posted September 21, 2011 Author Share Posted September 21, 2011 i've got the muscles but will this work with my £3.50 lidl vice?? Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted September 21, 2011 Share Posted September 21, 2011 I have been a looking into making a press brake I had a commercial gabro folder - good for 20" but thinner stiff, and being a proper folder this was real money I sold that and have now boughta monster of a 50 ton press, and have aquired lated V block and a press brake upper plate that when I get chance I wil fabricate into being mounted, but not for a while Today saw me being "Seriously Educated" by "Sir RV of Horsham" the 'genuis of fabrication' in pressbrake info,....was truly superb, .....I didn;t know that the bigger the "V" plate on the base the less tonnage required -..... but up the mm from 2mm upwards and the tonnage do seem to jump whatever ...... My "Target" is to be able to bend up decently 24" of 6mm which I now think with the right V block, and fabriction of top / base plates is a defo possiblity - when I get time to do this a post will be forthcoming - in the meantime look at this : http://www.smithmach...E7017915276.pdf The machine mart / calrke stuff is rubbish over less than 1mm stuff Nige Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted September 21, 2011 Share Posted September 21, 2011 Good info there Nige so for Landy-Novice to bend 3ft of 2mm he's looking at somewhere between 36 tonne for a 1/4" rad or 14 tonne for a 5/8" rad ... Nice to know what sort of pressures we are talking about. God only knows what pressure Longlandys press has Quote Link to comment Share on other sites More sharing options...
steve b Posted September 22, 2011 Share Posted September 22, 2011 Our press brake is a 4m bed 250t Colly ... which will do 10mm in 4m lengths with the right btm V tool As said above a wider btm vee will reduce the tonnage but increase the bend radius The general guide for vee width is 8x matl thickness cheers Steveb Quote Link to comment Share on other sites More sharing options...
Landy-Novice Posted September 22, 2011 Author Share Posted September 22, 2011 so my £20 idea has gone to a £450 press plus whatever else i need...... i assume the bigger vee will be better 'cos it works like leverage? and Nige, the 6mm target, is that 'cos you cant weld anything thinner without blowing holes? but thats a good chart!! i suppose this is another idea thats stays on paper....... PS. just to remind you im unemployed and at college!! money isn't my strong point and come on! i own a land rover! haha Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted September 22, 2011 Share Posted September 22, 2011 so my £20 idea has gone to a £450 press plus whatever else i need...... i assume the bigger vee will be better 'cos it works like leverage? and Nige, the 6mm target, is that 'cos you cant weld anything thinner without blowing holes? but thats a good chart!! i suppose this is another idea thats stays on paper....... PS. just to remind you im unemployed and at college!! money isn't my strong point and come on! i own a land rover! haha Well you can always do the other suggestion (can't remember if it was this thread or another) basically using a thin cutting disc in your angle grinder cut part way through the metal along the fold line... fold it and then run a weld along the inside to strengthen it again. It's cheap, I've never done it my self but I guess it depends on your grinding accuracy really as to how good it looks afterwards. Worth a play if it's your only option.... Quote Link to comment Share on other sites More sharing options...
muddy Posted September 26, 2011 Share Posted September 26, 2011 I agree with the above, done it quite often and you can get reasonable results. Obviously its no substitute for a proper folder but its a fair bit cheaper. Quote Link to comment Share on other sites More sharing options...
Night Train Posted October 4, 2011 Share Posted October 4, 2011 Good info there Nige so for Landy-Novice to bend 3ft of 2mm he's looking at somewhere between 36 tonne for a 1/4" rad or 14 tonne for a 5/8" rad ... Nice to know what sort of pressures we are talking about. God only knows what pressure Longlandys press has I'm going to need to make a press brake now. Just got a commission for a bit of short production run of a custom bracket and will need to bend some 5mm thick mild steel. The bend will only need to be two tabs of 30mm wide, 25mm long, with a 30mm gap between, bent to 90deg, so a total of 60mm width of 5mm. What sort of tonnage would I be looking for to bend that? Cheers. Quote Link to comment Share on other sites More sharing options...
Landy-Novice Posted October 4, 2011 Author Share Posted October 4, 2011 try this http://www.accurpress.com/images/tooling/bend_chart.jpg Quote Link to comment Share on other sites More sharing options...
Night Train Posted October 4, 2011 Share Posted October 4, 2011 Cheers, looks like I can get away with about 10 tons to get a sharpish bend on both tabs together. Thanks. Quote Link to comment Share on other sites More sharing options...
SwindonDisco Posted October 13, 2011 Share Posted October 13, 2011 just take it to the machine engineering shop on cheney manor - the one with a home made model t frame on wheels next to it, its on the left as you go towards the tip just before sheer value motors. Quote Link to comment Share on other sites More sharing options...
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