40Ton Hydraulic Press Brake

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Disclaimer: Everything i know on this subject was learned in the past 2 weeks. I’m open to all criticism. Decided I want to learn more about hydraulics, so I am going to replace my 20tSwag off-road finger brake (19” long) with a 36” long capacity. Rounding up it will have 40Tons of downforce. Powered by a car lift power unit at 2950psi. Main parts are 1” X 6” cold rolled. The middle of the press blade is 10” to the top of the hat shape. It “should” be grossly overbuilt”I drew this design from from the ground up with my limited knowledge on the subject.The biggest hurdle is timing the cylinders, I’m not going for extreme precision but I do want it pretty good. I plan to use a geared flow divider to hopefully Achieve “good enough.” Stroke will be 6”, no need for it to be that long but it gives me the option to move the blade out of my way. Anyway, stay tuned. Steel is ordered. I estimate the project to cost about $3000 and whatever after for tooling etc.



www.FirehouseFabricators.comZachLincoln 210mpLincoln SW200Hypertherm Powermax 45xp2x4 CNC Plasma Table.
Reply:Cut the gussets for the legs since i have this chunk of 3/8 i got for free sitting in myWay.


www.FirehouseFabricators.comZachLincoln 210mpLincoln SW200Hypertherm Powermax 45xp2x4 CNC Plasma Table.
Reply:

Originally Posted by BrooklynBravest

Disclaimer: Everything i know on this subject was learned in the past 2 weeks. I’m open to all criticism. Decided I want to learn more about hydraulics, so I am going to replace my 20tSwag off-road finger brake (19” long) with a 36” long capacity. Rounding up it will have 40Tons of downforce. Powered by a car lift power unit at 2950psi. Main parts are 1” X 6” cold rolled. The middle of the press blade is 10” to the top of the hat shape. It “should” be grossly overbuilt”I drew this design from from the ground up with my limited knowledge on the subject.The biggest hurdle is timing the cylinders, I’m not going for extreme precision but I do want it pretty good. I plan to use a geared flow divider to hopefully Achieve “good enough.” Stroke will be 6”, no need for it to be that long but it gives me the option to move the blade out of my way. Anyway, stay tuned. Steel is ordered. I estimate the project to cost about $3000 and whatever after for tooling etc.
Reply:The trick to "timing" the cylinders is a rotary flow divider,,I guess you need the tiniest one that you can find,,AND,, the answer is "NO" to the cheap divider,, as well as parallel connecting.It is too late for the other method,, that is connecting two cylinders in series,,because, for that, I believe the cylinders need to be different sizes,, I have seen that done on some sort of farm equipment.
Reply:one thing i have learned as well from college studies that covered hydraulics and pneumatics is you want your hoses to be the same length, even if it means putting a loop in one. as the different in length of the hose/ pipework can throw off your timing a little.although hydraulic fluid is is generally regraded as incompressable it does have a very very small amount of give so the length of hose has to be factored into you timing question
Reply:

Originally Posted by SweetMK

The trick to "timing" the cylinders is a rotary flow divider,,I guess you need the tiniest one that you can find,,AND,, the answer is "NO" to the cheap divider,, as well as parallel connecting.It is too late for the other method,, that is connecting two cylinders in series,,because, for that, I believe the cylinders need to be different sizes,, I have seen that done on some sort of farm equipment.
Reply:A divider is one way as it looks too late for rephasing cylinders. As ghost said hose length is critical.
Reply:If you can add an adjustment to move the cylinder up and down on one side as opposed to bleeding one side it will save you a lot of headaches.
Reply:

Originally Posted by arcflash

If you can add an adjustment to move the cylinder up and down on one side as opposed to bleeding one side it will save you a lot of headaches.
Reply:I saw a nice one at auction a while back 75T, 800$ Aint no way I would build it today before I looked, maybe even new at that cost. I did one but,,, I needed it, did in a day, had it all in stock for free.   Not as sophisticated, simple press.Last edited by Sberry; 9 Hours Ago at 06:25 PM.www.urkafarms.com
Reply:From my experience they go out of adjustment easier than they stay in. Any small leakage past the piston on one side will throw out your ram after enough cycles. If keeping the ram and bed parallel is important adding a way to compensate the stroke length on one side would be helpful.
Reply:

Originally Posted by arcflash

From my experience they go out of adjustment easier than they stay in. Any small leakage past the piston on one side will throw out your ram after enough cycles. If keeping the ram and bed parallel is important adding a way to compensate the stroke length on one side would be helpful.
Reply:Your cylinders are relatively small to think some adjustment will not be needed,,Heck, even a minor variation in material thickness of the part being bent can cause one side to be "out of time" with the other side.A huge volume is needed to compensate for all the possible "changes" that can occur,,An adjustment on one of the cylinder lengths will correct all of the issues. The real answer is going to have to be change to one big cylinder,,or,, move both cylinders to the center, one front, one back,, so that the cylinders are forced to work together.
Reply:Alright i guess it’s back to the drawing board…www.FirehouseFabricators.comZachLincoln 210mpLincoln SW200Hypertherm Powermax 45xp2x4 CNC Plasma Table.
Reply:Have you thought about something like this?https://www.pirate4x4.com/cdn-cgi/im...t-pc100004.jpg
Reply:

Originally Posted by RCcrawler

Have you thought about something like this?https://www.pirate4x4.com/cdn-cgi/im...t-pc100004.jpg
Reply:The big concern at this point seems to be that uneven forces under the brake will cause the 2 cylinders to respond unevenly. On this short distance (from one side to the other) the force differences will be minimal, so why not just prevent the brake from coming down unevenly and forget about the expensive hydraulics? I'm thinking a frame on each end with 4 rollers to run on the press frame so the hydraulic force is all directed straight down, and can't twist from end to end.  I see differences on a 40 foot machine with multiple cylinders, but for just 2 this close together it shouldn't be a big deal. I've also worked on implements with multiple cylinders plumbed in series and I wouldn't recommend it as a solution. They work great new, but any air or leakage makes them more wonky than the ones plumbed in parallel.The harder you fall, the higher you bounce...250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:

Originally Posted by BrooklynBravest

I'm actually sitting here right now seeing how to redesign it to that style.
Reply:Deep in it now. My Brain hurts.Ignore the cylinder mounting.

www.FirehouseFabricators.comZachLincoln 210mpLincoln SW200Hypertherm Powermax 45xp2x4 CNC Plasma Table.
Reply:A torque tube will keep blade straight Dave

Originally Posted by BrooklynBravest

Disclaimer: Everything i know on this subject was learned in the past 2 weeks. I’m open to all criticism. Decided I want to learn more about hydraulics, so I am going to replace my 20tSwag off-road finger brake (19” long) with a 36” long capacity. Rounding up it will have 40Tons of downforce. Powered by a car lift power unit at 2950psi. Main parts are 1” X 6” cold rolled. The middle of the press blade is 10” to the top of the hat shape. It “should” be grossly overbuilt”I drew this design from from the ground up with my limited knowledge on the subject.The biggest hurdle is timing the cylinders, I’m not going for extreme precision but I do want it pretty good. I plan to use a geared flow divider to hopefully Achieve “good enough.” Stroke will be 6”, no need for it to be that long but it gives me the option to move the blade out of my way. Anyway, stay tuned. Steel is ordered. I estimate the project to cost about $3000 and whatever after for tooling etc.




Reply:If you plan on using cold roll plate, I'd just forget it.  You don't need it.  The bit of additional tensile, and yield, strength, in the plane you're working with, isn't worth the additional cost.