/k/ here. I humbly request your shared knowledge on hydraulic shot presses. I could always just buy one, and still may, but I like to build things for myself. Can anyone provide schematics, or a parts list, or any other advice for building a 20 ton shop press? Will be used for bending sheet and plate and pipe, but also to press the occasional barrel into the odd trunnion, and who knows maybe I'll rebuild a bearing or two.
Going for basically pic related, but much taller, and possibly on a cart or with its own wheels.
My biggest obstacle here is that I am shit at welding. So my question here is can a build like this be done with just nuts and bolts and bushings? Are there any deal breaking cons to building a press which is held together with huge nuts and bolts rather than welded joints?
What gauge rectangular tubing/ channel/angle sock should be used for the frame to withstand around 25-30 tons of load. I want to overburdened it in case I someday decide I need more dakka.
>What gauge rectangular tubing/ channel/angle sock should be used for the frame to withstand around 25-30 tons of load. I want to overburdened it in case I someday decide I need more dakka.
The AISC has a very handy resource available that details exactly how to calculate loads. Start from the beginning of the code book and you might actually learn something useful. It will answer all your questions. If you want to just be on the safe side then i'd go with 3" thick solid steel square stock.
Bolt it together, then reinforce it with your "shit" welding. When you go to use it, use like a 10 foot pole for the jack. This way if it breaks you're like 10 feet away. Also, the jack alone is gonna be like $50. Add the cost of materials and what your time is worth to you, compare that to the price of one you can buy. And if that one fails, you got a warranty. And if you get hurt you can blame someone else.
>can a build like this be done with just nuts and bolts and bushings
In principle? Sure. You'll just need a lot of them, carefully arranged to avoid stress concentrations. Practically? To get the overlapping area for bolts, you'd probably need to do some welding anyway, though awkward fitups might be possible. Welding would be so much better that it's probably worth the effort to put in a bit of practice, even if just for this project.
And the robustness of the structure you'll need depends on factors besides the press force. Like the dimensions of the press. Though like >>935437 mentioned, you can just make it huge and not worry about it.
>I like to build for myself
>does anyone have a schematic or design
What. Assembling Ikea furniture to a set of instructions isn't building for yourself.
Also those suggesting bolts wouldn't be strong enough to cope under pressure, please bare in mind that steel framed buildings are quite literally held in place using nuts and bolts.
>Assembling Ikea furniture to a set of instructions isn't building for yourself.
OP is planning to fabricate the press frame from stock. If a construction worker builds something according to a blueprint, what do you think happened?
>steel framed buildings are quite literally held in place using nuts and bolts.
OP wants joints that will take stress comparable to a steel-frame building. If bolted, they'll have to be as large as those in a steel-frame building. If welded, they can be much smaller. There's a reason why the presses you can buy ready-made are welded.
>have to be the same size as those in a steel frame building
No they won't.
BS EN ISO 3506/80 M16 bolt shear strength is 60kN. If the top and bottom cross members of the frame incorpored 4 bolts each, 2 each side, the overall would be 24 tonne.
Bolts can be as strong as welding, gokart forums already proved that..
Don't know much about shop presses. friend of mine use to work at a radiator plant tho. they had this really cool like 140 ton press for something.. but man, the few poor fucks that got the tips of their fingers snipped off buy two flat plates is fucking amazing.
what im saying. Go for 140 ton hydraulic press. Get hamsters. Post on /b/ of your awesome new WEBMs
>Could this be built
Sure, but it would be a giant frame with a tiny-looking space for the ram and workpiece. Wood is a lot weaker than steel, and making strong connections in wood is much harder.
>BS EN ISO 3506/80 M16 bolt
So four 16mm high-strength bolts can carry the load. But they'd tear out of the mild steel structural shapes that are economical for carrying the load. Bolts need to have a large contact area (read: a lot of bolts) to reach anywhere near the strength of what they're joining.
See pic related? The outer structures of WTC 1 and 2 were made of welded prefabricated sections bolted together on-site. See the stair-step pattern of the break where sets of three columns broke off cleanly? That's where bolted connections failed at well below the strength of the steel they joined. The damaged welded sections bent, usually breaking in the middle of pieces rather than at the welds. Getting a full-strength connection from bolts takes large arrays with reinforcing plates like you might see on riveted structures from a hundred years ago.
>Bolts can be as strong as welding
Sure they can. They just need a larger, heavier connection to do it. Double-sided tape can be as strong as welding with a large enough contact area, and it has the advantage over bolts of avoiding stress concentrations. A fifteen-ton bolted connection in mild steel is rather substantial. A fifteen-ton welded connection in mild steel is less than a square inch, and can fit structural shapes without any awkward fitup or reinforcing plates.
Oh so the bolts are strong enough but the steel you're building the press out of isn't?
I'd have taken you a little bit more seriously if you hadn't accompanied your post with that photo.
>in b4 jet fuel can't melt steel beams
>Oh so the bolts are strong enough but the steel you're building the press out of isn't?
The specification given for the bolts was for a cold-formed high-strength alloy much stronger than the mild steel that would be reasonable to use for the press frame. And reasonable stock shapes for that would be a much thinner than the 16m bolts specified. Connecting thicker / stronger-alloy pieces, those bolts could have held the 24 tons mentioned, but in a reasonable structure for OP's situation, they would have torn out of the weaker metal as the bearing surfaces failed.
Do you have a better example of bolted and welded connections being broken in the same incident?
This press (while only 12 tons) uses bolts to hold c channel to square stock. Why couldn't more bolts be used to make a 20 ton press? Excuse me if retarded, but seems to me like the concept is sound.
If you don't like welding you can bolt or rivet but it is way less suited to fine work. Welding allows smaller parts while still being strong. That kind of welding is very skilled tho.
You can definitely make a chunky one. In a lot of ways bolting and riveting is superior to welding, it's quicker easier and you get less stresses built in to the structure at the end.
Also when did diy become retarded?
>OP wants joints that will take stress comparable to a steel-frame building. If bolted, they'll have to be as large as those in a steel-frame building.
You need to work on your understanding of structural analysis m8. This is really not the case.
This is a subsidiary reason I would like to avoid welding where possible. I have relatives and friends who weld and would probably do it for me if i provided the rods and a case of beer. But I like that a bolted structure can be torn down and rebuilt. I'm having a hard time believing the press could not be built with nuts and bolts. Ive seen some big damn nuts and bolts, and I'm not planning on building the frame out of plumbing pipe or something like that, so whats the problem?
Ah man this reminds me of the time I made my hobo printing press.
This got me by for a few years till I could afford to drop 2 grand on a real one.
You NEED to weld it anon.
Steel bolts are no match for this load.
Theres absolutely no way you could ever bolt it together.
>This press humbly disagrees with you.
I can find ones p easily for way less than 2 grand. But good job
Bear in mind that reused fastenings are much more likely to fail esp in this sort of application. The threads on the nut and bolt deform and weld together. Reusing fasteners often lead to the threads stripping or the bolts shearing. But fasteners a cheap so easy to replace each time you take it apart and put back together. Spit balling here because I remember it being the next big thing during my undergrad, what about adhesives? That might be way more straightforward manufacturing wise.
Nuts and bolts can't hold stuff together unless they weigh more than the pressing ability of the bottle jack!
JB Weld is an epoxy isn't it? My thought was more towards something like cyanoacrylate (superglue) since you could exploit its weakness in shear to take it apart. A quick Google says it might be a good option.
>I'm having a hard time believing the press could not be built with nuts and bolts.
You certainly CAN. It's just that for a large load, you'll need a large bolted area / thick steel pieces that are probably heavier / more expensive than you'd need in a welded frame. For example, >>935801 could have used thinner channel pieces if they were welded instead of bolted (and note that the top beam is welded together). >>935792 is an elegant solution if you have the vertical room for it. Note also that the bolt holes have reinforcing plates welded to give them the strength to resist tearing out. Doing that without welding would take thicker diagonals.
>Bear in mind that reused fastenings are much more likely to fail esp in this sort of application.
Actually, if set up properly, it shouldn't be an issue. Plan the connections so that the bolts will be loaded in shear rather than tension, and select bolts so that the load is carried by a solid shank, with threads only on the part that accommodates a nut.
>what about adhesives?
No adhesives are even close to the strength of steel. You'd have to have large overlapping sections to carry the load. Adhesives are very vulnerable to peeling, so the stress would have to be carefully balanced. It could be done, but I would hesitate to do it for the sake of safety. Mild steel tends to fail gracefully, bending and absorbing huge amounts of energy. High-strength adhesives like cyanoacrylate or epoxy tend to crack and fail suddenly. Under load, that could launch some heavy chunks of steel a fair distance.
Son, if your load is exceeding 20 ton you won't be building it in your garage.
>better get to welding that shit up, son
>It could be done, but I would hesitate to do it for the sake of safety. Mild steel tends to fail gracefully, bending and absorbing huge amounts of energy. High-strength adhesives like cyanoacrylate or epoxy tend to crack and fail suddenly. Under load, that could launch some heavy chunks of steel a fair distance.
My experience of adhesives are limited so that's some good info. It should be possible to do something like a glue steel ply at a join tho this is obv no good for op it's something I now want to piss about with
How thick do you think that channel is, and what size and material bolts would you recommend to replicate those designs?
Do you think 3/8ths or 1/4 inch channel and square tube be reasonable to use?
I will almost certainly never use this press to it's 20 ton capacity, but I want to make damn sure that it won't shear or snap and nail me to the wall.
And like I said, I could always buy one. But I WANT to make one. It's a personal sense of accomplishment sort of thing.
At this point I'm just trying to gather as much information and ideas as possible before I start this project with my tax return.
>How thick do you think that channel is
Eyeballing without a given scale, maybe a quarter inch? Probably not much more or less than that given the load and structure.
>what size and material bolts would you recommend to replicate those designs?
The size of the bolts depends on the number used - larger and fewer vs. smaller and more. With mild steel and the loading you described, a square inch of bolt-beam and bolt-column contact area per joint should give a good safety margin. With two points of contact per bolt and quarter-inch-thick frame material, that's eight quarter-inch bolts, 6x 3/8", 4x 1/2", 3x 3/4", or 2x 1". I recommend fewer, larger bolts if the logistics work for you since they'll be stiffer and easier to align precisely. What's your drilling capacity in mild steel?
I recommend using hardened bolts. You won't need the extra strength, but the hardness will help if you take it apart and put it back together. Since the holes won't exactly match the bolts, one or the other will deform a bit under load. Hardened bolts assure that the frame will deform to a consistent curve that will let you switch bolts around without any problems.
>Do you think 3/8ths or 1/4 inch channel and square tube be reasonable to use?
This depends on the span you need and the constraints on the size of the frame. A longer span needs a stouter beam, and a larger beam (depth and width) gives more strength per pound of material (so a thinner section would work). Probably, though.
>At this point I'm just trying to gather as much information and ideas as possible before I start this project with my tax return.
If you give me some dimensions and any other parameters you have in mind (floor/bench mount? bells and whistles?) for the press frame, I can draw something up on the weekend.
3/8 is overkill for what OP wants. Pic related is 3/8 structural steel supporting a concrete metal deck and about 200 tonnes of plane machinery.
4.5m span over 6m centres.
1/4 will be sufficient if you use the correct profile (ie, not RSA)
I'm thinking a floor model.
I'd like to make the lower shelf of the press able to raise and lower using either bolts or large steel pins, over a span of say 1.2 -2.5 feet.
Highest part of the top shelf would be around 5 feet so the lever on the bottle jack is easily accessable.
Jack should be mounted upside down so the lever is always in the same spot. Of course I'll need to modify it so the fluid goes where it needs to.
It should be as wide as a typical press so it can accommodate most common pressing work.
It should have inlayed LED lights which change color from green to yellow to flashing red to indicate progress towards 20tons of applied force.
It should have WiFi and a keyboard and a small LED screen so I can live shitposted about what I'm pressing that day.
It should come in an anime waifu paint scheme with a built in ona hole warmer.
It should have voice activation technology and a speaker system so it can protest when I apply large amounts of force. "But anon-kun that's where I accept hydraulic fluid...anon dont, my lever is sensitive"
Couple arduino boards should do the trick.
Finally, it should have locking wheels at the base for ease of transport around shop but stability when in place.
Jokes aside I appreciate the suggestions I've been getting.
Look on welding forums etc for examples and use Google image search.
Do NOT use cast press plates. They can snap and are rarely even.
Scrap metal prices are low as fuck right now so check your local scrapyards. You may even find a frame or press you can mod or fix.
There are plenty of strong bolted presses. It makes shipping them much easier. Just copy successful designs. You can measure and copy commercial presses. Most are quite simple.
>a span of say 1.2 -2.5 feet
That's a 67% difference in bending moment. Care to pin it down to a specific span?
Also, you didn't say what your drilling capacity is. What is the largest-diameter hole you can make cleanly and precisely in mild steel?
By span I meant it would be just over a foot of opening at the highest position the lower shelf can be in, and around 2.5 feet at the lowest it could be placed in. This would be to give clearance for larger things like fruit presses but be able to close that gap for smaller things like bearings and receiver flats.
My drill press (an old benchtop craftsman from the 80s) has a 3/8 chuck but it wouldn't be out of the question to replace it with a bigger one.
I priced these metals online. With shipping it comes out to 225. Will check local suppliers for these dimensions to avoid handling costs as much as possible.
Will these dimensions be adequate to support the stress on the press (using bolts) or are they a bit overkill? The angle would be for floor supports and the flat bar would be used to stabilize the frame.
>By span I meant
The span of a beam (a horizontal structural member that carries a vertical load) is how far it extends between supports. The span of the beams will determine the horizontal work room you will have in the press. The span is important to know for structural calculations because for the same load, a longer span requires a sturdier beam. 20 tons on an 18-inch span is a bending moment of 30,000 foot-pounds. On a 30-inch span, it's 50,000 foot-pounds. A channel profile that would work for a shorter span would not support the same load over a longer span. So again, what span do you want for the press?
>My drill press
The chuck size doesn't say much. What is the motor power and minimum spindle speed? Or what is the specific model?
>Will these dimensions be adequate
The channel needs to be a lot stronger unless you want a span of a few inches. Doubled 6x2x1/4 is about the minimum for a 20-ton press with a two foot span. 7" would give it a 30-ton capacity to match the bolt numbers I gave earlier. And two channels per beam means four total. Also, a two-foot span between columns means channels that are a few inches longer than that. The tube is overkill for the tensile load of the press, but that size would be nice for avoiding wobbles. Probably fine. The angle is too small unless you triangulate it, and the flat bar is too flimsy for that (it will buckle under any significant compression). I'd suggest 2x2x3/16 angle minimum, and three feet long (it needs to avoid tipping while you pump it up). The 1x1 angle would be useful for stiffening that if you want wheels. You'll also need a way to attach the ram to the channels.
I made this just last weekend, its only 5 ton since I wanted to keep it small and "tabletop" sized, its really just as simple as it looks, a sturdy frame, with a bottlejack attached,
now normally bottle jack don't work upside down, but the conversion for that is easy as fuck, Ill post pics of it.....
this is the jack opened up, now there are two holes at the bottom, one is for the hydraulic fluid backflow and the other is the intake hole, now normally when the jack is upright the fluid rests at the bottom so it gets sucked in the intake hole, and if the jack us turned upside down ofcourse it wont get sucked in to the hole, and that is why you'll need to add this small pipe that I've circeled red, ofcourse after this conversion the jack wont operate unless its upside down, and to retract the piston you'll need to add some pull-springs.
the total cost for the whole thing was 30 euros so its a no-brainer if you have the tools and the skills