Press frame - weld, bolt, bolt AND weld?

[Hopefuldave]

I've scrounged up enough to build a hydraulic press, 10-ton bottle jack, some fairly sturdy 125mm x 45mm hot-rolled channel section and some 10mm and 12mm plate, wondering how to join the top "lintel" to the uprights, simplest might be a pair of 24mm grade 10.9 bolts through the lot, wondering if it would be stronger to weld the parts together (given decent welds...) or perhaps weld after bolting up - any recommendations?

I'm hoping it'll look something like this:


It'll be 24" between the uprights (27.5 overall), 55 tall, planning to weld some 12mm plate into the open side of the horizontals and hang the bottle jack between the "lintels", couple of lengths of hefty angle (not drawn in yet!) spanning the bottom of the uprights.

Dave H. (the other one)

 

[rory1]

If your welds are good enough then you won’t need to bolt it , and if your bolts are big enough then you won’t need to weld it .

Without doing any maths I’d say that a m24 bolt would be much more than adequate

 

[Hopefuldave]

M24 grade 10.9 in double shear capacity is 28 tons, so with both sides having 2 bolts they should be plenty strong enough, my worry then would be rigidity, if it goes out of square it could spit out the work with a fair bit of energy...

Dave H. (the other one)

 

[frank horton]

this is mine.......I use a 25 ton Tangye ally jack......Note the winch on the side to lift the bed....... the white return springs are from and old Volvo bonnet mechanism...
also the head is able to move on mine, I repair a lot of antique vehicles and often have to press out seized pistons and or liners...this way I just move the head of the press and not have to balance the engine block....
this is bolted together ready for my next move AND as the floor is never that leval a little movement in the bolt holes help to get it set on the floor without shims etc....mine is not bolted down as I often need a forklift to load engine
blocks.......
this is quit reg taken to it's max tonnage, very stable and bxxxdy heavy.....
if u want more photo's or info just ask.....
NOTE to self must repaint it .........

 

[Dcal]

M24 grade 10.9 in double shear capacity is 28 tons, so with both sides having 2 bolts they should be plenty strong enough, my worry then would be rigidity, if it goes out of square it could spit out the work with a fair bit of energy...

Dave H. (the other one)

A 10t press is surprisingly gutless (Unless it's the the porta-power ram that has 10 Chinese tons.)
I've been beat trying to push out hub bearings in the past. (Not a problem with my 50t)

I've an old (over 50 years) factory made, press very similar to your design.
I can take a few measurements and photos if you want.

The @slim_boy_fat option, but floor standing might be nice, having heads that screw in is a useful feature.

Also I would use plate at least 25mm thick (more if you can get it) instead of the angle for the bottom anvils (is that the right term?)
The angle is useful and can be used on top of the bottom plates but have a tendency to rotate and either bend or spit something out as you've mentioned.

@frank horton nice design and far heaver built than the one I have.
What tonnage can that jack push?
The limiting factor on it is probably the short section of beam the jack attaches to (it "might" rack under an off center load)
A couple of gussets would make it bomb proof.

 

[frank horton]

sorry dont know how the map got in the post......

 

[frank horton]

Dcal ........
25ton is the max at the mo, if I can find a 50 ton Tangye will use that......then a few mods will be nec.......hahaha...
the jack is locked in position does'nt show....I'm super fussy when ligning up.......
u can just see it ...under the push plate there's a welded lug with a 1" center hole for push tooling....
again futher details just ask........

 

[frank horton]

oh and the magnet for picking up sockets and tooling, saves crawling about the floor........

 

[Dcal]

That's a useful tool.

I rarely go above 20t on my big press and when you do you get out of the way (just in case)

 

[Hopefuldave]

Thanks gents, some useful ideas!

I have a worm-geared boat-trailer winch in the junk pile, that should lift the table even with the work on it (1 ton rating), probably mount it on top with wire rope to each side via pulleys. If I went OTT I could motorise it...

I'm wondering whether to pay out (against my principles, really) and get a bigger jack, possibly one of the 20T air-over-hydraulic off EvilBay, but that might need a bit of redesign as the ex-MOD 10T will fit nicely between the lintels once inverted and attached to a trolley for side-to-side. Will 10T be enough though? Will anything ever be enough?

Even better would be to put to use the 240v hydraulic power pack lurking under the Dexion, but I haven't checked it out yet to see a) what pressure it makes and b) whether it works... (It was only 10 Local Currency Units!) That a) would also dictate what ram I'd need to get decent tonnage! I like the idea of the jack/ram being between the lintels out of the workspace and can turn some adaptors to thread into the jack's ram. Square threads, love 'em...

I rescued a foursome of springs from a trampoline that was being scrapped, so that's covered, and some 2" plate that will need cutting up for anvils - former forklift weight, surprised it isn't cast but there we go, bonus!

Dcal, the moving crossbeams won't be angle, I have some hefty 5" x 1&3/4" parallel-flange channel (enough for the whole of the frame, see drawing - a 55" length is almost a struggle for my boy to lift) I'll use with 10mm plate welded into the open side and linking front and rear beams, the angle will just link the very bottom of the frame to prevent it spreading, and run forward and back to provide for casters and wind-down levelling pads.

OR... I could buy one made of wet spaghetti off EvilBay, but where's the fun in that?

Dave H. (the other one)

 

[Maker]

Depends how confident in your welds you are, I'm not very so I'd just bolt it.

Definitely wouldn't bolt and weld.