Just in the thinking stages C Beam? for hydraulic press.

[AdrianH]

I just had one of those stupid ideas, and before I start on it thought I would ask for views on here.

Some time ago I was considering pressing some 2mm plate unto a U shape for my grinder holders, in the end I used a machine mart bender just!

At the time the plan was to use a fly press, then sold it on here because I did not have the space to use and nearly killed me moving it. But I could still do with being able to press some parts, put the odd bend in things etc. Even the becoming cheep 6 tonne bench presses take up a far amount of space so have been thinking of what I could do, small foot print, I could move, and cost not a lot.

So plan is to use some of the 80 x 130 I beam I got free and cut pieces at 22.5 degrees and make a C beam'ish shape as in this.

There was a post on here about modifying a Hydraulic jack to operate upside down, fasten that to the top and place any V's or formers on the bottom, add a few bars to form a base and see how it goes. I am not looking for anything over 5 or 6 Tonne.

I could see it having a limited throat depth but for my needs not really required and the distance from top to bottom will depend on the jack I get.

Anyone any thoughts before I delve in to the impossible?

Adrian

 

[Wendelspanswick]

Part of the problem with using I beams (RSJ, UB, UC) is the problem with flex, using it as you have drawn you will find that the beam will want to twist, so that the base will rotate round the vertical coloumn in relation to the top.
You might be fine with relatively small loads but once you start stressing the beam it will move.
It's one of the reasons that no one makes home made English wheels using freely available UB's.

 

[stormin]

Box in the sides with plate will go a long way to increasing torsional strength and rigidity. You could get even more creative with a series of diagonal stiffeners between flanges before over plating. All adds to the weight and makes it less portable though.

 

[Shox Dr]

IMO that's an accident waiting to happen. [As others have explained] Under pressure it will want to spit at great speed and force, whatever you are trying to bend etc

You would be better off, using to I beams [top and bottom], connected together with either large dia threaded x4, (calc required) or the channel you have with end plates bolted to the I beams.
It would all strip down for storage/moving.

 

[stormin]

IMO that's an accident waiting to happen. [As others have explained] Under pressure it will want to spit at great speed and force, whatever you are trying to bend etc

You would be better off, using to I beams [top and bottom], connected together with either large dia threaded x4, (calc required) or the channel you have with end plates bolted to the I beams.
It would all strip down for storage/moving.

How are large diameter threaded bars going to give any torsional rigidity between top and bottom I beams?

 

[Shox Dr]

How are large diameter threaded bars going to give any torsional rigidity between top and bottom I beams?

Very true, however I have seen it done. Although it was sitting in a corner.

 

[AdrianH]

OK I understand some of the points, not sure if I agree with some of them. I could make it into a 0 shape that would help with the twist concerns, but loose more flaxability. I am trying to find, or will be finding some figures for bending and twisting/rotational forces and see what is required to say deflect the top a few mm of the base, say 3 to 5mm.

One thing to take into consideration is that, if I limit the jack to a 5 tonne one, and that will bend 1 3/4 inch thick wall tube. Then that force should be acting in a line up and down, if I get the angle out by say 5 degrees then the force acting to twist the beam sideways will be 5000 kg x sin(5) which is in the region of 436 Kg, say 1/2 tonne to be safe and give a bit more leeway. Now if the beam with this figure would defect less then my 3 to 5 mm then would that still be an issue?

The planned overall height would be 650mm with overall width of 300 to 350 mm.

I wonder if there is anyone on here with something like solid works that could do a 3D model and come back with figures.

Adrian

 

[AdrianH]

A few things, I am trying to remember how to work this out and starting to determine what the beam is and it looks like it is classed as a universal beam and in Imperial measurements would have been the old 5 inch by 3 inch beam, and as most of the old engineering handbooks are Imperial I will work with that.
Speaking with someone at work they asked what I would be bending and when I said typically 3mm steel max around 200mm long or 1/8th Inch thick and around 10 inches long. They said I may not need 5 tonne.

I seem to remember some thread on press brake tooling etc and someone posted a table of force/weight per metre etc of various thickness’s for steel, if anyone can remember the post I would be grateful

Adrian

 

[Wallace]

The C frame you have drawn would need reinforcing at the rear to prevent the ends pushing apart which would in turn reduce twisting. The two forged C frames in this photo are for use on 2" 10 ton cylinders and have a hefty wall thickness, I can measure them for you if that would help give an idea to compare with your I beam.

 

[Welderpaul]

A few things, I am trying to remember how to work this out and starting to determine what the beam is and it looks like it is classed as a universal beam and in Imperial measurements would have been the old 5 inch by 3 inch beam, and as most of the old engineering handbooks are Imperial I will work with that.
Speaking with someone at work they asked what I would be bending and when I said typically 3mm steel max around 200mm long or 1/8th Inch thick and around 10 inches long. They said I may not need 5 tonne.

I seem to remember some thread on press brake tooling etc and someone posted a table of force/weight per metre etc of various thickness’s for steel, if anyone can remember the post I would be grateful

Adrian

'New' universal beam sizes are all based on the old imperial sizes so an old 5 inch by 3 inch beam is just a 127x76x13UB

 

[Paul G]

I agree with Shox Dr

Beam / column twists horribly but welding or bolting in the form of vertical oblong would work.
I'm not really in favour of welding as you eliminate adjustability, and making the tool capable of many jobs means it earns its workshop space.

Mine is two pieces of 25 plate joined by four 500mm long M20 studs. Pic shows it expanding 2" tube to form the front end one an exhaust,
and I have a different top that turns it into a pipe bender. My Seven has a roll bar from 1-1/2"NB (1-7/8" o.d.) stainless pipe that I made
using this tool. It takes about 7 tonnes to bend that.
The first job I did with this press was to make the eight wishbones for the car suspension and it's earned its keep ever since.


HTH
Cheers
Paul G

 

[AdrianH]

OK I will have to admit defeat here, I have overlooked a major point, whilst I can get the beam in my bandsaw at 90 degrees I can not at 22.5 degrees.

I am also struggling to figure out the formula for strain on the beam under load, when I do a Google search I seem to end up with d this by d that and integral signs galore.

So I have gone back to the old books and ended up with a formula of y = (Wd^3)/(3EI)

Where:-
y is the deflection at the end of the beam
W is load in pounds
d^3 is the cube of the beam length in inches
E is the modulus of elasticity in my book for structural steel is 29,000,000
I is the moment of Inertia, 12.1 in old book for 5x 3 inch I beam

This is from a formula for an end supported beam with load at free end as I assume that would be the closest to what I would need.

When I put in the numbers I would end up with a defection over 43 inches or close to 1.1 metres beam of 0.83 inches or 21mm.

The book does not list the moment for the other axis so I could not work that, but it looks as though 21mm deflection would be more then I would like anyway so the idea is a non starter.

If anyone can think of another way of working it out i would be grateful, or even a list of furmula I can understand and use with the figures that Google gives in metric I would be grateful.

Adrian