30 ton press

[thinfourth]

I have a 30 ton press and i am going to make up some folding tools for it

How thick and wide a sheet will i be able to fold

I was hoping to fold a sheet 500mm wide that is 3mm thick

Doable?

 

[Fintray]

Table supplied by Tig Paul in previous thread:



So yes.

 

[Wendelspanswick]

Table supplied by Tig Paul in previous thread:



So yes.

I think that table is missing a crucial element and that is the length of the bend that the figures are calculated for, I am guessing 100mm so I would say no.
3mm by 500mm is going to be tough and I guess you are looking close to 60 tons plus.

 

[Screwdriver]

The force is expressed in tonnes per metre so I read that as saying 3mm sheet can be bent at 30 tonnes over 1 meter if you set the radius of the bend to 3.3mm.

So I suggest the press above should in fact be able to bend 500mm with a radius of 2 - 3 mm.

S.

 

[Wendelspanswick]

The force is expressed in tonnes per metre so I read that as saying 3mm sheet can be bent at 30 tonnes over 1 meter if you set the radius of the bend to 3.3mm.

So I suggest the press above should in fact be able to bend 500mm with a radius of 2 - 3 mm.

S.

My mistake, I missed that.
Having bent 3mm brackets on various smaller presses it just seems a low figure for 3mm over that length.

 

[Screwdriver]

Hmm. 30 real tonnes though, not MachineMart tonnes.

 

[thinfourth]

Real tons

Fiddle with the safety valve and the same frame and ram can do 50 tons

It ain't a machinefart model

 

[Screwdriver]

Yes I was alluding to wendels comment about having used smaller models. There's an interesting build on Keith Fenners youtube channel and when you see the size of that giant, you realise just how big a (genuine) 50 ton press is.

<edit> Aha!

 

[Wendelspanswick]

Yes I was alluding to wendels comment about having used smaller models. There's an interesting build on Keith Fenners youtube channel and when you see the size of that giant, you realise just how big a (genuine) 50 ton press is.

<edit> Aha!

I've not used a hydraulic press, I've got a 7 Ton mechanical press, a huge flypress and a 45 Ton mechanical ironworker and they are all massively built, I can't see a 30 Ton Machine Mart press getting any where close to bending 3mm, 500mm long which is why I queried the figure.
But 'genuine' Tons makes sense!

 

[cianh91]

theres a lot of factors from punch size v size material type according to a trumpf bendguide to bend 3mm 500 long in a 24 v is roughly 12 ton pressure

 

[Paul.]

theres a lot of factors from punch size v size material type according to a trumpf bendguide to bend 3mm 500 long in a 24 v is roughly 12 ton pressure

Which is exactly what the chart says, 3mm plate on a 25mm vee needs 24 tonnes force per metre. these figures are for mild steel

 

[bobby-gg]

Loved that video, thanks for the link ;-)

I've got a 60 ton press, I'll post some pictures up of it so you can see the size of it

Rob.

 

[brewdexta]

I've just acquired a double acting ram for a future press build. A bit of an impulse buy, the kids were jumping all over me at the time I bid so I put a higher bid price than I really wanted to as I couldn't snipe effectively with one ankle biter plaiting my beard and another trying to change the web page to cbbc. Ended up paying 90 quid for a new old stock ram. Here's the details.

Open length (centre of pin hole) 1875mm
Closed length 1090mm
Piston 40mm
Cylinder 115mm
Pin holes 30mm diameter
Rose joints at each end.

Although this will definitely be a later year project, I will be keeping my eye out for the right bits of steel.

Any guidance on what size of press I should be looking to build with this ram?

Cheers
Andy

 

[dan.taylor.1]

Just multiply the area of the piston by the pressure you'll run it at to get the tonnage.

 

[brewdexta]

Thanks Dan, I'm thinking that the spec of the ram may be wrong and the rod is 40mm and the piston is 115mm, if the cylinder is 115mm then you would expect the piston to fit it I should have looked into this a bit more closely before bidding

I found this calculator for double acting rams so you can work out pulling and well as pushing force.

I shall have to do a bit more reading.

 

[dan.taylor.1]

The piston is the bit that gets acted on the rod is only in the front half of the ram, so yes 40mm rod 115mm piston and cylinder bore (though the boredom may be a bit more by the time you've taken seals into account depending how they worked it out!)

You need to know a few other measurements to work out speed like stroke. Obviously the in is faster as the ram is in there reducing the volume but the flow and pressure. are the same.

 

[AndyStobbs]

Think you can assume rod to be 40mm. Piston will be the same size as cylinder ID. Some single acting rams dont have a close fitting piston but a double acting will. Pull force is reduced by the csa of a 40mm rod. You can resolve all forces through trig to determine exact effective area,

 

[AndyStobbs]

Thats going to be a very tall press lol.

 

[Shox Dr]

Thats going to be a very tall press lol.

A ram like that would be better used in conjunction with a fulcrum, it would increase tonnage, and could be fitted behind to reduce overall height.

I've an Enerpac long stroke 50t (@10,000psi) ram for this very job, once I've all the steel

 

[Maker]

A ram like that would be better used in conjunction with a fulcrum, it would increase tonnage, and could be fitted behind to reduce overall height.

I've an Enerpac long stroke 50t (@10,000psi) ram for this very job, once I've all the steel

I've never seen one like that before, is it your own idea or do they all ready exist?