Hydraulic ram question

[SBK]

I have just been given a old ram which I fancy using on a tube bender.
It was used on a transit tipper.
there is some pitting on the ram.
Is it worth repairing the chrome ?
also any ideas one the approx tonnage this would be ? The ram is 80mm thick
The body is 110mm.
There are no markings on it.
can this be used with air or just hydraulics.

Cheers

 

[madkayaker]

tonnage is worked out by cylinder diameter and hydraulic pressure. there is a few calculators on google.

 

[normspanners]

The ram rod chroming doesnt matter if it is a single action ram which it probably is, unless it is a displacement ram then the chroming on the ram does matter because it will seal on the rod it wont push a lot if anything on air pressure.
You would have to make a spring return to retract the ram after bending.

 

[zzr1200]

I have just been given a old ram which I fancy using on a tube bender.
It was used on a transit tipper.
there is some pitting on the ram.
Is it worth repairing the chrome ?
also any ideas one the approx tonnage this would be ? The ram is 80mm thick
The body is 110mm.
There are no markings on it.
can this be used with air or just hydraulics.

Cheers

http://www.baumhydraulics.com/pages.php?pageid=4


hth

 

[SBK]

The ram rod chroming doesnt matter if it is a single action ram which it probably is, unless it is a displacement ram then the chroming on the ram does matter because it will seal on the rod it wont push a lot if anything on air pressure.
You would have to make a spring return to retract the ram after bending.

How can I tell if its single or displacement ?

 

[ben8vgte]

If it's single it will only have one inlet, looks a beast though!

I must get round to making one of those benders as well, are you making or buying the dies?

 

[SBK]

http://www.baumhydraulics.com/pages.php?pageid=4


hth

Thanks , just had a look and at 100psi air only rates it at 1200 llbs.
At 5000 psi hydraulic comes out at 62800 llbs
am I working this out right ?

 

[SBK]

If it's single it will only have one inlet, looks a beast though!

I must get round to making one of those benders as well, are you making or buying the dies?

Just got the box section today
Not sure on the dies they are a bit pricey ? Hows your casting skills Ben ?

 

[ben8vgte]

Thanks , just had a look and at 100psi air only rates it at 1200 llbs.
At 5000 psi hydraulic comes out at 62800 llbs
am I working this out right ?

If it's single you'll need to know the piston size inside the ram, as you say the body is 110mm maybe the wall thickness is 12mm at a guess. Would give you a piston around 86mm or 3.3"

3.3" @100 is 855lbs
3.3 @ 2000 is 17106lbs

 

[SBK]

should be ok if i wanna bend scaffolding then

 

[ben8vgte]

Funny you should mention casting, it is on the list of things to try! I've got a mill and lathe now so I was going to see if I could turn up some dies for mine, when I get round to it as usual...

I was tempted to buy one die you to see how they are made, then go from there.

 

[SBK]

yeah been looking into it too.got my mill up and running now.what lathe did you get ?

 

[ben8vgte]

Emco V10 http://www.mig-welding.co.uk/forum/showthread.php?t=43010

Should just about do what I want with it..

 

[normspanners]

How can I tell if its single or displacement ?

the rod is too small for it to be displacement I would say, so that chrome is just to stop the ram rod rusting.
when you work out the power of a displacement ram it is just calculated on the dia of the ram rod.

 

[SBK]

Ok that sounds good then just add couple of decent return springs then.
I can see that powering it on air wont be enough so I presume a hand hydraulic pump
Will be needed.

 

[normspanners]

If you dont need the full travel a large coil fitted inside the cyl around the ram rod will work it will just coil bind at full travel, but if you design the bender to not need full ram travel and still not coil bind that will work fine.

 

[SBK]

Good idea will have a think about it .
Ta Norm

 

[Shox Dr]

You only need around 2ton to bend most stuff in a Hosfeild/JM2/Protools. type bender The reason they spec 10t is they are cheaper than lesser tonnage rams.

I was advised of this when I spoke to Pro Tools, when building mine.

It looks to be a bit short on stroke, you'll be forever re-pinning even on -90* bends

 

[SBK]

Yes was thinking about that after looking through the plans again.
May just bite the bullet and buy one.

 

[ben8vgte]

I did see some engine hoist ones on ebay a little while back for not too much, I was thinking of them for mine. Long stroke and has a built in pump, or just pull the one off my hoist for now.