The 1750 rpm would come from an american motor, 60Hz 4 pole would theretically be 1800 with a bit of slip it would come down to 1750.
Have you calculated the output force? At 3000psi I calculate it to be around 18 Tonne.
Cheers. Mick.
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The 1750 rpm would come from an american motor, 60Hz 4 pole would theretically be 1800 with a bit of slip it would come down to 1750.
Have you calculated the output force? At 3000psi I calculate it to be around 18 Tonne.
Cheers. Mick.
Thanks Killer the specs are all from US suppliers so would make sense they aim them at US motor spindle speeds
With regards to the press capacity. By using the US imperial maths it works out to be about 40,000lb at 3000psi so <20T as you say...
I guess I aimed at 3000psi as that seems to be the max operating pressure for shaft driven pumps and spool valves that I have found.
Im sure the frame would be good for 50-60T but to be honest I havent stalled out the 20T cheapy. Of course a few things were stubborn but I always stopped forcing well before the ram stopped giving it!
The creaking and groaning is a big disencentive!
I guess what I am saying is I really want this big useful press height with fully functional hydraulic control. 18T will barely tickle this frame and considering I mostly use it for pressing bearings / bushings / sleeves and what nots Im thinking 18T will do the job?
If I ever want to upgrade I guess I just need to up the hydraulic pressure somehow!
Steve
[ame=http://www.youtube.com/watch?v=q79P0r66SG8]Press Talk 1 - YouTube[/ame]
for the win!
I actually visited Keiths workshop when we were in the US last month.
He truly is a gentleman and superb machinist.
Anyways - Keiths press is the inspiration.
S
I do like the mechanism for raising and lowering the bed.
And the little press brake attachment.
.
Yes, this raising / lowering mechanism is very good. Something like this should I use in my press.
Good God, Arthur. That is Barry Gartshaw standing alongside that press. Big Country Machine Tools. I am surprised the old ***** is still in business. I have been to two auctions that were supposed to be closing down going out of business. You can be sure of one thing about Barry's asking prices and that is that he has plenty of fat in the deal.Quote:
Originally Posted by wrinklearthur
The common motors you will source here will be either 2800 or 1400 rpm.
To get to 3000psi with a 5hp, a pump flow of about 2.5 GPM is about right.
With a 2800 rpm motor this works out to be around 3.3cc/rev...or 6.6cc/rev if using a 1400rpm motor.
Most common small gear pumps that you would use for this type of thing
would have the capability of going over 3000psi....4-4500 maybe. Construction of the cylinder starts getting critical at these pressures tho.
We have two presses at work...20T electric and 60T two stage hand / lever. I much prefer using the 60T press if what I'm doing requires and sort of feel at all.
Something that you could switch from electric to manual would be close to ideal.
I strongly suggest that you fit (depending on the electric pump setup you get, not all pumps have a relief valve built in) a relief valve with a return to tank and a flow control valve.
14 seconds for a stroke is kind of quick when you only want "just a fraction of an inch"
If you're just looking at getting a rapid descent with very little pressure you can get a fitting that lets you pressureise the tank to 1-2 psi which will move the piston down fairly quickly but without too much force, you then take over with the hand levers.
very few pumps have an inbuilt relief actually....most control valves do tho.
On the speed...yep, quick electric driven presses are a good way to break important bits....
So for an update. I have sourced all major bits and pieces.
Just waiting on an order of Ryco hose fitting adaptors to make the pump/valve/cylinder/filter all hook up to the hoses that Noel (AncientMariner) pilferred from a forklift.
Have constructed the travelling ram mount and all but done the 5 horse motor to gear pump mount.
This weekend hope to lick some paint on the mounts and then can start on the fluid tank and hopefully hook it together and start breaking important bits as Rick1970 has indicated !!!!
Next bits to procure is some "inchish thick" press plate for the bed. Overall size is 1300x500 which will make it a good workbench size!!!! And then some heavy bits of material to make up a pressbrake attachment...
Dave,
The flow control valve (spool valve) I have sourced has an adjustable pressure relief returning to tank. I havent actually got a pressure gauge in the plan yet so hoping the "pre-set" on the valve is closeish to safe otherwise I guess things will go big-badda-boom!
Steve