Operate hydraulics from outside cab

phmcd

I guess theres probably a simple answer to this but I just got the loan of a beating press which works off the tractor.
i'm not too well up on hydraulics so I have two questions.

First its a single acting ram with springs pulling it back so I connect the pipe to one of the spool valves and it works fine. To allow the spring to pull it back in however I have to push the lever in the cab the other way. this does allow the oil to go back but sound like it puts a lot of load on the pump.

Second problem is (as it says in the title) how could i operate the hydraulics from outside the cab? Are the extra handles i could get so that i could use them or use the one in the cab?

thanks in advance.

iverjohnston

I presume you mean a Bearing press?
Pushing the lever all the way the other way means the pump is blowing off the pressure regulating valve, and will do no harm when only doing so for the half minute its taking your ram to return to the closed position. I would have thought there would be a valve chest with operating lever on the press where you could keep a closer watch on proceedings. All in all this sounds like a very imprecise set-up, compared to a hand operated hydraulic press. You could be smashing more than you ever fix!

phmcd

Your right, i should have said bearing press.
I know what you mean about the setup, thats why i wanted to add some kind of control beside the press.
Its an old home made thing but works very well if it could be controlled better.

leex

OK be careful if following this info as every tractor and machinery is different and what appears safe in one install can be lethal in another, but I had a guy with a fairly old CASE tractor driving some fence posts last year and he had a very simple setup to rise/lower the lift when outside the cab.

1. length of heavy gauge hydrodare (attached to mudguard with multiple pieces of Galvoband) starting near lift handle and about 1meter long and was very rigid.
2. Rod inside this which had one end duck taped to lift handle and other end emerged outside hydrodare.
3. Hold end of hydrodare in one hand and push/pull rod to lift/lower lift with other hand.

Try this at your own risk.

pakalasa

You need to get a 'Manual Single Acting hydraulic valve, with Pressure and A Port to Tank in Home position'. Like this one;
http://www.ebay.ie/itm/BUCHER-HYDRAULIC-1-BANK-SINGLE-ACTING-VALVE-40-L-MIN-3-8-Free-UKandEU-Delivery-/250907793298?pt=LH_DefaultDomain_3&hash=item3a6b451792

You can mount this where you like then, outside the tractor. Two hoses will be needed then between the tractor and valve, and a third from valve to the piston.
The hydraulic safety relief valve on the tractor won't be used then.

phmcd

Thanks for the reply guys. Regarding the valve you mentioned I am trying to understand how it works in combination with cab lever. The cab lever can be pushed forward and back but when you let it go it springs back to a middle position.

pakalasa

You leave the hand lever in the tractor on, so that it keeps pumping oil. With this valve, the oil just goes straight through the valve on the press and back to the return connection on the tractor. This is no harm, as not pumping against pressure.
When you operate the lever on the press valve, the oil goes into the cylinder. You let it go and everything flows back to tractor.

See the sketch attached. Yellow part is the piston.

phmcd

Perfect. I'll order one. Thanks.
One other thing. I was also think of building a log splitter with a two way ram.
Is it possible to get a valve to do that also.
I guess it will be difficult because the lever in the cab would have to be moved from one position to the next or?

pakalasa

I don't know how good those valves on e-bay are. I never ordered one. Any hydraulic place would have one similar though.
You could work the logsplitter the same way, but I think the spring force wouldn't be enough, if it gets caught in a bit of timber.
Ideally, for the log-splitter you need a different valve, like this one; and a double acting cylinder (UP & down, 2 hoses).
http://www.ebay.ie/itm/BUCHER-HYDRAULIC-1-BANK-DOUBLE-ACTING-VALVE-40-L-MIN-3-8-LOG-SPLITTER-Free-P-P-/251196138664?pt=LH_DefaultDomain_3&hash=item3a7c74e4a8

This valve has 3 positions of the lever, up, down and center. The center position has Pressure (P) going to Tank (T) also, so you leave the lever in the tractor pumping oil continously. You need a 4th hose, going from the B port of the valve to the second port (lower) on the double acting cylinder.

On Safety - You need to work out what pressure is coming from the tractor. This pressure acting over the area of the cylinder will give the force it generates. The structure holding the cylinder needs to be able to withstand this force. Be careful !!

rancher

pakalasa wrote: »

I don't know how good those valves on e-bay are. I never ordered one. Any hydraulic place would have one similar though.
You could work the logsplitter the same way, but I think the spring force wouldn't be enough, if it gets caught in a bit of timber.
Ideally, for the log-splitter you need a different valve, like this one; and a double acting cylinder (UP & down, 2 hoses).
http://www.ebay.ie/itm/BUCHER-HYDRAULIC-1-BANK-DOUBLE-ACTING-VALVE-40-L-MIN-3-8-LOG-SPLITTER-Free-P-P-/251196138664?pt=LH_DefaultDomain_3&hash=item3a7c74e4a8

This valve has 3 positions of the lever, up, down and center. The center position has Pressure (P) going to Tank (T) also, so you leave the lever in the tractor pumping oil continously. You need a 4th hose, going from the B port of the valve to the second port (lower) on the double acting cylinder.

On Safety - You need to work out what pressure is coming from the tractor. This pressure acting over the area of the cylinder will give the force it generates. The structure holding the cylinder needs to be able to withstand this force. Be careful !!

Exactly be careful, this is high pressure hot oil, I'd advise you to deal locally...you'll have to get pipes made up anyway, reputable dealer who have to stand over a product won't be selling sh..e

phmcd

Thanks Guys.
All clear> Ill buy locally as ye suggest.
I know what you mean about making the frame for the cylinder strong enough.
I can get a dia 80 bore cylinder so the force generated will be pressure * cross sectional area.
One question the tractor is a MF390, what kind of pressure should I be getting there? I was guessing about 250bar?

pakalasa

MF390 - 2500 PSI for auxillary pump;
http://farmingforum.co.uk/forums/showthread.php?p=454652


2500 PSI = 172 bar = 175 Kg/cm2
At 80mm dia, this equals 8.8 tonne force.

phmcd

Sorted. Thanks.

phmcd

i'm also reading on the internet about open centre and closed centre hydraulics.
How do you know which one is on any given tractor?

pakalasa

On nearly all industrial valves, there will be a schematic symbol, on the valve itself. For a tractor, if you can get the part number you can look it up on the internet, ring supplier etc, or even better get your hands on the full hydraulic shematic.

iverjohnston

Hi phmcd, basically your Massey has an open centre system, in commom with most tractors out there. this is the normal outfit. John Deere used closed centre hydraulics from the early 1960's to about the 1990's (from the 2020's, the 3130 series, 40 series all up to the 55 series,the 3350 etc,all the round cab ones,) Die hard Deere men wouldn't have it any other way!. If you were to buy a deere like this, there is a plug you would have to install in the valve chest on your press, logsplitter etc. Otherwise the oil flows right through it and overheats. Not all aftermarket valve chests have this facility. It dosent matter because your 390 is perfectly straightforward.

phmcd

Thanks Nigel. I assume the Fiats are the same as thats what the guy I borrowed it was using it on.
Just to be clear about using the valve. Am I correct in saying that you can leave the lever in the tractor pumping all the time and do no damage as long as it can flow thru the valve back to tank?

iverjohnston

Hi phmcd,
Yes, you have double acting spool valves, so just plug the pressure line into one of the valves, and the return into the other. If you get them the wrong way round, push the control valve in the cab to the other position. If they don't have a "detent" to hold them in the right position, a bit of string wil be needed to tie them there.

phmcd

perfect, on y way to buy a valve pipes and MOST IMPOTRANT a bit of string.