Changing Front End Loader Rams from Single Acting to Double

[amen423]

I am in the process of changing the Hydraulic Rams for lifting the Front End Loader from single acting to double acting.

The loader make is a Horn-draulic and I want to know how to set the hoses up.

It has a 2 Spool Valve Control, 1 for the arms & 1 for the bucket. It has the inlet on the left and 2 outlets coming out the back and 1 outlet on the right which takes the oil back into the rear end.

The rams have 1 hose into each of them equally which are fed from the Spool Valve Control.

How do I set up the 2nd hose on the ram?

[oehrick]

If your single acting rams exhaust back into the transmission (usually via the filler) it sounds as if your spool valves are probably two port centre biased to dead head the pipes to the rams so the loader remains locked in position when neither lift nor lower is selected. for double acting cylinders you need to duplicate this so twin two port centre biased or some sort of changeover spool, I can see why double acting might be an advantage on the bucket ram but not on the lift rams, unless you are looking at using it in pile or stake driver mode. Any JCB breaking scrap yards within a days drive ??

HTH

EDIT Doesn't make quite as much sense reading as it did writing You need to have one lot of oil under pressure going through the valve into one end of the ram while the exhaust is running back from the other end through the same valve. A photo of what you already have would be useful but from the description it sounds like you may need different spool valves.
Not hugely relevant to the spools but in case you were not aware, the piston area of the open / gland end of a ram is almost always smaller than the blind end this means for the same pressure / flow rate / movement there is less force available with the ram closing and it will also close faster than it extends, with a larger surface area and hence volume of oil in the blind end you can sometimes have twice the exhaust flow rate from this end than the other, if the exhaust flow is restricted by the spool ports being too small you get the delightful situation where the already weaker end of the ram wastes some of that already reduced power forcing exhaust oil from the other end at no benefit.........

[amen423]

Thanks for your reply where I have noted what you have stated.

I want the double acting for when I dig so that it will go into the ground easier and not just rest on top when the ground is hard.

To assist you are some photos.
Below is the loader that I have adapted to use forks on the front.



Below shows the current Spool Valve. To lift the arms I use the lever on the left. I have another single Spool Valve on the right for another purpose and the middle lever controls the bucket.



Below is where the controls are for changing from using the bucket to remotes to the rear.



Below is the rear end.



Below is 2 of the double acting rams that I am going to use.



I have another tractor here which has double acting rams on it of which I have had a look and it will help me immensely.

I currently don't have the Super Major here and when I do I will attempt to set it up and see how I go.

If I have any problems I will update.

[oehrick]

Ah, it makes sense if you need the digging ability, looks a substantial enough loader and haven't you got some interesting return oil plumbing along with that nice raised PTO

I don't recognise the spool valves but maybe someone will and know if you can configure for D/A rams.

Best of luck with the conversion, hope you find a solution that keeps the cost down

[Old Hywel]

Sorry to disappoint you, but I think the valves are the least of your problems.
The lift rams don’t work directly on the boom, but effectively ‘pull’ the boom up via those flat bars with the three spare holes. If you attempted to push down, with the new rams, all that would happen would be the bars bowing out.

[mathias1]

Sorry to disappoint you, but I think the valves are the least of your problems.
The lift rams don’t work directly on the boom, but effectively ‘pull’ the boom up via those flat bars with the three spare holes. If you attempted to push down, with the new rams, all that would happen would be the bars bowing out.

Old Hywel,
I agree with your opinion on this. Will need a different setup to make it work. Maybe it's better to find a different type of front loader to fit?

[oehrick]

Well spotted, I'd not looked at the loader architecture, other than it looked to have similarities to the MIL loaders, knowing outback ingenuity I'm sure you will find a way through it