Opinions, Opinions

[KWentling]

How can you replace one spool for a motor application? Do you mean an internal modification or just add an external motor valve? I believe this valve came originally from a BH.[/QUOTE]

If it is a sectional valve (bolt together sections), a motor spool valve could be added or substituted. If it is not sectional, it might be possible to just replace the sliding spool inside the valve body with a motor spool. You would have to contact the manufacturer or a shop that deals with that brand of valve.

Not sure I understand the purpose of the check valve Farmerford mentions. If the PTO does not stop too abruptly when disengaged, that would work OK.

Kim

 

[kennyd]

Great explanations Kim:thumbsup:

 

[KWentling]

Thanks Kenny

Kim

 

[NCMau]

You need a motor spool valve. A regular "loader or log splitter" valve will not allow a motor to coast to a stop and you risk damaging or destroying your motor from the sudden stop, especially with a inertia load like a 30" blade . I didn't look at the valve Kenny linked, but most valves would have detents that allow you to push the lever to start the motor and it would stay in that position until you return it to neutral. If you could replace one spool in your 4 spool valve with a "motor" spool you could use it. What do you plan to use for an oil reservoir? You will need at least 10 gallons, and more is better to avoid aireation and heating problems.

Kim

You did a beautiful and professional job in building this project. I am trying to figure out why you went through such an elaborate and expensive scheme, when you could have just hooked up the cutter to tractor PTO.
I am just curious and trying to learn something.

 

[Farmerford]

Kim:

The check valve allows the motor to freewheel when there is no hydraulic fluid flowing from the pump. The CV has a very low cracking pressure (5psi if I recall). The pto pump quickly stops when I disengage the pto clutch, even it the pto is turning 540rpm. Therefore, there is no pressure from the pump forcing hydraulic fluid to the motor. Indeed, the gear type pump blocks any fluid flow from the tank, even though a vacuum at the motor tries to draw fluid.

A slight vacuum (5 psi I think) opens the check valve to allow the fluid that is being exhausted from the still spinning motor to flow back into the motor inlet port, which allows the motor to keep turning with very little fluid resistance. In fact, if I suddenly stop the pto at 540 rpm, the hydraulic motor and cutter drive train (90 deg gear box, blade holder, stump jumper, and blades) take a minute or more to spin down.

As you (Kim) pointed out, if the spool valve is a regular four way, three position directional control valve (whether monoblock or sectional) for double acting cylinders in which the work ports are blocked in neutral to keep the cylinder from drifting (rather than open to tank like the motor spool), then when the valve is closed the motor has neither a source for new fluid nor a place to send the exhaust fluid since the work ports are blocked at the valve. The check valve across the motor ports works fine in this situation.

 

[KWentling]

Got it. I guess I should have looked at your pictures! Pretty clever.

Kim

 

[aczlan]

My Massey 202 (industrial 35) tractor has a loader which is powered via a selector valve , by the onboard pump (I believe 4gpm). The loader is not as fast as it could be with an external pump, but it is adequate for my occasional usage.

There was also a front mounted pump that went on the front of the crankshaft to run the loader (Dads industrial 35 had that). I think it was a 7-10GPM pump (3/4" suction line, 3/8" or 1/2" pressure line connected to a tank built into the RH loader frame). If you have the hole through the front axle I might look into getting the right shaft and pump to switch to that. It makes the loader MUCH more fun to use.

Aaron Z

 

[NCMau]

There was also a front mounted pump that went on the front of the crankshaft to run the loader (Dads industrial 35 had that). I think it was a 7-10GPM pump (3/4" suction line, 3/8" or 1/2" pressure line connected to a tank built into the RH loader frame). If you have the hole through the front axle I might look into getting the right shaft and pump to switch to that. It makes the loader MUCH more fun to use.

Aaron Z

Thanks for the tip. I have the option of installing a front pump, but since I already have a PTO pump, I am going to stick with what I have. My loader frame does not have the ports and that would be another pain to modify. In addition, looking at the frame, I am not sure It would hold more than 5 gl. I would need at least 10 gl. for the additional hydraulics I want to install.

Maury