Reversible main PTO: another selector valve

[davesisk]

Hey folks:

This thought just hit me the other day. Many of us have mentioned how we wish the main hydraulic PTO was reversible. Well, it just hit me that you could add a selector valve to provide this capability. You could go manual (around $80) or electric (around $140), either one should work as long as it's a "double-selector valve" designed to allow you to operate another cylinder, and as long as it's rated for at least 8gpm @ 2500 PSI for one of the 400 series, or appropriately for one of the larger machines. Figure a couple or three hundred for the valve, fittings, and hoses, depending on your particular setup.

So, what you would do is this: Take the quick connects off the main PTO connections. Run 2 hoses (send and return) to the "input" side of the selector valve, then 2 hoses (default send and return) off the "default output" side of the selector valve, and 2 hoses (diverted send and return) off the "diverted output" side of the selector valve. Hook the default send hose and diverted return hose together with a "T" fitting, then put the quick connect on this (or add a third hose, then the quick connect). Hook the default return hose and the diverted send hose together with a "T" fitting, then put the second quick connect and/or extra hose on this.

Now, when you turn the main PTO on, the flow goes forward through whatever's hooked to the quick connects. Turn the main PTO off, change the selector valve to "diverted", and turn the main PTO back on and the flow goes backward through whatever's hooked to the same quick connects. If the flow is backward from what you want, then just switch the quick connects. It's probably a good idea to turn the main PTO off before instantaneously reversing the attachment by activating the diverter valve. It shouldn't damage anything if you don't, but it would definitely open relief valves somewhere until the attachment's inertia could be overcome and it's direction reversed... /forums/images/graemlins/wink.gif

Voila! Reversible main PTO! /forums/images/graemlins/cool.gif

Since it's probably quite easy to get a hose switched around while plumbing this, I'd test this on an attachment that is known to be reversible (like a power auger) since we've established that not all powered attachments actually are reversible (like a stump grinder).

I might decide to do this to mine sometime in the future. I know PT sells a reverse valve that you can hook to the power auger, but I think most folks would much rather be able to do this at the machine. I don't recall PT's price on the power auger reverser gadget, but it's probably more than a manual selector valve, and you have to actually get off the tractor to use it (what we they thinking? /forums/images/graemlins/shocked.gif)

I've attached a drawing to help with getting a mental picture.

Enjoy!
Dave

 

[jrlichina]

Why wouldn't you just use a motor control valve? Just get one with detents in all positions. You can get them for like $100 bucks from Surplus Center.

 

[davesisk]

Actually, that sounds like a perfectly valid idea as well. Presumably, you could even get speed control with a motor control, right?

Dave

 

[Charlie_Iliff]

Dave: Other than unwinding a stuck auger, what do you need reversible PTO for? Not that I don't think any such modification is worthwhile, I would be a bit concerned that I might reverse something that shouldn't be reversed. (I haven't a clue what happens if you reverse the flow to a motor that doesn't like it. Anyone done that?)
To unstick the auger which has encountered a root or rock and won't turn, I've always been able to wiggle it a little and lift it. Although not cheap, a couple of gender changing adapters are easy to cobble up, and will accomplish a temporary reversal only a minute slower than a button. Last resort - a pipe wrench to turn it backward a quarter turn. Not as convenient as a button, but cheaper, and unlikely to hurt the machinery. (Thus generally counter to my own usual approach to such things.)
But, no question the button or toggle switch would be cool - a pipe wrench seldom is in that category, even with a 4' cheater pipe - er - torque multiplier.

 

[davesisk]

Hey Charlie:

Excellent question. "Should we?" rather than "can we?". I wish I could get folks at work to ask more of those types of questions... /forums/images/graemlins/cool.gif

Ya know, now that you mention this, I'm having difficulty thinking of anything a reversible PTO would actually be useful for other than unsticking an auger. Wasabi, would reversing help unstick a trencher? Or is wiggling and lifting sufficient?

Any other thoughts on possible uses?

Dave

 

[jrlichina]

Yes you can get motor speed control valves as well. As far a reversing goes: auger, tiller, winch, drill, trencher, plumbing snake, and other implements you can make the you wish to reverse. Now for reversing a motor that only has one direction. Bi-directional motors have relief valves built into them to protect them during direction changes. If you reverse a non reversable motor you'll blow out the seals.