I want to be able to supply hydraulic power to the 3rd function without having someone sitting in the cab pressing the 3rd function button. I want to be able to mount a post driver on my telehandler, position it, then work the post driver from its valves while standing by the post driver.  Is it simply a matter of tracing the wires from the button on the loadall joystick and incorporating a switch to short curcuit the button?

This switch would also be handy when I want to drive my sweeper attachment with out having to constantly press the 3rd function button while at the same time trying to avoid moving the telehandlers joystick

That sounds about right. It may be easier to supply the third slice from another power source and put your new switch on that wire. If you go for this option make sure you have a fuse (10Amp) on the wire just in case it shorts with the body. You probably know that, if you haven't the post driver connected and you accidentally flick the switch the oil will have no where to go. This may be hard on the pump if for example the switch was on all day while you were loading. Consider putting a warning light on your new wire just to let the driver know the switch is on. Use a good quality switch (20-30 Amp contacts) to ensure reliability.

 

If your JCB has proportional hydraulic movements on 3rd service then chances are you will not be able to do it with an electric switch as these systems work on voltages and current flow. If its just an on/off service then their will be no problems but fit a switch with a lock on it so if someone borrows machine they wont flick it by accident and knacker the pump.

i couldnt do it and went back to tractor mounted driver

O'K but what were your problems?  All I can see are (a) making sure by key switches etc - that inadvertant use is avoided (b) appropriate electric switches/ fuses etc are used and (c) pressure is related to engine speed and with only a foot throttle some method to control this may be needed.

The point Aandr is making makes sense. If you can feather your third slice (the more you push the switch on the joystick the faster the oil flows) then an ordinary switch won't do your job. Because you have proportional control (like the hedge cutters) on your third slice.

But if your switch on the joystick is just on/off then your good to go. The lock on the switch is a very good idea. What type of a post driver are you going to mount? Don't forget to try it on the loader first before investing in the conversion.

most post drivers require a free return, how do you achieve that on a telehandler?

my manitou has no switches, maybe that was why it didnt work

It will get a return on the other pipe on that slice. one pressure one return. But it may be a little slower than if it was going straight back to the tank (a free return). Would your post driver not work if someone pulled the third lever and someone else worked the post driver controls? Or did it just work to slow for you?

Their are various ways of fitting a free flow return most expensive is to mount a tec real to boom similer to what would be used on a marsted forklift fitted with a tipping back plate these usually have two 1/2 pipes on them which you can tee together to get a good return flow then pipe it back to tank or through the return to tank filter if you what a proper job.

 Or just fit a 5/8 hydraulic hose to fixed part of boom back to tank with quick release fitting on it and have the return pipe on the attachment with a bit of slack in it just in case you need to telescope out a bit.

Most telehandler manufactures do not offer a factory fitted free flow return as an option, think they should be doing this as more people are using spread a bale attachments etc which run motors etc.

Hi. The best way to supply hydraulic oil to your post driver is to forget using the 3rd function on your joystick and add a electricaly operated priority flow control valve before the main spool valve on your JCB. This will supply the correct amount of flow to your post driver spool valve, which can be adjusted as required and can be switched on and off either in the cab or near the post driver, the remained of the flow that is not required will go to the main spool block. It would be a great idea if you can add a free flow return to the hydraulic system also. If you require any more help e-mail at justin@pandrhydraulics.com. See you all at LAMMA 2010.

This might me a touch over the top Justin as the height of the loader may need to be adjusted while driving the post? But you could always sell the patent back to JCB when your finished, it might be a nice wee earner? The electric flow valve won't be cheap, or will it? Maybe we're buying them in the wrong place!

Do you not think the post driver will have enough flow from the third slice and keep the cost of the project within reason? A switch a warning light and a small length of wire.

Hi. You will be able to adjust the height of the the loader because the electric flow valve will send the flow that is not required for the post driver to the main spool valve. No this item is not as cheap as using the third slice but I do not know how much flow is required for the post driver so there is a question mark over if it will work. If it was me I would mount the post driver on the back of a tractor and connect the hydraulics up to your JCB and try it, let me know how it goes. As for selling it to JCB I might be a bit late they probably use something similar on ther 360 excavators on the auxiliary services.

 

i cant help but put a comment on if ya look at my profile pic ya will c post knocker on tele porter all we did is is put mast fully out got lenth of 3/4 hydr pipe put return to top ot tank but you do need someone to operate the handeler so you can keep on banging the post in ya will find it alot faster than on ya own

Now then.....

What model JCB telehandler?? Some of these have what you want built in eh.  

Its a JCB 535 built 2004 with joystick control and  3rd function/boom extend  via buttons on joystick.

I've now connected the post driver to the telehandler while its still mounted on a tractor, had someone pressing the 3rd function button and tested the driver.  Conclusion: I need a better return as the driver doesn't drop fast enough.  I'd need a free return as has been commented on in this discussion but the best way to plumb it in - I'm not sure.

Try a temporary return from the valve on the driver to the lid on the tank (where you fill the oil) and see if you have the speed you want. Ensure the pipe wont jump out, as the oil might be hot!!