Control valve on post rammer

[JoshNZ]

The anvil is 200kg, or so it's supposed to be. The pulley system moves the anvil at 4:1 too, so ~800kg on the ram while it's holding it static. Does that change your math at all?

The intended use for the driver is to ram deadman for kiwifruit orchard ends (i.e. up to 2.1m pole of 300mm diameter, as deep as 1.7m into the ground) so it needs every bit of energy it can get. I think this model will end up being sold, have found a good deal on a new one with 300kg anvil in town. But it would still be nice to get it running to it's full potential before selling it. If that involved replacing that hose/elbow with a larger straight hose, I would! But if it involved buying a higher-flow control valve, I wouldn't haha. I could take the hose that's on there down to the hydraulic shop and ask them what they think I guess?

 

[oldnslo]

800 kg provides around 700 PSI

What size or diameter hose is on the return line?

Can you get a pressure gauge from the hydraulic shop so that you can monitor the pressure vs guessing at the problem?

 

[JoshNZ]

The return line is over an inch I'd say. Considerably larger than the cylinder line anyway, and it has to come back through the cylinder line before it gets to the return line. Evacuating the return line of pump return oil made no difference in drop speed anyway remember.

I could pickup test gear but, it doesn't make sense to when all it's going to tell me is whether or not to replace that hose+elbow line with a larger straight hose. Especially when just replacing the hose is probably cheaper than a guage and fittings! So I might just go ahead and do it. If it is the control valve it can get sold like that. Will still be a great bit of gear for a farmer, just not a deadman driver.

 

[JoshNZ]

I whipped that line off and measured an ID of just under 9mm on the end of that elbow. I'll take it into town and see what they can do.

 

[aczlan]

If you have enough length in the existing hose, I would take off the 90 and install the quick connect directly onto the hose so the hose is pointing straight up and down where it goes into the tractor and see if that behaves any better.

Aaron Z

 

[oldnslo]

Josh
I looked the picture of the elbow and it looks like it is a swivel elbow. you could possibly remove the hose from the elbow, remove the elbow from the tractor and hook the existing hose where the elbow was connected or is the hose to short?

 

[JoshNZ]

I left the hose in town today, was expecting a call back about it this afternoon that never came so I will pick it up tomorrow and see. I would think the hose is much too short to connect directly. Quite a firm fit as it is from memory.

Edit: I've just clicked with what you're talking about... I can remove the elbow on the tractor dump line. Don't even know why that is there. I'll see if it helps when I get the cylinder line back tomorrow.

 

[oldnslo]

Other option is add more weight to the anvil IF the frame work and tractor will support it.

driving 300mm (12") diameter post 1.7m (5 1/2 ft) deep is going to take some force especially if the ground is hard or rocky.

Best wishes on getting this working.

 

[JoshNZ]

I got another hose made, he was of the opinion that the one I had was way too small so I went up two sizes, the ID is now something like 15mm.
I don't think it has improved it at all... :mur:

One thing I noticed and hadn't given much thought to, when the anvil hits the post, the cylinder stops dropping. The cables do go slack but I would have thought the weight of the cylinder itself, plus the pulley block on top would keep it retracting all the way. Could a problem with the ram seals be causing friction? Is servicing the ram an expensive ordeal?

 

[oldnslo]

Is the fully block attached to the anvil or does it just sit on top of the cylinder? Seal friction can be an issue if the cylinder bore has been compromised. I.e. rusty from water intrusion, scored, etc. Normally a cylinder will not collapse from its own weight though.