It's time; either get started or....

[Xfaxman]

Again.

 

[NormL]

I sleuthed out the reason the hydraulics were not working - the second scenario has it!! The idler pulley doesn't help either because the two inch pulley driving the ten inch does not have enough sheave area gripping the belt to prevent slippage. So, I have replaced it with a three inch pulley and will try that tomorrow. If that fails, its back to the way I was driving it to begin with and experiment with the restrictors. I may even have to use a flow control to smooth out the operation of the machine. But for now, I'm relieved to have solved the mystery; solving the problem is so much easier when you know what it is!!

 

[NormL]

Looks like I'm back to what I had working before. The problem with using the extra pulleys and belts along with all the other stuff already down there makes it almost impossible to mount the idler pulleys needed to keep the belts extra tight. So back to driving the pump with one belt from the engine to the pump and clutching that with the idler. If restrictors don't solve the too rapid operation of the cylinders, then a flow control valve is next. I'm relieved its not the pump.

 

[Xfaxman]

 

[NormL]

Now that I am back with the five inch drive to ten inch driven pulleys I still had to add serious tension on the idler to prevent slippage. Now, when I give it work, the engine stalls unless I have the throttle wide open. That engine should not have a problem operating the machine; it's a two cylinder 18 HP Briggs and Stratton. Like before, the boom and dipper are moving too fast which tells me the pump is a high GPM unit and not really suited to the task. I picked up a flow control valve today but have not installed it as yet. With all the fittings and extra hose I need to get it working, I'm wondering if a new pump that is matched to the job and costs almost the same, is the better route. Thoughts?

PS: I will pose much the same question on the thread I have going on the hydraulics forum.

 

[Shaunshep]

I got that fitting installed so all the hoses are in place. I found some minor leaks and fixed them easily enough. The thing that had me worried was would that old pump off the bale loader still pump. Well, it pumps alright!! The bale loader was a tractor towed machine so the pump was PTO driven at 540RPM max. The way I am running it is probably quite a bit faster. I'm guessing the engine is running a minimum 1200 RPM or more and the drive pulley to driven pulley cuts it down to half that. I'm going to have to find flow restrictors for all the cylinders as they're moving far too fast. The problem I'm having is sourcing those restrictors. Anyone know where to look?

Punch out small copper discs and drill 1 mm holes or even smaller (depending on the speed you require) through their centres and fit one at each cylinder joint. Nip them up tight to compress the copper and make a perfect seal. This will restrict the flow and reduce the speed of travel.

 

[NormL]

Punch out small copper discs and drill 1 mm holes or even smaller (depending on the speed you require) through their centres and fit one at each cylinder joint. Nip them up tight to compress the copper and make a perfect seal. This will restrict the flow and reduce the speed of travel.

Shaunshep, welcome to TBN and thank you for that suggestion. I may be restricting some more of the connections before this project is done. I brazed a couple and on others took bolts and drilled the centers out to 1/16th", then tapped the fitting to be restricted just far enough to spin the bolt in a few turns and cut the bolt off with a cutoff blade in my angle grinder. Your method sounds simple and effective; just not sure how I'll punch out the discs. I might just snip them out in octagonal or hexagonal shape and bend the corners down till they fit into or over the fitting and proceed as you described from there.

 

[NormL]

I have been asked on a number of occasions what the specs for the pump are and have not been able to give an answer to that question - till now. Turns out that answer also explains what I have going on with the wonky operation of the hydraulics. The output measures a whopping 1.4 ci per rotation and even with stepping the speed of rotation down the volume of oil it tries to circulate simply stalls the pump or the engine or both. I have pulled the pump out and am about to install a .488 ci unit in its place. I'll need to make modifications to where the pump is mounted to accommodate dimension differences. While I'm at it I hope to install a pressure gauge so I can monitor that as well.

 

[NormL]

I have been asked on a number of occasions what the specs for the pump are and have not been able to give an answer to that question - till now. Turns out that answer also explains what I have going on with the wonky operation of the hydraulics. The output measures a whopping 1.4 ci per rotation and even with stepping the speed of rotation down the volume of oil it tries to circulate simply stalls the pump or the engine or both. I have pulled the pump out and am about to install a .488 ci unit in its place. I'll need to make modifications to where the pump is mounted to accommodate dimension differences. While I'm at it I hope to install a pressure gauge so I can monitor that as well.

The new pump is in and after fabricating a mounting plate out of 1/4" steel plate I bolted it all together, connected the input and output hoses and was able to successfully test the operation of the cylinders. With the restrictors in place they all moved well without the previous issues so that was positive for a change. The temporarily installed pressure gauge showed good pressure in the 2000 psi range but it only registered any pressure when I moved the boom or dipper. I take that to mean the absence of backpressure in the system when no work is happening. I took the gauge out because I don't have a convenient place to mount it.

I have not tested its digging capabilities yet; that will have to wait for tomorrow. Today was taken up with switching the away and back hookups of the valves on a couple of cylinders and taking care of some seepage where NPT connections are being used. Its finally looking like I can dig with this machine. Tomorrow should reveal what its capabilities are.

 

[NormL]

I finally took time out from gardening and yard care, etc, and tried out the "digger". It became evident quickly that I have design flaws to correct. The swing cylinder broke loose; it is supposed to remain stationary while a link does the swing. Next, the dipper does not lift high enough to allow for dumping the bucket. I'm wondering if I should have made the boom straighter. Well, it's too late for that so I'll do some changes to compensate. It's pretty obvious what kind of "engineer" I've turned out to be! Lastly, there still seems to be slippage in the drive to the pump so I will need to address that as well. I may have to get smaller idler pulleys and build a double set that tensions by turning rather than pushing. Our Swisher Zero Turn has that for the deck drive.