Backhoe update. I'm making progress (Video included)

[Short Game]

The day before yesterday, I crawled under the Kubota backhoe, which is sitting two 100' 10 AWG extension cords out in the field. I bought some 2X2X1/4 tubing to fit into the slots for the lower 3-point arms. Though the slots measured two inches, that wasn't quite exact. They were not quite parallel and the square tubes would not fit. I didn't want to grind the 1/4" material. I thought it better to grind the 5/8" stuff on the backhoe. My skinny, bad backed, old man body, lying on the ground, wielding a big, heavy, guardless, Makita grinder, was pure torture.

Anyway, I got the tubes to fit after a couple of hours. Yesterday when I got up I was about crippled from the ordeal. The mount on the backhoe has three 7/8" pin holes on each side. I drilled the two pieces of tubing to take the pin through one and a 7/8" bolt through another. The tubes are mitered to become horizontal to connect to the frame of a big old boat trailer I'm cutting way down for this project.

So anyway, the inspiration I got here is starting to become progress. I will get some pictures up soon.

I'm sure that I don't need a 41 HP diesel running at 2400 RPM to run the pump at 540, so I'm wondering what portable power (engine/gear reduction) setup would be optimum for running the PTO pump independently of the tractors?

 

[peavey]

Howdy Short Game, there is a fellow on this forum that goes by the handle J J who may be able to help you if you can locate him. I know he got me lined out on some hydraulic issues I was having in the early stages of my towable back hoe build.

 

[peavey]

I have a 13hp Harbor freight running my 7 gpm pump on my towable. I havent had any issues with it stressing the pump or engine. So far I have dug a ditch about 200 feet long, 3 to 4 feet deep in hard clay and rocky soil, then I dug a storm shelter 7 feet x 10 feet long x 8 feet wide. The little towable did a great job, I was really shocked.I can send you the link for the pump I used.

 

[Short Game]

Whatever engine I use, It'll probably be salvaged from something else.

I have noticed that J_J is always right there ready to help. He is very much appreciated. He knows enough about hydraulics that much of it goes right over my head. I'm starting at the bottom on that subject.

 

[peavey]

Yup, JJ really helped me out a lot. Told him what I was doing and he found the pump I needed and sent me the link to order it.

 

[Short Game]

Of course, I have that Kubota PTO pump and want to use that. I just wonder what kind of small engine will power it properly at 540. Assuming a reduction gear will be needed anyway, I'm hoping that the HP won't need to be huge. I have an old military Kohler 7 horse with a built-in reduction gear. It would be nice if that would do it.

Anyway, I've already bought the extra hoses to reach the PTO, so as soon as it's trailered, it should be ready to work behind a tractor.

 

[peavey]

you will have to find out what the gear reduction is first. The engine probably turns at 3200 rpm's as most do without the speed reducer. 540 rpm's is slow in comparison.

 

[Short Game]

It's 6:1, so durn, that is only 533.3. Came up short. :laughing:

 

[NormL]

It's 6:1, so durn, that is only 533.3. Came up short. :laughing:

OK. Now, the oversimplified progression would have you looking at 42 horsepower (7x6) and even with some loss due to friction, would you not still have ample power to run that PTO pump with your 7 hp? As long as it doesn't have hard starting issues it should be perfect.:thumbsup:

 

[Iplayfarmer]

I've always used the horsepower calculator in the wikipedia article to help calculate what's needed for a hydraulic system... Horsepower - Wikipedia, the free encyclopedia

Flow (gal/min) X Pressure (PSI) X 7/12,000 = Horsepower.

So, for 7 gpm at 2,000 psi you need a theoretical 8.2 horsepower. Give yourself a few extra HP for mechanical losses.