Backhoe Building a thumb for a model 48 Backhoe

[downsizingnow48]

Just as a reference point, see link below. This is the valve I used, it has built in work port reliefs that are adjustable. With a valve like this you can do the best practices setup as described by Chevy. $258 currently.

Surplus Center

 

[DanMc77]

That sounds fantastic. The work port reliefs would simplify the setup and eliminate several hoses and the external valve. Even though it's more $$ than the valve I ordered it might end up being about the same cost or even less.

The link does not work. Try again.

 

[downsizingnow48]

OK here is a different link. In the options section, spool "J" is the work port relief spool.

1 SPOOL PRINCE SV SECTIONAL HYDRAULIC CONTROL VALVE OPEN CENTER W/POWER BEYOND | Stack Valves | Hydraulic Valves | Hydraulics | www.surpluscenter.com

 

[downsizingnow48]

Also to consider. Someone recently put up a thread here where they took apart the backhoe control valve, inserted an additional work section to control the thumb, then put it back together. Very slick, no hoses at all needed.

 

[DanMc77]

Pat: Crap, why do you do this to me? Now I'm going to have to return the valve I just ordered!! LOL

Seriously, thanks for pointing me to this!! This looks like a fantastic valve that's configurable, extendable, and comes from a more reputable manufacturer. I can buy a 1-spool configuration with double work port reliefs and then tack on additional spools later, and configure them as needed, and only IF NEEDED. It gets rid of the external relief, extra hoses, and a lot of complexity.

Here's a link to the PDF giving more configuration detail for the valve. Its pretty amazing.
http://www.surpluscenter.com/Catalog/Catalog290-026.pdf

Kudos to Pat, downsizingnow48. Thanks again.

 

[DanMc77]

Hey TexasRanger:
How did you hook up your splitter valve? Did you just run the existing lines that go to the tractor over to the new valve, and then run new lines to the tractor? I can see that this would be super easy to do. I want to have a more permanent install, so it looks to me like I have to split the backhoe frame in order to get to the valve down below.

Am I missing something?

 

[texasranger556]

Yes the power beyond hose that you hook the backhoe to normally I just ran that to my valve and the power beyond from it supplies the backhoe. I tee'd the tank port on my valve with the backhoe return so I didn't have to run an extra hose to the tractor tank.

 

[DanMc77]

I have finally been able to get back to work on the backhoe thumb. I used this project as an excuse to go out an buy a decent lathe. I ended up with a South Bend 13"x36" machine that reportedly lived in a VoTech school. Here are the bosses for the thumb pivot right before being cut apart, and then after drilling a pilot hole.

 

[DanMc77]

Over the weekend I took it over to a good machinist friend. He has much bigger machines and a better welder, so he welded the bosses onto the thumb and bored the pivot hole. This is a large Lucas horizontal mill.

 

[DanMc77]

Backhoe bucket now with the thumb attached at the pivot. I'm very happy with this.
As for hydraulics, I think it will be easiest and cleanest to use a double-acting electric hydraulic pump. Then I don't have to cut into any existing hydraulic lines and I don't run the risk of slowing down the flow to the backhoe, and a whole slew of other issues.