TractorByNet.com - View Single Post

dfkrug · 07-25-2008, 02:28 AM

I next tried several kinds of valves in my quest for an economical solution.
I tried manual restrictor valves (photo 1, right), but 2 would be needed and
I would still need to get off the hoe to operate them, essentially turning
the thumb into a fixed thumb. The red valve is a solenoid-operated
poppet valve, which will cut off flow in only one direction. Again, 2 would
be needed.

I decided to go with a single solenoid-operated spool valve that would cut
off flow in both directions. I used this in preference to a solenoid-operated
diverter valve because those are a lot more money and they are much
larger, and require more hoses. By cutting off flow to only one side of the
thumb cylinder, I convert it to a fixed thumb, either fully retracted or
stopped anywhere in its travel. The 2nd photo shows the Hydraforce valve
I used. The 3rd shows my mock-up with the new valve. The valve was
about $40, but had to be ordered from a catalog from a reluctant distributor.

Next: the fabrication.

07-25-2008, 02:28 AM	#2 (permalink)
dfkrug Veteran Member Join Date: Feb 2004 Location: NorCal Posts: 2,351	Re: Custom hydraulic backhoe thumb I next tried several kinds of valves in my quest for an economical solution. I tried manual restrictor valves (photo 1, right), but 2 would be needed and I would still need to get off the hoe to operate them, essentially turning the thumb into a fixed thumb. The red valve is a solenoid-operated poppet valve, which will cut off flow in only one direction. Again, 2 would be needed. I decided to go with a single solenoid-operated spool valve that would cut off flow in both directions. I used this in preference to a solenoid-operated diverter valve because those are a lot more money and they are much larger, and require more hoses. By cutting off flow to only one side of the thumb cylinder, I convert it to a fixed thumb, either fully retracted or stopped anywhere in its travel. The 2nd photo shows the Hydraforce valve I used. The 3rd shows my mock-up with the new valve. The valve was about $40, but had to be ordered from a catalog from a reluctant distributor. Next: the fabrication. Attached Thumbnails __________________ See my TBN projects at: http://mysite.verizon.net/resyfcgt/ Kubota B21 rebuild 1 cy FEL bucket custom b/h thumb custom b/h subframe Diesel fuel dispenser Bucket dentistry custom hydraulic b/h thumb adapting a 4-in-1 bkt to my Kioti JD 4300 rebuild (new!)