Backhoe Thumb Hydraulic Options

[dfkrug]

This is an interesting idea that I haven't seen before, and sounds like a neat
idea. What valve did you use and got a pic or drawing of the plumbing layout?

It is all explained in my hyd thumb thread:
http://www.tractorbynet.com/forums/build-yourself/125912-custom-hydraulic-backhoe-thumb.html

My 4-in-1 is also plumbed this way using the identical valve. That setup has also worked flawlessly
for years in the real world.

I did it this way not just to save money. (It is a lot less, however.) I wanted to minimize hoses that
are in harm's way, attached to the side of the boom and dipper. A small, 1-spool solenoid valve
can be remotely mounted, with 2-spoolers (full diverter) are much larger.

Would this eliminate the problem of one overpowering the other and work kind of like a dual lid setup on a grapple bucket
where one will contact the item, stop until the other makes contact then tighten together?

The problem is not eliminated; I view it as a design challenge to account for, just like using bigger
than 1" rods on the thumb cyl minimizes rod buckling. The only challenge that is eliminated is
that there are no reaction forces pushing on the bkt by the thumb. (Bkt cyls are not usually
protected by OEM RVs in the stack.) The 3000psi limit of my Hydraforce valve was my biggest
design constraint.

 

[J_J]

Just add this valve to the bucket circuit .

Add some short hoses,

Add a 12v line from the momentary switch.

Default mode is bucket.

ttp://www.surpluscenter.com/item.asp?item=9-7852&catname=hydraulic

http://www.surpluscenter.com/Instruct/I9-7852.pdf

 

[avc8130]

Just add this valve to the bucket circuit .

Add some short hoses,

Add a 12v line from the momentary switch.

Default mode is bucket.

ttp://www.surpluscenter.com/item.asp?item=9-7852&catname=hydraulic

http://www.surpluscenter.com/Instruct/I9-7852.pdf

EXACTLY the plan!

Other than the hoses being longer, is there any problem with mounting the valve near the Kubota stack?

ac

 

[J_J]

No, you can install the valve anywhere.

 

[Leejohn]

I use one of those valves on one of my dump trailers and it works good.

 

[bindian]

I feel "fortunate" that Kubota was nice enough to "give" me the cylinder mount on the dipper stick. I almost feel like I am leaving food on the table if I don't take advantage of it.
ac

Better quality backhoe manufacturers install the mounts on the dipper stick to avoid cracking and liability issues when someone welds cylinder mounts on their dipperstick and the dipperstick loses it's temper around those welds.
hugs, Brandi