OK, now for the hydraulics.
I used the same strategy that I used with my hydraulic backhoe thumb:
a single solenoid-operated spool valve on one of the two sides of the
4-in-1 cylinders, plumbed in parallel with the bucket curl cylinders. The
only difference is the loader has 2 cylinders for the bkt curl and the hoe
has only one. For those who want to do it this way, I bought the
HydraForce SV08-24-6T-N-12DS, which should be under $50, depending
on where it is shipped from.
This approach has the advantages of less plumbing and lower cost than
a 4-way solenoid diverter, or a separate mechanical spool valve. The
parallel mode action, where the bkt curl and the 4-in-1 jaw are operated
simultaneously seems to work better, vs the mechanical spool valve. This
action is used for grading and grabbing piles of materials off a flat surface.
The disadvantages? For grappling work, the parallel hydraulics make it so
the the dump curl action will have priority over the 4-in-1 jaw opening. This
means that the bkt has to be fully dumped before the jaw opens or the
items grabbed has to be set down before the jaw can open. I have been
able to work within this limitation, no problem.
First photo shows the valve. Any brand should work, as long as it can
handle the flow and uses a spool valve (not a poppet valve). This unit
is rated 4.5
GPM.
Next are the cross-tube
FEL mounts, one on each side. The bulkhead
mount will be for the non-valved side QD; the other is for the solenoid valve.
There will be NO hoses added to the
FEL arms. The electrical connection
(white wire) goes thru the
FEL arms, as do the existing hoses. The dash-
mounted switch (just above the light switch) is a waterproof toggle.