Mechanical Thumb conversion to Hydraulic

[CDN Farm Boy]

I very quickly got tired of getting off the tractor to set the mechanical thumb and often found myself batting stuff around with the bucket to get it to just the right spot where I could leave the thumb in one spot. I had already installed a 4 spool hyd valve for remotes (3 rear, 1 future front) I run the BH off one of these rather than the PB loop which is WAY easier for mounting and dismounting.

I cheaped out and ran them off one of my other pairs of rear QD's rather than a valve mounted on the BH itself. If I get fed up with having 4 hoses to connect and have an extra $500 burning a hole in my pocket I might switch but for now, I'm up and running. The only mods I've done that aren't easily reversible is to weld 2 mounts on for the hose clamps. If I ever needed to it would take me about 10 min max to remove this and put the mechanical linkage back on.

2 x 10 cyl, 27' of 1/4" hose, some fittings and hose protector, all told, I'm into it for $250. All parts other than the QD's were from Princess Auto. I'd ordered extra male QD's when I did the remote install so I would have them available.


This is the cyl that will be replacing the mechanical linkage.


I had to cut the base mount off the cyl, turn it 90 deg and weld it back on and also narrow the head mount from 2" to 1.5". The base mount needs to be turned so the ports are on the side.


The ram was mounted and welded in place to ensure that the pin boss was perfectly in line with the cyl body.


The head mount needed to be narrowed to fit in the space of the old linkage


Lines were run on the outside of the stick and then go down inside the hole in the top of the boom


The width of the thumb actually provides some protection for the head port. Lines were plumbed direct to the ram, no QD's at this end as I never plan to use an auger etc.


The lines were fished thru the existing hose protector at the base of the main boom


I've got a 4 spool valve for remotes (3 rear, 1 future front) The BH is run off one pair with 3/8 couplers, the thumb is on the top 1/4" pair, easy to reach with my right hand by my left elbow.


Everything tucks in nice and tight from the operator's seat, zero change in visibility



If I leave the valve activated for the BH, I can still run the thumb but it is slow (flow is split between 2 open ports). If I neutral the valve powering the BH, the ram works nice and quick. This will give me incentive to order replacement detent kit that I lost the spring out of during install and have been using a cedar shim to hold open for now.

 

[J_J]

It seems it would be so much better to press a button or switch and move the thumb using a 3rd function valve.

It would connect in series with the BH valve. Either before or after the BH hyd.

Or, you could use a diverter to shift fluid from one of the outriggers to the thumb cyl . Default with no voltage would be outrigger. Press a button or flip a switch and and have thumb operate.

An off/on switch would latch the diverter to thumb operation.

Momentary push button would operate the thumb while the button is depressed.

Here is your 3rd function valve.

Surplus Center - 12 VDC 10 GPM OC DA SOLENOID VALVE

D03 subplate to mount the above valve.

Here is the selector/diverter valve.

Surplus Center - 12 VDC 13.2 GPM SAE 8 DOUBLE SELECTOR VALVE

 

[CDN Farm Boy]

More simple to use yes, certainly. But also more complex to install originally and much more expensive. I chose this route on purpose because of both low initial outlay of cash and the ease of installation (assuming you have an additional remote to power it). Not having 12v power at the BH to me is a big hurdle to using any sort of electric valve. On a FEL, sure not a big deal, but having a wire to deal with at mounting to me is just asking for it to get forgotten and ripped off when dismounting.

This is still a far cry better than having to get off each time you want to adjust the thumb and was sharing it as another option.

If (when?) I change from this, it will be to another valve tied into the existing valve & lines of the BH such that I would be back to only the original 2 lines to deal with at mounting, but that's where the extra $500 comes from.

 

[CDN Farm Boy]

An update having used this on several occasions totaling a few hours of use and it's great!

I'd post some pics but I always forget to take a camera out with me, then get all wrapped up in what I'm doing and never think of it until I'm done -- or as often happens, sitting here typing saying to myself "wtf, you forgot again" :banghead:

A few things I've done with it so far:
Sorted a rock pile
Pulled a bunch of fence posts
Sorted some scrap metal
Loaded a pile of junk (left in the corner of the field by the driveway by the PO) onto a trailer
Unloaded junk from above trailer (I need a dump trailer) into a bigger pile of junk left by the PO behind the barn
Pulled a bunch of weeds that grew up thru a pile of scrap lumber. This was actually the most interesting. These were mostly big azz burdocks some with taproots the size of a can of spray paint. I was able to pretty much pluck them one by one out of the ground and pile them up with NO dirt.

Anyone wondering if they should convert to hydraulic thumb, the answer is YES. Plumb it like I did, wire in a diverter like JJ suggested (thanks by the way) or plumb in a whole new valve into the BH. Whatever way you choose, just do it, you will be greatful.

I've got to get some pics next time I'm out........