Hi all I am new here and have what may be a stupid question. I live in Ireland and we dont have Thumbs as you call them. Does the thumb move or is it fixed I cant tell from the photo on this thread "Deere 310C" It looks real handy to pick things up with using the rear bucket could someone post more photos and if possible a specification for one to fit a 1979 Ford 550. Thanks.
Some thumbs move, some are fixed. There are two types here, the mechanical thumb and hydraulic thumb. Mechanical is generally fixed but there are a few that do move such as those from www.amulet.com . I had one on my backhoe. It was great for a mechanical thumb ( http://www.amulet.com/Templates/amulet_products/thumbs/hoeclamp/hoeclamp.htm ). Once you get into hydraulic thumbs, there are two types there. Direct link thumb and progressive linked thumb. For excavators progressive linked thumbs are the best (but that is my opinion and others on here may feel differently). Direct linked thumbs are different because the hydraulic rod connects directly to the thumb. It's range of motion is limited. A progressive linked thumb has extra linkage that connects the hydraulic rod to the thumb allowing a greater range of motion. This allows the thumb to close against the bucket even when the bucket is fully curled out. Great for rockeries, grading w/ a grade beam and grabbing things that are close to the machine etc. Here's a link showing the case backhoe I used that had the amulet thumb on it. When you curl the bucket in it closes the thumb. Pretty neat. Much better than a stiff mounted mechanical thumb. http://www.tractorbynet.com/photos/showphoto.php/photo/288 In the photos I posted, you can see the two different hydraulic thumbs. On the Kubota there's a direct link thumb. Notice how the hydraulic rod connects directly to the thumb? The other two pics you can see the extra linkage for the prog. linked thumb. On the 120, if I had the thumb complete rotated out it would close against the bucket. If it were a direct linked thumb it would not rotate that far out. Big pain in my opinion. Last pic is a JD mini excavator with a prog. linked thumb. Belongs to a guy I know in my area.
WOW thanks for the reply. It was very informative. Do you have a spec sheet for the dimensions required to fit a 1979 Ford 550 fixed thumb? Thanks again.
I watched the Amulet video. Two questions. 1. Can you stop the unit closing when digging a trench or does it not affect trenching? 2. What price is a unit? Thanks.
i think you can pull a pin and fold it up to the arm...
WooshNI, I'd imagine that you can weld something no the stick above the thumb and take the linkage I circled in red and pin it to your new welded piece at the other end of the arrow. If that makes sense. I unfortunately do not have any measurements for a Ford. If you email or call Amulet they can figure that out for ya.
Oh, and it doesn't get in the way of trenching unless you need a smaller bucket (12'' versus 24''). I dug dirt w/ my hoe all the time and it worked fine.