Welcome. I was considering getting a full size TLB before I got my 110 and one of my concerns was a thumb. I found these guys:
Hoeclamp
Pricey, but I think it looks like a quality product.
i would be skiddish of this type of thumb. find it easier to control the bucket separately from the hyd thumb. so you can "scoop" tree or what not towards you, and then move bucket up underneath something, and then apply the hyd thumb down onto what ever. or vice vs. and work the thumb up under something and then bring bucket down to grab a hold of something. if moving logs to a trailer, having hyd thumb operate separately from bucket. can possibly make it easier to position a log down. and slightly move things around. so things lay good on the trailer.
that and with separate hyd thumb, being able to possibly contract the entire cylinder for thumb. to move thumb completely out of the way, so you can use bucket. without taking thumb off.
ya someone could state, adjusting the boom and dipper stick and/or reposition the entire machine. but sometimes, it is nice working out in the pasture / woods. and reaching up under a large branch of a tree, and then snagging a hold of a bush. or working right up near a house or shed. and pulling out a fence post or deck post. and no need to position entire machine so it is 1" from touching house or shed.
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not sure how far the "extend" gives you, but if it is only 1 to 3 feet. do you really need a thumb ability stick an extra 1 to 3 feet out there?
extend is awesome for digging trenchs, as in you can dig more trench without having to reposition machine as often. or if you are digging out a basement, the extend can help you reach further away from machine and down to get a little more, and then swing around and drop spoils further away from the hole.
but do you really need to reach an extra 1 to 3 feet with a thumb, when most likely once you grab a hold of something, you will be moving tractor any ways, to transport what ever you have some place else?
i could see if thumb was used to help unload trailers of various things, were machine stays in one spot and moves what ever onto something else.
i might see partial use of a thumb that extends out with bucket, for demolition work. were ya cleaning up a house that was destroyed by storms, and moving debris from one spot into a dumpster or into a dump truck.
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i am all for keeping the extend operational when thumb is on. and could be very useful, but could you just buy a generic hyd thumb. and attach it to the part of dipper stick. that does not extend out?