homemade manual thumb

[Birdseye]

One last question, it looks like there is just a single strut/brace on one side only that holds the thumb at 90*. Has that been enough, Id have thought the large bucket hydraulic cylinder would bend that single strut and more support would be necessary to counter the force of the bucket when really squeezing something.

 

[Funny farm]

pic of it folded up. will be cut off and this beat up old attachment will be stripped down and mostly scrapped out. will keep the cyls for spares or to repurpose somehow. maybe a big log splitter..? the main frame that attaches to the tractor seems like it could be used to make a diff attachment mount maybe..? the thumb will definitely be moved to the new backhoe tho. just wish it was easier to tap into the hydraulics and make it powered.

 

[Funny farm]

One last question, it looks like there is just a single strut/brace on one side only that holds the thumb at 90*. Has that been enough, Id have thought the large bucket hydraulic cylinder would bend that single strut and more support would be necessary to counter the force of the bucket when really squeezing something.

the strut bar is heavy wall seamless pipe, and it is centered between the tines. it attaches to a pair of 3/8 thick brackets welded to a piece of 1in thick x 4in wide flat bar. and is also gusseted for good luck lol. i was concerned it would bend also but it seems to hold strong so far. when moving the rocks i had to hold pressure on the bucket curl continuously in order not to drop the heavier rocks, and the strut stayed straight. see what happens over some time.
the piece of channel closer to the pivot was just for added rigidity by the pivot. (was all just scraps and left over stuff from other jobs so i used what i had and figured i’d strengthen and modify as required).

 

[Birdseye]

I’m going to order one of those manual thumbs from Titan and reinforce the holes with DOM tube as suggested.

I can’t decide whether to order the 32” or 36” thumb. With the bucket positioned 90 degrees to the dipper, it measures 33.5” from bucket tooth tip to dipper. I’m sort of between the 32 & 36” lengths , all other aspects seem about the same except: a) maybe the 36” model stows better b) maybe the 36” model is more rigid because the strut is longer... It’s hard to know without owning one.

Any advice ?

32” model -
https://www.palletforks.com/tractor...mb-58-inch-steel-plate-attachment/122994.html

36” model
https://www.palletforks.com/tractor...plate-assembly-weld-on-adjustable/122982.html

 

[Tinkerer]

I would buy the 36" Extreme duty.
If the small amount of overhang is a problem it would be quite simple to trim it with a cutting torch or a saw.
You will find out quickly after using it a couple of times if it is tooo long.

 

[Birdseye]

Okay, thanks !

 

[Gasnoil]

Nicely done!

 

[Clunkahollic]

I really like the idea of adding a thumb to the back bucket for firewood, my question is tho, how much harder would it be to add a hydraulic thumb? You would need to plumb In a diverter operated off of maybe the outrigger.
I've been thinking about this for the last month and a half . That and adding a grapple on the front bucket.

 

[Funny farm]

I really like the idea of adding a thumb to the back bucket for firewood, my question is tho, how much harder would it be to add a hydraulic thumb? You would need to plumb In a diverter operated off of maybe the outrigger.
I've been thinking about this for the last month and a half . That and adding a grapple on the front bucket.

i would have preferred to build it as a hyd thumb but it’s difficult to safely tap into the hydraulics on this old machine. i thought about running it off the bucket cyl but don’t like the idea of not having dedicated control for it and having it move with the bucket. i read some stuff that if u tap in to the system wrong , u can render the relief useless and potentially create a dangerous situation where there is no relief valve possibly leading to damage or even injury. not being terribly knowledgeable with hydraulics i opted to just make it manual. figured i could likely convert it if i ever find a safe way to make it work hydraulically. without spending a fortune also. lol

 

[Tinkerer]

I had good results plumbing a 6 way diverter valve and using a stabilizer valve for my thumb.
I posted a thread with all details a while ago.

 

[Funny farm]

I had good results plumbing a 6 way diverter valve and using a stabilizer valve for my thumb.
I posted a thread with all details a while ago.

i will have a look for that thanks. once i get the valve leak issue fixed up i’m going to be putting the thumb on the “new” backhoe attachment. it’s currently still welded to the original attachment.

 

[Clunkahollic]

i will have a look for that thanks. once i get the valve leak issue fixed up i’m going to be putting the thumb on the “new” backhoe attachment. it’s currently still welded to the original attachment.

I wanted to look at it also, here it is
https://www.heavyequipmentforums.com/threads/my-manual-thumb-to-hydraulic-conversion.87899/

 

[Welder Dave]

Nice to see how another welder goes about building something. Tried and true methods used and not something that makes people cringe looking at how it was done. For people without the required skills, they might be pleasantly surprised at the cost to have someone experienced help them with the welding and/or designing. Thumb up.