MacPDaddy
Member
I really need some advice.
I saw the backhoe thumbs and thought it would be a great addition to my BH75 backhoe. After doing a little research, it came down to a bolt on model sold by Extreme Metal Products (Ebay for $325).
The thumb arrived and looked really nice, excellent fabrication and very tough.
After a short period of use I inspected the position of the thumb to insure it did not slide (a problem noted for the Wallenstein type design), it had not.
PROBLEM: I noticed that the hydraulic fitting on the cylinder was actually hitting the dipper arm, after pulling the thumb off, I noticed the dipper arm itself actually had a bend in it!!
The arm had a compression mark on the underside where the thumb bracket pressed against it and a dent in the top where the bolt closer to the bucket actually pressed into the arm.
At this point I will need to replace the dipper arm (Kubota part is $622 from tractorsmart.com).
QUESTION: Has ANYONE noticed an issue with bending a dipper arm, no matter how slight with one of these clamp on type thumbs (EMP, Wallenstein, or Bro-Tek)?
My assumption is that the bucket pressure pushes on the thumb and the resulting force is against the arm at it's mid point. I did check on the Kubota factory thumb for the BH65 and the support strut actually connects high up on the arm allowing the force to be directed up the arm rather than against it (no bending force on the dipper arm itself). I just find it hard to believe that I am the only poor soul who has seen this. Upon close inspection, the dipper arm is pretty thin steel.
I have one fallback I am hoping works out. I may end up having an arm fabricated by my father-in-law with a heavier gauge steel.
I still want a thumb, very handy item, I just need to understand why this happened and insure I can use one without damage.
I saw the backhoe thumbs and thought it would be a great addition to my BH75 backhoe. After doing a little research, it came down to a bolt on model sold by Extreme Metal Products (Ebay for $325).
The thumb arrived and looked really nice, excellent fabrication and very tough.
After a short period of use I inspected the position of the thumb to insure it did not slide (a problem noted for the Wallenstein type design), it had not.
PROBLEM: I noticed that the hydraulic fitting on the cylinder was actually hitting the dipper arm, after pulling the thumb off, I noticed the dipper arm itself actually had a bend in it!!
The arm had a compression mark on the underside where the thumb bracket pressed against it and a dent in the top where the bolt closer to the bucket actually pressed into the arm.
At this point I will need to replace the dipper arm (Kubota part is $622 from tractorsmart.com).
QUESTION: Has ANYONE noticed an issue with bending a dipper arm, no matter how slight with one of these clamp on type thumbs (EMP, Wallenstein, or Bro-Tek)?
My assumption is that the bucket pressure pushes on the thumb and the resulting force is against the arm at it's mid point. I did check on the Kubota factory thumb for the BH65 and the support strut actually connects high up on the arm allowing the force to be directed up the arm rather than against it (no bending force on the dipper arm itself). I just find it hard to believe that I am the only poor soul who has seen this. Upon close inspection, the dipper arm is pretty thin steel.
I have one fallback I am hoping works out. I may end up having an arm fabricated by my father-in-law with a heavier gauge steel.
I still want a thumb, very handy item, I just need to understand why this happened and insure I can use one without damage.