Thumb Kubota BH75 Damaged by bolt-on Thumb

[MacPDaddy]

EMP THUMB IS SOLD

I listed the EMP thumb and ended up selling it for $300 shipped to a Kubota BX owner (lost about $75).
Key difference with my sale is I gave warnings to using the thumb improperly. It would be good for EMP to do the same.

SO BRO-TEK or WALLENSTEIN STYLE?
I know a lot of people are reading this post and thinking that a Bro-Tek thumb is now the way to go. Based on this experience, I think any thumb, including both the EMP and Bro-Tek, can be bought and used. Both carry an equal amount of responsibility on the operator to keep the backhoe from getting damaged. I do think the BH75 is a bit on the strong side for a bolt on thumb with the arm thickness at only 1/8".

My 2 cents for using any thumb:

• Take care when using a thumb, know the limitations of your backhoe.
• Never pick up an unbalanced object (like one end of a log), the arm is subject to being twisted, again know your backhoe.
• Never grab-on to an object your backhoe cannot lift.
• NEVER NEVER grab an object that the backhoe cannot lift and attempt to move your tractor.
• Use an add on thumb at your own risk, most are not designed or built by the tractor manufacturer.

I forgot to post a picture of the new dipper arm installed.
Once I get the Roger thumb installed, I'll get some final pictures posted.

 

[joes_427_vette]

That is the price one pays for having a light weight back hoe and expecting normal digging results. A good rock pile like I have would twist the boom in a short period of time. My Bradco 611 will never have that problem. I believe it weighs 1800# and is built like a tank. They aren't the cheapest on the market but it is quality - quality.

 

[MacPDaddy]

That is the price one pays for having a light weight back hoe and expecting normal digging results.

Don't mistake this damage I am sharing with you to a poor light duty backhoe. A thumb is not used for "normal digging" and the damage resulted from my improper use, granted the BH75 dipper arm is not constructed to take a thumb. I would say the 611 is in the next larger class, what size tractor do you have it on?
Mine is on a 35 HP midsized tractor and it suites my needs perfectly. I stand behind Kubota quality as well, they are well known for great quality equipment.

Anyway, I think we both have bragging rights on our equipment, I am proud of the Kubota BH75 and would buy again if I had the choice, now I would not repeat the thumb issue, but I ended up with a nicer backhoe for it (including a thumb!).

 

[MacPDaddy]

CONCLUSION:
I think the story is over, I'll post some pictures of the thumb in action sometime in the attachments section.
For now, take a look at the installed thumb, I think it turned out really nice and I have to thank Roger for his excellent fabrication work.
I also appreciate everyone's comments and pictures that have helped out along the way.

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The thumb in storage position with the full support installed.
I think the only part I want to improve is how far down the bar goes with both support bars installed.
It's easy to leave the extension off and the thumb is still pretty functional.

The teeth meet the thumb nicely.
Keep in mind, with the bucket and thumb pivot points different, I can adjust the thumb to meet the bucket teeth as needed for the job.

You can see the reason for the curvy thumb.
With the mounting pin higher on the arm it needed to close the gap.
This really worked for me to get the thumb out of the way when stored too.

Storage position without extension.
You can see the location of the thumb attachment above the bucket pin really allows use of the bucket for digging without thumb interference.

Notice the thumb?
This was one of my goals in the thumb design.
I wanted the operator to have no blocked view.
If you look close, you can just make out the edges of the thumb.
Again, digging is primary, and I didn't want to remove the thumb to do so.

==========================================

Just for laughs, and in case you thought I used a high tech design method.....
Some cardboard boxes and paper towel rolls is all, definitely no computer design in this.
Roger did the magic in taking cardboard to steel (after he suggested I go ahead and use my prototype LOL).

 

[denmansoft]

My type of CAD program. Cardboard Aided Design!

 

[kthompson]

MacDaddy, good looking job. As to the comment about light weight back hoe, there is no machine built by man that nature can not destroy, one way or another.

 

[Ductape]

All it needs is a hydraulic cylinder.

 

[RobS]

That's great MacPDaddy! If there was a TBN award for design and fab, I'd have to nominate you and your fabman Roger. If I ever need a thumb, I'll be copying your design!