Custom hydraulic backhoe thumb

avc8130 · Dec 17, 2015

I like this for the switch:

Cpi Weatherproof Switch, Push Button B7151-516 | Zoro.com

Zip-tied to the handle so you can hit it with your thumb is very ergonomic. I have 2 on my Kubota. One for the thumb on the hoe and one for the diverter up front.

ac

bumperm · Dec 18, 2015

avc8130 said:
Zip-tied to the handle so you can hit it with your thumb is very ergonomic. I have 2 on my Kubota. One for the thumb on the hoe and one for the diverter up front.

ac

Good find!

That looks quite weatherproof. The switch I and Racerwannabe used doesn't look so, but is also waterproof according to the description on Amazon:

Amazon.com: Alpinetech 19mm 3/4" Waterproof Momentary Stainless Steel Metal Push Button Switch Screw Terminal Extended Button Normally Open 1NO: Automotive

The downside of the switch we used is "some assembly required", in that a mount of some sort needs to be fabricated - that may also be a plus, as one can build a mount to suit (though it took me two tries).

As you said, the rubberized switch lends itself to an easier zip-tie installation and there's significant appeal in that. I suffer from the, "I can make that!" syndrome - a sickness, but one that has served me well :c).

Racerwannabe · Dec 18, 2015

Good find indeed!

I'm going to look into that

Racerwannabe · Dec 19, 2015

avc8130 said:
I have 2 on my Kubota. One for the thumb on the hoe and one for the diverter up front.

AVC: Could I trouble you for a photo of both switch installs? Anything you would do differently? A bucket grapple may be in my future too.

I spent three hours on the machine yesterday pulling rocks and stumps on the snowmobile trails. That hydraulic thumb is AWESOME and really speeds up the work. What a great mod!

Racerwannabe · Jan 3, 2016

Thumb switch 2.0

Mounting block slips over shaft and stays there with two set screws. Zip ties best thing I could come up with to keep the switch on the block

Mo' betta :thumbsup:

BukitCase · Jan 3, 2016

Racer, it's hard to tell from the pic so if you've done this, ignore me :laughing: BUT, if that's gonna be your PERMANENT temporary fix (and a nice one), you might wanna use one of these

Irwin Tools 1877715 Countersink Drill Bit, 3/8-Inch, Black Oxide - - Amazon.com

in each hole, your zip ties will probably last about 3-4 times as long... Steve

avc8130 · Jan 3, 2016

Racerwannabe said:
Thumb switch 2.0

View attachment 452479

Mounting block slips over shaft and stays there with two set screws. Zip ties best thing I could come up with to keep the switch on the block

Mo' betta :thumbsup:

I guess you don't need that pic any more

.

I'm so sorry for not posting one. I just never remembered when I was out by the machine.

ac

Racerwannabe · Jan 4, 2016

BukitCase said:
Racer, it's hard to tell from the pic so if you've done this, ignore me :laughing: BUT, if that's gonna be your PERMANENT temporary fix (and a nice one), you might wanna use one of these

Irwin Tools 1877715 Countersink Drill Bit, 3/8-Inch, Black Oxide - - Amazon.com

in each hole, your zip ties will probably last about 3-4 times as long... Steve

Great idea. Have one of those, just didn't think to break the corners of the holes. Will get 'er done!

Racerwannabe · Jan 4, 2016

avc8130 said:
I guess you don't need that pic any more .

I'm so sorry for not posting one. I just never remembered when I was out by the machine.

ac

No worries ac. Part of the fun is coming up with the design on your own. In this case, I was very constrained by the size of the scrap of aluminum bar stock that I had kicking around in the shop. That block has some tooling marks on the other side that I couldn't avoid. If my OCD really kicks in this spring, I might have to butter them with Bondo and paint the thing. Right now just having a ton of fun playing with the thumb to rip out stumps and rocks before the ground freezes (which will likely be tonight!)

arkydog · Jan 31, 2016

boy, i hope i can get someone to help. i get confused easily an have read this thread probably 10 times and have figured out that the diverter valve for my bh77 mechanical thumb needs a sv08-24-t6-n-12ds. i can't figure out which hydraulic cylinder with the least amount of re-work i should order. a part number and from where would be greatly appreciated. my stroke and healed broken rt. ankle has me limited getting on and off the backhoe to change the thumb setting. i can get a neighbor to do some welding for me which is a help. i would appreciate any information. even a pm would be great.

thanks rob