A BH1976 Thumb on my BH75

[06B3030]

I have a B3030 with a BH75 backhoe. I want a thumb, but unfortunately, it doesn't have the dipperstick upper mount. I figured I'd start with the Kubota BH1976 Mechanical Thumb, and can always add hydraulics later. I took all the dimensions for the placement of the mount on the dipperstick, off of a BH77, and made a paper template of the side plates. I'm going to make a filler plate for the recessed area of the dipperstick, and tack everything together with the thumb positioned in the upright, non-used position.

I figured I'd throw the thumb on, and it took all of 30min...really easy! I used the old pin to hold the thumb on the outbound side to keep it positioned while I drove the new pin in.

It will be a couple weeks before I can get to this, so I'll update as I get things done.

 

[fried1765]

I have a B3030 with a BH75 backhoe. I want a thumb, but unfortunately, it doesn't have the dipperstick upper mount. I figured I'd start with the Kubota BH1976 Mechanical Thumb, and can always add hydraulics later. I took all the dimensions for the placement of the mount on the dipperstick, off of a BH77, and made a paper template of the side plates. I'm going to make a filler plate for the recessed area of the dipperstick, and tack everything together with the thumb positioned in the upright, non-used position.

I figured I'd throw the thumb on, and it took all of 30min...really easy! I used the old pin to hold the thumb on the outbound side to keep it positioned while I drove the new pin in.

It will be a couple weeks before I can get to this, so I'll update as I get things done.

View attachment 112770

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Lookin good !

 

[Runs With Scissors]

I like it!

I am also going to add a hydraulic thumb this year.

Since you already have to add the upper portion of the mechanical thumb, I am thinking it would be wise to have the measurement's of the cylinder you plan to use, so you can make that upper part to accept the cylinder as well.

 

[06B3030]

I like it!

I am also going to add a hydraulic thumb this year.

Since you already have to add the upper portion of the mechanical thumb, I am thinking it would be wise to have the measurement's of the cylinder you plan to use, so you can make that upper part to accept the cylinder as well.

The "stock" Kubota mount has a cutout on the upper flange to accommodate a hydraulic cylinder. From what I've seen in other threads, some have had to modify the cylinder so the hydraulic connector is pointing in the right direction.

 

[Runs With Scissors]

The "stock" Kubota mount has a cutout on the upper flange to accommodate a hydraulic cylinder. From what I've seen in other threads, some have had to modify the cylinder so the hydraulic connector is pointing in the right direction.

View attachment 112830

Gotcha

 

[Chanceywd]

Gotcha

If you use this cylinder it has the fittings clocked to the side. It is almost perfect length and the shaft end fits the thumb perfect too. When i used it to get the thumb up tight I plugged and welded the base end to rebore the hole about a half inch shorter if I remember right. You will want to chek this like he is doing with it held up. Then I welded a 1" shaft collar on each side. I had to mill a little off each side to fit the spacing but it really works nice. I was able to snake 1/4 hoses thru with the other ones.

Bill
I checked and measured my work. I relocated the base end hole about 3/16 to a quarter, shortening the mounting pin spacing from 19" to about 18-13/16". I did this for 2 reasons. to make the thumb tuck up tight to the cylinder and keep the shaft from touching the dipper arm when fully extended. Now it misses the end of the dipper by about 1/4" which if it was to contact would damage the rod for sure.

I tried to take some pictures but I am having a hard time downloading to my computer from my phone. If I can get them I will add them here.

Hydraulic Cylinder Welded Double Acting 2" Bore 10" Stroke Tang 2x10 WTG NEW | eBay

Hydraulic Cylinder WTG 2x10 ---Bore: 2" ---Stroke: 10" ---OD: 2.38" ---Rod: 1.25" ---Retracted: 19" ---Extended: 29" ---Overall length: 20.7" ---Pin hole size: 1" ---Port size: SAE 6 ---Column Load: 9,420 Lbs ---Max Operating Pressure: 3500 PSI ---Color: Black.

www.ebay.com

 

[Runs With Scissors]

If you use this cylinder it has the fittings clocked to the side. It is almost perfect length and the shaft end fits the thumb perfect too. When i used it to get the thumb up tight I plugged and welded the base end to rebore the hole about a half inch shorter if I remember right. You will want to chek this like he is doing with it held up. Then I welded a 1" shaft collar on each side. I had to mill a little off each side to fit the spacing but it really works nice. I was able to snake 1/4 hoses thru with the other ones.

Bill
I checked and measured my work. I relocated the base end hole about 3/16 to a quarter, shortening the mounting pin spacing from 19" to about 18-13/16". I did this for 2 reasons. to make the thumb tuck up tight to the cylinder and keep the shaft from touching the dipper arm when fully extended. Now it misses the end of the dipper by about 1/4" which if it was to contact would damage the rod for sure.

I tried to take some pictures but I am having a hard time downloading to my computer from my phone. If I can get them I will add them here.

Hydraulic Cylinder Welded Double Acting 2" Bore 10" Stroke Tang 2x10 WTG NEW | eBay

Hydraulic Cylinder WTG 2x10 ---Bore: 2" ---Stroke: 10" ---OD: 2.38" ---Rod: 1.25" ---Retracted: 19" ---Extended: 29" ---Overall length: 20.7" ---Pin hole size: 1" ---Port size: SAE 6 ---Column Load: 9,420 Lbs ---Max Operating Pressure: 3500 PSI ---Color: Black.

www.ebay.com

Thanks for posting that Chancey, I will probably go with that cylinder and more or less copy what you did in regard to installing the cylinder.

I don't want to "hi-jack' this thread, so I am gonna make a new one when I get a little closer to "pulling the trigger".

 

[Chanceywd]

Thanks for posting that Chancey, I will probably go with that cylinder and more or less copy what you did in regard to installing the cylinder.

I don't want to "hi-jack' this thread, so I am gonna make a new one when I get a little closer to "pulling the trigger".

I think if I was doing what the OP was doing I would position that new mount at 19 center for this cylinder to save altering the base end. But in my BH77 instance that wasn't an option as the mount was already welded on. The base end is 1.5 wide like the shaft end and the mounting area for the base is 2.5" I welded on a spacers to get it to that so it wouldn't be slopping around and or bending the pin. One last thing was I mounted the rod end with the grease fitting up so it wouldn't get packed with dirt.. It is accessible for grease when it is down.

Bill

 

[Tarmy]

This may help, or not. BH76 and my add on ram

 

[06B3030]

It's finally done!!!!
Really happy with the way it came out.

I decided to not cut out the sides like the factory mount. I think it's stronger, and not necessary to hook up a cylinder. I could always have it come out the back side like Tarmy did. The reality is I don't see myself going to a hydraulic thumb, it's not something I use that often.

I did have some concrete to move...and the thumb worked as expected!!

 

[Runs With Scissors]

Looks good.

I like mine.

It's not as nice as a hyd. thumb, but it still works "pretty good", I think your gonna like it.

 

[06B3030]

Looks good.

I like mine.

It's not as nice as a hyd. thumb, but it still works "pretty good", I think your gonna like it.

Definitely...it give me a "capability" I didn't have before!

 

[Chanceywd]

It's finally done!!!!
Really happy with the way it came out.

View attachment 114451

I decided to not cut out the sides like the factory mount. I think it's stronger, and not necessary to hook up a cylinder. I could always have it come out the back side like Tarmy did. The reality is I don't see myself going to a hydraulic thumb, it's not something I use that often.

I did have some concrete to move...and the thumb worked as expected!!

View attachment 114452

Nice work on the fit and finish. I can make things that work but seldom get to the painting level that looks as good as yours!
I was using my thumb last week redoing a small frog pond we have by the driveway. A lot of rocks and to be able to grab those bigger ones is a back saver. I put a bxpanded quick change on last year and find they mess up the thumb/bucket where they come together. I made a extension for the thumb that helps
Out of 3" channel and it comes between the center teeth of the 16" bucket.

 

[06B3030]

Nice work on the fit and finish. I can make things that work but seldom get to the painting level that looks as good as yours!
I was using my thumb last week redoing a small frog pond we have by the driveway. A lot of rocks and to be able to grab those bigger ones is a back saver. I put a bxpanded quick change on last year and find they mess up the thumb/bucket where they come together. I made a extension for the thumb that helps
Out of 3" channel and it comes between the center teeth of the 16" bucket.

Thanks...with a little prep work, the Kubota "rattle cans" work really well!!!

How do you like the BXpanded "Quick Change"? I almost pulled the trigger on one until I found this video... BXpanded Thumb Failure. It's mainly focused on the BXpanded Thumb, which doesn't come close to the quality of the Kubota thumb unit. Once I saw this I became concerned about their "overall" quality.

Here's the post in OT regarding that video...Thread Link

 

[Chanceywd]

Thanks...with a little prep work, the Kubota "rattle cans" work really well!!!

How do you like the BXpanded "Quick Change"? I almost pulled the trigger on one until I found this video... BXpanded Thumb Failure. It's mainly focused on the BXpanded Thumb, which doesn't come close to the quality of the Kubota thumb unit. Once I saw this I became concerned about their "overall" quality.

Here's the post in OT regarding that video...Thread Link

The quick change, so far so good but that pin you have to put a bolt in like kubota does as any kind of typical hitch pin will come out in use. I wonder if that has been some of the failures of others with the pin backing out while using and not being noticed. I do a lot of my own welding and have for years in employment. Some of the work when you look at it on the quick change is less than stellar. I personally think they need better fixtures in the assembly as I can see where the sides are not parallel. I looked at putting in shim spacers to make the mount as tight as possible but the space isn't parallel, kind of wedge shaped if you get my meaning. If it fails I will probably make one from scratch like I have in my hydraulic thumb, narrow bucket and root ripper. Like you and RWS I enjoy welding and making things.
Bill