Backhoe Thumb

[Buggs67]

I finally got the thumb welded on. It was 60 yesterday and I wanted to do it outside in the full sun. First I had to drade the driveway/lane and that ate time but I got it well tacked on and tried it out.

I took these at night with a flash so it may be hard to see but the thumb is a little too long (This is the 24"); about 4". My first thought was just cut off the extra length, but then I thought it'd be better to cut off the top of the thumb and redrill the hole. That would preserve the last tooth which extends a little further than the other teeth. But that would also move the connection of the crossbrace up higher unless I also redrill a hole for it to connect to the thumb.

The upside of all this cutting/drilling is I can somehow align the holes on the mount and thumb so there would be a storage position which is currently missing. As others have remarked you have to use a bungee cord such to secure the thumb up out of the way or remove it entirely.

Another possibility is taking 1" off the bottom and 3" off the top. That would move the attachment of the crossbrace to the thumb only 3". BTW my BIL has a nice steel band saw to do the cutting and my neighbor/friend has a full machine sop so he'll drill the holes in the correct location.

If you look close or zoom in you can see my half-ass welds. I used my Titanium 125 w/.035 FC wire which is only rated to 3/16" and the mount is 1/2" and the dipstick is 1/4" or more. I'll finish burning it in when all is said&done. I tried to pick up a 36" long log and the overextended teeth made it harder. But it did pick it up (4-6 times).

Any advice would be appreciated.

 

[arrow]

I need some enlightemnment.
I have never seen a bolt on mechanical thumb needing welding to the boom. I guess yours didn't have the drilled ears toward the top of the boom to fit the upper pin in?
Who makes this one?

 

[AchingBack]

I finally got the thumb welded on. It was 60 yesterday and I wanted to do it outside in the full sun. First I had to drade the driveway/lane and that ate time but I got it well tacked on and tried it out.View attachment 734667
I took these at night with a flash so it may be hard to see but the thumb is a little too long (This is the 24"); about 4". My first thought was just cut off the extra length, but then I thought it'd be better to cut off the top of the thumb and redrill the hole. That would preserve the last tooth which extends a little further than the other teeth. But that would also move the connection of the crossbrace up higher unless I also redrill a hole for it to connect to the thumb.

The upside of all this cutting/drilling is I can somehow align the holes on the mount and thumb so there would be a storage position which is currently missing. As others have remarked you have to use a bungee cord such to secure the thumb up out of the way or remove it entirely.

Another possibility is taking 1" off the bottom and 3" off the top. That would move the attachment of the crossbrace to the thumb only 3". BTW my BIL has a nice steel band saw to do the cutting and my neighbor/friend has a full machine sop so he'll drill the holes in the correct location.

If you look close or zoom in you can see my half-ass welds. I used my Titanium 125 w/.035 FC wire which is only rated to 3/16" and the mount is 1/2" and the dipstick is 1/4" or more. I'll finish burning it in when all is said&done. I tried to pick up a 36" long log and the overextended teeth made it harder. But it did pick it up (4-6 times).

Any advice would be appreciated.
View attachment 734666

Looks just a tad too long. Hope it works well, though.

 

[monkeyman9]

I finally got the thumb welded on. It was 60 yesterday and I wanted to do it outside in the full sun. First I had to drade the driveway/lane and that ate time but I got it well tacked on and tried it out.View attachment 734667
I took these at night with a flash so it may be hard to see but the thumb is a little too long (This is the 24"); about 4". My first thought was just cut off the extra length, but then I thought it'd be better to cut off the top of the thumb and redrill the hole. That would preserve the last tooth which extends a little further than the other teeth. But that would also move the connection of the crossbrace up higher unless I also redrill a hole for it to connect to the thumb.

The upside of all this cutting/drilling is I can somehow align the holes on the mount and thumb so there would be a storage position which is currently missing. As others have remarked you have to use a bungee cord such to secure the thumb up out of the way or remove it entirely.

Another possibility is taking 1" off the bottom and 3" off the top. That would move the attachment of the crossbrace to the thumb only 3". BTW my BIL has a nice steel band saw to do the cutting and my neighbor/friend has a full machine sop so he'll drill the holes in the correct location.

If you look close or zoom in you can see my half-ass welds. I used my Titanium 125 w/.035 FC wire which is only rated to 3/16" and the mount is 1/2" and the dipstick is 1/4" or more. I'll finish burning it in when all is said&done. I tried to pick up a 36" long log and the overextended teeth made it harder. But it did pick it up (4-6 times).

Any advice would be appreciated.
View attachment 734666

If i were you, I'd cut off the last few teeth with a grinder and cutting wheel. Then grind some deeper teeth in later if you really think you need to. Much easier and no messing with holes.

 

[rdinatal]

My first thought was just cut off the extra length, but then I thought it'd be better to cut off the top of the thumb and redrill the hole.

Hmmm, check for clearance in every position.
(If not already, multiple times)

 

[rdinatal]

I have a job to really utilize and work the BXpanded thumb this weekend. Moving large rocks, stumps, etc.

Will post some pics, if I remember....

 

[Buggs67]

Hmmm, check for clearance in every position.
(If not already, multiple times)

I ran it back and forth after he first 4 tacks. All good, just too long.

 

[Buggs67]

I need some enlightemnment.
I have never seen a bolt on mechanical thumb needing welding to the boom. I guess yours didn't have the drilled ears toward the top of the boom to fit the upper pin in?
Who makes this one?

It's not a bolt-on. It's designed to weld to the dipstick. I guess I could've drilled the mount in 6 places and then drilled and tapped the dipstick and bolted it up.

It's by Titan attachments the 24" size. It was about $164 plus tax. They also make a 36" for larger machines. And a smaller clamp-on style for small machines like a BX (it's made in China and available everywhere it seems); but it only fits dipsticks up to 5" wide iirc..

 

[Buggs67]

If i were you, I'd cut off the last few teeth with a grinder and cutting wheel. Then grind some deeper teeth in later if you really think you need to. Much easier and no messing with holes.

That is the easy way. I'm gonna consult with my machinist friend.

The real drawback with this thumb is that it has no storage position, you know, like just rmoving one pin and swinging it up to the dipstick and reinsterting the pin.