Thumb for mini hoe

[MuncyBob]

"My goodness those are some fine thumb pictures you posted there! Large too!"



Well, you know what they say about large thumbs.............


large gloves!! LOL!

 

[bbabineau]

How's the testing coming? I have an upcoming project where a thumb would be very helpful-- is the fabricator interested in making more?

I told the fabricator that the target price was $225 which would make it competitive with those on ebay that need to be modified and welded to the mini hoe. After making mine he said he would not make another for the $225 but it would be closer to $300 plus shipping.

As for my testing, I would probably make one or two changes. I think I would ask for the first set of teeth on the arm to be left with the full tube rather than cut out into the teeth. This would add some strength to the very end of the thumb. I would also want the thumb an inch or two longer.

If anyone is interested, I will again approach him to see if he has the time and desire to make a few more!

Bob

 

[BobRip]

bbabineau, I am building a thumb and as much as possible I am building it like yours. Is there anything that you would change? Is it holding up well?
Thanks for any comments on this.

 

[KentT]

Bob,

If you can, I'd suggest that you make the thumb slightly curved forward. This will allow it to firmly grip rounder objects (trees, rocks, etc.) without requiring as much "curl pressure" to keep it clamped tightly against the thumb...

Without the curve, it is only the pressure against the point of the teeth that is holding the object... Most aftermarket thumbs are curved. Note mine, before we shortened it...

http://mypowertrac.com/DesktopModul...ImageID=23&alias=mypowertrac.com&ImageSize=10

 

[BobRip]

Bob,

If you can, I'd suggest that you make the thumb slightly curved forward. This will allow it to firmly grip rounder objects (trees, rocks, etc.) without requiring as much "curl pressure" to keep it clamped tightly against the thumb...

Without the curve, it is only the pressure against the point of the teeth that is holding the object... Most aftermarket thumbs are curved. Note mine, before we shortened it...

http://mypowertrac.com/DesktopModules/Polle.PiGa/ImageShow.aspx?ModuleID=384&GalleryID=6&ImageID=23&alias=mypowertrac.com&ImageSize=10

Thanks, I think I can heat it up with the weed burner and put some curve in it. Some other questions:
1. What size bolts did you use between the top plate and the bottom plate (long bolts)?
2. What size bolt did you use to pivot the thumb on?
3. Are those 5/8 inch receiver pins?
4. I have assumed that the thumb is made of two inch square tube. Am I correct?

 

[KentT]

Unless I'm mistaken, my thumb is made of 3.5" C-channel, and the mounting plates that are welded to the boom are 4" C-channel. (The plates are slightly wider than the PT's boom.) The thumb attaches to the mounting plates on the boom with standard hitch pins and clips -- I'm guessing 4.5" ones. Consequently, I can take the thumb off, leaving only the mounting plates, by pulling the two hitch pins.

The minihoe is in TN and I can't go verify...

 

[BobRip]

Thanks KentT. I put the curve in it kinda. I cut some slots, heated it up and it mostly bent at one slot. I will now weld the slots back in. I think I will use all hitch pins for easy removal per your suggestions. What size bolts did you use between the top and bottom plates?

bbabineau, can you answer the question that I put below? It's good to get several opinion and I am pretty much copying your design.

 

[KentT]

What size bolts did you use between the top and bottom plates?

No bolts were used, The plates are welded on, and the thumb and its brace are attached with pins...

 

[BobRip]

I am attaching a few parts pictures. KentT, do you think I put enough curve in the thumb. It's not too late to bend it a little more?

I used the weed burner to heat the thumb, but it seem to bend all along one of the cuts. I would like comments on additional bending and where if anybody has suggestions. I think I should straighten the one that is bent too much and bend the other two slots.

 

[KentT]

Bob,

I think that amount of angle will work fine. Now, just weld up the cuts necessary to bend it...

It's looking good. How long is it? While you're "playing with measurements" see if you can make it adjustable so that at one position it will go completely inside the bucket, yet in another position it will mate up with the bucket teeth...