Backhoe How similar are the BH77 hoe & the B26 hoe?

[lhansman]

Hi Jim

My B26 came with the quick attach option but not the thumb. FYI there were a number of new pins that come with the thumb to accomodate the additional width of the thumb attachment. I don't think there were any diameter changes but I had the dealer install the thumb kit for me.

Regards,

Lauren

 

[jim_wilson]

Hi Jim

My B26 came with the quick attach option but not the thumb. FYI there were a number of new pins that come with the thumb to accomodate the additional width of the thumb attachment. I don't think there were any diameter changes but I had the dealer install the thumb kit for me.

Regards,

Lauren

That makes sense. There would have to be a longer pin for the pivot point where the bucket attaches to the dipperstick in order for the thumb to be installed. I don't think they could change the diameter at all - the pin still has to fit thru the hole on the dipperstick.

I'm hoping when I go to the dealer today that I can get some dimensions off a BH77 and/or a BT820.

 

[radair]

...Picture A: distance between the center points of the two pins on the actual quick attach - on the BH77 bucket it would be the two pins that attach the bucket to the dipperstick

http://i868.photobucket.com/albums/ab247/jdwil44/DimAdistance_between-QApins.jpg

Picture B: distance between the upper mounting point of the thumb cylinder - or extension bar in the case of the BH77 - and the bucket pivot point on the dipperstick

http://i868.photobucket.com/albums/ab247/jdwil44/QA-bucket-dimensionB.jpg


Picture C: distance between the center points on the two pins on the pivot arm

http://i868.photobucket.com/albums/ab247/jdwil44/dimensionC-pivotarm.jpg


Picture D & E: distance between the center points of the upper connecting arm ( D ) - and the bucket pivot point and the extension arm pin on the dipperstick ( E ).

http://i868.photobucket.com/albums/ab247/jdwil44/dimensionD-E-arms.jpg



Picture F: I couldn't find anything that was very clear - but basically what I need is the WIDTH of each of the pin points or maybe a better way to put it is the width of each of the components where they fit onto the dipperstick. If the dipperstick on the BH26 is for some reason wider than the dipperstick on the BH77 - then nothing will fit.

http://i868.photobucket.com/albums/ab247/jdwil44/imgF-width-dimensions.jpg

Hi Jim - I took some measurements this morning for you. A couple of the c-c dimensions were tricky to get accurately as the main pivot pin is longer and the "housing" is wider than the other 3 pins, i.e. the ends of the pins are not in the same plane.

All pins are 1" diameter.
A = 5 1/2"
B = 23 13/16"
C = 9 13/16"
D = 9 13/16"
E = 5"

Dipper is 3" wide.
Main bucket pin/thumb pivot housing ~= 9 5/8" (pins are a little longer than the housings they sit in)
Other 3 bucket pin housings are 6 1/16" wide
Thumb strut pivot is 5 1/2" wide

The linkage pieces do indeed say BT820 on them. BT820-1 and BT820-2 for the left & right links, BT820-BK for the back piece.

I attached a photo for reference. I can email you a higher resolution photo if it would help. Let me know if you need anything else!

BTW, this mechanical thumb is very well designed. I love this machine.

 

[jim_wilson]

Hi Jim - I took some measurements this morning for you. A couple of the c-c dimensions were tricky to get accurately as the main pivot pin is longer and the "housing" is wider than the other 3 pins, i.e. the ends of the pins are not in the same plane.

All pins are 1" diameter.
A = 5 1/2"
B = 23 13/16"
C = 9 13/16"
D = 9 13/16"
E = 5"

Dipper is 3" wide.
Main bucket pin/thumb pivot housing ~= 9 5/8" (pins are a little longer than the housings they sit in)
Other 3 bucket pin housings are 6 1/16" wide
Thumb strut pivot is 5 1/2" wide

The linkage pieces do indeed say BT820 on them. BT820-1 and BT820-2 for the left & right links, BT820-BK for the back piece.

I attached a photo for reference. I can email you a higher resolution photo if it would help. Let me know if you need anything else!

BTW, this mechanical thumb is very well designed. I love this machine.

Excellent!

Thanks for that info.

Now I need to get some measurements from a B26. I've been to three dealers in this area in the last week and nobody has one on the lot. I think I'm going to try contacting some TBN members and see if I can get some measurements from a B26 owner.

 

[Carl Bert]

Excellent!

Thanks for that info.

Now I need to get some measurements from a B26. I've been to three dealers in this area in the last week and nobody has one on the lot. I think I'm going to try contacting some TBN members and see if I can get some measurements from a B26 owner.

I've got a B26 with the hyd thumb and QA bucket. I'll try and get you the measurements today.

 

[jim_wilson]

I've got a B26 with the hyd thumb and QA bucket. I'll try and get you the measurements today.

View attachment 265309

That would be extremely helpful - thanks.

 

[Carl Bert]

That would be extremely helpful - thanks.

Ok to start off, I am a woodworker, so all of my measurements are squared up first then measured across. Does that make any sense? In other words if one pin sticks out 2 inches more then another that I am measuring to, I bring the other pin out the 2 inch difference, with a square then measure across. Is that the way you took your measurements, or did you go from actual pin to pin, no matter what the depth difference was? Here are my measurements. If I did it incorrectly, I can retake them tomorrow. Let me know, it's no problem.

A = 7 1/2"
B = 21 1/4
C = 9 7/8
D = 9 7/8
E = 5 5/8
F = 2 15/16 (that's the arm itself) if you want the measurement to to where the QA bracket actually sits then it's 3 7/8"

Pins are 1"

Hope this helps, let me know if you want me to retake the measurements, or if there's anything else I can do to help

 

[jim_wilson]

Ok to start off, I am a woodworker, so all of my measurements are squared up first then measured across. Does that make any sense? In other words if one pin sticks out 2 inches more then another that I am measuring to, I bring the other pin out the 2 inch difference, with a square then measure across. Is that the way you took your measurements, or did you go from actual pin to pin, no matter what the depth difference was? Here are my measurements. If I did it incorrectly, I can retake them tomorrow. Let me know, it's no problem.

A = 7 1/2"
B = 21 1/4
C = 9 7/8
D = 9 7/8
E = 5 5/8
F = 2 15/16 (that's the arm itself) if you want the measurement to to where the QA bracket actually sits then it's 3 7/8"

Pins are 1"

Hope this helps, let me know if you want me to retake the measurements, or if there's anything else I can do to help

Hi Carl,

I think I know what you mean by 'squared up and measured across'.

I attached a pic to detail what I think you mean.

Another question - when you measured - did you measure from the center of the pins - or on of the edges ( like A or B in the attached pic).

Some of the dimensions you and Radair took match up - they're actually the ones that correspond to the parts I found that are the same between the BT820 and BH77 hoes - so that makes sense. I just wanted to make sure the same methodology was used to do the measurements - because it's looking like the geometry on the hoes is not the same (bummer).

 

[Carl Bert]

Hi Carl,

I think I know what you mean by 'squared up and measured across'.

I attached a pic to detail what I think you mean.

Another question - when you measured - did you measure from the center of the pins - or on of the edges ( like A or B in the attached pic).

Some of the dimensions you and Radair took match up - they're actually the ones that correspond to the parts I found that are the same between the BT820 and BH77 hoes - so that makes sense. I just wanted to make sure the same methodology was used to do the measurements - because it's looking like the geometry on the hoes is not the same (bummer).

Yes that picture shows exactly what I mean. I measured from the center of each pin as shown in diagram B. Let me know if there's anything else I can do.

 

[jim_wilson]

I found what the no go issue for trying to use the QA attach setup from the BT820 on the BH77 hoe is: the pin at the end of the dipperstick on the BT820 is a 1 1/8" diameter pin - and the BH77 has a 1" diameter pin at the end of the dipperstick.

I ended up ordering the QA piece from Messicks' and it came in today. After taking it out of the box I could tell the holes where the two pins go thru were different diameters - and I remembered that the pins on the BH77 were all 1". I did some quick measuring - and double checked my BH77 hoe - and sure enough - the holes where the dipperstick pin would go thru on the QA piece - are 1 1/8".

This could be made to work - if some bushings were made to make up the difference between the 1" and the 1 1/8" pin - but I don't have access to a lathe any more, and I don't know of anybody who does.

I'd still love to have QA ability on the BH77 hoe - but I think this just turned into a fabrication project instead of parts swapping project.