Backhoe Thumb...weld or bolt?

[akpilot]

I considered both options, in the end I chose to weld it on, it didn't weigh as much and it was simpler.

 

[Dataway]

Pilot...have you got your 1" pins running through bushings there?

If so, what did you use for bushings? I'd rather not have to make something up on the lathe...anything off the shelf with a nice enough fit?
Thanks,
JohnnyB

 

[escavader]

Welded mine.Nice lip of steel overhanging the dipper stick on my BOTA SO IT DIDNT HURT A THING.Been on for several hundred hours now with no issues
ALAN

 

[andymil]

Doesn't Woods make an accessory BH thumb that uses the bucket pins for a mount?

I started a thumb for the hoe I made but haven't finished it yet. I was going to use the pin in the dipper for the links to mount the thumb instead of the bucket pivot pin. This puts the thumb about 5" from the bucket. I thought this geometry would work better and the links move a little less than the bucket. I'll just need a longer pin.

I haven't got to the mount for the other end yet. I haven't ruled out a cylinder instead of a fixed thumb.

 

[akpilot]

Dataway
I made 7/8" pins with my new lathe (for the practice) I didn't use any bushing material as they won't be roatating except for when I fold it up, therefore I didn't see much value. I'm going to drill the pins for grease zerks mainly to keep the rust down in the joint, if left on for long periods.

 

[Dataway]

Pilot,
Bushings was probably the wrong word...it looks like you have sleeves covering the pins in areas between the thumb halves.... the sleeves look to be welded to the inside of the thumb halves and the pins slide through them. It appears you have the sleeves limiting the side to side movement on one end of the link rod. I'd like to do a similar setup.
Thanks,
JohnnyB

 

[akpilot]

sorry ....They are made from heavy wall tubing that I bored to the correct size for the pins, here is a pic just prior to welding the main mount.

 

[Dataway]

Thanks pilot...just what I needed to know.
Nice work btw
JohnnyB

 

[Dataway]

One more question for the T.U.s (Thumb Users).

I'm laying out my pivot points etc. How about some input on where you position the thumb most often. 90 degrees to the boom or extended toward the bucket, or less than 90 degrees to the boom (farther from the bucket).

I'm trying to decide how many, if any, adjustment points I need, and how much they should deviated from 90 degrees in either direction.
Thanks,
JohnnyB

 

[dfkrug]

I'm trying to decide how many, if any, adjustment points I need, and how much they should deviated from 90 degrees in either direction.

You might also want to consider using a CAT 1 toplink, which you already
have, or you can buy one for $20. That would give you infinite adjustments,
but it would not allow full retraction to put the thumb in a storage position
against the dipper. I just removed mine when not in use. CAT 1 toplinks
are also available in different lengths.

I have long since gone hydraulic, but I used my mechanical fixed thumb
most often in a position approximately 75-deg from the dipper, towards the
bucket.