Backhoe thumb

[Green MT Welder]

i was wondering if anyone has plans for a mechanical thumb for a backhoe??

[DSW]

I don't have plans but have worked with a number of machines with them. Are you thinking of a fixed thumb or a hydraulicly actuated thumb?

[Flyingpig]

My father in law has been lusting for one for a while now.

[Green MT Welder]

I was thinking more on the lines of a fixed thumb for a 580D Case

[DSW]

Personally I would not use a telescoping brace. Remember that all your bucket thrust will be trying to collapse the brace. You will need a good sized pin to prevent this. On large machines they often have multiple holes for adjustment.



This one attaches to the boom on both points. I would be careful about bending the boom with one of these.
thumb.jpg



Here's a drawing with some dimensions I found for this style.
http://cdp-backhoe.com/backhoe_thumbs.htm

This drawing uses a single mounting plate base that will stiffen the boom if you mount the entire unit to the boom.
thumb dwg.jpg


Most I have worked with use the bucket pin as the pivot, like that shown in the pict by Iron head. You can get the correct size bushings ( replacement bucket bushings) and a longer pin from Case to do this. Use a good heavy plate for the jaw 3/4"+ and cut some serrations on it to grab material. A hook or lip at the bottom works well if you plan on using it to pluck curb or sidewalk.

Here's a couple more things that might help. These are on a Case so they may work best for your application.
thumb2.jpg
thumb3.jpg
thumb4.jpg

Hope these help.

[Green MT Welder]

Thanks's everyone you have been a great help as usual

[nkdmrt]

Go to http://www.excavatorthumb.com/

then click the link the model size you need and you can see some good pictures and info. There is some good info at that site.

Nick