BH77 - has anyone considered converting mechanical thumb to hydraulic?

[bumperm]

To save having to cut off and re-weld the tubing end (to reposition the cylinder's ports to the side), this cylinder has adjustable ports, though a little pricey at $171:

http://www.baileynet.com/product/19560

I'll report back on how it turns out. My current plan is to use the hydraulics from my existing 3rd function valve located just forward of the cab on the right side. That means two additional quick connects and an electric connector when installing and removing backhoe, but I think worth it. There's not much room for a foot switch (I have big feet), so I may use push buttons on the right joystick.

bumper

 

[dfkrug]

To save having to cut off and re-weld the tubing end (to reposition the
cylinder's ports to the side), this cylinder has adjustable ports, though a little pricey at $171:

Interesting cylinder from Chief. Never seen one like that with movable ports.

Note that tierod cylinders have that ability, and their only other advantage is they are cheap.

I do not like tierod cyls, but I modified one for my hyd thumb because of the ports.

 

[CDN Farm Boy]

Interesting cylinder from Chief. Never seen one like that with movable ports.

Note that tierod cylinders have that ability, and their only other advantage is they are cheap.

I do not like tierod cyls, but I modified one for my hyd thumb because of the ports.

I have one tie rod cyl here but you can't change the orientation of the base port relative to the pin. Head port yes but not the base.

Big down side to tie rod cyl is that they take up much more space than their thread-head counterparts

With your thumb & valve setup, do both of them work simultaneously from the same control or does it require 2 separate controls to move them together?

 

[dfkrug]

With your thumb & valve setup, do both of them work simultaneously from the same control or does it require
2 separate controls to move them together?

I have a toggle switch on my hoe dash. Flip it ON, and the curl function moves both bkt and thumb. One
control.

Flip the switch OFF and the thumb stays fixed whereever it is.

 

[bumperm]

I just finished my BH77 mechanical thump to hydraulic conversion. Thanks for all the creative ideas Dave!!

See post #36 on Dave's thread for details. I opted for a push button on the right joystick.

http://www.tractorbynet.com/forums/build-yourself/125912-custom-hydraulic-backhoe-thumb-4.html

bumper

 

[CanuckPT]

Congrats!

Sent from my iPhone using TractorByNet

 

[beckmurph]

You may answered this question already:
Did you look into the hydro thumb on the bh92. As in, could you have used the hydraulic components from the bh92?

 

[bumperm]

You may answered this question already:
Did you look into the hydro thumb on the bh92. As in, could you have used the hydraulic components from the bh92?

I didn't check - didn't occur to me. Now that you mention it, though, I guess my thinking is that the bigger BH92 would probably have a larger diameter curl (bucket) cylinder than does the BH77. I looked up the part 7K505-43010 on Messicks, $705.45!!! But unfortunately no description as to size - must be bigger though. In any case, one of the design considerations mentioned elsewhere on this forum, is with a hydraulic thumb you don't want the bucket to way over power and damage the thumb, its cylinder, or over pressure the thumb side hydraulics - - so a reasonably close match, considering the linkage and leverage, will have the curl cylider acting upon the hydraulic thumb, at least in the same mechanical manner, as it did when the thumb was manual.

I haven't let the thumb and bucket come up against each other with max force yet - - have picked up a big rock to test it, but plan on sneaking up on max force operation to see how it behaves, hopefully without bent steel and hydraulic spray.

bumper

 

[CDN Farm Boy]

I haven't let the thumb and bucket come up against each other with max force yet - - have picked up a big rock to test it, but plan on sneaking up on max force operation to see how it behaves, hopefully without bent steel and hydraulic spray.

bumper

I have many times, including prying back and forth against it grasping the top of broken off fence posts to pull them put of the ground. No issues yet

 

[broncorm]

Nice job
Ready to put a kit together? I'll take one.