BH77 - has anyone considered converting mechanical thumb to hydraulic?

[bandit67]

I thought I'd talk to someone like WR Long to see if they could come up with an electric-over-hydraulic setup like they have for the FEL remotes. They add a hyd block to the FEL block, so maybe something similar could be added to the backhoe hyd block. I'd like a switch setup that I could add to the backhoe bucket curl joystick, like on a mini-ex.

Actually might be a nice project for them to take on, since I'd bet they'd sell quite a few kits to owners of the smaller backhoes with mechanical thumbs. Worth a phone call, I guess.

If I was a hydraulic guru, I'd design & build my own setup, but since I'm not, it would ultimately be cheaper for me to just buy someone else's properly designed system.

[vic4news]

You might want to look at the Woods documentation for their mechanical to hydraulic conversion kit. Might give you some ideas of how you want to plump the valve.

http://www.woodsequipment.com/upload...ls/MAN0815.pdf

[Gary Fowler]

I have a B26 with hydraulic thumb and man is it handy. I like the foot control plate as it allows you to continue with full function of the hoe will closing or opening the thumb although it is a little cramped on the operator platform with the paddle folded out. I bought it used with 68 hours last June and have 220 hours on it now. The thumb is plenty sturdy and needs same hydraulic pressue as the hoe to operate correctly. Seems to me that one could splice in an extra block on the Hoe controls and run to the thumb control valve pretty easily. You will need to weld on some clips to hold the new hydraulic lines in place. The fingers on the thumb need to match up so that they fall between the teeth on the bucket not on top of them.

[CanuckPT]

If I am correct (and I think I am) my dealer offered me a mechanical thumb or hydraulic thumb on my bh77 when I bought it in 2011. I didnt get either one (had already went over budget) but later after my purchase became interested and did research to find that it is offered and is pretty beneficial to those who would use it alot. Wish I had just a mechanical one myself!

I'm about to pull the trigger on a Bro-Tek thumb for my BH77. I'll let you know how it goes!'

[KubotaToy]

I let the dealer talk me into getting hydraulic thumb on my L45 which was already set up for it. Best money I ever spend!

[CanuckPT]

Nice! I wish it was in my budget!

[ericdube]

Have a read through this thread if you haven't already. If you can do it on a BX, then I'm sure it's definitely possible on a BH77!

http://www.tractorbynet.com/forums/k...lic-thumb.html

[bandit67]

I'm about to pull the trigger on a Bro-Tek thumb for my BH77. I'll let you know how it goes!'

I hated that thumb on my BH75, and sold it within a couple months of getting it. The Kubota thumb on the BH77 is far superior. Still plan to eventually convert it to hydraulic.

[My Hoe]

Knowing the kind of damage that can happen to hyd thumbs, I elected to spare myself the trouble to modify my mechanical one.....If I was relying on using it for work (which I don't) then a hyd thumb conversion would be on my christmas list

That said, I love the mechanical thumb....

wdchyd,

Can you please expand on this statement: "]Knowing the kind of damage that can happen to hyd thumbs, I elected to spare myself the trouble to modify my mechanical one....." Just never heard of any issues, other than if you try to put a thumb on a bucket where the teeth don't "mesh" between the two, then you can bend parts, I'm told. In other words, as Gary Fowler, said, above: "The fingers on the thumb need to match up so that they fall between the teeth on the bucket not on top of them."

Curious as to what issues you've run into.

Thanks,

My Hoe

[wdchyd]

Not to poo-poo on anyones wishes to install one but realize I do cylinder rebuilding, and that includes damaged ones

Many bent rods (leading to scored barrels cuz the piston head cocked sideways internally) have been diagnosed back to the problem of induced load

Meaning a force pushing in to the thumb piston is greater than the hyd cylinder can survive from another source......the bucket curl.

The bucket curls larger displacement and leverage can put extreme forces while clamping down using the curl cyl, unless there is a relief setup to allow extra pressure to relax (ie:work port reliefs in the control valve) during curl cyl use

If the hyd thumb is properly installed, the thumb cyl should go back in when there is too much pressure.....not bend and self-destruct. Without the safety of the reliefs plumbed in to the base end of the thumb cyl, the pressure intensifies greater than the rated pressure of the cylinder (assuming the thumb cyl is smaller than the curl)

Ideally either work ports reliefs or sizing the cylinder large enough to match is my recommendation

I actually have no problem with hyd thumbs, just not on my machine, I don't make a living with it