BH77 - has anyone considered converting mechanical thumb to hydraulic?

[bandit67]

I agree that reliefs are an important feature to avoid damage. However, if I find a kit without the reliefs built in, then that just means I will take more care, and use the thumb to clamp items rather than using the bucket curl cylinder to clamp. It is my own backhoe used primarily on my property for personal use.

wdchyd, I'm sure you see mostly commercial damaged thumbs, and as you know, commercial guys are extremely hard on equipment. Time is money, and everything they do is SIGNIFICANTLY faster than the work the average private equipment owner does, especially since the hydraulic systems on commercial units allow much faster movements. Something the smaller, non-commercial units are not capable of.

So if the "kit" I find to install on my machine does not have a proper relief valve on the thumb kit, I'll just take more care to avoid damage. If I was capable of designing & building my own hyd thumb conversion, then I'd include a relief valve.

As to that issue, I will find out if the company that is considering offering us a hyd conversion kit for the BH77, also includes the proper relief setup.

 

[bandit67]

I just got an email from the company that I've been speaking with after asking about the relief setup. I got this reply:

We don't usually do a cross-over relief system on the smaller backhoes (usually just on the larger excavators and backhoes), but I can definately look into pulling one together for you with pricing if you would like. On the smaller backhoes we size the hydraulic cylinder so that the column load of the cylinder can handle the breakout force of the bucket to avoid buckling.

The delay has been that they haven't been able to get their hands on a BH77 to get actual measurements off of. A while back, I offered to assist with getting them the dimensions if they had difficulty getting ahold of a BH77 at their local dealer, so they will be sending some dimension sheets for me to fill out and take pictures of my BH77 so they can get to working on a thumb kit for it.

I'll update this thread as I hear how things are progressing.

 

[wdchyd]

Check out this one from a thumb



it was 2.500" dia......believe it or not the cyl barrel was not damaged, the gland was wrecked though

 

[CHDinCT]

Check out this one from a thumb

View attachment 310125

it was 2.500" dia......believe it or not the cyl barrel was not damaged, the gland was wrecked though

A little duct tape and it should be good as new.

 

[CanuckPT]

I just ordered a mechanical thumb for my Kubota BH77 from Richard at Bro-Tek! Can't wait to bolt that puppy on and try it out when it arrives!!

 

[bandit67]

Update on the hydraulic thumb option. The company I've been talking to is working on it right now. I've submitted photos & dimensions to them to get their current compact hydraulic thumb version modified as required to fit the BH77, because they had not been able to get ahold of one locally. They are hoping to get their hands on a backhoe in the next few weeks to set everything up and test it. If they can't get ahold of a BH77 in a reasonable amount of time, we've discussed doing final fitting/testing on mine.

We're discussing 2 options for thumb control.

Hydraulic Foot Pedal Control: Includes 2" Bore Hydraulic Cylinder, Hydraulic Control Valve with Foot Pedal, all hydraulic hoses and fittings for connections, and any pins and mounting hardware required.

Push Button Control on Backhoe Joystick Handle: This set-up would include a new control grip with a built in momentary switch, electric selector valve, 2" Bore Hydraulic Cylinder, and all hydraulic and electric connection hoses/fittings/etc. Selection would be between the boom swing function and thumb circuit. This would give you the thumb control in your left hand and bucket control in the right hand so you could use them at the same time. Also, the thumb control and bucket control would both be in the left-right direction of the joysticks.

 

[ericdube]

Update on the hydraulic thumb option. The company I've been talking to is working on it right now. I've submitted photos & dimensions to them to get their current compact hydraulic thumb version modified as required to fit the BH77, because they had not been able to get ahold of one locally. They are hoping to get their hands on a backhoe in the next few weeks to set everything up and test it. If they can't get ahold of a BH77 in a reasonable amount of time, we've discussed doing final fitting/testing on mine.

We're discussing 2 options for thumb control.

Hydraulic Foot Pedal Control: Includes 2" Bore Hydraulic Cylinder, Hydraulic Control Valve with Foot Pedal, all hydraulic hoses and fittings for connections, and any pins and mounting hardware required.

Push Button Control on Backhoe Joystick Handle: This set-up would include a new control grip with a built in momentary switch, electric selector valve, 2" Bore Hydraulic Cylinder, and all hydraulic and electric connection hoses/fittings/etc. Selection would be between the boom swing function and thumb circuit. This would give you the thumb control in your left hand and bucket control in the right hand so you could use them at the same time. Also, the thumb control and bucket control would both be in the left-right direction of the joysticks.

Personally, I think the hydraulic foot pedal control would be the way to go. This is identical how you operate the thumb on larger backhoes, and works quite well.

Do you have any estimates on the cost? I'm going to be buying a BH77 backhoe with my B3350, and depending on price I might consider upgrading to a hydraulic thumb depending if the price was reasonable. Thanks!

 

[bandit67]

Mini Ex's have the thumb control in the joystick controls. That's the only machine I've used a hydraulic thumb on. None of the full size TLBs I've run have had the thumb.

My concern was getting the foot control set up so that it doesn't take up too much platform space, because there isn't a lot of spare room, but we've had discussions on that, and thrown some ideas back and forth, as per an email response:
"I understand your concern with the foot pedal. I think if we were going to go that route we would probably mount the pedal on a small platform off to the side like you suggested earlier. From what I could tell from your pictures that should certainly be plausible. As for feathering, you can control the thumb pretty well with the foot pedal. We also size the lines, valve and cylinder based on the GPM and Pressure of the backhoe so that it functions smoothly, so I don't think you need to worry about that part."

Pricing I've been given is $595 for foot pedal & $990 for pushbutton control. Their current model foot pedal is $595. Not sure if adding a small platform for the foot pedal will impact price. "Price Includes 2" Bore Hydraulic Cylinder, Hydraulic Control Valve with Foot Pedal, all hydraulic hoses and fittings for connections, and any pins and mounting hardware required."

If the foot pedal option can be set up without eating up too much platform space, I'll probably go that route, since I also need/want to add a 3rd function valve to the FEL so that I can finally add hydraulic angle rams to my snow plow this year.

None of these hyd add-ons are cheap, but I'm tired of wasting time having to manually operate the thumb, snow plow angle, etc. Over the life of a machine, it's a small price to pay. And I'd get a lot more use out of the attachments if they were easier to use.

 

[jim_wilson]

Excellent.

Glad to see somebody is looking into this - I've been thinking of doing the exact same thing on the BH77 hoe on my B3200.

I hadn't seen anybody offering a kit to do this - so I was spending the time searching all over the internet to see if there was a cylinder available that would work - trying to figure out where to mount the valve - and plumb it in to the existing valve stack - etc.

The plumbing out to the cylinder is the easy part - the BT820 hoe on the B26 tractor is so similar to the BH77 in size - that I bet you could just lift the plumbing from the valve out to the cylinder from the BT820 and use it on the BH77.

How far along is this company in developing a solution Bandit67?

Any idea on what the cost will come in at?

I am definitely interested in this if something comes together.

Where is this company you're dealing with located? Any TBN'ers local to them that could let them take a look at a BH77?

 

[bandit67]

I expect that they should have it ready for us in the next couple months. They've been trying to get their hands on a BH77 locally. If they can't do that soon, then we'll use my machine to test everything. They already have a thumb kit for compact hoes with a hydraulic upgrade to their kit - I just asked them to retrofit the hydraulic upgrade to the BH77's mechanical thumb.

See pricing they've discussed in my post above.

 

[jim_wilson]

I expect that they should have it ready for us in the next couple months. They've been trying to get their hands on a BH77 locally. If they can't do that soon, then we'll use my machine to test everything. They already have a thumb kit for compact hoes with a hydraulic upgrade to their kit - I just asked them to retrofit the hydraulic upgrade to the BH77's mechanical thumb.

See pricing they've discussed in my post above.

Great.

I already have the Kubota manual thumb on my BH77. Just having an upgrade that converts it to hydraulic was exactly what I was looking for.

If they're located in the New England area - let me know. Maybe I can help out to get this going.

It's funny. I've been going over my B3200 the last few days trying to think out some of the improvements I'd like to make. And just today I thought I would start looking into the hydraulic thumb thing too (along with some other things) . So I sat down tonite and started searching - and came across this thread. I must have missed it - because I don't remember seeing it before.

 

[CDN Farm Boy]

How are they tying in the plumbing of the new valve?

I've got the perfect cyl waiting, just have to cut off the base mount, rotate 90 deg and re-weld. I thought about using a diverter valve with a switch on the boom stick but I'd have to get 12v power to is somehow - and remember to unplug the wires when I remove the BH. I could run lines to one of my other sets of remotes but then again an extra set to hook & unhook every time. It would be nice to have it plumbed off the existing BH valve but as I understand it, you can't mount valves in series.

$600 sounds like a smokin deal to me for a complete kit - but I'm used to hydraulic prices up here in Canada.

 

[My Hoe]

We're discussing 2 options for thumb control.

Hydraulic Foot Pedal Control: Includes 2" Bore Hydraulic Cylinder, Hydraulic Control Valve with Foot Pedal, all hydraulic hoses and fittings for connections, and any pins and mounting hardware required.

Push Button Control on Backhoe Joystick Handle: This set-up would include a new control grip with a built in momentary switch, electric selector valve, 2" Bore Hydraulic Cylinder, and all hydraulic and electric connection hoses/fittings/etc. Selection would be between the boom swing function and thumb circuit. This would give you the thumb control in your left hand and bucket control in the right hand so you could use them at the same time. Also, the thumb control and bucket control would both be in the left-right direction of the joysticks.

Please correct me if I'm wrong, but isn't the non-foot pedal control simply an electric solenoid? And IF that's correct, doesn't that leave you with ZERO FEATHERING ABILITY on the thumb?

If so, THAT, plus possibly no relief valve, seems like quite a bit of potential for trouble--bent rod, etc....

Have you read the instruction manual, someone posted a page or so back, for the addition of a hydraulic thumb to the Woods BH80-X "Groundbreaker?" Some feel that is a superior hoe to begin with (no offense, but they DO offer a hydraulic thumb option on their B-class-sized hoes) and I'm wondering if the team working on your conversion couldn't benefit from reviewing it's foot pedal control valving/setup, which I BELIEVE would allow feathering.

Since Woods are often fitted to Kubotas, I have to believe there's some valuable info in there, for the "hydraulic gurus" to use.

Why reinvent the wheel?

Just my .02

 

[bandit67]

The foot pedal control DOES allow feathering. They already have a hyd thumb option. I have just asked them to fit the hyd thumb upgrade to the BH77's mechanical thumb.

Some feel that the Woods hoe is superior? Big deal. Give me one example of someone who has owned both the "superior" Woods hoe and the Kubota hoe. I've owned 2 Kubota hoes on B series, and though the current hoe doesn't have a lot of hours on it, the first one did all I asked of it, a lot of what it was able to do, coming as a surprise. I don't think you'll find too many B series owners out there who have done more hard digging than I have.

I found someone with a good reputation for putting out quality tractor components that was willing to look at fitting their existing hydraulic kit to the BH77 so that I, not being a hydraulic guru, didn't have to attempt to do myself. Woods wasn't willing to do that for us, at least not in the past.

 

[Gary Fowler]

I have a B26 and the foot control pedal on my hydraulic thumb. It folds up and locks with a pin when not in use and is completely out of the way. I don't know if my platform is larger that yours or not, but even with it folded down, it is still plenty of room for your feet. It is mounted on the right side of the control tower just above the floor.The way the hydraulics are set up, the thumb seems to be as strong or stronger than the bucket. I can curl it up against the thumb and it stops the bucket and vice versa, I can push the thumb against the bucket and it stops without any damage. I have no idea how any one can bend a cylinder on these unless he lets the dipper down on a rock so it contacts the cylinder rod. Neither of them should have the power to bend the others hydraulic cylinder.
I think if I were putting on a thumb, I would go with the foot pedal simply for less money, more control and no electrical component to go bad.

 

[My Hoe]

Deleted--people who won't (or can't?) READ ACCURATELY, and who are then RUDE, when I'm trying to HELP them, are not worth my time.

 

[bandit67]

Thanks for the valuable input.

You jumped into the thread acting like the folks I'm talking to were a bunch of yahoos that didn't know what they were doing after you apparently hadn't read through the thread. All of these issues have been discussed. And Woods didn't offer a hydraulic thumb when the BH80 was first introduced, so their marketing about it being designed for a hydraulic thumb has had to be changed. Yes, it was the only one for a while that could be installed on a B series cab machine. I certainly didn't find the Woods unit to be a superior option on my B3030 open station because it hung so far off the back end since there was only one frame available. Now, there are 2 hoe options for the B series cabs. Woods & Kubota. I suspect now that Kubota has addressed the cab issue, that Woods share of the market has dropped off dramatically.

As for the hydraulic thumb, there's no reason it can't be designed to safely operate without damaging the hoe or the hydraulic cylinders and in all reality, doesn't require any additional strength added to the hoe. If Woods was forced to reinforce their hoe once they added hydraulics to their thumb, then maybe it wasn't so superior to begin with. Keep in mind that these are fairly small machines, with low hydraulic flow, and the pictures of damage you may have seen typically come from larger, more powerful commercial units.

However, I'm not going to get into a Woods vs Kubota hoe p***ing contest, as owners of both brands seem quite happy with their hoe.

You get all defensive, come across with a certain tone in your first post disrespecting the company that is working on the thumb, then come back with an even more obnoxious tone in your second post, then end it with "peace"? Nice.

I see you decided to delete your obnoxious post. Thank you.

 

[bandit67]

Just to clarify for those that may still be interested in the option of joystick control of the thumb. The electric solenoid push button switch that can be mounted on top of the joystick will switch back and forth between thumb open/close and boom left/right swing, so when you hit the switch to use the thumb, the right joystick curls the bucket and the left joystick opens/closes the thumb. And yes, you can FEATHER the thumb with this configuration, just like you can with the foot pedal configuration.

Gary, thanks for the heads-up. They're working on some ideas for keeping the foot pedal out of the way, and the B26 flip setup is one of the options they're investigating.

 

[jim_wilson]

I have a B26 and the foot control pedal on my hydraulic thumb. It folds up and locks with a pin when not in use and is completely out of the way. I don't know if my platform is larger that yours or not, but even with it folded down, it is still plenty of room for your feet. It is mounted on the right side of the control tower just above the floor.The way the hydraulics are set up, the thumb seems to be as strong or stronger than the bucket. I can curl it up against the thumb and it stops the bucket and vice versa, I can push the thumb against the bucket and it stops without any damage. I have no idea how any one can bend a cylinder on these unless he lets the dipper down on a rock so it contacts the cylinder rod. Neither of them should have the power to bend the others hydraulic cylinder.
I think if I were putting on a thumb, I would go with the foot pedal simply for less money, more control and no electrical component to go bad.

That's the kind of option I would prefer. I think a B26 style foot pedal with the thumb being on it's own hydraulics would just be a better setup all around - vs - piggybacking off the hydraulics of one of the existing valves in the control stack for the hoe.

The problem with separate hydraulics is: how do you add it in. I've looked at the setup on the BH77 quite a bit - and the only way I can see to make it it work is somehow graft another valve inline - and they control it with some linkages from a lever - or a foot pedal.

 

[CDN Farm Boy]

That's the kind of option I would prefer. I think a B26 style foot pedal with the thumb being on it's own hydraulics would just be a better setup all around - vs - piggybacking off the hydraulics of one of the existing valves in the control stack for the hoe.

The problem with separate hydraulics is: how do you add it in. I've looked at the setup on the BH77 quite a bit - and the only way I can see to make it it work is somehow graft another valve inline - and they control it with some linkages from a lever - or a foot pedal.

This is what I've been wondering. And where do you put it?

How is it done on the B26? Do they come stock with the extra valve in the stack already and the option of the aux lines gives you the linkages to the valve and the boom lines?