Hydraulic controlled bucket QA?

[Xfaxman]

This is would work. Port A, extend. Connect port B and C with a tee to retract. The cylinder would be solidly mounted in the center. The rods could be the pins.


Pictures from Google Image Search

But don't know where you could find one the right size, probably could have one made by a good hydraulic shop.

 

[powerstroke444e]

After using a bobact with xchange I really want this form my b26 backhoe buckets and front bucket. I am thinking about just buying the bobcat parts and making them work???

 

[CDN Farm Boy]

But any time I can steal while having coffee, eating, etc, I try to put to good use - and since this particular mod will help both of us (and probably lots of lurkers :=) it would help if I had an idea of your welding/machining capabilities, either owned or accessible - some of my "brain farts" aren't as simple as others... Steve

I'm better than most with a welder and have a buddy with a 2x2 CNC plasma table. He also has a lathe. Trying to keep as simple as possible for obvious reasons.

 

[CDN Farm Boy]

This is would work. Port A, extend. Connect port B and C with a tee to retract. The cylinder would be solidly mounted in the center. The rods could be the pins.

View attachment 338269
Pictures from Google Image Search

But don't know where you could find one the right size, probably could have one made by a good hydraulic shop.

This would be ideal if I could get one the right size. You would have to have long enough rods that the engagement part never went past the seals though. It would be easy enough to build, in fact, I already have a "build it yourself" cyl waiting for a good use. I'd just have to get a matching one.

 

[BukitCase]

You said you only have 24" max - so 6" pins x 2, + 6" stroke X 2, + whatever thickness of pistons x 2 - math seems to be winning again :=(

Or were you being conservative on available space? Are your two bucket mounts really only 24" apart inside? Not familiar with Kubotas/models/sizing. My 580B should have plenty of room for a couple of the ideas we've been tossing around, but I realize it's a bit bigger than the average TBN'er rig :=)

I do like the twin piston cylinder tho, it'd simplify the rest of the build... Steve

 

[CDN Farm Boy]

Tight measurement is actually 25 1/4" between the pin bosses (now that I double checked). I want to leave a bit of room between the ear and the end of the pin when fully retracted but I could probably go up to 24 1/2", possibly even 24 3/4". There's less than 1/8" of slop between the bucket ears and the corresponding part of the QA so allowing for 1/4" clearance would probably be adequate.

I could also comfortably get away with 5 1/2" pins, including a bit of taper on the end. With a full-size mock-up, I may be able to get this down to 5 1/4"

5 1/2 pin x 2 = 11
5 3/4" travel x 2 = 11.5 (allows for the 1/4" clearance)
For a total of 22.5 leaving 2 or 2 1/4" for two pistons

A bit closer to beating the math but still not beaten.
I'll have to dig out my cyl to see how thick the piston is but I still have my doubts that I'll be able to get 2 of them with nuts into the 2" space :-(

Yes the twin piston idea certainly makes things easier if it would fit.

 

[aczlan]

If you don't already have one, Surplus Center sells a steering cylinder that might be able to be adapted with a center port and 2 rams vs one: 2x8x1.25 DA DOUBLE ROD HYD CYL

Aaron Z

 

[Xfaxman]

And you can get weld od ports here: Cylinder Components | Screw-In Glands | Gland Retainer Rings | Base Plates | Pistons

I think a 1 1/2" cylinder would be large enough, if you could find a steering cylinder like Araon posted.

 

[CDN Farm Boy]

Thanks for those links.

I'm quite familiar with the steering cylinders from full hydraulic steering on off-road buggies and was my first though....."If I could just get one of those that both ends went out but I've never seen/heard of them" In fact, I went this week to one of the biggest hydraulic shops in my area (over 1M population) and they have never heard of them (the double piston) -- ever. A quick phone call to their custom cyl builder and got a MINIMUM quote of at least a grand, more like $1500 or better to build what I'm asking -- if it could even fit within my space requirements. That's not going to fly. But I do know I could easily build it for under $500 with 2 of the Build-it-yourself kits, including some $$ to my buddy with the lathe.

Xman, That's a very helpful link. Looking at the different parts on it pointed out that there was a missing component from the original math -- while the piston thickness was accounted for, missing was thickness of the head area. This is significant as I'd want the engagement part to stop before it went thru the head seals, which by my reading of the measurements on this page will add approx 4" to the design which I certainly don't have room for.

I did a mock-up out of some electrical conduit I had kicking around and I can get by with 5" pins extending from 24 3/4" max allowable width at full retraction. So to try the math again:

5" pin + 2" head thickness + 5" stroke + 1" piston & nut X 2 is still more than the 24 3/4" I have available. Dang math wins again. Argh.

This would be a nice option on the next larger frame tractor but just ain't going to work for me.

On the next option......

 

[BukitCase]

OK, the crappy weather made me even lazier than usual - :thumbdown:

Here's one thought that's been worming its way thru my "little grey cells", as Inspector Poirot would say -

You might need the thick bushings shown in order to keep the full diameter of the pins trapped/guided, I would set this up so the pins can't ever escape the bushings unless you dismount the cylinders.

The "dogleg" for pin offset would need to be at least 1/2" x 1-1/2" flat bar, and the offset from centerline would need to be as little as possible and still get each cylinder to bypass the other one. Otherwise there would be too much side stress. If there's room, one of the two attachments to the "dogleg" should be a clevis - although the flex this would introduce might require too thick of a pin bushing for everything to fit

If you cut off anything on the cylinders that sticks out and isn't necessary, I think this would get you under your total width limit. It would also test your statement about welding skills (not that I doubt you)

It might be necessary to only mount each cylinder at its rear, letting the long bushing keep the other end aligned.

Best I got so far... Steve