Thread: Any one know about hydraulics?

Hi there,

Personally I suspect that you should have an independent hydraulic line to each cylinder on each side. Like you say, if you have a situation where the loading is not uniform the pressure in one cylinder will become high than the other. What will happen then is if you have both cylinders connected in a common line, the lighter side (with the lower pressure) will tend to lift at a faster rate, warping the bucket.

I don't know enough about hydraulics to know what the asnswer is or even if it would really be an issue. Perhaps you need to look at the worst case senario in terms of non-uniform loading and work out if it would really be enough to warp the bucket?

Perhaps in industry they use something that mitigates such issues. Have you thought of a single central ram similar to tip trucks?

Edit: I just had a closer look. It appears as though the lever is central. Why not have a single centralised hydraulic ram? Or, a single central ram that disengages the lever.

Simon

I think you will be fine just splitting the flow off via a tee. Looking at the pivot point, it looks like the bucket will tip by itself, so the cylinders wont be working hard to tilt the bucket. Worst case add in a couple of meter out flow controls at the cylinder ports to get some back pressure going on.

Regards Phil.

Originally Posted by simonl

Hi there,

Personally I suspect that you should have an independent hydraulic line to each cylinder on each side. Like you say, if you have a situation where the loading is not uniform the pressure in one cylinder will become high than the other. What will happen then is if you have both cylinders connected in a common line, the lighter side (with the lower pressure) will tend to lift at a faster rate, warping the bucket.

I don't know enough about hydraulics to know what the asnswer is or even if it would really be an issue. Perhaps you need to look at the worst case senario in terms of non-uniform loading and work out if it would really be enough to warp the bucket?

Perhaps in industry they use something that mitigates such issues. Have you thought of a single central ram similar to tip trucks?

Edit: I just had a closer look. It appears as though the lever is central. Why not have a single centralised hydraulic ram? Or, a single central ram that disengages the lever.

Simon

I think there are fancy cylinders that will move in a synchronized fashion, but they're mighty expensive.

The whole process started when trying to work out how to actuate the latch hydraulically, but nothing cheap nor simple came to mind.

The next idea was to use a single, central cylinder as you suggest. Problem is the bucket pivot is in the wrong place, so you'd need a very long stroke to get the bucket over to 45 degrees, and thus a long cylinder, but there's not enough room to fit it. I then considered moving the pivot point, but apart from the surgery required, the bucket isn't designed for the stresses that kind of mounting would create.

So a short (8") cylinder each side is the most feasible solution I've come up with, but never having done any hydraulics, was worried there was some rule I was breaking.

If I go with this, I think it'll just require operator training - i.e. make sure the load is spread evenly across the bucket.

Originally Posted by RustyArc

I think there are fancy cylinders that will move in a synchronized fashion, but they're mighty expensive.

Not that I think you need it, a geared flow divider would be the cheapest option.

First google hit. http://www.casappa.com/eng/02product...i/divisori.htm

They work like two (or more) gear pumps mechanically connected internally to each other, so flow through one gear set drives the other one, and puts the same flow through that other pump. (The cylinder with higher pressure, will back drive the same flow to the low pressure cylinder).

Because they are positive displacement gear elements, the accuracy is as good as the fluid loss between the face of the gears and housing. Accuracy better than 10% can be had on the cheap. They get complicated and more expensive when you get into pressure and temperature controlled.

Interestingly enough, the first google hit was to an Italian company. They have that Aluminium housing / gear pump market sown up. Not that I think you would need it, but a two channel gear divider like that could be had for $600ish.

Regards Phil.

(P.S My last post for the year boys. I'm going out to smash plates at a Greek Resteraunt, and I'm not even Greek. Happy New Year Boys).

Hydraulics used to be very expensive prior to the internet when you were essentially held captive by the local hydraulic repair man.... These days the internet can be your friend for finding parts cheaper...

Another option and I do not know how good they are is cable control with a 12V winch...

Loaders and other heavy machinery I have ever dealt with just use tee pieces for dual rams.. You just have to design the rams so one cannot overload your design..

Looking at the photos, the bucket has offset mounting, hence when you release the catch, the bucket (because of offset mount) then rotates to discharge the load.

Hence all you need hydraulics to do, is return the bucket to the horizontal position and hold in that position after the load has been discharged.

I believe a single cylinder in the center of the bucket would be sufficient to achieve this task. You would only need a single acting cylinder (pressure on one side of the cylinder piston) to pull the bucket back to the horizontal position after it had rotated. This would do away with the need for complicated hydraulics (flow divider valves, two cylinders, less hosing), by only needing one cylinder, hosing to the remote hydraulics on the tractor. Apply the KISS principle.

Agricultural cylinders are readily available thru agriculture outlets and tractor dealerships.

One cylinder in the middle will not work on that device without massive re-engineering of it.. There is just no room... Single acting cylinders can be in itself a real PITA to fit to a tractor.. they are mostly designed for double acting cylinders

Originally Posted by RustyArc

Posted this in the Welding forum and it was suggested here might be more appropriate...

So we've got a "tipping carryall" to go behind a tractor - very handy for moving material around, but it uses a lever to release a catch at the back to tip the bucket, which is hard to use if the tractor has a cabin.

IMG_0696.jpgIMG_0702.jpg

So the idea is to fit a hydraulic cylinder to each side like so:

CarryallMod.jpg


That way it can be tipped from within the cabin using the remotes. Also, it should allow the bucket to be crowded back a bit more.

I think it will work OK, although I'm not sure if you need more than a t-piece splitting the line to each cylinder? I've noticed loaders often have a control block with extra relief valves, which I assume is to help balance the pressure between two cylinders. If one side is more heavily loaded than the other, I'm guessing the bucket will get twisted?

Any suggestions welcomed.

I have had a rear bucket similar to yours for several years. It got quite a fair of use moving mulch, pebbles, sand, crushed rock and the like, and sometimes even dirt. That said, it became completely and utterly useless the day I bought a new tractor with front end loader (FEL).

I believe you may not yet have found out how these things work. A rear scoop is essentially a "poor mans replacement" for a FEL. Say if I wanted to speread out a truckload of mulch, I used to back into the pile with the empty bucket low, raise the full bucket, drive to where the mulch was needed. Then pull a cord attached to a vertical lever that did release the bucket catch, letting it tip the contents. Then drive away, on the way back to the pile lower the bucket and let it for a moment skid on the ground, which rotated the scoop to the up position and re-engaged and armed the catch. I actually had even modifed the catch, such as to have two raised positions depending on job at hand. Once one gets the hang, one can do about 5 round trips before leaving the seat. Sometimes I also had to use the bucket to scoop up soil, helping with a shovel to fill it, as it does not work nearly as well for soil as an FEL does.

The reason for the long explanation, I do not think adding hydraulics makes much sense. All that is needed is a simple rope attached to a catch release lever. These rear buckets are a primitive simple device. There is nothing that you can do better with a hydraulic actuator. You will gain only complexity by adding a hydraulic actuator. Better start saving for a real FEL, rather than spend time and money into a remote hydraulics actuator.

I found a few old pictures of my trusty old Iseki (I had that for nearly 20 years) with the rear scoop mounted (it was made by Kanga in Dandenong, costing some $4 to 500 about 10 years ago.) You can easily see the near vertical long catch release lever, with an eye on top for the "remote control" rope. I hope it gives you some inspiration on modifying yours.


Iseki1.jpgIseki2.jpgiseki3.jpgIseki4.jpgIseki5.jpgIseki6.jpg

A tee piece should work (as the pressure between the cylinders will tend to equalise), but looking at the application the bin will "self tip" tip if not held up - the hydraulics you are suggesting are really only to retract the bin. Rather than two cylinders, one at each end, what about one in the middle laying along the frame and then using some roller chain (like they do on forklifts) to allow the bin to tip or retract the bin. Half the cost (only one cylinder and hose), no need for complicated control circuits and compact enough that you can shorten the bin to tractor distance as you could with the original idea.
(I can sketch something if you are not clear on what I am suggesting)

Michael

Keep it simple, forget the hydraulics for this, just use a bendix cable with a lever in the tractor cab, just needs one "D" shackle or similar to connect at the time of connecting to the three point linkage.

Much easier for the simple process of "tripping" the bucket.

https://www.google.com/search?q=bend...26532086810249

Originally Posted by RustyArc

Posted this in the Welding forum and it was suggested here might be more appropriate...

So we've got a "tipping carryall" to go behind a tractor - very handy for moving material around, but it uses a lever to release a catch at the back to tip the bucket, which is hard to use if the tractor has a cabin.

IMG_0696.jpgIMG_0702.jpg

So the idea is to fit a hydraulic cylinder to each side like so:

CarryallMod.jpg


That way it can be tipped from within the cabin using the remotes. Also, it should allow the bucket to be crowded back a bit more.

I think it will work OK, although I'm not sure if you need more than a t-piece splitting the line to each cylinder? I've noticed loaders often have a control block with extra relief valves, which I assume is to help balance the pressure between two cylinders. If one side is more heavily loaded than the other, I'm guessing the bucket will get twisted?

Any suggestions welcomed.

I have a tee piece linking the Lift cylinders on My Homemade front loader and this set up works fine and have had no issue with warpage of the arms.

I would have thought that a mechanical release would be easy enough to make and much cheaper.

I am interested in your work as I intend to make something very similar to fit my 65hp Fiat which needs the diff lock released. I am guessing something is worn or broken inside. I have not been able to find a manual for it.

I don't suppose anyone knows anything about these (Diff locks). I was told by the guy I got it from that it was the right brake jamming on, as it does when you use it. I will look at this as well, at the same time as the diff lock. Funny how the tractor does not want to turn! I would have thought that with one brake applied it would not want to go straight. It takes all kinds.

Dean

Originally Posted by Oldneweng

my 65hp Fiat which needs the diff lock released. I am guessing something is worn or broken inside. I have not been able to find a manual for it.

What model Fiat is it?

QUOTE]Loaders and other heavy machinery I have ever dealt with just use tee pieces for dual rams.. You just have to design the rams so one cannot overload your design..[/QUOTE]

Its a +1 there. Thats all my 4 in 1 bucket uses to open the jaws. irrespective of what I do with it say grabbing tree roots on one side, no issues. So if you were to have an unevenly weighted load, no biggie.

But yeah as others have mentioned, a mechanical cable type arrangement with some thought will probably do it fine for you. Had thought of some kind of return spring for the bucket, but looking at your fotos again, guess it would just do that by itself once emptied.

If you went to a an FEL setup, you wouldnt go back Wouldnt be without mine. After spending a fair amount of my childhood with a grey MF 20 with only a 3 pt linkage and carry all, I certainally appreciate FEL.