How many "TnT" owners

[MtnViewRanch]

Couldn't you just plumb it like my front blade. Simple and this works to angle the blade. I don't know why this wouldn't work for tilt on a 3pt. Or am I missing something?

 

[orezok]

Well after a little research the easiest way to handle two cylinders is with a rephasing cylinder arrangement. Using double acting cylinders and two way valve the base of each cylinder is plumbed to the valve and the two rod end ports are connected together. Check valves are also used. Setup this way the cylinders can both move equal amounts (assuming the cylinders are the same size bore, stroke and rod size) . With this method there is no need to have a fixed connection between the two cylinders to keep them syncronized. The two cylinders move together not independently, while one is retracting the other is extending at an equal rate. The advantage is that you get a full range of motion to the hitch arms, tilting the implement in both directions the maximum amount.

I may not be understanding your statement, but it seems that if you "send" the same volume of fluid to both cylinders, the one that is retracting will travel farther than the one that is extending. This is because of the lesser displacement caused by the cylinder rod. Same reason that extend has more power than retract. I guess you could mount one cylinder opposed (up side down) to equalize the strokes.

 

[jenkinsph]

I may not be understanding your statement, but it seems that if you "send" the same volume of fluid to both cylinders, the one that is retracting will travel farther than the one that is extending. This is because of the lesser displacement caused by the cylinder rod. Same reason that extend has more power than retract. I guess you could mount one cylinder opposed (up side down) to equalize the strokes.

Look at the diagram again on my last post. The fluid moves between the rod sections of the cylinder so the displacement is the same. You can mount the cylinders in either position.

 

[jenkinsph]

MtViewRanch,

You could plumb it that way, that is how my backhoe swing cylinder is done. But notice in both of these cases you are rigidly fastened to a pivot point, this forces the position of the cylinders. With a 3ph this it may be difficult to tilt smoothly, one side may react before the other. If you run the hoses to the base end of the cylinders and then tie the two rod ends together this problem is eliminated. Also note less hoses and fittings too.


Me, I just want to cover all bases before I spend more money.

 

[orezok]

Look at the diagram again on my last post. The fluid moves between the rod sections of the cylinder so the displacement is the same. You can mount the cylinders in either position.

Unfortunately, there is no diagram in your post displayed on my computer.

 

[MtnViewRanch]

Steve, I had thought more about what I was thinking when I posted earlier, and yes I have realized that the center has to be a fixed position. I think that in trying to get it to what I think would have been simple and not costly I just plain over looked the obvious.

 

[gpflepsen]

Is this what you have in mind? http://www.tractorbynet.com/forums/hydraulics/161377-hydraulic-side-link-idea-am.html

I added post 15 to the above thread on arranging the cylinders so they are timed together independent of load. As suggested there, go with rod-side admission to limit the pressure in the slave loop oil.

 

[jenkinsph]

Unfortunately, there is no diagram in your post displayed on my computer.

MY BAD, I meant the link in my post #39, the link will take you to the diagram.

 

[jenkinsph]

I added post 15 to the above thread on arranging the cylinders so they are timed together independent of load. As suggested there, go with rod-side admission to limit the pressure in the slave loop oil.

That is a good point since in use the cylinders would be turned base up. Whats the deal with the check valves on the left cylinder are these necessary to function?

 

[gpflepsen]

That is a good point since in use the cylinders would be turned base up. Whats the deal with the check valves on the left cylinder are these necessary to function?

The orientation of the cylinders really is not important. The check valves allow the cylinders to remain in phase, or lets them return to phase at the end of the stroke in either direction. I'd consider them necessary for implementation, but not function. Without the CVs, you'd be breaking fittings to bleed, fighting to regain any lost timing, fighting to achieve synchronization at end of stroke, etc. The CVs allow bypass flow around the piston when the cylinder is at the end of the stroke, letting the other cylinder travel to the end of its stroke when they are out of time.

 

[dcyrilc]

Couldn't you just plumb it like my front blade. Simple and this works to angle the blade. I don't know why this wouldn't work for tilt on a 3pt. Or am I missing something?

That should work, but that machine is really begging for some dirt time.

 

[dcyrilc]

Steve, I had thought more about what I was thinking when I posted earlier, and yes I have realized that the center has to be a fixed position. I think that in trying to get it to what I think would have been simple and not costly I just plain over looked the obvious.

I guess I missed that too.

 

[MtnViewRanch]

That should work, but that machine is really begging for some dirt time.

Come on now, those pics were taken just after I was done refurbishing it. It is a little dirtier now.

 

[jenkinsph]

The orientation of the cylinders really is not important. The check valves allow the cylinders to remain in phase, or lets them return to phase at the end of the stroke in either direction. I'd consider them necessary for implementation, but not function. Without the CVs, you'd be breaking fittings to bleed, fighting to regain any lost timing, fighting to achieve synchronization at end of stroke, etc. The CVs allow bypass flow around the piston when the cylinder is at the end of the stroke, letting the other cylinder travel to the end of its stroke when they are out of time.

I agree in theory about the orientation of the cylinders not being an issue but in real world practice the tilt cylinders clevis connections seem to be made for rod down installations and are not symetrical.

So if you install the check valves on one cylinder you can correct phasing issues, is there any need or advantage to having check valves on both cylinders? And does this address the leak down issues that others have talked about with top link cylinders? So far leak down hasn't been an issue for me because when in use I make enough minute adjustments in realtime so as not to notice.

Right now I have a Deere factory top and tilt kit and was considering buying the same tilt cylinder to add on since it has the proper mounting configuration. I will have to see about adding the check valves to it, if ithat is a pain I might be better served to try to get an aftermarket phasing cylinder with the proper bore, stroke and clevis arrangement.

My real reason for wanting to use a single circuit for both cylinders is that I use the joystick to control the top and tilt. On both my 4520 and 110tlb with diverters the joystick operates the same, pedals and transmissions are the same so it allows me to switch between either tractor without any extra thinking (which I am not good at).

 

[MtnViewRanch]

Is there going to be a problem with the balls in the hitch binding up with all the tilt that 2 cylinders are going to give you? I am pretty sure that they would on my tractors. Something that is easy to check out before a lot of time and $$$ is spent.

 

[dcyrilc]

Come on now, those pics were taken just after I was done refurbishing it. It is a little dirtier now.

Oh good, glad to hear it get fed the dirt it deserves. LOL

BTW, if that's the result of a refurb, nice job... it looked new!

 

[dcyrilc]

Is there going to be a problem with the balls in the hitch binding up with all the tilt that 2 cylinders are going to give you? I am pretty sure that they would on my tractors. Something that is easy to check out before a lot of time and $$$ is spent.

Rob (3rrl) hasn't mentioned any binding problems on his setup, but he does have independent controls.

 

[jenkinsph]

Is there going to be a problem with the balls in the hitch binding up with all the tilt that 2 cylinders are going to give you? I am pretty sure that they would on my tractors. Something that is easy to check out before a lot of time and $$$ is spent.

For my uses having two cylinders is the same tilt as using one cylinder and winding up the adjustable link tight or leesening it all the way. On my setup the stroke is 4 inches so no problems with that. If you had longer stroke cylinders say 8 inch that may very well be a problem.

 

[ronjhall]

I installed TnT on my Kubota B2910 10 years ago. Do not use it on all task, but it sure is great to have for landscaping projects.

 

[kruszert]

This looks like a very useful addition to my DK35. Now I have to figure out how to install and where to put the valves.

DK35vince - - if you are still reading this post would you mind giving me a little more info about your TnT set up.

Reggie