Hydraulic top link

[crazyal]

In the future I'm planning on adding two remotes but not sure if I'll have time to do it this summer. I looked at the Hydralink but it seams to me it would be a waste if I'm just going to add TnT down the road. I was thinking that I could use a top cylinder from a TnT set up and connect the two ports with hydraulic lines and a simple ball valve and fill it with hydraulic oil and get the similar results. Valve open would float, valve closed would lock it at that length (barring any internal piston leak).

When I add the remotes I would just be able to remove the valve and put quick connects on the ends of the hydraulic lines. Plus unlike the Hydralink I could mount the valve within reach from the seat.

Why I'm thinking of doing this is I want to make a grading scraper. Most people who have them seam to let them float when using them. For short runs this would be a PIA vs if everything but the valve will be used for a TnT then it's not really costing much.

So what do you guys think? Waste of time? Should work just fine? Would work but not that well?

 

[Zebrafive]

You would have to be able to move the cylinder to the length you want and then close the valve. I can see where this may be hard to do without hydraulic power. It might also be hard to make minor adjustments.

 

[crazyal]

It wouldn't be for minor adjustments into I have the remotes installed but more of an easy way to make any attachment float. When the grader is sitting flat on the ground closing the valve would just set the length. The only reason for closing it would be for transporting, either to the spot on the road or if I want to turn around or back up to do another pass.

While searching for hydraullic top links I'm finding some with this set up on them.

Is that just so both hoses mount next to each other or does the block serve another purpose?

 

[Rustyiron]

Fill me in on a TnT. What is it? As for your hyd. rop link, If you are able to build a grader box you can surely build a hyd top link. I've made a few using a short cyl. and welding speed balls on the ends. Maybe I don't understand wuthout knowing what a TnT is.

 

[Gordon Gould]

Crazy that is a DPOCV or Double Pilot Operated Check Valve. I can tell you this because I just learned it :laughing: ( ie don't trust me 100% )
It is ment for a safty devise. It holds the pressure in the cylinders in case you blow a hose. It will also hold the cylinder if you have a leaky control valve.

 

[rjkobbeman]

It wouldn't be for minor adjustments into I have the remotes installed but more of an easy way to make any attachment float. When the grader is sitting flat on the ground closing the valve would just set the length. The only reason for closing it would be for transporting, either to the spot on the road or if I want to turn around or back up to do another pass.

While searching for hydraullic top links I'm finding some with this set up on them.

Is that just so both hoses mount next to each other or does the block serve another purpose?

Crazy that is a DPOCV or Double Pilot Operated Check Valve. I can tell you this because I just learned it :laughing: ( ie don't trust me 100% )
It is ment for a safty devise. It holds the pressure in the cylinders in case you blow a hose. It will also hold the cylinder if you have a leaky control valve.

Crazyal,

That unit you have a pic of is identical to my HTL from CCM. I am sure it is the same unit.

Like Gordon says, that block is a check valve. It is a safety. If you blow a hose, the cylinder will not move. It requires significant pressure (as is supplied by the pump when you are actually wanting to move the cylinder) to move. This means that a valve in the "float" position will not work... if you ever wanted to use it for that (normally not required in the HTL application).

I got mine right after I got my tractor last year. It is priceless. You will love it if/when you get one.

I can see the Hydralink being handy if you just want a top link that is easy to adjust. If you want to lift an implement off of the ground it is pretty much useless in my opinion. It is pretty much a cylinder that is in "float" or "lock" mode. There is no hydraulic pressure to lift.

 

[Chilly807]

You may have a problem with the hoses and isolation valve because the volume on each end of the cylinder is different. One end has only the end of the piston, the other has the rod as well. In other words, when you retract the cylinder, the displaced fluid volume as the piston moves back will be greater than the space it has to fill.

Sean

 

[kennyd]

Search the term "dpocv" for lots of reading on those cylinders, they will NOT work with the two hose and ball valve method you proposed.

 

[Big Wave D]

It seems that the cylinder would have to have a closed system. The hose ends would have to be connected to one another, thus saving you from having more fluid on one side of the piston than the hose it can go in too.

If you spliced a simple ball valve into your 'loop', it seems you'd at least have float and lock, plus you could crack the ball valve open just a touch and have a 'controlled' or slower reacting float.

For those of you who really know what you're talking about, tell me if I'm hot, cold, or insane, please.

Thanks

 

[kennyd]

It seems that the cylinder would have to have a closed system. The hose ends would have to be connected to one another, thus saving you from having more fluid on one side of the piston than the hose it can go in too.

If you spliced a simple ball valve into your 'loop', it seems you'd at least have float and lock, plus you could crack the ball valve open just a touch and have a 'controlled' or slower reacting float.

For those of you who really know what you're talking about, tell me if I'm hot, cold, or insane, please.

Thanks

Everything you wrote is true, except if you have a DPOCV. Search it like I suggested above.

 

[Big Wave D]

Everything you wrote is true, except if you have a DPOCV. Search it like I suggested above.

Thanks for the validation on my thought process.

I do understand what you were saying about that special cylinder. It takes the working pressure of the pump to over come the check valves or what ever device they use to prevent fluid from escaping when lower than operating pressure.

I'm thinking lifts where people are on board would be mandated to using those.

 

[Gordon Gould]

Crazy - when I use my grader I always use a top link to start then switch to a chain top link for one more pass to finish up. If I start off with a floating top link and a hard road the grader will jump around quite a bit when it hits an embedded rock or hard spot as there is nothing to hold it from kicking or rolling up. Also if the back is not real heavy it will tend to roll forward on the front blade with normal cutting. ( Mine doesn't do this but some do ) After I get everything loosened up I take the pin out of the fixed link and use the chain so I can follow the road contour better and still pick the grader up.
What I am trying to say is that I don't continually switch between fixed and float. I only change once. You may also find that to be true so your float valve may not be that important.
Maybe when I get my hydraulic top link I will be able to throw my chain link away.

 

[kennyd]

FYI: You cannot "float" a cylinder with a DPOCV either

 

[crazyal]

Sounds like the check valve would defeat what I would like to be able to do.

I think the hydralink has some air in it to account for the difference in volume between the side with the rod and without it. Technically I think I could just add a breather to one port and fill a reserve up with oil and have a valve between it and the other port on the cylinder. It may be more work than it's worth.

I think you'll need a remote that's able to do float.

 

[crazyal]

Crazy - when I use my grader I always use a top link to start then switch to a chain top link for one more pass to finish up. If I start off with a floating top link and a hard road the grader will jump around quite a bit when it hits an embedded rock or hard spot as there is nothing to hold it from kicking or rolling up. Also if the back is not real heavy it will tend to roll forward on the front blade with normal cutting. ( Mine doesn't do this but some do ) After I get everything loosened up I take the pin out of the fixed link and use the chain so I can follow the road contour better and still pick the grader up.
What I am trying to say is that I don't continually switch between fixed and float. I only change once. You may also find that to be true so your float valve may not be that important.
Maybe when I get my hydraulic top link I will be able to throw my chain link away.

There's a video on YouTube of a LandPride grader behind a pretty small tractor. With the ripping teeth down it jumps quite a bit but it also looks light. Once they pull them up it's much smoother. I figured that I would just add weight to the rear of the grader but I've never used one so it'll be a learning experience.

 

[rjkobbeman]

There's a video on YouTube of a LandPride grader behind a pretty small tractor. With the ripping teeth down it jumps quite a bit but it also looks light. Once they pull them up it's much smoother. I figured that I would just add weight to the rear of the grader but I've never used one so it'll be a learning experience.

Although I love my CCM hydraulic top link, it is really nothing out of the ordinary... except maybe the check-valve. If you don't want that, there are a lot of places to get a regular HTL.

I have a Land Pride grading scraper I use to grade my long gravel drive... and never see the need to float the top link. I actually use the top link to cut "more" or cut "less". Floating would prevent me from doing that. My 3ph is set all the way down so the grading scraper is resting on the ground. The HTL is used to change the angle of attack and take a bigger or smaller bite.

 

[fixit]

OK if you only want to adjust the lenght or let it float then i would thing you could have a ram with a tap on each port connected to a small tank that is big enough to except the difference in volume between the rod side and the non rod end

Open both taps and it will float. Then lift arms to set to lenght then shut valves to lock off:thumbsup:

Just thinking aloud so might well be wrong or missed the point:confused2:

 

[crazyal]

Although I love my CCM hydraulic top link, it is really nothing out of the ordinary... except maybe the check-valve. If you don't want that, there are a lot of places to get a regular HTL.

I have a Land Pride grading scraper I use to grade my long gravel drive... and never see the need to float the top link. I actually use the top link to cut "more" or cut "less". Floating would prevent me from doing that. My 3ph is set all the way down so the grading scraper is resting on the ground. The HTL is used to change the angle of attack and take a bigger or smaller bite.

My drive is almost 3/4 of a mile long with plenty of changes of grade. On flat ground I would think just setting the standard top link would be fine but at the transitions points I'm wondering if I would bit in too much. My thought was I could just let it float and use weight and blade height adjustment to control the bite.

Part of the reason I'm thinking of holding off on the remotes is I'm still not positive exactly what combination I would want.

 

[MtnViewRanch]

My drive is almost 3/4 of a mile long with plenty of changes of grade. On flat ground I would think just setting the standard top link would be fine but at the transitions points I'm wondering if I would bit in too much. My thought was I could just let it float and use weight and blade height adjustment to control the bite.

Part of the reason I'm thinking of holding off on the remotes is I'm still not positive exactly what combination I would want.

When in doubt, get it all. Get all of the valves with float and auto kick-out detents. That way you have every alternative and you can't go wrong. Costs a little bit more, but worth it.

At transition areas, I put the side link in float mode so as to allow the blade to twist through the transition. Makes for a very smooth job. :thumbsup:

 

[skipmarcy]

My drive is almost 3/4 of a mile long with plenty of changes of grade. On flat ground I would think just setting the standard top link would be fine but at the transitions points I'm wondering if I would bit in too much. My thought was I could just let it float and use weight and blade height adjustment to control the bite.

Part of the reason I'm thinking of holding off on the remotes is I'm still not positive exactly what combination I would want.

This is where alot of practice comes into play and is exactly what the hydraulic toplink is for - so you can adjust/tweek on the fly as you watch what you are doing. If you have your cutting blade floating, whether using the front or rear blade, as material builds up in your box and/or over the blade you will find it bites more and more. With the hyd. cyl. you can tweek this as you go and get a much better grade. Hint - the slower you go while grading with a boxblade, the easier it is to learn how sensitive your cut angle is and adjust your toplink. Ideally your toplink should be roughly in the middle of it's stroke when your boxblade is nice & flat on level ground, this way you have alot of control whether pulling or pushing. This is why I made my own cylinder up to match my exact length requirements for my particular tractor. Personally I used a DPOC valve for my cylinder but some don't, it's just a good safety when a heavy implement is on the hitch or when your control valves get a little worn and leak down some.