sickle bar hydraulics / Kubota 2620

[CDN Farm Boy]

FYI - open circuit means that when you actuate the hydraulics oil is pushed into the side that you want to use, i.e. lift side and the opposite side of the cylinder has the pressure released and allows the oil to flow back to the reservoir

Sorry but I disagree with you. Your description is how any hyd system works.

Open center refers to the design of the pump that it is variable displacement depending on load. Closed center uses a fixed displacement pump that is always trying to move fluid and is subject to over heating issues if the fluid has nowhere to go which in a closed center system gets accounted for somewhere downstream (I know my way around an open center system pretty decent thanks to JJ and others on here but not a closed center system)

 

[J_J]

Man you guys are losing me on this stuff. So from what I am reading here the back on the tractor where I connect the hose back to the tractor when not in use is because there has to flow there correct? Like I could not just disconnect that back hose?

The front of the tractor for the loader there are 4 hoses, do they need to be " looped" thru when not in use? Like can I just use one of those?

The hydr cylinder on the mower has a fitting on each end of the cylinder, but only one hose coming out.

There are at least two ways to operate the sickle bar mower cyl.

If you use the BH connection, you need a single spool SA valve for gravity down and power up.

You can unplug the two hoses in the curl circuit on the loader and use the curl up hose to operate the sickle bar mower. I am assuming you have QD's on the curl hoses.

Have you determined if the sickle bar cyl is a SA or DA cyl. If the cyl is DA, you would use both curl circuit for the cyl as power up and power down.

If the cyl is DA and you need float on the sickle bar mower, you could use the lift circuit.

 

[powerscol]

does anyone know if I can use the hydraulics on the back of a Kubota 2620 to control a sickle bar mower? The sickle bar only has one connection for lift and it is gravity down. When I don't have the backhoe on the machine I connect the in and out hydraulics together, can I just use one of those for the mower?

Yes you can - however you do not have a float feature (if you do even better) so you will need to pump against one of your closed ports to lower. Using your rear hydraulic ports, say A-B plug the sickle mower into just one of them, say A. To raise you move your lever to A. In neutral position after moving to A the bar will remain where positioned. To lower you will need to move your lever towards B to bleed off A. You will be dead heading the pump, so be careful.

For the sickle bar to operate properly, you will need to bleed off all pressure to the cylinder so the bar will float on the balance spring and operate properly. Ideally you would want a float circuit to do this. That's why I added a second remote form Kioti on my Bobcat tractor that had the float feature. Bobcat does not offer this on their rear remote valve set.

On your sickle mower hydraulic cylinder the second port probably has a breather valve, but changing it to double acting will not help much as you will not be able to get it to float. If you could post the model sickle mower you have that might help.

There is probably another way to plumb this so your not dead heading the valve to get the bar to lower, but it does work.

Hope this helps - the best solution is check with your Kubota service folks and see if they know how to set you up with a float feature. Some Agg equipment needs this to run properly.

Hope this helps - Keith

 

[CDN Farm Boy]

Yes you can - however you do not have a float feature (if you do even better) ...

I missed something in the OP's post he's talking about the power beyond loop NOT rear remotes. He does not have float because he does not have a valve when the BH is removed.

The rest of your info is great but he needs to get a valve in there first.

 

[powerscol]

I guess I read the OP post wrong. In his statement "does anyone know if I can use the hydraulics on the back of a kubota 2620 to control a sickle bar mower? " I assumed he had rear remotes.

Sorry if I confused anyone.

 

[Creamer]

Yes you can - however you do not have a float feature (if you do even better) so you will need to pump against one of your closed ports to lower. Using your rear hydraulic ports, say A-B plug the sickle mower into just one of them, say A. To raise you move your lever to A. In neutral position after moving to A the bar will remain where positioned. To lower you will need to move your lever towards B to bleed off A. You will be dead heading the pump, so be careful.

For the sickle bar to operate properly, you will need to bleed off all pressure to the cylinder so the bar will float on the balance spring and operate properly. Ideally you would want a float circuit to do this. That's why I added a second remote form Kioti on my Bobcat tractor that had the float feature. Bobcat does not offer this on their rear remote valve set.

On your sickle mower hydraulic cylinder the second port probably has a breather valve, but changing it to double acting will not help much as you will not be able to get it to float. If you could post the model sickle mower you have that might help.

There is probably another way to plumb this so your not dead heading the valve to get the bar to lower, but it does work.

Hope this helps - the best solution is check with your Kubota service folks and see if they know how to set you up with a float feature. Some Agg equipment needs this to run properly.

Hope this helps - Keith

I disagree. Any sickle bar mower that I have used - all semi-mounted or trailer type - could use a double acting cylinder without float as their is float built into their mechanism. My NH 455 mower runs off my loader hydraulics and i do not sue the float. It compresses the cylinder more than enough to allow the lift mechanism on the mower to provide the float. I have also used IH Model 1100, JD #37, #9, &#7 and they all worked this way. I have never worked with a 3 pt mounted mower but I would think the lift mechanism would be the same. I am not sure what type of Sickle bar mower the OP has.

 

[powerscol]

All I know on my IH 1300 3pt mount, I need to take all pressure off the cylinder for the balance spring to do its job, otherwise it puts a lot of pressure on the 3pt linkage as it tries to follow the ground. Its a single hose cylinder with a breather in the second port. Also has a restriction valve in line to slow the up motion.

 

[Creamer]

All I know on my IH 1300 3pt mount, I need to take all pressure off the cylinder for the balance spring to do its job, otherwise it puts a lot of pressure on the 3pt linkage as it tries to follow the ground. Its a single hose cylinder with a breather in the second port. Also has a restriction valve in line to slow the up motion.

With a single acting cylinder the pressure has to remain relieved or the mower cannot go lower. There is nothing to move the cylinder other than gravity and it does not have a lot of effect once the sickle bar is on the ground. Unless the pressure remains relieved the mower can go up but not down anymore.

With a double acting cylinder the cylinder completely compresses and takes the load off of the linkage allowing the mower to float much more freely.

 

[powerscol]

I am still confused. Perhaps J_J can help. I am a bit green on this, but my double acting cylinders stay pressurized on both sides during use (will not move up or down with lever in the center neutral position), unless I put it into float. So it appears I need to learn more.
Keith

 

[cointoss]

This is what worked with my John Deere 5200 and B7800 kubota. I used one line on the curl side of the loader controlled hose with a one hose hydraulic cylinder that came on my sickle bar. The weight of the bar would lower the bar slowly by gravity due to a vent in the cylinder.