Rotary Cutter Stabilizer chains - brush cutter

[survriggs]

Does anyone have any solutions (preferrably pics) for placing 3ph stabilizer chains on a Kubota B7800 to limit the drop on brush cutter. Seems pretty cluttered back there to get chains down to the lift arms or back to the cutter.

/forums/images/graemlins/confused.gif

 

[greg_g]

Check chains are intended for tractors without functioning hydraulics - or at least without position control. I've used them temporarily while awaiting parts to fix a hydraulics problem. The fact you're considering them for a Kubota sounds to me like you've got a leakdown problem. If I owned a B7800, I think I'd fix the hydraulics, rather than apply a steel bandaid

//greg//

 

[survriggs]

Greg: Point well taken. My 7800 does not have position control, it has the quarter inching valve system. It has done this since it was new (it has 39 hrs. on it). There are no visible leaks and it goes down very very slow. I also figured (maybe erroneously) that the chains would take some of the stress off of the 3ph system???

 

[flusher]

Check this link. I think it has the info you need.

Check chains

That link contains this photo (see attachment) which shows the slick way to attach these chains.

I have a new B7510HST that has the same slow leak-down on the 3pt.
My tractor has a knob for controlling the up-down speed of the 3pt. According to info in another thread, turning this knob full OFF is supposed to stop this problem. Haven't tried it yet since my leak-down is so slow that it doesn't cause me any problems when brush hoggin' or back blading.

 

[flusher]

Here's the Link.

MikePA: Please review your message before posting it. It's simple not to create a long link that widens the entire thread. Just insert a descriptive word or two between the {url=http://whatever}<font color="red">Enter words here</font>{/url} instead of the entire URL. Replace parentheses {} with square brackets in previous example. Alternatively, if you use the Instant Markup language URL link, the first prompt is for the URL. The second prompt is for a description. Do not simply paste in the URL again. Type a short description of the link.

 

[greg_g]

</font><font color="blue" class="small">( My 7800 does not have position control, it has the quarter inching valve system. )</font>
Actually, the quarter inch system is position control. Classic leakdown. Since it's a new tractor, I'd exercise the warranthy - rather than spend money on bandaids. Besides that, freight costs more than the actual cost of stabilizer chains themselves.

Fix the problem, not the symptoms.

//greg//

 

[JerryG]

If the quarter inching system is position control it is taking the cheap way out. True position control will stop the lift at any position not just at quarter inch intervals. If someone had the Kubota reports on the quarter inch system, I would bet that is was designed to save Kubota some money.

 

[greg_g]

</font><font color="blue" class="small">( If the quarter inching system is position control it is taking the cheap way out. )</font>

Based solely upon info I found on the Kubota website, the "quarter inching valve " is apparently what passes for position control on the B7800. The B7x10 series gets it too, in addition to a "true " position control.

In a press release, Kubota says "The Category I, 3-point hitch incorporates a new quarter inching valve that acts as a regulator, enabling the operator to make smaller adjustments at the lower link end. The lever guide can move in ¼-inch increments making attaching/detaching implements easier while enhancing grading performance."

//greg//

 

[greg_g]

</font><font color="blue" class="small">( It has done this since it was new (it has 39 hrs. on it). There are no visible leaks and it goes down very very slow. I also figured (maybe erroneously) that the chains would take some of the stress off of the 3ph system??? )</font>

I'd bring it up with the dealer as a warranty item. Assuming the B7800 hydraulics are vented, you can have fluid seeping past the lift cylinder and back into the sump - and never see a drop on the ground.

If you rely on chains to compensate for leakdown, your lift arms will eventually go into a float condition. That's problematic too, because chains necessarily check the lift arm movement in the down direction - but are useless in stopping them from moving upwards. When that happens, some working angles - like mowing perpendicular across a crease - will cause scalping

//greg//

 

[catvet]

I to have problems with my brushhog on my B7800. I don't believe (for me) it's a hydraulic leak problem as much as a positioning problem with the 1/4 inching system. If I raise the brushhog to go over an obstacle I can't figure anyway to get it back to the same position. there isn't a "stop" that places the 3-point at a set height.

You can move the 3-point in small increments but not set where it is going to stop. Perhaps I misunderstand this whole system but that is how I see it. I'm pretty new to tractors.

 

[JerryG]

catvet,
That is how that system works.

 

[survriggs]

Greg:
</font><font color="blue" class="small">( your lift arms will eventually go into a float condition )</font>
What do you mean by this?
</font><font color="blue" class="small">( but are useless in stopping them from moving upwards )</font>
The only way I can see that the lift arms would move UP while operating the cutter is if I would bump the lever???
I'm not questioning your advice, I'm just thick-headed sometimes and don't quite understand.

 

[greg_g]

When a leakdown condition goes unchecked, there will eventually be nothing holding the lift cylinder in place. As a result, the lift arms will move up and down (float) in sync with the motion of the implement attached. Some tractors intentionally have a FLOAT position on the lift control levels - I think it's actualy just a bypass - since there are some conditions when you WANT the lift arms to follow the terrain.

As far as the lower lift arms moving up with stabilizer chains, the same explanation applies. In a leak down condition, the chains do not present a physical stop in the UP direction - as they do in the DOWN direction.

But then again, who knows what Kubota has got engineered into this 1/4 inch business. I might be completely in the wrong ballpark.

//greg//

 

[catvet]

</font><font color="blue" class="small">( catvet,
That is how that system works. )</font>

That's what I figured. I would think that stabilizer chains would be a great advantage with this sort of system to allow you to get back to the same height you were previously at. Otherwise you end up scalping the ground.

 

[JerryG]

If a person has a quarter inching system and using an implement that needs to be returned to the same position repeatedly, the check chains are the best way to go.

 

[greg_g]

</font><font color="blue" class="small">( If a person has a quarter inching system and using an implement that needs to be returned to the same position repeatedly, the check chains are the best way to go. )</font>

In the absence of a B7800 owner's manual indicating otherwise, I find it difficult to comprehend Kubota NOT provisioning this "quarter-inch" control system with some kind of adjustable stop for the lift lever.

If true, it gives renewed meaning to the word "cheap" that was used earlier in this thread.

//greg//

 

[JerryG]

My understanding of the quarter inching valve is that you hold it in the direction that you want it to go and when you let off it self centers. If you tap it in that direction it will raise or lower one fourth inch but the lever self center when it is let off. It isn't like true position control that the height of the implement corresponds with where the lever is. If this isn't right, I am sure that someone will correct me.
<font color="blue"> If true, it gives renewed meaning to the word "cheap" that was used earlier in this thread. </font>
You got that right. I can see where it would be fine if you were just mowing with a belly mower or a finish mower, but not for anything that is ground engaging.

 

[JustGary]

I personally can't wait to find out about the quarter-inching valve, but here's how the one-inching valve works on my L2800.

It has a standard position type lever with float at the far forward position and all the way up at the rear position. The total travel of the handle on the lever is probably eight inches or so. I'm at work right now or I'd post a photo of the lever for you.

If you start with the lever all the way back (arms up) and then push it forward a little bit, the arms will fall a little bit. If you push it forward further, it will fall more. In general, this action is in one-inch increments, but down travel speed is controlled by the knob near the front of the seat. You get the feeling that you have decent control going down because of the speed adjustment.

On the other hand, if you pull the lever toward the rear, nothing will happen until you pull it far enough for the valve to get to the next increment. You know when you get to the next increment because the arms then rise one inch. Suddenly. With full force. No feathering, no force adjustment. One inch at the arms means about six inches at the tail wheel of a five foot mower, by the way, and when that baby jumps, the whole tractor does. That's the source of complaints with the one-inch valve that Kubota will replace.

I presume that the quarter-inch valve will work in the same way except that 1) it moves in quarter-inch increments instead of one inch, and 2) I hear that it feathers better rather than just jumping to the next increment all of a sudden (in other words, a proportional indexing valve).

At least I hope #2 is true, and as soon as my dealer gets the part, I'll know for sure.

Obviously, someone with actual experience with the quarter-inch valve could tell us for sure about the action of the lever.

- Just Gary

 

[Bird]

Gary, your tractor has "position control" instead of a quarter inching valve and they're two entirely different things.

 

[JustGary]

Dawg. Sorry. I should have known to keep my fingers shut. I've read the posts about the Kubota fix for the L2800, and thought that the fix was a quarter-inching valve. I just frustrated that mine doesn't have it yet. Thanks.

I'm sorry for the interruption. Please continue the thread in your normal manner!

- Just Gary