Floating Top Link?

[keeney]

I have seen reference to a "floating top link" in regards to a rear rotary cutter.

How compatible is a floating top link with a quick-hitch like i-Match?

- Rick

 

[beenthere]

Without the iMatch, I had a chain to replace the top link for my rotary cutter. Worked great.

After the iMatch, I have the chain (two of them) running from the top link of the iMatch to the rear of the rotary cutter (replacing the steel straps that would bend if the rear of the cutter wanted to raise). The iMatch is connected with the adjustable OEM top link.

 

[greg_g]

</font><font color="blue" class="small">( I have seen reference to a "floating top link" in regards to a rear rotary cutter.

How compatible is a floating top link with a quick-hitch like i-Match? )</font>
A rotary cutter rides on one rear wheel and the two lower lift arms. Lifting that rear wheel off the ground for transport is the job of the toplink. Unfortunately, a rigid toplink will also pick the mower up when the nose of the tractor dips. Conversely, it may bury the front of the mower when the nose of the tractor rises.

To cope with this problem, some slack has to be engineered into the toplink configuration. And that's normally done on the implement end. I've got a whole box of miscellaneous brackets/bolts/bushings/pins/et cetera that can be rigged for various floating toplink applications. The most common is a U-shaped bracket on the mower, to which the adjustable toplink is connected. Lengthening the adjustable toplink permits the U-bracket to move with the rise and fall of the tractor nose.

Beenthere's chain (no QH) provides a similar function. But if you use your QH with a rotary cutter, you should stay with an adjustable toplink between the tractor and the QH. But I strongly recommend a floating toplink between the QH and the mower.

//greg//

 

[RalphVa]

My LX4 cutter came equiped with a floating link to the rear tail wheel. This gives 3 to 4 inches of float there and isn't enough for very uneven terrain. Also, it somewhat locks the lift arms and won't allow them to be raised more than about 2 inches. I have to disconnect the top link to raise the cutter 4 inches off the floor needed to put it onto 4x4s that JD recommends (I've bought some dollies instead: pics in JD owning/operating forum.)

Therefore, I recently purchased some chain to use as the top link and posted some pictures in the JD owning/operating forum section. I'll likely buy a Pat's quick hitch gizmo for the draft arms, as disconnecting and reconnecting these are a chore. I plan to buy a KK carryall for the 3 pt and will use the top link provided by JD for this.

 

[greg_g]

</font><font color="blue" class="small">( My LX4 cutter came equiped with a floating link to the rear tail wheel. This gives 3 to 4 inches of float there and isn't enough for very uneven terrain. )</font>
Not the same thing. You want "float" at the TPH, to COMPENSATE for rise and fall at the rear wheel. I'd say you've got something else adjusted wrong to cause the problems you describe

//greg//

 

[RalphVa]

If you look at the geometry, the top link is longer than the bottom draft arms. Raising the draft bars then cause the top link to push down on the tail wheel. The draft bars will raise about an inch before they take up the 1 1/2 to 2" float in the tail wheel section. Then they won't raise any more because they're trying to push the tail wheel into the ground.

Basically, the only float is the 3 to 4 inches in the shock absorber or springs in the tail wheel assembly located just behind where the top link is connected.

I conclude that I need more float and have bought the chain for this. I did a search for this on all the forums and came up with pictures of chains being used in place of the top link. Folks often lower their front buckets to about the same or slightly lower than the top edge of the cutter that could hang on a stump and throw the cutter up towards the seat. The bucket would then contact the stump first and stop the tractor. No one on the forums has ever had this happen; they just heard about it.

I'll also have to adjust the chain up tighter if I know there's a possibility of backing over the edge of a creek bank, too.

What seems to me the ideal top link, short of having a hydraulic one, is a shock absorber designed to be the right length to not allow the deck to drop too low but would keep the cutter from rearing up if it contacted a stump.

Ralph

 

[greg_g]

</font><font color="blue" class="small">( If you look at the geometry, the top link is longer than the bottom draft arms.)</font>

Obviously I can't see your geometry, but you just described pretty much what I suspected.

Since adjustable toplinks aren't typically included with TPH implements, one must assume you're using the one that was already on your 4010. If it's already screwed down to its shortest length, I strongly suggest you buy a (much) shorter one. Then re-evaluate your situation. I also see that the LX4 doesn't seem to come equipped with a floating toplink bracket. You might want to consider investing in one, they're worth it.

When properly set up, it should be reasonable to expect 10-12 inches of "float" where the deck mates to the TPH. The rear wheel should be load bearing, not spinning in the breeze. And when you lift with the hydraulics, the entire deck should raise on a horizontal plane, instead of coming up like a garbage pail lid.

//greg//

 

[Henro]

<font color="blue"> But I strongly recommend a floating toplink between the QH and the mower.
</font>

Greg,

At the risk of illustrating how slow I can be sometimes, I have to ask what a "floating toplink" is.

I know the way my Woods rotary cutter is set up, with a U shaped piece that allows movement up and down of the rotary cutter to follow the ground, but the top link is set to a fixed lenght, so it in itself is not floating, just the linkage of the rotary cutter that it is attached to is.

How exactly does this floating top link you referred to work? I'm curious...

 

[greg_g]

</font><font color="blue" class="small">( I know the way my Woods rotary cutter is set up, with a U shaped piece that allows movement up and down of the rotary cutter to follow the ground, but the top link is set to a fixed lenght, so it in itself is not floating, just the linkage of the rotary cutter that it is attached to is. )</font>

You just described one style of floating toplink bracket. Some rotary cutters are simply are sold without them. My IMC cutters have a variation; the three sided bracket.

Woods/Landpride/IMC (and probably others) understand the need, and include floating toplink brackets as standard equipment on their rotary cutters. But from what I can tell John Deere, decided that JX4 owners have to buy their own.

//greg//

 

[Henro]

<font color="blue"> You just described one style of floating toplink bracket. </font>

Yes, I guess I did.

But back to my question. What where you referring to?

The reason I am asking the question a second time is because I incorporated float in my TNT and whether it makes any sense or not still remains to be seen...

I am almost done with my instalation but it is not quite finished yet. So I don't know if the extra money was well spent or not.

 

[greg_g]

</font><font color="blue" class="small">( The reason I am asking the question a second time is because I incorporated float in my TNT and whether it makes any sense or not ... )</font>
I don't think so. The TNT remains on the tractor, regardless of the implement attached. But not all implements need to "float". Matter of fact in some, rigidity is key to efficient operation.

Consider the TNT as part of the TPH, and a floating toplink bracket as part of the implement. Install floating toplink brackets on only those implements that need them.

//greg//

 

[RalphVa]

I need some pictures to know what some of you are talking about. Have seen pics of chains in place of the screw-type top links. My LX4 has some form of slip link in the linkages that telegraphs back to the tail wheel. Haven't seen any pics of adjustable or movable top links or mechanisms that some of you are talking about.

Seems as though brush hogs need wheels in front like is on some of the rear finish mowers, but then the hydraulics need to be able to float. The Woods finish mowers seem to have chains rigged from where the top link from the tractor attaches and run back to the tail wheel.

Here's a pic of my planned chain for the tractor top link.

Ralph

 

[greg_g]

</font><font color="blue" class="small">( My LX4 has some form of slip link in the linkages that telegraphs back to the tail wheel. )</font>
Then you'll be disappointed to learn that what you think is a linkage, is just a toplink pin for their iMatch.

There are more, but I'll upload shots of the U-type Henro's got, followed by the 3-sided type I've got. Both as you will see, provide the missing pivot point required for terrain following, while retaining the rigidity required for lifting on the horizontal plane.

//greg//

 

[greg_g]

and the 3-sided type

//greg//

 

[JackIL]

Ralph and Greg,

Attached in this post and the following 3 replys are photos from the JD LX4 Operators Manual that illustrate how the floating hitch works with the IMatch Coupler and without it. The float capability is built in to the top portion, but it doesn't look like the usual floating link on other cutters. It functions the same whether there is an IMatch coupler or not.

You set the rear tail wheel to get the proper height in the rear and then lower the front with the 3PH until it is slightly lower than the rear in most cases. At that point you set the depth stop on the control lever of the 3 PH so you can always return to the same front cutting height. Then you adjust the length of the top link of the 3 point until the pin B in the photos is in the center of the slot. This provides the full range of float and also picks up the rear tail wheel the proper amount when the cutter is lifted for turning or transport.

JackIL

 

[JackIL]

Details of float mechanism. Note the Slot.

 

[JackIL]

Without IMatch.

 

[JackIL]

Float Mechanism details. Without IMatch.

JackIL

 

[tomnky]

Look at a a Woods RM500 Finish Mower, It has a form of floating toplink.

 

[greg_g]

</font><font color="blue" class="small">( Float Mechanism details. Without IMatch. )</font>
Doesn't look like it permits much play (float) at all Jack, but then again - we're only talking 4 foot cutter here, I usually think in larger terms.

But it pretty much reinforces the idea that the toplink on Ralph's 4010 must be too long - which effectively cancels what little freedom of movement is shown in your JX(x) illustrations, AND, that his chain idea is not compatible with JD design

//greg//