Rotary Cutter Conversion...

[Chip812]

Has anybody successfully converted a rotary cutter (a bush hog) from a 3-point hitch arrangement to a trailer type cutter? I'm having a heck-of-a-time with my tail wheel... when I get done cutting it looks like I've been plowing... Every turn just drags the wheel... It rotates fine by hand when raised off the ground but won't pivot for squat while on the ground... Yesterday it finally snapped off... Now I'm stuck not knowing whether to fix/replace/convert... Either way, $$$...

 

[JDseller]

Chip, does your rotary cutter have a solid top link mount???(like the first picture I posted) The reason I am asking is that many of the older and cheaper cutters did not have any flexibility in the top link. So when you have it set where you want it to mow. Which should be the front a little lower than the back. As soon as your front end goes down into a small depression the tail wheel is picked up off the ground. That lets the tail wheel turn sideway and then drag when the mower comes back down. When you go up a grade with the front end the tail wheel is trying to lift the entire mower rather than just the back end. This will make it not work well too. What I have done on many cutters is to remove the top link and replace it with a piece of heavy chain.(see second picture, I use a heavier chain but this shows you what to try) You want it to be a little loose when the cutter is at mowing height. This way the tail wheel can follow the ground contours much better. The chain will tighten when you go to lift your mower. Then you should set your three point position control lever stop so you go to the same height each time. I have seen guys just let the mower down all the way and with the rigid hitch that makes the tail wheel carry the whole load of the rotary cutter. The tail wheels usually break real quick when you do this.Try this before starting a major project trying to make yours a trail type mower.

Plus on real tight turns you should be lifting the cutter off the ground anyway. I keep mine low enough that if you turn sharp on the ends the side runners will drag dirt. So it is second nature for me to lift it up a little while turning.

 

[JDseller]

Chip here are some pictures of newer rotary cutter that have a pivoting hitch from the factory. The JD 609 has a slot that lets the back brackes move. Look just behind the top link mount. The red cutter has a more common hitch that just uses chains onthe cutter so the hitch can pivot. In the picture with it unhooked you can see it laid clear down.

You made able to make your cutter like this if you don't want to use a chain istead of the solid top link.

 

[Dean]

The tail wheel fork or pivot mount has been damaged reducing the caster angle sufficiently such that the wheel no longer casters reliably. This is invariably caused by backing into an immovable object.

Repair or replace the damage and it will work properly.

Dean

 

[Anonymous-0]

Back in the late '60's, my dad took on the FMC SideWinder line of rotary mowers. Every 5X5 or 6X6 mower used the same deck, and could be assembled as either a pull-type or a 3-point.

The 3-point mowers had what could be best described as a pivot link where the top hitch link attached, and it had a plate that would contact the upright arms to limit the travel at perpendicular with the upright arms. The triangular mounting bracket for the tail wheel also pivoted on its mounts at the deck, and the tail wheel was set up to swivel. There were two angle iron brackets at the rear of the deck with a series of matching holes set up to limit the upward/downward pivoting of the tail wheel mounting bracket. [I know this stuff so well after 40+ years because as a teenager I was tasked with assembling each deck for delivery.]

I'm guessing the problem most likely stems from a solid connection at the 3-point top link, rather than having one capable of pivoting. But it's only an educated guess.

 

[Chip812]

The rotary mower I have is a 'Big B'... They come standard with about 1 foot of chain in the top link... Similar (in theory) to the picture of the red rotary cutter already posted (by JDSeller). When there is slack in the top link, at least half of the weight is on the tail wheel (the other half is carried by the mower)... When I turn right, I get a nice, semi-circular groove cut into the ground... when I turn left, the wheel casters like it is supposed to... when I go straight, the wheel flops from one side to straight making a groove about 4 feet long and then 4 feet of working correctly... that was before it snapped off...
P.S. I haven't hit anything with the tail wheel assembly (I don't ever have a need to back up)...

 

[JDseller]

Chip then just rebuild the caster wheel with a little more caster in it. Most of the ones I have seen the front of the tire is just about under the pivot. If yours is one of those that the bracket is just on one side it is probably twisted too. The simple ones are just two straps with a bolt through the wheel with either bearings or a bushing in the wheel.

I had one with the one side bracket that never worked very well so I used the wheel and pivot pin and made a straddle mount one and it is still being used twenty years later.

 

[Dean]

If the tail wheel will not caster properly it has too little caster angle.

I suppose it is possible that it was so designed but such is hard to imagine.

Perhaps the fork was built out of tolerance or it was damaged during shipping, set up, etc.

Dean

 

[Chip812]

(quoted from post at 09:45:56 06/19/12) If the tail wheel will not caster properly it has too little caster angle.

I suppose it is possible that it was so designed but such is hard to imagine.

Perhaps the fork was built out of tolerance or it was damaged during shipping, set up, etc.

Dean

I think you may be correct about the caster angle... Additionally, the pivot pin is/[i:2c9f484232]was[/i:2c9f484232] at an angle (probably because I had it cutting so low) and was probably binding as well... It is my understanding that the pivot pin must be as straight up/down as you can get it...

 

[Brian G. NY]

Fix the tail wheel and make sure the caster is right.
Unless you only mow large fields with no obstacles, you don"t want a trailer type mower.
Two years ago I converted my trailer Bush Hog to 3 point and am very pleased,
I built my own fork for the tail wheel and it did not have sufficient caster so I had to do it over. It works great now!