modifying bushhog cutter to fit tractor,

[deepNdirt]

I have been on a search for a good used 4 ft. rotary cutter( Bushhog )
seems as though this size is hard to come by used, or at least no one is wanting to get rid of theirs, anyway! I have came accross several 5-6 ft cutters, at resonable price some might need sheet metal work etc,etc,
My question is...... -----> can one cut a 5 ft bush hog down to a 4 ft box and replace the blades with that of a 4 ft cutter? I have the tools to do this and I'm sure it would turn out OK, my only concern is, would the gear box be ok for smaller Hp tractor, Such as a 22 hp, my tractor has 3 speed PTO I've been told to only use a 4 ft.
I've never used a cutter with this tractor, although the 4 ft. cutter I sold with my compact Kubota was perfect match for that 18 hp tractor,
(((thanks for any advice)))

 

[MarkV]

Personally I would try a 5' cutter and take smaller bites, if needed, when mowing rather than cutting the mower down. You may be light on HP but if what you are cutting is is done on a regular bases and your not trying to clear land with it you should be fine. I think the problem you would run into cutting the mower down is the size of the stump jumper. You would have to replace it as well as the blades which would not make it economically practical.

MarkV

 

[deepNdirt]

I had thought of buying one of these used 5ft cutters and trying it out for size to see how it would work out with the tractor, and once the purchase is made its mine, this is why I'm wondering if modifying it to a 4 ft. would be comprehensible? I would be paying approx 225-275 for a used cutter, the bottom of the cutter is rather beatup so I was thingking I could cut this part off along with some portion off the topside and re-welding a skirt around it to the size of a 4 ft. cutter,
I can get new 4 ft blades for 60.00 and i already have some heavy sheet metal for the skirting, I think I can leave the 3 pnt alone, although maybe cut down the wheel support arm,... with me doing this myself I think I could get by with material cost only for around 125- bucks, on top of the purchase price of the cutter, having me 350-400.00 total,... a new 4 ft cutter will cost 600+
I have found advertized a few used 4 ft. to buy for around 350-375 but I'm always a day late or a dollar short,..............

 

[Will_C]

As long as your tractor can handle the 5' cutter 9I mean raising it, being heavy enough so the cutter does make you tractor unbalanced, etc.), I agree with Mark-just use the 5 footer and take smaller bites if you struggle for power. Cutting one down just seems like to much work.
Will

 

[deepNdirt]

As long as your tractor can handle the 5' cutter 9I mean raising it,
Will

I'm sure it would lift it with no problems, my only concern would be the gearbox rating? my tractor has a 17 hp rating at the PTO, but as I said it has 3 speed pto and I would think this determined HP rating would be at the low speed of the PTO... Plus I'm thinking a cutters gearbox would be matched rated accordingly to the size of the blades/Cutter is?..... However if the manufacture use the same gearbox for say 4-5-6 ft cutters then there woulod be no concern at all....

 

[J_J]

I would say you could use the gear box with no problems, as it was built for larger HP tractors. With it built for larger tractors, means that it will last longer with the HP you will put to it. rpm will be the same, and the gearbox with shorter blades will turn less weight, etc. So, it really comes down to, if that is what you have , then use and modify it to suit.

One note of interest is that larger bush hogs, have a higher blade tip velocity, and most turn at around 540. Did you say your tractor had a three speed PTO? . What are the speeds?

 

[kthompson]

JJ touched on the big issue, you will loose a good bit of tip speed. This is why he is asking for the PTO speeds to see if you could step up to the next speed and it be OK for the input but give the tip speed back.

There is by far many many more 5 foot cutters out there and than ever will be of 4 foot even with all the compact tractors being sold today (my thoughts). Very few people will buy any kind of mower rough or finish narrower than the tractor.

 

[MarkV]

I had thought of buying one of these used 5ft cutters and trying it out for size to see how it would work out with the tractor, and once the purchase is made its mine, this is why I'm wondering if modifying it to a 4 ft. would be comprehensible? I would be paying approx 225-275 for a used cutter, the bottom of the cutter is rather beatup so I was thingking I could cut this part off along with some portion off the topside and re-welding a skirt around it to the size of a 4 ft. cutter,
I can get new 4 ft blades for 60.00 and i already have some heavy sheet metal for the skirting, I think I can leave the 3 pnt alone, although maybe cut down the wheel support arm,... with me doing this myself I think I could get by with material cost only for around 125- bucks, on top of the purchase price of the cutter, having me 350-400.00 total,... a new 4 ft cutter will cost 600+
I have found advertized a few used 4 ft. to buy for around 350-375 but I'm always a day late or a dollar short,..............

I think the part you are missing is that the stump jumper, the round disk that the blades attach to, on a 5' mower will be larger than one on a 4' mower. If you cut the deck down to 4 foot blades from a 4 foot mower will not work because of the size of the stump jumper.

I would not worry about the gear box. They are rated for the max HP they can handle not the minimum they need.

MarkV

 

[deepNdirt]

I would not worry about the gear box. They are rated for the max HP they can handle not the minimum they need.MarkV

yes I realize a low Hp tractor would not do damage to a gearbox of a higher HP recommendation cutter, but I'm thinking the other way around, like would the tractor Hp/PTO need to be close compatible to the gear ratio of the cutter,
in other words if the tractor is running at 4500 rpm to be able to run the cutter at 1000 rpm something not match up, IMO the tractor going to wear out, now on the other hand if the tractor can run at (example) 2500-3-k rpm and the cutter will run 1500 revolutions per minute, this would be like a 2 to 1 ratio and this would in no doubt have less wear on the tractor clutch & engine, then trying to over run the tractor to keep up with the cutter,
ha! am I making any since? I am getting answers telling me it will be OK to run a 5 ft. cutter, and I trust that it will work, i gues what I need to know is ---> why have I been told to use a 4 ft cutter only? and what would be the worst case scenario to use a 5 ftr, Now keep in mind that my tractor is only 48" wide at rear tires and weight around 1800 lbs dry. this is one of the reason by me thinking of 4 ft. cutter. so would fallow the tractors path, although I do have a couple of 5 ft plows etc,etc, but they are not PTO driven,

 

[Bill Hoffman]

Got a 4 foot Woods for sale. Had it on a YM155D. Worked well. Needs paint.
Where are you?

Bill

 

[J_J]

deepNdirt ,

Somewhere, I remember the rule of thumb for cutter size, and it was 5 HP per foot of bush hog cutter width. You can cheat on HP, but not much. Sharp blades make a difference also.

20 HP = 4 ft
25 HP = 5 ft
30 HP = 6 ft

Don't know how that applies to the bat-wing mowers.

 

[deepNdirt]

deepNdirt ,

Somewhere, I remember the rule of thumb for cutter size, and it was 5 HP per foot of bush hog cutter width. You can cheat on HP, but not much. Sharp blades make a difference also.

20 HP = 4 ft
25 HP = 5 ft
30 HP = 6 ft

Don't know how that applies to the bat-wing mowers.

This make since and is in easy layman's terms as I need..
and yes I agree that some tractors can cheat in Hp rating, My old L140kubota was only rated at 18 hp but could do the work of a 25 hp tractor
a 4 ft bush hog was no problem for it, I used the Kubota for 11 years,
I knew its capabilities, although I have only owned this Yan for a couple months and have used it very little, it seems rather strong for its size as far as pulling, I have'nt used the PTO, I'm sure the 3 speed of the PTO will help to match up to a cutter,...... so we might say! the gearbox is of no real concern?.....

and Bill H.
I am in NE Ga. close to the UGA Bull-Dawgs Country ... Thanks for the offer but we be some distance apart

 

[kthompson]

There is a wide range of weights for 5 foot cutters. A heavy one would be too much for your tractor where as a light one would probably be fine weight wise. The problem to me would be IF you are pushing the HP issue and can not cut the full width you could run into a problem if you ever were forced to cut the full width such as first cut in a field or between trees or such. Does a 5 foot cutter require you to use your lowest gear (for travel, not PTO) if not then you can also shift to lower gear for those times. A lot will depend on what you are mowing. But if you mowing stuff that will not damage the front end of your tractor as is in picture, think you will be OK.

 

[sandman2234]

Consider this statement with a grain of salt...

Most bush hog type mowers are rated for 540 pto speeds and might be interesting in the balance end of things if you attempt to run them at a faster rpm.

Yes, a lot of bush hogs are rated at 1000, and are probably geared as such. I am not aware of any that are rated a a higher rpm, but who ever said I knew everything?

Mostly brought this up to see what others had to say about it.
David from jax