10' (twin 5' blades) brush hog question

[farmer2009]

As rough as my ground is, I want a 3ph mounted mower, not a towable batwing type.

That's where a batwing or at least a pull type would shine. Rough ground. They have a floating hitch that allows them to keep a more even cut. It also reduces ground contact. It also takes a lot of the weight of your tractor very nice on steep hills.

 

[dieselcrawler]

I've never though about a flail mower. Never used one, or even seen one in person... food for thought.

 

[leonz]

I've never though about a flail mower. Never used one, or even seen one in person... food for thought.

I have post about the Land Pride/Maschio flail mower with a picture of
one with the rear trash door open a few posts up the page from your
first thread on Sept 9,2015 which is post number one.

 

[LD1]

Interesting thread.

I too have though about doing the same thing in the distant future only 8' (to be able to trailer without permit). But since 4' cutters are more expensive than 5' cutters, and typically alot lighter duty, I was going to fab one.

Start with a couple of 5' cutters that come up used all the time for a few hundred each. ($400)
that will get me the a-frame, tailwheels, stump-jumper/blade carrier, etc. But doubt I would use the gearboxes as blade speed would be too low with 4'

A 4x8 sheet of 3/16 (7ga) costs a whole whopping $130

New set of 4 blades and bolts ~$100

Pair of 2:1 gearboxes: $200 each

Center gearbox (only expensive if you buy an OEM one) ~$300

PTO shaft $150

Total: $1280 and some time.

Certainly beats the $2500+ used prices I am seeing.

But I have some of the same questions. Counter rotating blades or do they spin the same direction?
Overlap in the middle? Blades "timed" to not hit?
Why the need for the rubber things that drive the outboard gearboxes? Why not directly coupled with the whole unit protected by a slip clutch on the main box?

 

[leonz]

Hello LD1,

Most if not all the larger wing type rotary cutters have
huge radial steel spars that strengthen the mower from
the center of the gearbox due to the stress of the rotation
and to reduce steel flexing and weld cracking.

Depending on the manufacturer the rotary cutter may or may not have a wind tunnel
weldment to create the pressure gradient to make the rotary cutter work better.
The other issue is that one rotor is trailing to prevent blade strikes where both blades
will overlap to some extent but not come in contact with each other.

The gearbox with two shafts would make the left rotor spins counterwise and the right one clock wise I believe.
The wing section requires that the offset shaft trail the center shaft to allow it to be raised and lowered without binding and the proper driveline angles/bearing supports to allow freedom of movement up or down with the correct placement of The universal joint or joints.

If you are referring to the Dodge type one piece rubber couplers they are a much safer, less costly method to protect the drive train that allows some starting torque to develop for the rotary cutter to work as a slip clutch would slip too much from the required torque at start up.


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Interesting thread.

I too have though about doing the same thing in the distant future only 8' (to be able to trailer without permit). But since 4' cutters are more expensive than 5' cutters, and typically alot lighter duty, I was going to fab one.

Start with a couple of 5' cutters that come up used all the time for a few hundred each. ($400)
that will get me the a-frame, tailwheels, stump-jumper/blade carrier, etc. But doubt I would use the gearboxes as blade speed would be too low with 4'

A 4x8 sheet of 3/16 (7ga) costs a whole whopping $130

New set of 4 blades and bolts ~$100

Pair of 2:1 gearboxes: $200 each

Center gearbox (only expensive if you buy an OEM one) ~$300

PTO shaft $150

Total: $1280 and some time.

Certainly beats the $2500+ used prices I am seeing.

But I have some of the same questions. Counter rotating blades or do they spin the same direction?
Overlap in the middle? Blades "timed" to not hit?
Why the need for the rubber things that drive the outboard gearboxes? Why not directly coupled with the whole unit protected by a slip clutch on the main box?

++++++++++==================++++++++++++++++++++++++++++++++++++++++++++++++

 

[orangeandgreen]

"But I have some of the same questions. Counter rotating blades or do they spin the same direction?"
Yes, they are counter rotating, at least on all the 10 footers that I have seen.
"Overlap in the middle? Blades "timed" to not hit?"
The Woods cutters I have both advertise 6" of overlap and the blades are timed.
"Why the need for the rubber things that drive the outboard gearboxes? Why not directly coupled with the whole unit protected by a slip clutch on the main box?"
The "rubber things" allow slight misalignment as the cutter flexes so no damage is done to the gearboxes. A slip clutch is still needed.

 

[LD1]

The "rubber things" allow slight misalignment as the cutter flexes so no damage is done to the gearboxes. A slip clutch is still needed.

I kinda assumed that. But I can think of other couplers that would last longer and be easier to service and find parts for.

I may be wrong, but it seems like I see a lot of issues posted on here about those rubber couplings and them being a weak link.

I think I would rather go with short PTO shafts before I went with them rubber couplers.

 

[Soundguy]

I am also dreaming up a way to build my mower so that it can flex in the center, to allow it to better follow the contour of rough ground. I have a few years to think about this design and how to overcome the issues with it.

V cut mower. think of a 15' batwing missing a wing.

for variations like bumps nad hills, a batwing does better.

I have both a 10' 3pt and a 15' batwing... both have their uses..

 

[Soundguy]

I kinda assumed that. But I can think of other couplers that would last longer and be easier to service and find parts for.

I may be wrong, but it seems like I see a lot of issues posted on here about those rubber couplings and them being a weak link.

I think I would rather go with short PTO shafts before I went with them rubber couplers.

mine might fly apart tomorrow.. but so far so good.

 

[RedNeckRacin]

My MX 10 is counter rotating and timed. The side gearboxes are protected by a double roller chain on the driveshaft. The main input shaft has the slip clutch on it. You also couldn't give me a trailered mower on a steep hill. I want as much weight on the tractor tires as possible to keep me on the hillside.