Mini Skid Brush Mower Build

leotech · May 17, 2012

Hi Everyone,
I've been trying to wack down thistles, small trees, > 2", and field grass, 5-8ft high. I did notch a old 5hp mower in the front with my plasma cutter and made it into a brush mower. It did a great job but limited to 20" width. It's weird to be in a valley of thistles.

My plan is to build a hydraulic brush mower attachment for Ditch Witch SK500. Track width is 42" so a 48" width is what I'm expecting to cut. Based on the specs of the Aux circuit, it is 12gpm 2500PSI.

questions I have is the following.

Direct Drive off hydraulic motor or Right angle Gearbox to hydraulic motor?

RPM of most brush mowers? What size motor to start looking at?

Since I'm trying to build a "standard" brush mower, using standard parts, I don't want to get a gearbox that is odd size. Other makes and models I can steal from?

For the blade, a 24" circle with 2 to 4 blades on pivot point.

I already have a blank quick mount plate, plasma cutter, Miller 211 MIG setup with Flux-Core .035".

Thanks,
Curtis

bcp · May 17, 2012

Blade tip speed thread:

http://www.tractorbynet.com/forums/owning-operating/91240-rotary-cutter-bladt-tip-speed.html

leotech · May 17, 2012

Since I'm not planning on doing golf course finishes, it doesn't need to be that fast right?

SSdoxie · May 17, 2012

The hydraulic cutters I have seen use a gear box and the motor is coupled to it where the PTO is on tractor version. I think you would be well ahead to look for a decent used 48" pto cutter the convert it to your loader mount and hydraulic drive.

woodlandfarms · May 19, 2012

Check out power-Trac.com for ideas.

Our mowers are direct drive 3 blade affairs, I think 800 rpm motors.

Not an easy build with balance being so important.

I think finding an old brush hog with a locked up gearbox would be the a ticket

On our directdrive there is a lovejpy I between.

J_J · May 19, 2012

I agree with SSdoxie in getting a 48 in bush hog and adding a hyd motor that will run at 540 to 600 rpm to the gear boxshaft and add your skid steer plate to the 3pt section, or get the adapter to go from skid steer to 3pt attachments.

Remove the wheel on the back and cut about a 6 in slice off the back side and make it into a hinge flap.

Raise the flap to vertical when cutting, and when not cutting, lower the hinge plate and cover the blades.

Maybe something like this.

http://www.brushwolf.com/

http://www.youtube.com/watch?feature=player_embedded&v=S72dXWzYdeI

http://www.youtube.com/watch?feature=player_embedded&v=S72dXWzYdeI

Right Angle gear boxes.

http://www.surpluscenter.com/sort.asp?catname=powerTrans&keyword=PGRA

brokenot · May 20, 2012

No matter which way you choose to go with your home-built cutter, take a look at the factory built models for examples of what drive motors they use. I'd think they *have to* be using motors with internal reliefs, (or a separate manifold with reliefs), because when you turn the mower's oil supply "off" with the blade(s) already up to speed, the rotating assembly is going to go from spinning to not spinning pretty quickly.

That will be hard on things. Something to do with Newton's First Law of Motion....

3238dpw · May 23, 2012

Here are some links that might help

http://www.tractorbynet.com/forums/build-yourself/183482-homemade-hydrolic-brush-cutter-land.html

Brush Cutter Project - TractorByNet.com

[ame=http://www.youtube.com/watch?v=YRlXeLFUX68&feature=channel&list=UL]MVI 3284 - YouTube[/ame]

[ame]http://www.youtube.com/watch?v=_-BpZk3X_sI&feature=plcp[/ame]
[ame]http://www.youtube.com/watch?v=CAr2R29UpN8&feature=channel&list=UL[/ame]

There are other links I have but thay are on other forums and I believe we can not link to other forums. If you PM me I will send you the links

Derik · May 26, 2012

I am very interested in this thread. This is something i have been thinking of doing for a while now. We have a toro dingo 525 and a dw sk650. We either sub out brush mowing or for small jobs rent a billy goat brush mower.

leotech · May 30, 2012

I searched far and wide for a mower deck but could not find any in my area that were in ok condition or reasonable price.

I ordered the following items for my build.
1. 40hp gearbox 1:1.45
2. stump jumper plate
3. blades
4. blade bolts

Next is sizing hydraulic motor.

Since I only have 8gpm @ 2500psi, I'm somewhat limited in sizes. I've calculated in order to have a input speed of 2500rpm for output of around 3600rpm, I would need a high speed motor of around 0.5cu in.
Surplus Center - 0.580 cu in PARKER MGG20025-BB1B3 HYD MOTOR

It seems a bit fast so I might size the motor for a 1.0cu in for half the input speed for output spindle of 1800rpm.

Thanks,
Curtis