Homeade Brush Cutter.....for skid steer...

Complete · Jun 3, 2009

Hey guys new here have a couple questions.

I recently picked up and old brush cutter. Real similar to this

I can't complain the price was FREE

I wanted to turn it into something similar to this

My problem is I have no idea what size or spec hydraulic motor I should use.

Could anyone help me with this task?

Here is my machine

Sunkistdds · Jun 3, 2009

Is the cutter wider than your skid? Nice machine not to scratch up for no reason.

I'd put some guage wheels on the now front and get a suitable HYD motor... ur question: Just look up the specs on torque and volumn on a commercially produced unit or ask a dealer and match it, won't be cheap unless you find an old bone yard for like a state DOT and get it there. That BH has a 6 spline 1 and 3/8 shaft I think so hooking up would be a breeze. Looks like a week end job.

Complete · Jun 3, 2009

Sunkistdds said:
Is the cutter wider than your skid? Nice machine not to scratch up for no reason.

I'd put some guage wheels on the now front and get a suitable HYD motor... ur question: Just look up the specs on torque and volumn on a commercially produced unit or ask a dealer and match it, won't be cheap unless you find an old bone yard for like a state DOT and get it there. That BH has a 6 spline 1 and 3/8 shaft I think so hooking up would be a breeze. Looks like a week end job.

Well the hog I picked up the under side blade disc was completely rusted away so I cut that off and fixing to cut the gear box off.

I just need to find a suitable hyd motor to bolt in place of the original gear box

GATC35 · Jun 3, 2009

Go here:

http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=10821

flusher · Jun 3, 2009

My rotary mower is a 6-ft Hawkline that has a 50-hp rated gearbox.

http://www.gohawkline.com/RCSeriesCutterManual.pdf

I run it off my Mahindra 5525 tractor that has 45 pto hp. These mowers are designed to run at 540 rpm at the pto. I believe the gearbox is 1:1.

So, I'd look for a 50-hp hydraulic motor to adapt this particular mower to your skid steer. Maybe something like this

https://www.surpluscenter.com/item.asp?UID=2009060311563878&item=9-1743-B&catname=hydraulic

Complete · Jun 3, 2009

See I don't want to hook into the gear box I want a direct drive hyd motor so I can run the 20gpm line on my skid steer. That and there is less power loss from the hyd motor, to the gear box, to the blades.

A direct drive motor should spin a little faster and cut more dense brush.

J_J · Jun 3, 2009

What is you output in GPM to your aux circuit.

Complete · Jun 3, 2009

J_J said:
What is you output in GPM to your aux circuit.

I have 20gpm circuit and I have a 38gpm circuit. Plan on using the 20gpm want to try and cut stuff up to about 4" in diameter.

J_J · Jun 3, 2009

If you have an output of 25 GPM, and you want to turn the cutter at around 540, then you will need a 10 cu in motor. Now you will have to find a shaft and stump jumper assembly to match up with the motor via a flex coupling.

J_J · Jun 3, 2009

20 GPM at 578, you will need a 8 cu in motor.

38 GPM at 549, you will need a 16 cu in motor.

https://www.surpluscenter.com/item.asp?UID=2009060312125154&item=9-4338-08&catname=hydraulic

http://www.nextag.com/lovejoy-coupler/stores-html

Have to watch out for psi limitations.

Is your GPM output variable with in the two ranges. You could vary the engine rpm to set a pump output to match up the motor you want to use, but , then you have to consider your ground speed.

J_J · Jun 3, 2009

I have a bush hog that I am planning on adding a hydraulic motor to the input of the gearbox.

J_J · Jun 3, 2009

Here are some items that you might find interesting.

Complete · Jun 3, 2009

Yup here is the idea...just the homeade version...

Or with 4 blades

jenkinsph · Jun 3, 2009

For this application I would consider a Commercial Shearing Inc. M76

M76 with 1 1/2" gears
2140 in lbs torque @ 2500 psi
570 rpm @ 20 gals/min.
about 18-20 hp ( and that is about max for this circuit)

I would employ a relief valve as in the picture and would dial down the pressure to the minimum amount needed to get the job done. You also will need to make sure you have motor spool setup for the hydraulic control valve. There is a lot of merit in keeping the gear box and a slip clutch and you should give that a lot of thought. I would much prefer the gearbox and bearings deal with the blade spindle thrust instead of the hyd motor.

The above motor meets you requirements though, matching the shafts might be another issue entirely.

Steve

TracksNIowa · Jun 4, 2009

I dont want to derail your thread, but I was hoping to get in and learn as well because I want to fabricate my own mower for a skid steer too.
I have a a case 1840 skid steer with standard flow hydraulics. The book says 15.3 gpm at 2300 psi at normal engine rpm. Can someone tell me if this is the whole tractor or just to the auxilieries lines? I am trying to figure out what my 1840 is capable of so I can correctly size the motor.
I would also like to talk design. I have read with keen interest the other related threads on this forum about building your own mower. One thing I was wanting to incorporate into my mower (possibly built from a retired 5 foot 3pt bush hog), is the moon shape cut out on the front or felling saplings and heavier brush. I have seen this more commonly on the high flow models designed for cutting heavy brush. I think this would be a benefit if you were clearing in timber etc to not have to shred the whole sapling, but to just cut it off at the ground. Any thoughts or pointers from those who have used or built this equipment would be great.
Also I was thinking of having a removable lead wheel, so i could use it for trimming grass etc, but remove it for cutting heavy brush in the timber?
Thanks for listening to my babble, I am stuck over seas right now, but I promise to post pictures of my project when I am done!

Beau Nelson

TracksNIowa · Jun 4, 2009

Two more thoughts, has anyone built their own clear plastic door to protect the operator? Any pics, or can you buy one after market?
And finally will my std flow 1840 run a 5 foot mower in heavy brush if i go reasonably slow, or is that too much mower?
Thanks,
Beau

J_J · Jun 4, 2009

TracksNIowa said:
I dont want to derail your thread, but I was hoping to get in and learn as well because I want to fabricate my own mower for a skid steer too.
I have a a case 1840 skid steer with standard flow hydraulics. The book says 15.3 GPM at 2300 psi at normal engine rpm. Can someone tell me if this is the whole tractor or just to the auxiliaries lines? I am trying to figure out what my 1840 is capable of so I can correctly size the motor.
I would also like to talk design. I have read with keen interest the other related threads on this forum about building your own mower. One thing I was wanting to incorporate into my mower (possibly built from a retired 5 foot 3pt bush hog), is the moon shape cut out on the front or felling saplings and heavier brush. I have seen this more commonly on the high flow models designed for cutting heavy brush. I think this would be a benefit if you were clearing in timber etc to not have to shred the whole sapling, but to just cut it off at the ground. Any thoughts or pointers from those who have used or built this equipment would be great.
Also I was thinking of having a removable lead wheel, so i could use it for trimming grass etc, but remove it for cutting heavy brush in the timber?
Thanks for listening to my babble, I am stuck over seas right now, but I promise to post pictures of my project when I am done!
Beau Nelson

Beau,

That 15.3 GPM would be only for the aux hyd. I have the 1445c, and it is 18 GPM, and I have all the stuff to do this adaptation for my 5 ft bush-hog.

15.3 GPM will allow you to use a 6.5 cu in hyd motor at 540 rpm. I was going to build a large L shape motor mount and bolt it to the front part of the bush-hog and couple the motor to the gear box shaft. Do a search for the motor you need at Baileynet.com, or Surplus Hydraulics. They have all kinds of motors with different shaft, so you will have to couple the hyd motor up with the PTO shaft. Your aux valve, is probably a motor spool valve, but to be safe, add some relief valves at the motor, so it can spin down.

Complete · Jun 4, 2009

jenkinsph said:
For this application I would consider a Commercial Shearing Inc. M76

M76 with 1 1/2" gears
2140 in lbs torque @ 2500 psi
570 rpm @ 20 gals/min.
about 18-20 hp ( and that is about max for this circuit)

I would employ a relief valve as in the picture and would dial down the pressure to the minimum amount needed to get the job done. You also will need to make sure you have motor spool setup for the hydraulic control valve. There is a lot of merit in keeping the gear box and a slip clutch and you should give that a lot of thought. I would much prefer the gearbox and bearings deal with the blade spindle thrust instead of the hyd motor.

The above motor meets you requirements though, matching the shafts might be another issue entirely.

Steve

Steve,

THANKS for the info thats what I was looking for

The relief valve could it be had at a place such as Grainger?

Beau,

No problem man the more people the merrier

jenkinsph · Jun 4, 2009

Yes, Grainger should have them also the hyd motor supplier. Commercial Shearing is a good quality brand and in this use it is turning slow so it should last a long time.
This is a cast iron motor that is pretty much bullet proof.

Steve

Sunkistdds · Jun 4, 2009

What you are talking about is industrial duty... more than most farm units do. If you are going to get an application that seems to be as financially rewarding as cutting 4" brush would be for yourself or commercially, and you have saved on the subunit as you have, why not just go to the dealer of the above, or another that you like and have them part out the whole unit from motor to blade. Nickel and diming on something as heavy duty as this makes little sense. When you want to work, you need to have a suitable tool... unlike some of us that try to beat the system be cause it is fun or necessary.