skid steer brush cutter motor. HELP!!!!!

J_J · May 26, 2015

pairofhounds said:
Thanks what motor?

The PTO motor I posted can use your 26 GPM to turn that hyd motor at 626rpm into your gearbox.

J_J · May 26, 2015

Xfaxman

Can you tell us the cu in and the gearbox ratio?

Any idea of blade tip s peed?

pairofhounds · May 26, 2015

Looking for 15000+ fps

Xfaxman · May 26, 2015

J_J said:
Xfaxman

Can you tell us the cu in and the gearbox ratio?

Any idea of blade tip s peed?

I called Grace Mfg., he said they are using a different motor now and not sure what my 5 year old mower had in it. The gearbox is 1-1:46. At 22 GPM the motor shaft RPM would be 700, blade tip speed, 14640.

J_J · May 26, 2015

Now if we only knew the other gearbox ratio we could figure the spindle speed and blade tip speed.

His skidsteer puts out about 26 GPM.

J_J · May 26, 2015

pairofhounds said:
Looking for 15000+ fps

Your GPM, gearbox ratio will determine the spindle speed and the length of the blade will determine the blade tip speed.

If you had 700 rpm spindle speed.

5 ft blade tip speed = 10,990 fps

6-------------------- = 13,188 fps

7---------------------= 15,386 fps

If your spindle speed is higher, then blade tip speed will be higher.

Your ground speed will also have something to do with the quality of cut.

oldnslo · May 26, 2015

If you want a piston style motor I would look at Rexroth A2FM or Parker Voac F12 (I think) bent axis motors. These are used extensively on mulchers and will take the abuse. These are by no means inexpensive motors but tehy will do the job if sized correctly.

Tejas · Oct 8, 2016

I know this is an old thread, but I have struggled with finding good info over the last few years. I have pieced together much of it over a few forums and countless hours surfing the net. To the OP, you are correct, the manufactures care not to share their "trade secrets". There are some fair deals in the hydraulic rotary cutter worlds and there are clearly some that are outrageous.

I resigned a Bradco 72" cutter and converted from a (missing) Hi-flow motor to a Standard-flow motor. Took me about a year...mostly gathering intel. I also built a 60" cutter for a neighbor, for his 15GPM Bobcat 763...from scratch, except for adapting the deck from boom-mount to Skidsteer QA. I did this one on a DIY forum on Texas BowHunter... DIY/ build along hydraulic Shredder - TexasBowhunter.com Community Discussion Forums

The only real reason to go to a Direct Drive system is for the larger output shaft...this gives us the ability to go to a larger / heavier blade carrier. Why, well because it is a flywheel and stores energy and allows for much higher performance when attacking heavy brush/ small trees.

If you ever found what you were looking for, I hope you post the info on here. Thanks!!