making a chipper for a PT?

[woodlandfarms]

I have followed Jims thread on the Post Hole Digger. Bummed that the PT does not make a chipper. How hard would it be to put a pump on a chipper at the PTO connection? Anyone try this yet?

Carl

 

[BobRip]

Might be better to use a motor instead of a pump.
Should not be too hard (easy for me to say cause I am not doing it). You would get about 15 horsepower, so don't use a really big chipper.

 

[woodlandfarms]

Sorry... Motor... Just can't wrap my head around hydraulics and motor in the same sentence...

I am considering either the 1430 or the 1845 (1845 is in the lead but the 1430 fits the wallet). But, only 15HP? You have to be kidding. How in the heck do you till with this thing? I know it does not have the ground pulling oomph that a CUT has, but this makes me nervous about brush-hogging. How does is swing a 72" swath when a 27hp PTO can only do a 60....

So, just so I have PT correct in my head. It is nothing more than a diesel / gas driven hydraulic pump. The pump that drives the lifts and steering is the same pump that drives the wheel motors?

Thanks for the PT 101 lessons guys...

 

[J_J]

Sorry... Motor... Just can't wrap my head around hydraulics and motor in the same sentence...

I am considering either the 1430 or the 1845 (1845 is in the lead but the 1430 fits the wallet). But, only 15HP? You have to be kidding. How in the heck do you till with this thing? I know it does not have the ground pulling oomph that a CUT has, but this makes me nervous about brush-hogging. How does is swing a 72" swath when a 27hp PTO can only do a 60....

So, just so I have PT correct in my head. It is nothing more than a diesel / gas driven hydraulic pump. The pump that drives the lifts and steering is the same pump that drives the wheel motors?

Thanks for the PT 101 lessons guys...

No, my 1445 has three pumps. wheel motors have their own pump, steering and lift have their own pump, and the PTO has a pump. The pump are matched to the motors. It isn't only the horse power, but the torque generated by the hydraulic motors. Even a CUT does not deliver all the available horse power to the PTO. Power-Tracs have been bushogging for about 16 years.

 

[BobRip]

Sorry... Motor... Just can't wrap my head around hydraulics and motor in the same sentence...

I am considering either the 1430 or the 1845 (1845 is in the lead but the 1430 fits the wallet). But, only 15HP? You have to be kidding. How in the heck do you till with this thing? I know it does not have the ground pulling oomph that a CUT has, but this makes me nervous about brush-hogging. How does is swing a 72" swath when a 27hp PTO can only do a 60....

So, just so I have PT correct in my head. It is nothing more than a diesel / gas driven hydraulic pump. The pump that drives the lifts and steering is the same pump that drives the wheel motors?

Thanks for the PT 101 lessons guys...

The 422 has about 15 HP on the PTO. The 1430 and 1845 are more, I don't know how much more. I expect the 425 is also 15 HP.

 

[J_J]

The 1445 takes about 26 hp to run the PTO pump. You should have less HP out to the motor, due to the loss in efficiency.

The efficiency of a hydraulic pump to motor is about 85 %.

 

[J_J]

I have followed Jims thread on the Post Hole Digger. Bummed that the PT does not make a chipper. How hard would it be to put a pump on a chipper at the PTO connection? Anyone try this yet?

Carl

There is no reason why you could not build a chipper for the PT. A 4 or 5 in chipper would take about 20 hp. You must consider this, those chippers turn in the thousands of rpm and most hydraulic motors with a high displacement will turn slow maybe around 500 to 750 rpm. You need HP and speed on a chipper.

 

[RegL]

There is no reason why you could not build a chipper for the PT. A 4 or 5 in chipper would take about 20 hp. You must consider this, those chippers turn in the thousands of rpm and most hydraulic motors with a high displacement will turn slow maybe around 500 to 750 rpm. You need HP and speed on a chipper.

PTO on a cut is also only 540rpm. Chipper speed is achieved through belts and pulleys. You could probably do the same with a hydraulic motor driven chipper.

 

[J_J]

PTO on a cut is also only 540rpm. Chipper speed is achieved through belts and pulleys. You could probably do the same with a hydraulic motor driven chipper.

You are right, I have a Bearcat PTO chipper that I use on my Kubota 22 hp diesel. It chips and shreds fairly well, but it takes just about all the available HP to run it, A 4 in log will slow it down somewhat. Again, you need lots of gpm and pressure, and the right motor.

 

[J_J]

Just some data that someone might can use.

Hydraulic Pumps & Motors

Pumping = 1 Hp = 1 GPM x 1500 Psi
(linear relationship i.e. 2 GPM @ 1500 Psi = 2 Hp)


Hp to drive hydraulic pump = Psi x GPM / 1714


Efficiency - typically assume hydraulic pump/motor efficiency of 85%


Hydraulic motor torque (in-lb) = Pressure (Psi) x motor displacement (in3/rev) / (2 x Pi)


Hydraulic motor speed (RPM) = 231 x GPM / motor displacement (in3/rev)


Hydraulic motor power (Hp) = Torque (in-lb) x RPM / 63025

 

[BobRip]

Just some data that someone might can use.

Hydraulic Pumps & Motors

Pumping = 1 Hp = 1 GPM x 1500 Psi
(linear relationship i.e. 2 GPM @ 1500 Psi = 2 Hp)


Hp to drive hydraulic pump = Psi x GPM / 1714


Efficiency - typically assume hydraulic pump/motor efficiency of 85%


Hydraulic motor torque (in-lb) = Pressure (Psi) x motor displacement (in3/rev) / (2 x Pi)


Hydraulic motor speed (RPM) = 231 x GPM / motor displacement (in3/rev)


Hydraulic motor power (Hp) = Torque (in-lb) x RPM / 63025

The PT 422 and 425 are rated at 8 GPM at 2500 PSI = 20,000 somethings. Divide that by 1500 and you get 13.3 horsepower. 13.3 * .85 = 11.33. Sorry for my previous memory of 15 horsepower. That's what I get for counting on my memory. Thanks for the lession J_J.

 

[J_J]

Bob, this is not stuff that I keep in memory either. I give credit to the age of computers, and the Internet.

 

[J_J]

You are right, I have a Bearcat PTO chipper that I use on my Kubota 22 hp diesel. It chips and shreds fairly well, but it takes just about all the available HP to run it, A 4 in log will slow it down somewhat. Again, you need lots of gpm and pressure, and the right motor.

It ain't no PT, but it is one **** of a mulcher/chipper.

http://craneworks.com/displayphoto.asp?photoID=46771

 

[woodlandfarms]

The PT 422 and 425 are rated at 8 GPM at 2500 PSI = 20,000 somethings. Divide that by 1500 and you get 13.3 horsepower. 13.3 * .85 = 11.33. Sorry for my previous memory of 15 horsepower. That's what I get for counting on my memory. Thanks for the lession J_J.

OK. now I am going to show how bad I failed physics. The 1850 is rated 8GPM at 2500PSI.. So, wouldn't it be 11.33HP? I am missing something huge here...

 

[J_J]

I believe the 1850 is rated at 18 gpm, at 3200psi

 

[MossRoad]

I would think that if you could find an old chipper that ran on a 10HP or less motor you could adapt it to a hydraulic motor very easily. Those gas engine chippers usually turn the engine at 3600 RPM and have belts that drive the chipper. You would have to gear up a hydraulic motor with pulleys of the proper size to get the chipper to turn at the original speed.

I seriously thought about this a while back. I even went to a lawn and garden dealer that has some used chippers. I could have picked one up with no engine for about $300 and then put another 3-4 hundred in a hydraulic motor and pulleys, etc... it looked to be a very doable project. However, I realized I have little use for a chipper right now. Maybe in a few years.