GPM Requirements for attachments

[Mahindra One]

I posted this on another forum with limited feedback. Hope to get some thoughts from you guys. Thanks

Having a tractor with Skid Steer Quick Attach front end is really a bonus but I'm finding that the GPM requirements for attachments such as a tree shear are well beyond my 8.3 capability. Knowing a little of Hyd's I am wondering if using an attachment with a less than recommended GPM rating on the tractor would result in it just flat not working or just working slower. Has anyone out there had experience with this? As you can guess, my current interest is in a tree shear.

 

[jbooth]

For the most part your attachments will work slower. Rotating attachments such as mower decks and circular saws will have less momentum and possibly less RPM and therfore not cut as well. Shears and pistion operated attachments power will be governed by your pressure. Same pressure same power just slower cycle time. You should be able to calculate cylinder operated cycle times by measureing cylinder diameter and stroke.

I use a skid steer mounted tree saw that works much better on my hi-flow system than just my aux hydraulic system. 30 GPM vs. 19 GPM.

You may experience hydraulic oil overheating if you try runing the rotating/hydraulic motor attachments without an oil cooler. Even with an oil cooler my hydraulic system get the hi temp alarm at hi ambient temperatures. I doubt you will see temperature problems with a shear.

 

[Stonehaller]

I agree that a cylinder operated shear should work fine. It would just operate slower. I would not recommend any hydraulic motor driven attachments. If you really need a high flow, motor driven, attachment then you could look into an auxiliary hydraulic pump driven off your PTO.

 

[Mahindra One]

That's sound advice. I think when considering the cost of a shear and an auxiliary pump together it would be much wiser to just sub it out considering the amount I have to deal with. Thanks

 

[jdonovan]

the GPM requirements for attachments such as a tree shear are well beyond my 8.3 capability.

Most of the standard flow skid attachments want something in the 12-20 GPM range, and the high flow are 30+.

Anything with a cylinder will work fine, just slower.
Rotating motors, will work poorly, if at all.

The other thing to look at is pressure. Most of the SS are running 3000+ PSI systems, many tractors are 2000-2500 which drops the force you can develop by as much as 33%.

 

[schmism]

If push comes to shove you can always mount a PTO powered hydraulic pump to get the GPM you need. IF you happen to find a stump grinder or trencher or something cheep.

 

[bigbull338]

most tractors dont have high out put GPM hrydro pumps.thus making any hydro attachments run pretty slow on the loader.if you want todo that youd better better off getting a skidsteer or a industreal backhoe with the high out put hydro pump.

 

[Dirthog]

yes you could mount a pto pump but remember you only have so much hp to work with if you pull everything the engine will produce to run a bigger pump you have nothing left to move the machine there is a reason the skid steer has 50-60hp or more

 

[jdonovan]

as dirtdog said the SS are much higher HP machines.... 8.3 GPM @ 2500 PSI is only about 12 HP.

A high flow SS 30 GPM @ 3000 is over 50 HP available.... huge difference.