BX25 Mid PTO Pump or BUST

[magicheater]

Theres the ROPs tube. Not much volume but a great radiator.
larry

That's for sure but a foldable ROPS would have a problem though.....

 

[SPYDERLK]

Well aware of all that. I'm only suggesting copying standard specifications, that fit within the horsepower rating of his machine, to give him a wide range of attachments he could run if he wanted to.

Toro Dingo 220
20 HP
10.8gpm
3000psi relief

Bobcat MT52
18.8HP
12gpm
2900psi

Ditchwitch SK350
20HP
12gpm
2300psi


I could go on, but my point is that my suggestion was standardized specs that would give him a huge range of attachments to choose from. Clearly many of those machines will stall the motor if they run up to full system pressure. That happens, I've run all of them and more. The key to those attachments working is flow, not pressure. They rarely ever hit pressure relief. I'm suggesting proven design parameters. I know they go against conventional hydraulic "wisdom", but it works, every day, on tens of thousands of commercially produced machines. Some tweak the relief pressure, some don't, but they all have a higher flow rating and have the same or less horsepower than the tractor in question.
Mr. HE

Actually, Im thinking you may may missed that his tractor is rated at 17PTOHP. All those implements are rated above that. Can those implements operate ok at 80% flow or is full rated speed a must? OP can pump around 9+gpm at close to 3kpsi.
BTW Bobcat vs Ditchwitch figures do not compare correctly. ... one or both are wrong.
larry

 

[Iplayfarmer]

Actually, Im thinking you may may missed that his tractor is rated at 17PTOHP. All those implements are rated above that. Can those implements operate ok at 80% flow or is full rated speed a must? OP can pump around 9+gpm at close to 3kpsi.
BTW Bobcat vs Ditchwitch figures do not compare correctly. ... one or both are wrong.
larry

Are those implements going to run better at full pressure, partial flow? Or are they going to run better at full flow partial pressure?

My bet it full flow partial pressure. How often to you activate your safety bypass pressure setting while using a power broom, etc.?

 

[SPYDERLK]

Are those implements going to run better at full pressure, partial flow? Or are they going to run better at full flow partial pressure?

My bet it full flow partial pressure. How often to you activate your safety bypass pressure setting while using a power broom, etc.?

But then I run my power broom from the PTO at idle ... far from 540, but pretty hi torque on occasion. With drive by low pressure hydraulics it would just stop. Then, with my HP limited system Id be looking for more pressure than the engine-pump combination could provide. Some implements are full speed critical -- like a mower or blower. Many arent. All implements however are torque critical. Without pressure capability behind the flow youre just out of luck.
larry

 

[Artisan]

Well......other than a deep hole in the ground... what's ya all think about a
prince # SP20B16***** Not for log splitting, a system a guy can plug
"stuff" into and do a lil work. The BX25 only has I think 3GPM's or so at the
curl, looks like almost 10GPM's from this if I can pull it off. (I drew a tank,
it is sweet! Well...we will find out when I post a pic for the pros to criique' anywho)

I found a Hydraulic T-Post driver that pulls 5.3GPM that might be perfect
for such a system, I "think" . Daunser has a hydraulic pump, EP6 that
might do OK. The gent at Danuser suggested
I can prob not spin the dirt off the auger. Not having run one, I am not
sure if that is a big deal or not.

I am drawing up what I think might be a proper circuit, stay
tuned, will she go, or will she BLOW! :laughing:

Log Splittin' is DEFINATELY on my mind, a whole differnt animal I do
believe. My limited knowledge says I am either - or, either a single gear
pump OR a hi/lo pump...I thunk...

 

[SPYDERLK]

Well......other than a deep hole in the ground... what's ya all think about a
prince # SP20B16***** Not for log splitting, a system a guy can plug
"stuff" into and do a lil work. The BX25 only has I think 3GPM's or so at the
curl, looks like almost 10GPM's from this if I can pull it off. (I drew a tank,
it is sweet! Well...we will find out when I post a pic for the pros to criique' anywho)

I found a Hydraulic T-Post driver that pulls 5.3GPM that might be perfect
for such a system, I "think" . Daunser has a hydraulic pump, EP6 that
might do OK. The gent at Danuser suggested
I can prob not spin the dirt off the auger. Not having run one, I am not
sure if that is a big deal or not.

I am drawing up what I think might be a proper circuit, stay
tuned, will she go, or will she BLOW! :laughing:

Log Splittin' is DEFINATELY on my mind, a whole differnt animal I do
believe. My limited knowledge says I am either - or, either a single gear
pump OR a hi/lo pump...I thunk...

Seems that might be 1 size too high ... but close. Can you get a HP vs RPM curve for your engine. And the ratio that the mid pto is driven? It would be nice to see if it will be able to power the pump to 3Kpsi somewhere in the range.
larry

 

[Artisan]

I need to interject...

I am not capable of selecting a pump, I now know enough to be dangerous ,
having said that day by day, bit by bit I am picking up things. I am SUPER APPRECIATIVE
of the input from you guys, some day hopefully I can return
the favors... I'm in Los Angeles, I don't think anyone will be sending me a
commode to tune up any time soon but you pay the shippin' we'll take a
looksee k' ?

(If you ever going to build ask me for what to patrol your plumber on... )

My interject is the gent that suggested this pump suggested perhaps run
the said pump at 2500 PSI. I just can't completely fathom why
but I am sure there is method to the madness. Perhaps when I post up
my proposed circuit more tells will make the tale...

 

[SPYDERLK]

I need to interject...

the gent that suggested this pump suggested perhaps run
the said pump at 2500 PSI. I just can't completely fathom why
but I am sure there is method to the madness. Perhaps when I post up
my proposed circuit more tells will make the tale...

Thats because the HP to run it at 2500psi = [2500/3000] x 20.17 = ~16.8HP. A good ploy. Answer to my question in post above would let us determine if theres anywhere in the rpm range that you could develop 3Kpsi with the system.
larry

 

[Artisan]

Thats because the HP to run it at 2500psi = [2500/3000] x 20.17 = ~16.8HP. A good ploy. Answer to my question in post above would let us determine if theres anywhere in the rpm range that you could develop 3Kpsi with the system.
larry

Making sure I follow you Larry, is this the Question;

And the ratio that the mid pto is driven?

If it is the question I don't understand, if your asking what will the RPM usually be run at, well, based on past posts by others, for the short duration the system is needed between uses, I would say 100% or 2500RPM, pedal to the metal while system is running.

 

[SPYDERLK]

If you can get an rpm vs HP curve for your engine from Kubota [I know they have it], then we know how much HP is available from the engine at each point in the range. If we know the reduction ratio of the mid pto it tells us what rpm the pto turns at any chosen engine rpm. Blending these info streams will let us determine how much power is available from pto at every ptorpm. That and the pump table will enable us to see if 3 kpsi can be sustained somewhere in the rpm range with your engine and any given pump. It may be that we find your engine running 1750 rpm will turn that pump against a 3kpsi pressure. We know from the table it wont do it at the engine rpm corresponding to 2500pto speed.
larry