The Forestry Forum

General Forestry => Sawmills and Milling => Topic started by: Percy on August 03, 2017, 08:30:14 PM

Title: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: Percy on August 03, 2017, 08:30:14 PM
My guess is all have pretty much the same units working in parellel. My question is what is the GPM rating of each unit. I cant seem to find specs in my manual. The reason I need to know is after 10,500 hours, one of the pumps has swallowed the big onion. Not the electrical part but the pump itself. I want to replace both with a pair of similar 12 volt units that will fit but are two stage pumps. They go like crazy when there is a small load on them, the specs say at 610 psi the pair in parellel will do around 6.6 gallons per miniute and around 2.5 at high pressure...My mill has a relief valve built in I believe so no worrries of over stressing anything. I think this could speed up hydraulic "waiting time". Am I thinking correctly here??? Heh
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: Larry on August 03, 2017, 08:55:10 PM
The problem I see is if the pumps shift from low speed to high speed at the wrong time.  Say you are turning a big log at low speed and without warning the pump shifts to high speed due to a decreasing load.  Might spin the log into the next county. :D

Not sure if this would be a problem or not.
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: MartyParsons on August 03, 2017, 09:21:16 PM
Hello,
  pumps are 2 gal per min. Relief is set at 2200 psi. Yes the Super and the old LT70 are 4 gal per min. 2+2=4.  I would think if you have the Super the hydraulic lines are larger I.D. you could go to 8 gpm. Any more gpm and you will start to have issues. Weakest link deal.
Hope this helps.
Marty

The Super LT70 is 8 gpm at idle. I think if you run the blade at load rpm it goes to 14 gpm. Very dangerous to have this much gpm. This valve bank different than the 40 Super.

Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: Percy on August 03, 2017, 10:10:04 PM
Thanks Larry and Marty. I think I will go for the two stage pumps. Might be a tad slower at a heavy/lift/turn/whatever but it seems I spend alot of time waiting for the loader to drop/side supports to position etc. If I wasnt so long in the tooth, Id get that super 70 in the wide model. My 70 is over 14 years old and does the job. Just slow hydraulics and up/down. Id like to fix that up down thing eventually. Maybe an air cylinder in the mast... Hmmmm
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: JB Griffin on August 04, 2017, 05:59:34 PM
Marty, I'm curious to why you say 14gpm is "very dangerous". Baker runs 12.5 gpm on there Dominator and Cooks run 14 on the AC36.
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: Dave Shepard on August 04, 2017, 06:10:28 PM
Is all of that going into the log handling, or is it split with head travel functions?
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: JB Griffin on August 04, 2017, 06:50:27 PM
If the head ain't moving it ain't using no flow.
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: Dave Shepard on August 04, 2017, 07:14:45 PM
Ok. Didn't know if it used a multi section pump with dedicated flow for each function.
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: JB Griffin on August 04, 2017, 09:05:00 PM
The baker at work has a standalone hyd powerpack that runs every function on the mill.
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: 4x4American on August 04, 2017, 09:58:07 PM
Percy don't worry about how long your teeth are, sawmill men arent allowed to retire til after 80 you got plenty of time to pay it off and why waste all that time waiting on your head to go up and down lol
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: Percy on August 04, 2017, 10:35:58 PM
 
Quote from: JB Griffin on August 04, 2017, 09:05:00 PM
The baker at work has a standalone hyd powerpack that runs every function on the mill.
That would be the ultimate solution, cept Im really low on ac power at my millsite.



Quote from: 4x4American on August 04, 2017, 09:58:07 PM
Percy don't worry about how long your teeth are, sawmill men arent allowed to retire til after 80 you got plenty of time to pay it off and why waste all that time waiting on your head to go up and down lol
Ya I hear you. Im on the "freedom 85 " retirement plan :D That super sounds good..or a 3500/4000....but theres that ac power thing again. Im goin out for lottery tickets rite now....later
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: 4x4American on August 04, 2017, 11:44:42 PM
The 70 super is only offered with a diesel engine as far as I know so that solves that problem!
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: Percy on August 05, 2017, 05:22:52 PM
Quote from: 4x4American on August 04, 2017, 11:44:42 PM
The 70 super is only offered with a diesel engine as far as I know so that solves that problem!
a little over 90 grand in canukistsanian currency.
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: JB Griffin on August 06, 2017, 09:48:10 AM
Percy, why not build a gas or diesel powered hyd unit?
One of those HF 22hp should pull a 10gpm pump and thats better
than stock forsure.
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question.... is
Post by: Percy on August 06, 2017, 12:10:29 PM
I
Quote from: JB Griffin on August 06, 2017, 09:48:10 AM
Percy, why not build a gas or diesel powered hyd unit?
One of those HF 22hp should pull a 10gpm pump and thats better
than stock forsure.
This is prolly what I'll  eventually do but  i think a 5 hp diesel would be enough doncha think? It would have to be running all day
Title: Re: LT40 Super hydraulic/LT50/LT70 DC Hydraulic pumps specs question....
Post by: JB Griffin on August 06, 2017, 12:56:15 PM
The old rule of thumb I heard was 2hp to1gpm.