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Need more power

Started by woodbeard, August 25, 2005, 05:47:50 PM

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woodbeard

As I mentioned in my previous thread, my '92 LT30HDG24 is having a real hard time supplying power to the hydraulics.
The bed and hydraulics of this mill were from the prototype of the LT60, and have 2 motors, like a super hyd., presumably to run the chain turner, and possibly bigger cylinders on other stuff.
I spoke with the parts dept. at WM today, and we came to the conclusion that my 24hp Onan is just way too small to run this stuff. The smallest engine on a super is 35hp. I tried disconnecting one of the motors as per their suggestion. It helped a little, but not enough.
A new 35 horse engine will run about 5 grand or so and require a lot of refitting, so I am thinking of putting together a separate power unit for the hydraulics. Any ideas on how I might go about this? The 2 hyd. pumps draw a total of 400 amps. What size engine and alternator do I need?

Tom

It seems to me that you could live with the two motors on the hydraulics if you maximize the alternator and use a battery that will hold a big load.

I'm reminded of dumb situation I was in once when a Motorcycle mechanic suggested that I needed new brakes.  Since I was going on a 500 mile trip over the weekend asked him if he thought they would last till I get back.  He said, "sure, if you don't use them much".   

Since the hydraulics are used only intermittently, the rest of the time can be used for charging.

There are 100+ amp alternators out there that can keep a battery pretty hot.

Before I spent thousands of dollars on a new motor, I would spend one or two hundred on new alternator and battery.   It might fix the problem.

woodbeard

Well, the manual states a "105 amp max." rating for the stock alternator, and the battery is a deep cycle/starting battery which is about as big as can fit in the box. I suppose I could ask WM about getting whatever alternator is supposed to go on the super hyd. mills. How big an alternator can a 24hp engine pull?

Tom

The automotive generator place where I got my last alternator (I get them rebuilt) told me that my current one is 120 amps.   I never noticed a difference in engine load between it and the 80 amp that was original.

jpad_mi

Generating 400amps of  current (4800watts) will take a good bit of horsepower! I can see why there isn't much left for sawing. I purchased the engine on my mill from a guy that owns a company that makes DC gen-sets. You may want to contact the guy to discuss your needs. I'll PM you the website. 

I would think that if you end up adding a second engine, that you'd be better off removing the electric over hydraulic pumps and going with a gas engine w/direct coupled hydraulic pump and remote resevoir. The intermediate step of generating DC power seems like it would be very inefficient.  Of course this will present a lot of challenges getting it all re-connected.
Jeff P. in Michigan

Ianab

I was thinking along the same lines a JP, is it practical to fit a auxillary gas engine to run the hydralics?
If you need 4800 watts thats like 6hp? and a little Honda industrial engine would do the job. Would certainly be cheaper than fitting bigger engine to the mill.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

Minnesota_boy

I'd take the easy way out and replace the deep cycle battery with a heavy-duty starting battery.  I never uear the battery down and leave it that way, so a deep cycle isn't really needed.  You only need 400 amps when you are lifting the biggest log onto the mill.  The rest of the time the hydraulics are not being stressed out that much.  The 100 amp alternator should easily keep the battery charged unless you are loading a big log, taking only one slice and then removing the rest of the log.
I eat a high-fiber diet.  Lots of sawdust!

johnjbc

105 Amps at 12 Volts gives 1260 Watts.
If 746 Watts is 1 H.P.
Then 1260 Watts is   1.7 H.P.
That load shouldn't make that much difference to 24 H.P. engine except at idle. Have you tried speeding up the idle.

I  doubt that you use the hydraulics 10% of the time So a average charge of 40 Amps should keep your Battery up.
LT40HDG24, Case VAC, Kubota L48, Case 580B, Cat 977H, Bobcat 773

twoodward15

Multiply that by 3.5 to get the 400 AMPS that he needs and you'll notice a big horsepower difference. 7 horsepower less than 24 makes a big difference.
How about buying a generator to run your hydraulics?  A 6000 watt job would do fine and I'm sure you'd find other uses for it like running your house when the power is out!!!  If you look hard enough you can probably find one for way under a thousand dollars.  Probably even under 500 if you really try!
108 ARW   NKAWTG...N      Jersey Thunder

RMay

I would replace the battery , my mill was doing the same thing with a deep cycle battery.
RMay in Okolona Arkansas  Sawing since 2001 with a 2012 Wood-Miser LT40HDSD35-RA  with Command Control and Accuset .

woodbeard

OK, well the battery will be the first thing I will try, then. I can always use another battery for something or another.
I have tried holding the idle higher by hand while running the hydraulics, but it still wants to conk out.
If I end up getting a generator, how do I get 12vdc out of it?

johnjbc

Not sure where the 3 ½ came from. But when the hydraulic pump is running the load would be split with the battery providing 300 amps and the alternator providing 105 amps. I wonder if your battery could be sulfated and not able to take a full charge.
I think you also need to stay with a heavy duty deep cycle. A regular car battery will fail quickly if charged and discharged reputably like this application requires.
LT40HDG24, Case VAC, Kubota L48, Case 580B, Cat 977H, Bobcat 773

Fla._Deadheader


A few of the guys swear by them round cell batteries ???  CRS  ::) ::) ::)
All truth passes through three stages:
   First, it is ridiculed;
   Second, it is violently opposed; and
   Third, it is accepted as self-evident.

-- Arthur Schopenhauer (1788-1860)

johnjbc

To get 12 volts  at high current you would need a real big battery charger.
LT40HDG24, Case VAC, Kubota L48, Case 580B, Cat 977H, Bobcat 773

Minnesota_boy

Quote from: johnjbc on August 25, 2005, 09:42:39 PM
I think you also need to stay with a heavy duty deep cycle. A regular car battery will fail quickly if charged and discharged reputably like this application requires.


Just to be contrary, I found that the deep cycle wouldn't last 3 seasons, while the standard heavy-duty starting battery has lasted me 6 years.  Just make sure you get a heavy-duty one so you aren't deep-cycling it.  If it can produce 800 cold cranking amps, it will last a long time.
I eat a high-fiber diet.  Lots of sawdust!

woodbeard

Hmm.. well earlier today I had to take the battery to the auto parts store to get it charged- it would not start the engine. I figured it was totally drained, but when they put it on the machine it showed a fair charge, and only needed 25 minutes charging. I thought that was odd

Tom

You might have a weak cell. 

It might be a good idea to check all of the electrical connections between the battery and the hydraulic pumps too.

Dirty terminals can keep a battery from charging and also keep the power from leaving the battry too.

Buzz-sawyer

How many volts is your alternator putting out at idle and at speed?
    HEAR THAT BLADE SING!

woodbeard

Don't know. I will check that tomorrow.

RMay

RMay in Okolona Arkansas  Sawing since 2001 with a 2012 Wood-Miser LT40HDSD35-RA  with Command Control and Accuset .

Kevin_H.

Be carefull of the old "this battery is good" from the parts store people. The last time I took in a battery, they tested it and said nothing was wrong with it, it just needed to be charged. I popped the top off of it and showed them the dry cell and the crack in the case and asked how the battery could still be good.

I left with a new battery.
Got my WM lt40g24, Setworks and debarker in oct. '97, been sawing part time ever since, Moving logs with a bobcat.

twoodward15

How about a gel battery?  I think that's what fla deadheader is talking about.
John, he needed 4000 watts, not 1260.  I just multiplied 1260 by 3.5 to get roughly 4000 watts.
108 ARW   NKAWTG...N      Jersey Thunder

ladylake

On my B20 timberking the hydraulics are driven by a 6Hp Briggs with the pump mounted right on the motor. Would it be hard to change the lines and bypass the electric pump?    Steve
Timberking B20  18000  hours +  Case75xt grapple + forks+8" snow bucket + dirt bucket   770 Oliver   Lots(too many) of chainsaws, Like the Echo saws and the Stihl and Husky     W5  Case loader   1  trailers  Wright sharpener     Suffolk  setter Volvo MCT125c skid loader

Fla._Deadheader


I would really be interested in knowing why WM has that split power band on the side of their mills. We run a 100A Delco and it charges whenever the engine is running.

  We don't have ALL the goodies that is being discussed here, but, we DO overuse the battery, sooo, we keep an eye on the acid level and top off when needed. We use a Wally World, starting-trolling battery. Cost of $ 48.00 and easy to get replaced.

  Them round cell jobs are supposed to be very good.
All truth passes through three stages:
   First, it is ridiculed;
   Second, it is violently opposed; and
   Third, it is accepted as self-evident.

-- Arthur Schopenhauer (1788-1860)

johnjbc

I was addressing the question of how much load the alternator is putting on the engine it is 1260 Watts or 1.7  H.P.
The rest of the 4000 Watts has to come from the battery, the alternator can't supply any more or put more load on the engine.
The extra power has to be put back into the battery when the hydraulics aren't being used.
From Woodbeards experience at the parts store I'm betting that the existing battery was left discharged at some point and the plates have Sulfated.
When a Lead/acid battery is charged the plates turn to Lead oxide. When you draw power the Sulfur in the acid combines with the Lead to produce Lead Sulfide. If the battery is left discharged the Sulfide hardens and eventually charging can't  convert it back to Lead Oxide. So the battery loses capacity.

Deep Cycle Batteries
When any battery goes through a charge/discharge cycle some of the plates flake off and fall to the bottom of the case. They build up and eventually short out the battery. The plates in a Deep Cycle Battery are built to minimize this, but in doing this they can't provide as much power per square inch of plate surface.  Another words you need a bigger battery for the same amount of cranking amps.
I suspect that Minnesota_boy replaced a small Deep Cycle with a honking big Car Battery. All things equal the Deep Cycle should last longer in the Woodmizer application. Maybe Sparks can comment on this.

Just what I remember from Mr. Palmers lecture on batteries in tech school
LT40HDG24, Case VAC, Kubota L48, Case 580B, Cat 977H, Bobcat 773

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