Need more power

[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.

[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

[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.

[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.

[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!

[RMay]

I would replace the battery , my mill was doing the same thing with a deep cycle battery.

[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.

[Fla._Deadheader]

 A few of the guys swear by them round cell batteries   CRS 

[johnjbc]

To get 12 volts  at high current you would need a real big battery charger.

[Minnesota_boy]

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.

[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?

[woodbeard]

Don't know. I will check that tomorrow.

[RMay]

here is some good info I got when I had a battery go bad http://www.forestryforum.com/board/index.php?topic=9594.msg131219#msg131219

[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.

[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.

[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

[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.

[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

[johnjbc]

FDH
I think it is a safety issue. Keeps you from rolling a log on your self.
If you were standing beside the mill and accidentally put the stops down the log could end up on your lap . Some people do strange things. Ever saw a dog?

[twoodward15]

Now I get it John,  Wow, that was a brain fart.  Sorry.
I'll agree with Fla deadheader on this.  The round cell batteries he is talking about are the optima gel batteries ( I think).  These batteries are fantastic.  They are expensive, but they'll last you a really long time.  They can be charged and discharged numerous times without any damage.  They can be installed in any position (upside down) you want to install them.  Vibration doesn't hurt them.  Heat doesn't affect them.  I have one in my SUV.  My buddy had one in his truck that he traded in last summer.  it was 7 years old and still working fine.  He had a high output alternator on it and a bunch of extra lights on his roll bar.  So bright you could see into tomorrow with them on.  I would suggest them in a heartbeat if you want to spend the hundred or so bucks on one.

[submarinesailor]

Otima batteries

Read some very good write-ups on these.

Bruce

[Percy]

The LT40 Supers use a 140 amp alt and my LT70 uses a 190 amp alt which is probably what you neeed to keep the battery up seing as you have the  chain turner etc.  Find a good partsman and he should be able to find a part # of an alternator that will work/bolt on.  Neat mill by the way...

[Buzz-sawyer]

Initially it sounds like your alternator/battery may not be up to snuff.
However, being as I am frugal(cheap) and like a inexpensive fix.....here are 2 od em.
Use your neighbors second hand lawn mower engine coupled via direct coupler to a 2 stage hydraulic system..then your primary engine is doing NOTHIN but cutting.......should cost under $200 bucks....no need for energy consuming electric over hydraulic anymore!!!

Second.................Do as recomended match up the alternator to its automotive cousin.....then head to the you pull it salvage yard and get a 160 amp alternator.....most all the newer ones charge at idle and are awsome......should cost under 50 bucks w/ core charge.

[rebocardo]

It does not matter if you are talking cars, trucks, or equipment, upgrading to a higher amp alternator can make you go from bad to worse in regards to charging because many only charge that high at a very high rpm. At or near idle they can range from only 40-60 amps.

What you need to do is figure out the RPMs under normal load and then buy or build an alternator to work in that RPM curve and adjust the alt speed for peak output (near idle) using the proper sized pulley.

[Buzz-sawyer]

In my recent experience most all the newer ones charge at idle 

Alternator - Delco CS130D Series
160 Amp, 12 Volt, CW, 6-Groove Pulley

Used On:
(2000-96) Chevrolet, GMC Pickups, SUV, Vans 4.3L, 5.0L, 5.7L, 6.5L, 7.4L



This Alternator Puts Out 160 Amps, And Works Perfect At A Idle since modern vehicles suck massive amps for electric utilities while idling........I will check what the idling output is if anyone is intersted.............

These alternators make a great welder too

[Furby]

These alternators make a great welder too

I've heard that before, but not sure how to set one up. Just run the cables right off of it?

[woodbeard]

Well, Buzz, you were right on the mark about the alternator and battery.
I couldn't find my multimeter, so I just took the alternator down to the parts store where it tested bad. Not only that, but it was only a 60 amp alternator.
In addition, the battery was rated at 625cca/850ca.
So I picked up a rebuilt Delco 100amp alternator, and a new battery with a 800cca/1000ca rating. Got everything put back together, and things seemed to work pretty good, but the motor wasn't idling right, and died a couple times. I looked at the plugs, and they were covered with soot, presumably from the engine being pulled down so much, and not enough juice for a good spark. So, I loaded up a log ( successfully ) and cut it into slices just to run the engine full throttle for a while. When I let it back down to idle, it ran just fine, and was able to run all the hyd. functions without dying, and with both hyd. pumps.
 

Thanks everyone for your input on this, I'm really glad I don't have to do any wacky inventing to get this mill to do what it's supposed to do. I still may end up wanting a bigger alternator, but the 100amp is all that was available today. We'll see how it goes when I get to sawing up this pile of sasafrass.
 

[sparks]

The alternator output should be 14.5 to 14.7. It should be within 1/2 a volt of that at the battery 14.0 to 14.2. If if the difference is more than a half volt check all the connections between the alternator and the battery for corrosion.

[sparks]

One more thing, most cars do not idle at 1300rpm. Our mills do so at this rpm most alternators will put out it's maximum amperage and voltage. I would just be careful of automobile alternators. They usually can't handle full output day after day. We have our alternators built to our spec's for durability. We do have a 105amp for your mill if you ever need it.     Thanks all.

[Fla._Deadheader]

  Sparks, what's the reasoning for having the two part power strip on the side of the WM frame, power on both ends and none in the middle ?? 

  On our homebuilt, we run the Alternator full time, and never need full charge rate We do not have a log turner, but, we use plenty of amperage ??  Thanks

[woodbeard]

I don't think I've seen one with a power strip on the far end. Not that I've seen that many Woodmizers, but mine certainly doesn't have one, just the one at the forward end.

I am still having some trouble with the engine bogging down while running the hydraulics. I am starting to wonder if the 100 amp alternator isn't going to cut it. Or maybe it is something with the engine? One thing I notice is that after I let off the hydraulics, the engine has a hard time coming back up to full idle. I assume there is some sort of governor, maybe it needs some tinkering with?

[Fla._Deadheader]

 Woodbeard, you are correct. My brain ain't functionin right now. 

[Buzz-sawyer]

Well I am betting, from what you said about soot on the plug you need to look through the fuel and ignition system......you have fixed the charging system and eliminated those weakness from the situation.......you should be cutting full on ........

[Fla._Deadheader]

 I agree with the Buzzer, 

[Ianab]

If the plug has been sooted up it might be stuffed now.
A new plug is simple to try and opening the throttle at low revs is where a weak plug will give problems. 

Ian

[woodbowl]

woodbeard,
    I glad you got your alternator problems solved.---------I run a 78 amp Delco Remy alt on my lt40hd (converted from manual) I've tried marine batts, they have a lot of capacity and do OK I guess, but they don't really deliver the quick power that I need. I now run with a high cranking amp batt such as 900 cranking amps. It will really spit it out for about a year. (150,000 bf) After that, I take it out, put it in another vehicle and get another new batt for the mill. Batteries don't last me too long with the amount of charge and discharge that they go through. This way, I've always got a good hot batt and if electrical problems arise, I can iliminate that right away.

[woodbeard]

Yes, I had made a point to replace the plugs and wires when I looked at them, and promptly forgot all about it.  The plugs I can probably get anywhere, but I imagine I may have to order the wires from WM? One is charred a bit from where it laid against the exhaust pipe, and that plug was more grungy than the other.

[RMay]

Fla. Deadheader the power strip on both ends of the frame is for the remote operator station 

[Fla._Deadheader]

 Thanks Roy, Now I'm REALLY cornfuzed 

[Rockn H]

Woodbeard, most parts stores can match your plug wires fine.  Just take the old ones in with you so they'll know what length and ends you need.

[sparks]

On an LT60/70 you can operate the mill at either end. We tested this and decided not to put them on the mills. By the time you ran cables you were losing to many amps through the wire. So we still just use the one strip near the hitch end.  Thanks

[gmmills]

    My LT 70 has power strips on both ends of the mill. With this set up you can turn a log with the saw head at the far end of the mill.  Don't have to look through the head.  The mill also has a 190 amp alternator. Even thought about putting an additonal strip on my old LT 40 super. Have the extra strip. Never took the time to put it on the mill.

[woodbeard]

Well, I replaced the plugs and wires, which was probably a good thing to do anyway, but it hasn't solved the problem. What is happening is this:
When using the chain turner or the loader, the engine often ( not always ) slows way down, to where it sounds like it is going to quit. I can most always get the log loaded or turned, but when I let off the lever, the engine frequently ( about 60% of the time ) won't return to normal idle speed. If I nudge the throttle arm on the carb., the arm will push back at me and get itself back to where it is supposed to be. Sometimes this happens when I use the other functions as well ( clamp, toeboards, etc. ) but usually only before the engine gets really warmed up. It is definitely a lot better since I replaced the alternator and battery, but I think something still aint quite right.

[tnlogger]

 woodbeard have ya got an amp prob or can you borrow one soulds like the armature on your pump might be glazed over. or the bushes. how hot is the pump motor getting after you use it to load a log? worth a check.

[woodbeard]

Both pumps seem to be running nice and cool, Gene. There's only about 200hrs on the hydraulic system, it all seems to be working just fine.
This morning I found I was able to keep the engine up to speed by applying a little pressure against the throttle linkage with my finger, keeping it from dropping down too far. Well, back to the manual to figure out the linkage and governor.