Up and Down power feed problems

[abooley]

The Up/Down motor on my LT40HDG24 recently gave up the ghost. So I bought a new one. Today on the job, after sawing 2 30" oaks, the saw head would not raise. I removed the cover and found the motor extreemly hot. Has anyone else ran into this issue before, or have a suggestion on correcting the problem? I don't want to burn up another motor, they are expensive.

[sgschwend]

Can you determine if the object the motor turns is bound up?

Sorry I don't know about your machine, but it sounds like the motor is being overloaded; needed to deliver a lot more power than usual to do the lifting of the saw head.

[abooley]

There is nothing binding up. The head will travel down normally. The belt tension is fine. Wire connections are sound. If the battery is going bad, could this cause the motor to overheat? The motor is DC, and ran directly off the battery.

[Buck]

I was thinking wire connections and your switch....and now you cant get tech support til Monday too.

[Magicman]

Loose connections can cause low voltage, which will raise the current draw.  Be sure that all of your battery connections are tight.  Follow each lead, including/especially the ground and be sure.

If your motor is overloaded, there are not many items that could do that.  You could have a dry or partially frozen bearing in your gearbox.   Gearboxes have been a popular subject here, and many of us, including myself, have had to replace bearings.

Be very careful when dealing with that gearbox.  Be sure and securely chain that sawhead to the top to keep it from dropping on you.

[woodmills1]

how many hours would lead me to gear box or electric

[backwoods sawyer]

If there is not the correct amount of slack in the up down chain, this can increase the power needed as well. Be sure to check the bearing in on the idler sprocket as well as the bearings in the gearbox. You may have block the head up and remove the chain to check all of the bearings, and the gearbox. Do you oil the chain on a regular basis? A dry stiff chain can give you problems as well.

[Bill Gaiche]

If the battery is not fully charged this will cause the motor to draw more amps and this will create more heat also. If not this, you are more than likley as stated have something binding or needs lubricated.

[bandmiller2]

Abooley,I would agree with Bill sounds like low voltage seeing as nothing seems to be binding.An automotive volt meter would be a good addition,even a small drop in voltage can give you a big jump in amperage [amperage=heat]Batteries can fail in many ways and can loose capacity wile still starting the engine,check the charging voltage.Frank C.

[Brucer]

If it was the battery, I would expect to see other problems showing up. I've had a battery slowly fail on me and it didn't have any unusual effect on the up/down motor (sure affected the starter).

Voltage drop across a loose connection or a faulty switch would be most likely to cause an electrical problem with a specific motor. Mechanical binding is the most likely non-electrical problem.

If you've got access to a voltmeter, use it to measure the voltage drop across the motor while someone operates the up/down switch. If it's significantly less than 12 volts you've probably got an electrical problem in your up/down circuit.

Mechanically, it is possible to get directional binding -- more friction in one direction than the other. In an emergency I was able to raise the head of a mill by turning the gearbox pulley by hand (WARNING: this is a good way to amputate a finger if you aren't careful). I probably wouldn't have been able to  do it if there was excessive friction in the system.

Follow Magicman's advice about chaining the head to the top of the mast when you are troubleshooting. At least one FF member has had the head come crashing down when a mechanical part failed.

[Gary_C]

Check the slides on the vertical mast rails for rusting and friction. I've had that problem with mine after it sits for a long time. Easy solution is to take sandpaper to the slide area to remove the roughness and rust and then lube the rails. You've got to do it on all four places.

[bugdust]

I seem to be starting to have the same problem, but mostly when raising the saw head off the support. If I move the up/down lever several times the saw head finally begins to raise. Only a couple times have I experienced a problem while sawing. I first thought the belt was slipping, but found that wasn't the problem. I believe the problem is in the motor. Even though I had only 150 hours on the mill, the warranty had expired. My first WM mill was a LT40 non-hydraulic and experienced zero problems, but the newest is the same size, but with hydraulics. One of my past posts described paint bubbling/chipping problem, now this. I almost forgot, the debarker motor blew up internally. That was under warranty, thank goodness.

[Chuck White]

Don't forget to clean and lubricate the contact points on the drum switches.

If they're not lubed, they can and will arc and then you won't have a good connection.

[MartyParsons]

Hello,
Do you have or know some on who may have a clamp on amp meter? If we had a amp reading that would help.
I had a new mill a few year back that did this and the ground bolt was lose. All of the grounds are connected with a 1/4" bolt. It is located at the back of the operator station.
Marty

[bugdust]

In my case lubing the contact points didn't help. Marty's idea might be the answer, I'll just have to check it out. Thanks Marty.

[abooley]

Here is the conclusion of the matter with my up/down travel. Unfortunately since I was in the midst of a rather large job I was unable to glean from all who responded.

Here is what I tried to rectify the problem. I had just replaced the up up/down motor the week prior to this problem. I ruled out the motor being the cause on this basis. I rechecked my connections which all appeared fine. I scoured the mast rails with steel wool and lubricated them. The motor still heated quickly and slowed to half speed. I took the battery in to be checked, it was at 11 volts. The date stamp on the battery indiacated it was purchased in either 2004 or 1994. ( The mill is a 94' I purchased used, so I cannot be certain). From this I decided to buy a new battery, which I figured would be a good investment even if it didn't fix my problem. I installed the battery and cut for two days with the guard removed, so I could check the motor temperature periodically. The motor became warm qiuckly but did not get overly hot. There were times when I was raising and lowering alot to give the customer what he wanted when it did get hot but this did not hamper the speed or  function of the travel. What fixed it for sure, I don't know. The main thing is the job is done , the customer is happy and I got paid. A side note, in the lot of logs I cut there were two red oak logs 38" the but log had a flare taking it to 42". I had to whittle a bit but got them through. Both logs clear with no blems. Guess what the customer had me cut them into...... 2x4's for kick boards in horse stalls! His horses have the most expensive stalls around.

[Bill Gaiche]

Good that its fixed. Thats the important thing. On to the next job with a little confidence that all will be well. bg

[Magicman]

Since the motor is still getting warm/hot I would make further test to determine if you still may have a problem.
You really need to use a clamp on ammeter to determine how many amps the motor is actually pulling.

Now would be the time to chain the saw head to the top and examine all of your up/down mechanism.  Stretched chain (which will really load up the motor) worn sprockets, seized bearings, up/down gearbox.

[PeEll guy]

We had the same problem with our HD40..Turned out to be the battery...