Up and Down Motor on LT40

NHHillbilly · July 15, 2009, 08:46:08 PM

Sawing today and all of a sudden the up and down didn't work. Did some checking and it was a wire that had broken right at the rubber grommet where it went in to the motor. took it apart and ran a new wire to the motor. The only problem is that when I hooked everything back up the motor worked opposite what the control was telling it todo. Just reversed the wires for now to finnish the job but what caused this and how can I correct it. I know that I hooked up the wires correctly cause they were color coded.

Alex

woodmills1 · July 15, 2009, 09:57:10 PM

nice to see a post, too bad it was for a problem. hope you get a fix and by the way how is the 40 treatin ya did ya remeber to change the up down gear box oil in her.

pineywoods · July 15, 2009, 10:20:21 PM

did you take the motor apart or just re-splice the wires??

NHHillbilly · July 16, 2009, 06:57:54 PM

Mill is workin great, Jim. Did change to oil. I had to take the motor apart to get to the break. It is up and runnin hr fix. Just wondering what causes it to reverse polarity.

Slabs · July 16, 2009, 07:49:16 PM

What's the possibility that you might have twisted the motor 180 degrees on reassembly?? That would explain it. The up-down motor is a permanent-magnet type motor and is reversed by changing polarity. No real problem if it gets reversed and the wires have to be reversed.

Did I get that one right Sparks?? Been a while. Can it be reinstalled 180 out?

woodbowl · July 16, 2009, 10:19:39 PM

My up/down motor was moving slow the other day so I thought I'd put another brush kit in it for about the 5th time over 14 years. I decided to check it with the jumper cables first to make sure the wiring wasn't shorted somewhere. It did move a little faster so now I'm thinking it could be a contact or corroded terminal. I did all this with the key off so the current wouldn't cross in the event I connected it backwards. After a while I decided to run it up a little higher and proceded to hook it back up,, Somewhere along the line I turned the key on and forgot to turn it off. When I clamped the jumper cables on and threw the lever, nothing happened. After a few seconds I could smell that dreaded hot electric smell and I took the cables off as fast as I could. Now I know that wasn' dry leaves I was hearing making that frying sound. Fearing the worst I waited a moment and tried the controls for the up and down. The motor not only worked, it was much faster that ever. Not sure what just happened, but I'm happy to have a faster motor. I cleaned all the terminals anyway, but it made no difference. It was moving so fast I could hardly hit the number. Hey Slabs, what did I did?

Polly · July 16, 2009, 11:14:22 PM

i was sawing a couple weeks ago and my lt40 up down repositioned the saw head in the middle of the cut , i thought i was seeing things so i set it again and it done same thing what caused this and no i dont drink moon

8)

Slabs · July 17, 2009, 08:22:19 PM

Quote from: woodbowl on July 16, 2009, 10:19:39 PM
Hey Slabs, what did I did?

Beats me Olen. My best guess would be that you inadvertently moved the connector that was the original problem and caused it to wipe clean. I'd go back in there and check clean and tighten all the connectors you have access to.(with the battery ground terminal removed)

NHHillbilly · July 18, 2009, 05:42:20 PM

Putting the motor back together 180 Degrees backwards makes sense. Guess I will just leave it be. Pain in the butt to take it out. Thanks. Gotta love this place and all the info.
Alex