Power feed problems

[Dieskyver]

Ok guys an gals,

    I ve read several posts/threads and haven't seen my specific problem and was hoping I can narrow it down before I call the WM tech.
The problem start with the forward drive would shut down along with the blade guide. After a few minutes/30-45 sec, they responded until bout two weeks ago when the ground wire that the blade guide and speed control switch share went up in smoke.
    I called wm and tech said replace the wire and check connections. I did it and it worked fine til Saturday and the forward drive failed but blade guide is still functional. 
  With the forward drum switch engaged, I can rotate Spd control switch and when I get to the middle of the rotation the drive motor will start beeping and then stop when it's "wide open" or in the slow end of the range. 

I wanted to get the ff diagnosis before I returned to wm


Oh yeah. It's a 96 lt40 super h.

[drobertson]

Without being able to see all that you have going, and just based on your description, I would guess(guess) you might have a faulty rheostat in your speed dial, just a guess, I would suggest to get a volt meter ready, pull some covers and make the call, one of the techs will walk you through it pretty quick,  hope all goes well,  david

[Dieskyver]

Thanks,
  Hopefully I can find the time during business hrs today or tomorrow.  I'm really hoping to have it fixed by the weekend. This is my brothers mill and he said he heard that wm can be built out of parts from hardware store. This seems like a common part.  Would u advise a hardware store solution?

[Dieskyver]

Update...

    Took off early today and removed panels.  Looked for loose/bad connections like a good sawyer/electrician would do and found my problem. It was at the on off switch. I hope that it fixes it for a while. I did call wm to verify the high pitch noise was normal.
    After hanging up, I noticed that it looked(I was watching with the cover off) like the motor might be struggling a bit to move the head down the rail. I have to turn the speed dial up to nearly half way to get it to start moving.
I removed the belt on the motor and pushed it manually down the rail.  Most post here say it will be easy and I guess it is considering the size/weight of the head but it requires some force.
  An obviously, the motor doesnt labor at all with the belt off. All the "rollers" seem ok. No obstructions. I removed the covers and inspected the ones on top of rail too. They do have a bevel I assume that's by design. 
Also. I can lift the blade tensioner/guide side of the head and get about 3/4 - 1" of play up and down. 

Is this normal?

[barbender]

The head is heavy, but once you get it moving, it should push fairly easily. You need to check your track roller bearings. Make sure they are all turning freely and that they aren't adjusted too tight. Make sure there is nothing dragging or binding, it causes too heavy of a load and you'll burn up the H-bridge for the drive control, about $385. I'm very conscious of anything restricting the movement of the head after cooking one of those :(

[Brucer]

... Also. I can lift the blade tensioner/guide side of the head and get about 3/4 - 1" of play up and down. 

Is this normal?

Yep. There are rollers on the outside of the top rail and the inside of the bottom rail to keep the sawhead from tipping toward the bed of the mill. There is nothing to restrain it from lifting away from the bed, since the weight of the motor, and the sawhead, plus the cutting force all work together to prevent it from lifting.

[Magicman]

There is nothing to restrain it from lifting away from the bed, since the weight of the motor, and the sawhead, plus the cutting force all work together to prevent it from lifting. 

Just as a note; on older sawmills there are cam followers and the newer ones have stops that allow the sawhead to lift up but prevents it from tipping completely over and off of the rail.

Another note;  if/when you replace the cam followers on the sawhead, the "tipping preventer" rollers do not need changing even if they are frozen.  The only time that they contact the rail is to prevent the head from tipping too far.  (that tip came from Bob Hooton, the traveling serviceman  )