Belt Tracking ?

[mike90045]

It's just not happening for me.   I've got a flywheel (metro) that actually has grooves cut into it, and a ribbed belt. No matter what I do, after 20 seconds or so, the belt travels outboard, and hangs on by 1/8 th of its width, very scary.  Well, not as scary as a cracked flywheel.    But twisting the engine, and the alternator, I can't get the thing to track the grooves in the center.
 The alternator has a grooved pulley, with no flanges on it, and the belt tracks off it too, to about 50% off.

I've come across some info on the web, about flat belts and pulleys, with the pulleys needing a crown, which keeps the belt centered.  I'm about to grab a couple rolls of electrical tape, and build up the center of my flywheel, and see if that helps. I
guess most of you have ribbed belts on plain flat flywheels, and the grooves are not really needed.
 http://woodgears.ca/bandsaw/crowned_pulleys.html

I've also heard that a bad belt with a warp in it, can do this too, but a replacement is about $80, so before I buy a new one,
I'd like this thought confirmed. (engine shipped with the belt on flywheel and alternator pulley)

Any suggestions, if the belt falls outboard, what direction should I twist the engine or/and alternator ?

[ronmar]

Which direction should I twist the engine or alternator?

Whichever direction puts the flywheel and pully in parallel...  I would use a long straight edge near the middle of the flywheel diameter(as close to crankshaft as possible) extended out past the generator pully.  Then you can measure from the straightedge to the two extreme points across the generator pully diameter to insure the gen pully is perfectly in parallel with the engine flywheel.  You can also stack a square block on the genny pully to get it out far enough to allow you to sight along the block and the face of the flywheel. The eyeball is the best alignment tool...  These two really need to be in parallel for the belt to track true.

You need to check for parallel with the belt in place and tensioned. How much tension are you putting on it?  A lot of tension on a frame that can flex could cause the two to go out of parallel and the belt to track to the outside. So if the alignment changes with belt tension, then there is an issue with your mounting scheme.  IF things look in parallel and it is still tracking off to the outside, you can flip the belt inside out and try it again.  If it suddenly tracks inward, then I would say the belt is the issue...

Good Luck

[38ac]

I would go back to square one and aline the generator head to the flywheel with a straight edge. If the belt still crawls off to the side then I would suspect the belt. Do the grooves on the flywheel match the grooves on the belt?  As you said this is not a common problem, my belt doesnt move a bit on a plain flywheel.

[rleonard]

Put the belt on the other way.  Still climb the same direction?

Bob

[mike90045]

Put the belt on the other way.  Still climb the same direction?

Bob

I'll give that a shot.   as many times as I've had it off and back on, I never thought about left or right handness.  It's always gone one way to the edge.  So I'll mark it, and pay attantion to it.   I've tried the straight edge, and it all seems right. 

 I can't (or shouldn't) lfip the belt inside out, and run with the ribs in the air, as that would stress it in ways it likely shouldent.

[BruceM]

I also wonder if the grooves on belt and pulley are a proper match.  They should keep a properly tensioned belt from walking, assuming decent alignment when tensioned.

As I recall there is an automotive standard, and a different industrial standard for these belts...

[Tom]

Place a long straight edge across the face of the Listeroid flywheel, long enough to extend to the generator pulley. Square both to the straight edge with the generator pulley on the outside of the shaft. After aligning move the generator pulley to align with the groves on the flywheel.

If you want I'll grab my welder and come help you with it. Let me know.

Also could you post a new pic of how things are setup now?

[bandmiller2]

Mike is your flywheel wide enough so you could run the belt on the ungrooved section and just move the alternator to one side a little.?? sounds like the groove don't match up. Frank C.

[mike90045]

Mike is your flywheel wide enough so you could run the belt on the ungrooved section and just move the alternator to one side a little.?? sounds like the groove don't match up. Frank C.

Yes, it appears wide enough, but that would put the alternator pulley nearly at the end of it's shaft.  Possibly moving it all the way inward would catch the other flat spot.  Alternatively, I could just bondo the flywheel groves, if I can discover what in the states, will stick to indian bondo.

[mike90045]

I've ended up putting a couple of layers of 10 mil pipe wrap tape on the flywheel, creating in effect, a crowned pulley. That's been working (with Toms fabulous adjustable alternator rack) for about a week now. no belt wander.   Pulleys were parallel, belt has been reversed and no joy either orientation, but bulking up the center of the flywheel worked.

I'll see how long it lasts.


http://woodgears.ca/bandsaw/crowned_pulleys.html

[Tom]

If that holds up fine, if not you might try moving the alternator pulley in or out and run the belt on a flat/ungrooved part of the flywheel. My flywheel actually has grooves worn in the paint the belt tracks so well.

[buickanddeere]

Amazing how a crowned pulley keeps the belt centered against what at first seems to defy physics. 

[rosebud]

Mike,

I am running into the same belt wandering problem.....
A year has passed....did the tape continue to work for you?

How wide is the tape you used  ?

regards
rosebud

[mike90045]

Mike,

I am running into the same belt wandering problem.....
A year has passed....did the tape continue to work for you?

How wide is the tape you used  ?

regards
rosebud

The tape has been in use for over a year, and works fine.    In the plumbing section of the hardware stores, is the Pipe Wrap Tape.  It's 10 mil thick, and comes in 2" & 1" wide.   I put 1 layer of 1" down as a base, and then 2 wraps of the 2" over it.      Be sure to apply it in the direction that the belt will TIGHTEN the tape onto the flywheel, do it the wrong way, and after 10 minutes of running,  it may peel all the tape off in an instant, and throw the belt.

Since the large engine flywheel has so much surface area, there is not much stress on the tape. I've had to rewrap mine about 2 times, from slow creeping decaying the nice flatness of the tape.

[buickanddeere]

belt will climb to the largest diameter portion of the pulley.
Rare are a set of pulleys to be lined up true under load on every axis.