Topic: belt chatter

[johntaves]

When I let the clutch out to go, the belt screeches, chatters, and makes a heck of a racket. It seems it will shake the mower to pieces. Once it is hooked up it seems to go OK, but it might need more tension on the spring to prevent it from slipping when I go up hills. I have tried two different 5/8 width belts, one black and the other is green. Both make the racket. I tried a 1/2 belt and it has no problem slipping nicely, but it just doesn't seem to have the necessary traction.... oh...

While typing this I realized that it might make a difference which side you put the clutch on the mower.

I just checked and indeed the engine spins clockwise (from the top) and I put the clutch on the left side of the mower, which means the clutch is on the pulling side not the return side. This has to be the problem.

As it grips it will tension the belt on the side that the clutch is trying to bend. That tension will straighten the belt which will loosen the belt and release the grip, which will then release the tension, let the clutch resume bending the belt, and adding grip, thus it oscillates....

In retrospect it seems rather obvious that I should have thought about what side to put it on before I started bolting things on, but that's what you get when a software developer grabs a wrench.

jt

[Squidd]

OK..Nevermind..LOL  

Sounds like you "figured out" the problem...

Now go fix it and tell us how it worked...

[johntaves]

With the clutch on the right side it works great.

It is pretty grabby, rattly, and makes a good scream as it engages. Does someone know what type of belts work best to allow a quiet smooth engagement? I'm building this as a cool errand runner and entertainment for the kids, so it needs to be polite.

Also, I put a jackshaft on it and a peerless 920. Its not easy to up and down shift while in motion. I am pretty sure it is because the transaxle has to turn both belts and the jackshaft, which has a lot of mass. In addition, when the clutch is pushed in, the front belt loosens and starts rubbing on the guides, which adds a lot of friction. Soooo, has anyone put a clutch on the rear? I am thinking I just need to run a link back there. Anyone, have thoughts on that?

Thanks,

jt

[George Herrin]

Best bet is play around with spring tension. The softer the spring the easyier and smoother the engagement. BUT too soft it will slip and give problems if driven hard like a racer. Its a matter of finding a happy medium that will work best for what you use it for.

[johntaves]

Are you guys able to make your mowchines take off smoothly and quietly?

I used an A belt on my B pulleys and that helped, and I put a weaker spring on it, but it still grabs pretty suddenly. My next step will be to play around with the clutch geometry to get it so that the pedal moves a lot in relation to the clutch travel so that it is less sensitive to a slight pedal movement.

But, even when I am really careful and try to let the belt engage slowly, the belt just doesn't want to slip politely, it rattles and squeals and makes a bit of a ruckus.

I know that you'd rather have race prep questions, but I'm hoping my boys will enjoy going for rides on it. As it is now, they plug their ears when we take off (I made a jump seat for them so they ride between my legs).

jt

[Squidd]

Couple things I do to "smooth things out...

Use new pulleys or clean the ones you have...rusty, greasy or Bent pulleys have uneven "grab" to them and can cause jerking and screeching

Try a couple different size "idler" pulleys to get slight adjustment of tension on engagement....

Try "larger" pulleys (if you have the room) if your using a 4" and 2" try a 6" and 3" or 8" and 4" (same ratio).. smaller pulleys have less surface to grab and may squeal before fully engageing...

HTH...

You should be able to get relatively quiet and chatter free/smooth engagement..