Belt runs off of pullery

[Randy Walton]

I have a 570 Inca jointer/planer that runs like a dream when its running. But because of some health problems it has sit unused for a few years. I'm having difficulty after reinstalling the drive belt as the belt creeps over the small lip of the upper pulley. I've asked in another specific related forum with no responses. I thought since this is machinery problem and a number of you are very talented with fixing and repairing machines you might be able to give me some suggestions.
Posssibly the pullerys aren't aligned? Need some shims?
You'll notice in the photos the belts looks a little ragged but that's acutally a new belt I've beat up by installing and uninstalling repeatedly. I've attached some photos to show the problem. the first 3 show the belt at rest in the position it should be, the last 2 show the belt after just a couple of rotations starting to creep over the lip. In these photos the belts are not really tensioned but just held in place with the weight of the motor.
Thanks! Randy

[Jerry Bruette]

Randy

I'm guessing that your pulley's aren't coplaner. This could be caused by a bad bearing or even some wear on the motor pulley (could be worn like a cone and not flat anymore).

The problem could also be from not having your belt tight enough. If your flat belt is made the same way as a timing belt it needs to be tensioned properly or it'll run off to one side.

Jerry

[Randy Walton]

May be possible. I did replace the upper pulley because a belt broke when I last used the planer and in just a short period of time the belt wore a flat spot on the upper pulley but I didn't notice any damage or wear to the larger motor pulley.

[Josiah Bartlett]

I think your motor pulley is supposed to be crowned, and that is what keeps the belt on the pulley. You will need to adjust your motor until the belt rides in the middle of the upper pulley. The motor probably needs to be tilted so the upper part of its pulley goes inwards.

[Don Jarvie]

As Jerry said make sure the 2 pullys are co-planer, ie - lined up. The motor pully or upper may be slightly in toward the planer so it is pulling the belt toward the planer.

[Randy Walton]

Jerry, Josiah, and Don, thanks for the suggestions. Not being very mechanically blessed I appreciate any and all suggestions. A little more info, I did replace the upper pulley. After my last use of the machine the belt slipped when running and the heat and friction wore a flat spot on the upper pullery, so I replace. When I reinstalled I simply pushed it on as far as I could and tightened. So maybe this is why it's not aligned. The larger pulley on the motor like Josiah mentioned is crown with no lips or edges on the pulley. The upper pulley only has a lip or edge on the side nearest the motor.
I think that the only way I might possibly move the upper pulley away from the body of the machine is with shims (metal)? I'm not sure I can get a straight edge between the two pulleys to see if they're aligned.

[Jim Heffner]

I think some of the other posters here are on the right track about the belt,
but I see one other item that has been overlooked. I'm not certain that the correct belt is installed on the machine. From past experiences with other types of belt driven machines, I was always told that the belt should ride deeper into the pulley, other words having some of the sides of the pulley
above the belt when it is installed and properly tensioned for the machine.
Most belt driven machines only need a maximum of 1/2" to 3/4" deflection
for proper operation and not to overload or stress the bearings. Hope this helps.....something else to look at, that may be the problem.

[Jerry Bruette]

Jerry, Josiah, and Don, thanks for the suggestions. Not being very mechanically blessed I appreciate any and all suggestions. A little more info, I did replace the upper pulley. After my last use of the machine the belt slipped when running and the heat and friction wore a flat spot on the upper pullery, so I replace. When I reinstalled I simply pushed it on as far as I could and tightened. So maybe this is why it's not aligned. The larger pulley on the motor like Josiah mentioned is crown with no lips or edges on the pulley. The upper pulley only has a lip or edge on the side nearest the motor.
I think that the only way I might possibly move the upper pulley away from the body of the machine is with shims (metal)? I'm not sure I can get a straight edge between the two pulleys to see if they're aligned.


Randy

You don't have to use a staight edge to align the pulleys, I prefer to use a string pulled tight across their faces. You place the string so one end is flush across the face of one pulley, and the other end is away from the other pulley then slowly ease it over to the pulley to see if and when all four edges line up.

I know that's clear as mud but it's hard to explain without pictures. It pretty much does the same thing as a straight edge but the string is easier to get into awkward places. You'll also need to make sure both shafts are paralell.

Jerry

[Randy Walton]

Jim, thanks for the response! The only thing I'm sure of is the belt :D.
Jerry, that is clear and something I wouldn't have thought of, I'll give that a try tomorrow.
If they are out of line like we are thinking now. As I look, the only way the upper pulley could be moved would be away from the body of the machine and to do that I would need to add a shim of some sort. The lower (motor) shaft not only has the drive pulley, but also the idle belt pulley. I mention this becase I'm not sure it could be moved closer to the motor.
Again, I really apprecaite all the help!

[Don Jarvie]

Randy, you got the upper pulley off to replace it so loosen it up and move it to the right (at least thats how the pictire looks). You can use a ruler and put it flat on the motor pully and you should be able to see if its off.

Also, don't be afraid to eyeball it. It doesn't have to be dead on but close enough so the belt stays on.

If all else fails you can replace each pulley with one that would go with a fan belt. As long as they are the same diameter it would work. You may have to hunt around to match them but it may be worth a shot if you can't get the pulleys to work.

Good luck