4" long belt sander roller crown

[kwfiggatt]

I just looked at Machinery handbook, 19th ed. and they recommend 1/8" diameter per foot of pulley width for crowning on flat belt pulleys.

I have an old belt grinder that with flat pulleys that has tracking issues. I may try to cut some crown into the idler and see how it goes. Thanks for the idea!

Kevin

 

[Doozer]

I have a Peerless brand belt sander, probably from the 1920s.
It has a tight and a loose pulley, meant for line shaft use.
The bottom of the casting says, "Made in England".
It is a 4x36" belt model.
It has crown in the drums and no tracking adjustment.
Works fine and interesting that it has no tracking adjustment.
I guess if the drums are crowned, you don't need it.

-Doozer

 

[Rob F.]

I have a Peerless brand belt sander, probably from the 1920s.
It has a tight and a loose pulley, meant for line shaft use.
The bottom of the casting says, "Made in England".
It is a 4x36" belt model.
It has crown in the drums and no tracking adjustment.
Works fine and interesting that it has no tracking adjustment.
I guess if the drums are crowned, you don't need it.

-Doozer

Both pulleys are crowned?

 

[Froneck]

I did have a belt sander that had adjustments on either side. Served two purposes one was to tension the belt the other was to get the belt to track but it would not! With some effort the belt would track when idling but when used the belt would go to one side or another. Since it was my belt sanded I crowned both rollers with a file, spinning the roller in a lathe. Worked! After adjustment the belt stayed in the center when used. It was a use sander when I got it so any crown could have worn off. Not sure how much I removed but crowned it a few times until the belt tracked when used.

 

[James H Clark]

James; .020" taper? Per inch? or ends reduced .040 on diameter?

Sorry, Froneck. I should have explained it a little better, I was trying to say that I made the drive wheel .020" bigger in the center of the wheel than on either edge.
JC

 

[Froneck]

No problem James! So am I to assume the diameter is .020" bigger in the middle, each side has been reduced .010" on the radius or .020" on diameter