daystate 110 compressor belt

I used a straight edge across the faces of the pulleys. I loosened one of the pulleys and slid it out to match the other one. I am an old power plant mechanic and have done tons of motor to pump alignments. I did not check the vertical plane for alignment, I could easily see the horizontal offset with one yard stick. 

misalignment can cause early belt failure, proper tension is a must do, also go to 2:40 mark in the video,, my pulleys had the same outside dimension, so I did not need to measure to the edge of the groove. not all hubs are the same

https://www.youtube.com/watch?v=BzMnc3FCtdI
 
Doug, you are correct, over tight cause early failure,, I hope you purchased an extra, because by the sound of your reply, you did not loosen the motor bolts before installing and stretched/forced the belt onto the pulley, here is a quote,

"Tensile cord damage can also occur if the belt is pried or rolled onto the sheave during installation. In extreme cases, foreign objects in the drive can damage the belt severely enough to cause breakage."

notice the article said can, as opposed to will,, from this source

https://www.linearmotiontips.com/troubleshooting-v-belt-wear-and-failure/

wish you the best, it is a pain to stop and do maintenance when you just want to pump up some air and go shoot 

. It is the nylon plys that give the belt its ability to transfer the load, without them/when they break, it is just a rubber band,, Oh Snap
 
Doug, you are correct, over tight cause early failure,, I hope you purchased an extra, because by the sound of your reply, you did not loosen the motor bolts before installing and stretched/forced the belt onto the pulley, here is a quote,

"Tensile cord damage can also occur if the belt is pried or rolled onto the sheave during installation. In extreme cases, foreign objects in the drive can damage the belt severely enough to cause breakage."

notice the article said can, as opposed to will,, from this source

https://www.linearmotiontips.com/troubleshooting-v-belt-wear-and-failure/

wish you the best, it is a pain to stop and do maintenance when you just want to pump up some air and go shoot 

. It is the nylon plys that give the belt its ability to transfer the load, without them/when they break, it is just a rubber band,, Oh Snap

New belts AOA sent were wrong size to small this is a 13 mm 30 inch belt. I did take bolts out like manual say I’m not that sill as I don’t think you could stretch the belt that far. All good now.