View Full Version : Pulley alignment...with laser

03-09-2008, 03:50 PM
I aligned several pulleys running some ventilation fans. The motors are 125 hp on Yasukama (sp) controlers. I used a lign of site laser to help me align them.

Step 1.

I would attach a piece of angle iron, approximately 12" to the drive pulley. A second piece of angle iron was clamped to the fan's pulley.


Step 2.

I set up the laser so i would get the same reading across both ends of the drive pulley's angle iron. I would measure the incoming beam, supose it was at 1", then i would make sure the outgoing beam was at 1". This would ensure the beam was parrallel with the drive pulley.


Step 3.

Now i could measure from the edge from the second angle to find out if it was in or out too far. I would then push or pull the fan's pulley in order for the 2nd angle to have the same offset as the drive pulley's angle. Sorry no pictures, but i do have another one of the laser on its transit. Oh yeah the laser was leveled before doing any work and set at a 90 from the floor.


This worked great. Not the Perfect way, but a little more accurate then using a string. Even at that, the person before me used string to align the pulleys. The biggest difference i have found, so far was " out over a span of 80".

Rob :)

03-09-2008, 04:44 PM
What's all that stuff on the right in the last photo?


03-09-2008, 04:46 PM
Those are filters. A huge wall of filters. The wall is 10' high by about 50 long.

Rob :)

03-09-2008, 06:10 PM
Don't forget to recheck the alignment after tightening the belts and running for bit. I've had to work on fans that size that would bow the frame when the belts were tightened, no telling how much they deflected when that motor started (even with incremental winding starts). Anyway, we ended up having to get the manufacturer to beef up the frames.

Long story short: Recheck alignment after belt tensioning and after running the machine a bit. Alignment may need to be tensioned position, not cold and unloaded.


03-16-2008, 09:14 AM

I did the last 2 with tension on the belts first. I was concerned about moving the pulleys once they had tension but there didn't seem to be any difference. Personally i don't understand why people don't use power blets when installing something like this. A power belt would be alot better then four belts that can stretch at different rates. The local supply shop also said power blets are good for 20% more power on the same pulleys. Sounds like win win

Rob :)

03-16-2008, 09:56 AM
We have some lasers that have guides that locate in a pulley groove and spread a line at similar unit. Not sure why both pieces are both lasers, one would think one could be a laser and the other a target.

Not my money, sure is sweet though.