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marc5180
03-09-2007, 04:56 PM
Come across a few belts recently on motors that have snapped due to being to tight. I was told today about a tool that can be bought to measure belt tightness. I was told that it had a spring in it which indicates weather its too slack or too tight, anyone heard of it and where i can get hold of one?

chillin out
03-09-2007, 06:13 PM
I think mechanics use these a lot to tension the water pump belts on cars.

Snap-on should have one.

Chillin:):)

marc5180
03-09-2007, 07:02 PM
sounds good thanks, i imagine they are pricey from snap on but il have a look.

chillin out
03-09-2007, 07:36 PM
Found a link for you...
http://www.primetools.co.uk/index.php?page=products&cat=search&start=41&num=20

Chillin:):)

marc5180
03-09-2007, 07:56 PM
Great, thanks Chillin, just what im after:)

Brian_UK
03-09-2007, 08:06 PM
The other option is the "90° twist test".

Hold the belt between your forefinger and thumb, if you can twist the belt through 90° without struggling then the tension should be about right.

There you go, no charge ;)

Dan
04-09-2007, 01:56 AM
Hold the belt between your forefinger and thumb, if you can twist the belt through 90° without struggling then the tension should be about right.

There you go, no charge

I like that. The tensioning tool Graingers sells is basically a reverse acting fish scale. Most belts should not have more than an inch of travel when pushed down with reasonable force. When you have multiple belts, replace the loose ones.

I am told that there are no more "matched sets" of belts, even though you can buy a multiple pulley belt for commonly sized air handlers.

I see all these Harley Davidson motorcycles with what appears to be a damn timing belt instead of a chain. We have all these adjustable pulleys and belt sizes with angles and wedgy cuts.

Am I wrong, but isn't the duty of a Harley Davidson belt drive sufficiently adequate for most air handlers? What am I missing?

Tesla
04-09-2007, 02:25 AM
I bought mine from the pulley and belt supplier - special order for about Oz$50. Don't really use it much now - I've got a good feel for it, but it impressed a few building managers. I needed to carry a chart of tention for the different belts.Any way have you seen the new vented pulley design? they weigh about half as much and run the belts 17degC cooler. Cheers Bro

US Iceman
04-09-2007, 03:13 AM
Am I wrong, but isn't the duty of a Harley Davidson belt drive sufficiently adequate for most Air (http://www.refrigeration-engineer.com/forums/glossary.php?do=viewglossary&term=17) handlers? What am I missing?


Some of the belts are dependent on the application. The cog belts and notched belts I believe have limits on the wrap angle of the pulley. You can probably find some good information from Gates.

http://www.gates.com/brochure.cfm?brochure=5262&location_id=6196

http://www.gates.com/index.cfm?location_id=534

Note: you may have to register for access to the information, but this should provide a start...

I used to use the notched belts in lieu of the standard v-belt because I thought the ran cooler due to the increased surface area and the notches providing a cooling effect when rotating.

paul_h
04-09-2007, 06:01 PM
I use either the belt twist test like Brian_uk said, or a clamp ammeter on the motor.
I tighten and test using visual/audio and amps.
If it's pulling too high amps I loosen the belt, if it's slipping and the pulleys and belts OK I tighten until FLA met.

marc5180
06-09-2007, 05:21 PM
Great thanks guys

Freonboy
02-09-2008, 09:00 AM
Go to a Fenner belt agent and they will be able to give you a belt guide with all the relevent tables for proper belt adjustment. You will also be able to get yourself a belt tension tool, which are inexpensive. ;)

Regards.

Don Davis
02-09-2008, 04:46 PM
I use either the belt twist test like Brian_uk said, or a clamp ammeter on the motor.
I tighten and test using visual/audio and amps.
If it's pulling too high amps I loosen the belt, if it's slipping and the pulleys and belts OK I tighten until FLA met.

I recommend you discuss this with belt/sheave manufacturers. I believe you will find belts are not intended to slip and will quickly wear the smaller sheave to where the belt looses full contact and becomes incapable of transmitting full HP.

martinw58
02-09-2008, 09:27 PM
i got one of these tools from bearing services a belt and bearing supplyer