drive belt

[Boet]

Bluesman, question for you: Are the pulleys anodized or not? I will explain my question.
The best way to go about alu drive pulleys, is to run it unanodized for 50 hrs or so. The belts does wear the pulleys down a bit, but once it have "mated" to the belt, you should anodize the pulley. It makes for much longer pulley and belt life. NEVER anodize a new pulley, then it will never mate with the belt, and constantly keep on buggering up the belts.

[tandemtod1]

If it helps.
Our first belt spat it's teeth out at 250hrs. The second belt was earmarked to be changed at 450hrs but somebody forgot and it spat it's teeth out at 520hrs. The third belt was changed at engine overhaul 700hrs and still looked OK
When fitting a new belt, leave it a bit slack and warm the engine up until the reduction drive is hot and then set the belt tension to "TAUGHT" We found that if you tensioned the belt to the spec of 2% stretch when cold, then when it warmed up the belt was far too tight and you risk damage to the belt and bearings. Check your belt tension after everything is hot and then when it has cooled down you will be able to see what the correct tension is cold. Then you will know what is normal for your pre flight inspection. All the belts that we purchased came from Belting Supply Services in Wadeville, Germiston and I can't remember exactly what we paid but it was nowhere near R1500 more like R400
Your belt should last way more than 72 hours if it is tentioned correctly.

[bluesmancoops]

If it helps.
Our first belt spat it's teeth out at 250hrs. The second belt was earmarked to be changed at 450hrs but somebody forgot and it spat it's teeth out at 520hrs. The third belt was changed at engine overhaul 700hrs and still looked OK
When fitting a new belt, leave it a bit slack and warm the engine up until the reduction drive is hot and then set the belt tension to "TAUGHT" We found that if you tensioned the belt to the spec of 2% stretch when cold, then when it warmed up the belt was far too tight and you risk damage to the belt and bearings. Check your belt tension after everything is hot and then when it has cooled down you will be able to see what the correct tension is cold. Then you will know what is normal for your pre flight inspection. All the belts that we purchased came from Belting Supply Services in Wadeville, Germiston and I can't remember exactly what we paid but it was nowhere near R1500 more like R400
Your belt should last way more than 72 hours if it is tentioned correctly.

Yes I believe the problem was a belt "set too tight" with heating up the engine caused a lot of stress on the belt causing it to snap - no teeth were damaged, they were not even worn
have fitted a Gates GT3 and very happy now

[Boet]

Do not let oompie Gates find out about it....shhhhhhhh. Very unhappy for HIS products being used in anything aviation You still have not answered my question, Is the drive gears anodized or not?

[bluesmancoops]

Do not let oompie Gates find out about it....shhhhhhhh. Very unhappy for HIS products being used in anything aviation You still have not answered my question, Is the drive gears anodized or not?

Hi Boet - I actually don't know - they look like they are aluminium (they are not they just look like that)

[Tobie]

As part of scheduled maintenance, how often should the belt be replaced, ie. every ex hours? I am referring to a belt driven prop on a Challenger.

[Morph]

From what I can see every 100 hours. My Chally lasted over 250 hours

here is a doc with the replacement schedules and specs for the Challenger

[Tobie]

Morph, you never seize to amaze! Thanks