spare alternator belt

prkaye · #1 01-01-2009, 06:55 AM

A local builder put a spare alternator belt roughly in-place so that if his alternator belt fails while away, he can put the spare on without having to take the prop off.
I'm looking at my setup, and having trouble visualizing where I could place a spare alternator belt and not have it be in the way, and how I could secure it. Does anybody who has done this have a photo they could share?

Mel · #2 01-01-2009, 07:09 AM

Phil,
This is an old trick that some started many years ago. Generally it doesn't work very well.
One problem is that you now have an item that can cause trouble if it comes loose and becomes entangled in the prop hub.
The other problem is that deterioration of the belt is caused by heat and age as much as wear. Therefore, when the original belt fails, the "back-up" belt is not much better than the original.
These belts don't fail that often anyway. I've been flying my -6 for 16 years and have changed the belt once. Come to think, It's probably time to change it again.
Thanks for the reminder.

Geico266 · #3 01-01-2009, 07:13 AM

Quote:

Originally Posted by Mel

Phil,
I've been flying my -6 for 16 years and have changed the belt once. Come to think, It's probably time to change it again.
Thanks for the reminder.

I never thought I'd live to see the day that Mel needed reminding of anything.

Mel · #4 01-01-2009, 07:17 AM

Quote:

Originally Posted by Geico266

I never thought I'd live to see the day that Mel needed reminding of anything.

One is a loss of memory...
And I forget what the other one is.

prkaye · #5 01-01-2009, 08:11 AM

OK thanks for that tip. That's what I was concerned about - the spare belt getting in the way, or getting tangled. I think I'll leave it out.

Ron Lee · #6 01-01-2009, 08:15 AM

Carry a spare on trips and change it out on some regular schedule during your condition(al) inspection.

gasman · #7 01-01-2009, 12:47 PM

Quote:

Originally Posted by Mel

Phil,

These belts don't fail that often anyway. I've been flying my -6 for 16 years and have changed the belt once. Come to think, It's probably time to change it again.
Thanks for the reminder.

It's now been 17 years................. You need to think 17 years.........

noelf · #8 01-01-2009, 05:49 PM

...on my -6A, using Van's 60A internally regulated alternator, and the recommended belt, I found that I could only install the belt if...I removed the ring gear, slipped on the belt, strrrrrrrtched the belt over the alternator pulley, and then reassembled. So, even if a spare belt was somehow placed behind the prop out of the way...I still would have to remove the prop and ring gear to get the new belt installed.

If I had used the next size longer belt, then the alternator pulley would have hit the lower fiberglass cowling, so that was not an option.

In the old days of typewriter repair (IBM Selectric), it was common for the field guys to install a second, spare motor-drive tooth belt inside the typewriter, loosely around the drive shaft clutch. This labor saving procedure was beneficial when the first belt wore out, and the spare belt could be slipped in place in just a few moments (the replacement of the first belt...the first time...was on the order of 30min). About halfway through the life production run of these typewriters, the belt material chemistry was changed and it was found that the life of these drive belts had lengthened to the point that if a spare belt was provided, it did not get used because service life environment made it no better that the belt that had worn out.

For me, it looks like installing a new, fresh belt is the way to go.