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I'm an idiot...

gtae07

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Fayetteville, GA
So I had to make some CRES bushings to fit the alternator to my airplane. The bushings themselves turned out great and pressed in just fine. I'm actually quite proud of how they turned out given I made them on a HF mini lathe from Craigslist...

The problem is that I forgot to write down the dimensions of those bushings before I pressed them in, and I probably need to keep a spare set on hand in case the alternator ever goes bad :bitchslap

Now I get to buy some thread rod and make a tool to press them back out far enough to measure the OD. D'oh!
 
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Bill Bowman

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Mar 28, 2007
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I often find myself doing the same kind of stuff. At least now you'll have the tooling to removed the bushings down the road.
 

dreamingmuscle

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Tryon Oklahoma
Don't think we need to debate that. :lol_hitti

How long will these new bushings last and how well will you store this new information. Is it truly worth pulling them out to get information for a part you needed and made without the information in the first place.

Glen
 
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Robbie B

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When you get the dimensions take a paint pen and write them on the alternator. I’ve got common stuff written down on my car under the hood.
 

matt_i

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Mar 14, 2008
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SE Michigan
What is CRES?

Internet thinks it might be Corrosion REsistant Steel (?) SS303 or SS304 (?)

As suggested, I'd just press them when required at the time of change.

Maybe better would be making the tool you need (pilot driver, etc) right now and carefully labelling it. That would save a lot more time later in my opinion.
 

jrb2

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Feb 21, 2009
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Lincoln, Ks.
There you go telling the whole world that you put a non-certified part on your airplane!! A while back there was a discussion on Pilots of America about the ridiculous cost of a small part. I suggested that I could make it in about 10 minutes on my lathe and no one would ever know the difference. The whole forum blew up, you would have thought I publicly suggested not filing a flight plan!
 
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gtae07

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There you go telling the whole world that you put a non-certified part on your airplane!! A while back there was a discussion on Pilots of America about the ridiculous cost of a small part. I suggested that I could make it in about 10 minutes on my lathe and no one would ever know the difference. The whole forum blew up, you would have thought I publicly suggested not filing a flight plan!
It's a homebuilt--(almost) everything's non-certified ;) This alternator is for a 1995 Dodge van; cost me $130 from Summit and has all the power I need vs. the $500+ "airplane" model that puts out less power. I can pick up a replacement from any auto parts store if needed.

I need a little more power as I'm using automotive-style electronic fuel injection (http://sdsefi.com/aircraft.html) which runs about 10 amps between fuel pump, ECU, and coils; the amenities like heated seats (to keep the wife happy) draw a good bit of power too.

I think the last time I filed a flight plan was almost 19 years ago, on my long solo cross-country :D

What is CRES?

Internet thinks it might be Corrosion REsistant Steel (?) SS303 or SS304 (?)
Yeah, your interpretation is correct, it's stainless. 416 round stock from McMaster.

As suggested, I'd just press them when required at the time of change.

Maybe better would be making the tool you need (pilot driver, etc) right now and carefully labelling it. That would save a lot more time later in my opinion.
Yeah, one way or another I'm going to make the tool now and store it. My big concern is with a failure "on the road"; as noted I could probably get a replacement alternator anywhere, and if I'm close to home I can fly back on the secondary alternator, but if I'm way out I'll need to replace it in the field. I'll need the bushings to make it fit, and I'd really like to have a spare set in my "flyaway kit" (the bag of tools and things like jack adapters, spare inner tube, "get home" alternator belt, etc) along with the bushing press/puller. That way I maybe won't have to press the old ones out in the field, and if I booger one up I'll have a spare. Can't feasibly lug my lathe around with me, after all, even if it is a HF benchtop model.

Don't think we need to debate that. :lol_hitti

How long will these new bushings last and how well will you store this new information. Is it truly worth pulling them out to get information for a part you needed and made without the information in the first place.
The ones I made should last years; honestly they will probably be lifetime (of the alternator) parts. It's if/when the alternator dies on the road that I'm concerned.

The parts would be stored in my flyaway kit; I'd keep the dimensions stored electronically with all my other documentation (I have the build drawings, wiring diagrams, parts lists, and so on stored on Google Drive and my phone/tablet), as well as maybe noting them in paint pen as described above.
 

coljar

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Sep 26, 2010
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Belpre, Ohio
My problem is, I'll document on scraps of paper and I wind up having a whole drawer full of scraps of paper. You would think I'd learn to use a notebook.
 

Innovate1

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Jul 28, 2014
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Illinois near St. Louis, Missouri
I had a homebuilt airplane a long time ago. Had to get the gas tank fixed. Took it one place and they wouldn't touch it - tried to explain it was a homebuilt and non-certified. Took it another place and told them it was for a home made tractor. They fixed it no problem. People freak out when you tell them it's on an airplane. Too many lawyers and liability.

Mine was a bit simpler though. No electrical system so no alternator to wear out. Just hand prop to start. :)
 
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