Re: REFLECTOR: Leveling: Center Line

[Dave Black <asterisk@erols.com>]

David,


>     Well, it is now clear that my bottom fuselage is somewhat
> twisted.. in order to get bulkhead locations level side to side.. I
> end up with a cowl that is 3/4 inch high on one side...  Any
> suggestions? 

Get the bulkheads right. Don't worry about the cowl. Really! 
You'll get plenty of time to do whatever you want with the cowl later. 

> Is this a freak occurance? 

It's not common. It's probably due to your kit being stored in some odd
position for all these years. Fiberglass can flex.

> Also, I went ahead while I
> had the thing loose again and turned it over and cut out the nose
> gear door hole according to the factory markings... Cut it perfectly
> straight... And at a glance it doesn't look like its perfectly
> centered to the centerline.. Perhaps not crucial.. 

Slow down! 

In my humble opinion, this is WAY TOO SOON for you to be cutting holes in your
fuselage. You should have it leveled and stabilized so you know for sure which
way is up before you start making cuts. To me, that means canard bulkhead,
firewall, gear bulkhead, keel, and side conduits installed before cutting the
fuselage. 

> Do the factory markings tend to be off? 

No. They are ALWAYS off! 
Use them only for a reference. Measure for yourself before cutting anything. 
All the more important with your twisted fuselage. 

> Conclusion,,, fuselage is Asemetrical..
 
Everyone's fuselage is asymmetrical. Yours is just more so than most. 

> It's not going to untwist in the air is it?? 

No.

> I assume I'm going to have to just level the bulkheads and worry about
> the back later... right?

Absolutely.

> What should I do?? 

Start by leveling your fuselage the best you can at the bulkheads and doors.
Put whatever weight you need on it to hold it in that position. Given enough
time and/or enough HEAT, the twist will relax. Yes, fiberglass can "melt"
somewhat like a candle does, although to a much lesser degree. For more
information on fiberglass, there is no better person to ask than Alan Shaw,
and he's always willing to help.

But even without relaxing the fuselage first, you can begin installing those
bulkheads, keel, and ducts. An amazing thing about the Velocity kit -- the
more you put together, the STRONGER it becomes. Consider Simon's recent
postings on the strength of the fuselage. That's hard to believe when you're
handling what seem like relatively flimsy kit pieces, but absolutely true. I'd
suspect that simply installing those parts will reduce your fuselage's
tendency to twist. And I can assure you that when you eventually put the top
on, its twisting days are finished!

Everyone's centerline is curved, but it does not matter. Your centerline is
whatever YOU decide it is. After your fuselage is straightened and stabilized
to your satisfaction, draw a new centerline and use that for your
measurements. Just make certain it's midway between the sides. You certainly
do not want the innards of your plane reflecting whatever residual twist
remains in the original fuselage. 

The twist in your aging kit may add a few complications early in your building
experience, but should make no difference whatever in the finished airplane. 

Enjoy,
Dave Black
SW RG TopDoor