Fairing question...

[Tina Marie]

(I've got a certified airplane, so I hope you guys won't run me out
of here on a rail, but...)

I need to replace some of my fairings on my Tripacer. They're all simple,
mostly flat aluminum, some with one or two bends in them. I can form
them (I bought my SO a metal bender/shear/break for Christmas. He never
uses it, but I just love it) without too much trouble.

Here's my problem. After I make 'em, I have to attach them to the plane.
And this nearly always requires making holes in them - and no matter
what I do, the holes in the new fairing never line up with the holes on
the airframe. I don't know how to mark where to drill - if I hold it
up to the airframe, the airframe holes are behind the fairing and I can't
see them. Measuring works sometimes, but then I end up off by 1/16, and
it gets worse by the time I get all of them done.

There's got to be a magic trick to making the holes the right size, in
the right place, and I figured I'd be most likely to find it here.

Thanks!

Tina Marie
--
Life is like an analogy. http://www.tripacerdriver.com

[Corky Scott]

On Tue, 15 Jul 2003 19:33:56 +0000 (UTC),
(Tina Marie) wrote:

>
>(I've got a certified airplane, so I hope you guys won't run me out
>of here on a rail, but...)
>
>I need to replace some of my fairings on my Tripacer. They're all simple,
>mostly flat aluminum, some with one or two bends in them. I can form
>them (I bought my SO a metal bender/shear/break for Christmas. He never
>uses it, but I just love it) without too much trouble.
>
>Here's my problem. After I make 'em, I have to attach them to the plane.
>And this nearly always requires making holes in them - and no matter
>what I do, the holes in the new fairing never line up with the holes on
>the airframe. I don't know how to mark where to drill - if I hold it
>up to the airframe, the airframe holes are behind the fairing and I can't
>see them. Measuring works sometimes, but then I end up off by 1/16, and
>it gets worse by the time I get all of them done.
>
>There's got to be a magic trick to making the holes the right size, in
>the right place, and I figured I'd be most likely to find it here.
>
>Thanks!
>
>Tina Marie
>--
>Life is like an analogy. http://www.tripacerdriver.com

Tina, sounds like you need a tool called a "hole finder". It's two
long spring steel straps that are welded together at one end. One
strap of the open end has a nub on one that has a hole in it. The nub
is sized to fit tightly into the hole you need to duplicate. The
other strap goes on the outside of the material and has a hardened nub
in it too that is the proper size for a 1/8" drill, or something like
that.

You fit the new fairing over the airframe, then slide the hole finder
in place and pop it into the hole you need to drill. Or, fit the hole
finder first, then insert the fairing between the piece that's lodged
in the hole you want to duplicate and the drill guide piece.

Once all is in place, drill through the drill guide. The drill will
center in the hole you want. Then you remove everything and step the
now created guide hole out to the size you need using a step drill or
whatever works for you.

Alternately, there are hole finders that have the nub that goes into
the hole you want to drill acurately, and a point on the strap that
goes on the outside. You put the guide into the hole, get the
fairing in place and then tap the outer strap with a hammer and the
point dimples right centered in the hole you want to drill. Then you
just have to drill on the dimple to the size you need.

Will this tool do the trick? I've seen them in Wicks, Aircraft Spruce
and Aircraft Tools. I have several sizes in my shop.

Corky Scott

[Drew Dalgleish]

On Tue, 15 Jul 2003 19:33:56 +0000 (UTC),
(Tina Marie) wrote:

>
>(I've got a certified airplane, so I hope you guys won't run me out
>of here on a rail, but...)
>
>I need to replace some of my fairings on my Tripacer. They're all simple,
>mostly flat aluminum, some with one or two bends in them. I can form
>them (I bought my SO a metal bender/shear/break for Christmas. He never
>uses it, but I just love it) without too much trouble.
>
>Here's my problem. After I make 'em, I have to attach them to the plane.
>And this nearly always requires making holes in them - and no matter
>what I do, the holes in the new fairing never line up with the holes on
>the airframe. I don't know how to mark where to drill - if I hold it
>up to the airframe, the airframe holes are behind the fairing and I can't
>see them. Measuring works sometimes, but then I end up off by 1/16, and
>it gets worse by the time I get all of them done.
>
>There's got to be a magic trick to making the holes the right size, in
>the right place, and I figured I'd be most likely to find it here.
>
>Thanks!
>
>Tina Marie
>--
>Life is like an analogy. http://www.tripacerdriver.com

-If your old fairings aren't completely destroyed flatten them out and
use as a pattern to drill through
- Get a hole duplicator. It's 2 joined straps of metal the top one has
a hole in it and the bottom one has a pin that sits in the hole in the
fuselage. Available at your favorite aviation tool store. but it
doesn't work very well on curved surfaces.
- get some clear lexan and make your fairings out of it. You can see
right through it to drill in exactly the right spot. Then use it as a
pattern for your aluminum fairings or just paint it and only you'll
know the difference.
Drew

[Tina Marie]

In article >,
Corky Scott > wrote:
>Tina, sounds like you need a tool called a "hole finder". It's two
>long spring steel straps that are welded together at one end. One

That's _exactly_ what I need! Thanks! I had no idea such a thing
existed.

Thanks!

Tina Marie
--
Life is like an analogy. http://www.tripacerdriver.com

[Kevin Horton]

In article >, Tina Marie
> wrote:

> (I've got a certified airplane, so I hope you guys won't run me out
> of here on a rail, but...)
>
> I need to replace some of my fairings on my Tripacer. They're all simple,
> mostly flat aluminum, some with one or two bends in them. I can form
> them (I bought my SO a metal bender/shear/break for Christmas. He never
> uses it, but I just love it) without too much trouble.
>
> Here's my problem. After I make 'em, I have to attach them to the plane.
> And this nearly always requires making holes in them - and no matter
> what I do, the holes in the new fairing never line up with the holes on
> the airframe. I don't know how to mark where to drill - if I hold it
> up to the airframe, the airframe holes are behind the fairing and I can't
> see them. Measuring works sometimes, but then I end up off by 1/16, and
> it gets worse by the time I get all of them done.
>
> There's got to be a magic trick to making the holes the right size, in
> the right place, and I figured I'd be most likely to find it here.
>
> Thanks!
>
> Tina Marie

Some suggested using a hole finder, and that would certainly do the
trick. But there is another, cheaper way (and if you are flying a
Tripacer, you probably like cheap, er..., good value :):

Put some strips of masking tape running away from each hole.

Carefully mark a fine line along each strip of tape, with the line
running through the centre of each hole.

Put a tick mark on each line at a certain distance from the centre of
the hole (e.g. 2" from the hole).

Put the fairing in place and secure it somehow (duct tape?).

Extend a line onto the fairing, and then measure back from the tick
mark to find where to drill the hole.

Put a cleco (or screw) in the hole to hold the position, and repeat for
each hole.

Good luck,

--
Kevin Horton - RV-8
Ottawa, Canada
http://go.phpwebhosting.com/~khorton/rv8/

[RobertR237]

In article >, (Tina
Marie) writes:

>
>(I've got a certified airplane, so I hope you guys won't run me out
>of here on a rail, but...)
>
>I need to replace some of my fairings on my Tripacer. They're all simple,
>mostly flat aluminum, some with one or two bends in them. I can form
>them (I bought my SO a metal bender/shear/break for Christmas. He never
>uses it, but I just love it) without too much trouble.
>

Not only will you not get run out of here but if you dump that husband, I would
be willing to bet that you would get a few marriage proposals.

Please send photos of airplane. ;-)

>Here's my problem. After I make 'em, I have to attach them to the plane.
>And this nearly always requires making holes in them - and no matter
>what I do, the holes in the new fairing never line up with the holes on
>the airframe. I don't know how to mark where to drill - if I hold it
>up to the airframe, the airframe holes are behind the fairing and I can't
>see them. Measuring works sometimes, but then I end up off by 1/16, and
>it gets worse by the time I get all of them done.
>
>There's got to be a magic trick to making the holes the right size, in
>the right place, and I figured I'd be most likely to find it here.
>
>Thanks!
>
>Tina Marie


See Corky Scott's replay. He has the solution for you.

Good luck.

>Life is like an analogy. http://www.tripacerdriver.com
>
>


Bob Reed
www.kisbuild.r-a-reed-assoc.com (KIS Builders Site)
KIS Cruiser in progress...Slow but steady progress....

"Ladies and Gentlemen, take my advice,
pull down your pants and Slide on the Ice!"
(M.A.S.H. Sidney Freedman)