News:




  • May 20, 2019, 03:41:33 AM

Login with username, password and session length

Author Topic: Wing Hole Cut Out  (Read 437 times)

Offline Motorman

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 4546
  • Millville NJ PDQ Flying Clown Country
Wing Hole Cut Out
« on: May 14, 2019, 01:04:21 PM »
Wing is tapered in plan and thickness and it's a full fuselage. How do you make a template or something to mark out the hole for the wing when you don't have a set of plans or anything?


Thanks,
Motorman 8)
There will be a sunny day and we will fly our airplanes.


Offline bob whitney

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1511
Re: Wing Hole Cut Out
« Reply #1 on: May 14, 2019, 02:07:14 PM »
wing it H^^
rad racer

Offline badbill

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 373
Re: Wing Hole Cut Out
« Reply #2 on: May 14, 2019, 02:21:21 PM »
Wing is tapered in plan and thickness and it's a full fuselage. How do you make a template or something to mark out the hole for the wing when you don't have a set of plans or anything?


Thanks,
Motorman 8)

If I'm not misunderstanding what you want, Just wrap a piece of solder around the wing and then carefully transfer to paper. Done it a million times.
Bill Davenport
AMA 28141


If some is good, and more is better, then too much is just right!

Offline Dave Hull

  • 2018 Supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 754
Re: Wing Hole Cut Out
« Reply #3 on: May 14, 2019, 02:59:22 PM »
Pretty easy to take a piece of a cereal box cardboard and make a succession of cuts with scissors and get the shape. I'd mark the wing (could use blue tape) about where your sides are and fit the template to that.

If the wing is smaller, like a Goodyear or a 1/2A, I use a contour gauge like this:

   https://www.amazon.com/General-Tools-Contour-Duplicator-6-Inch/dp/B00004T7RA

I have one with a 6" span. They come larger, which would make it more useful to you. On mine, I just make sure the pins move freely. A little oil helps. You can protect balsa with another piece of that cereal box or a piece of heavy mylar tape or film.

A bit of patience and you're there....

Divot

Offline Motorman

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 4546
  • Millville NJ PDQ Flying Clown Country
Re: Wing Hole Cut Out
« Reply #4 on: May 14, 2019, 03:04:28 PM »
How do you find the center line of the leading edge?

There will be a sunny day and we will fly our airplanes.

Offline Dave Hull

  • 2018 Supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 754
Re: Wing Hole Cut Out
« Reply #5 on: May 14, 2019, 03:14:26 PM »
Finding the LE and TE using the cardboard method is actually one of the best things about it. Sorry I didn't include that. Make your initial blank about as tall as the overall wing. Taller doesn't hurt. Make a vertical LE and TE cut to match the chord. Then do the cuts to converge on the curvature. Now put a reference mark on the LE about where you think the centerline is. Then place the template on the top surface and transfer your LE mark to the template. Then use the template on the bottom surface and transfer the line to the template again. If the wing is symmetric and built accurately, you can split the difference between the template marks and re-mark the true, best-fit centerline. Works on the TE too, but that is usually a trivial case.

Note that as you get the curvature closer, you can lay a pencil down on the wing and push it up against the template. This will give a true surface curve, just offset. That is why it is helpful to make the cardboard blank a little taller. You get several iterations of cut, trace, cut to get you a perfect match.

You can do much the same thing with the pin contour gage. Just adjust a row of pins forward of the wing where you think the centerline is, and same for the TE. So you can only easily do this for wing chords a bit smaller than your gauge.

Divot
« Last Edit: May 14, 2019, 03:47:28 PM by Dave Hull »

Offline Perry Rose

  • 2015
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 996
Re: Wing Hole Cut Out
« Reply #6 on: May 14, 2019, 08:27:31 PM »
No matter how you cut it use an incidence meter when you glue the wing to the fuselage.
I wouldn't take her to a dog fight even if she had a chance to win.
The worst part of growing old is remembering when you were young.

Offline Matt Spencer

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 3379
Re: Wing Hole Cut Out
« Reply #7 on: May 15, 2019, 12:05:28 AM »
Get the CENTERLINE both sides first .
Maybe blocking & chocking - tapeing / weighting fuselage to a level surface .
Use a offcut or a THING the right height , adjacent , and scribe / scrible along ea. side .

Often pays to mark WING with Fuse. posn. Thus you get LE , TE , & High Point . And you can cross referance .

Back to the fuse , get the LE, TE, & High Point marked . Then away you go , particularly if youve got a curve . LL~
So cutting a cardboard template to fit the wing , at the posn. the fuse. fits . Seperate Fr. & R.

Then if your really worried , Cut another ful length , drawn from those two , and a few dimensions .
Or taped together in situ if youve got 3 or 4 hands .

Thus the templates adjacent the fuselage prescribe the corect cut out .
The more curvacious the fuselage , the better to put pre determined height marks from parallel things ( sticks , squares )and suchlike.

Obviously with the LE - TE & High Point ( Spar ? ) positioned accurately , the rest / curve , will fill in easier .  :P

Offline Brett Buck

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 9642
Re: Wing Hole Cut Out
« Reply #8 on: May 15, 2019, 04:45:59 AM »
Wing is tapered in plan and thickness and it's a full fuselage. How do you make a template or something to mark out the hole for the wing when you don't have a set of plans or anything?

    Measure the chord where it will go through the fuselage. draw a line on the template material, mark out the chord along the line.  Then draw in the trailing edge thickness on it where the TE goes. Using a template made of the root chord as a French curve, line up the LE at the centerline, and draw the shape of the airfoil using the root chord template, so that the curve lines up with the surface at the TE. This is not *exactly* the right shape, but far closer than you can cut it out. It's much eacier to do than to describe, so maybe I will demonstrate when I get home.

   Brett

Offline Dave Hull

  • 2018 Supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 754
Re: Wing Hole Cut Out
« Reply #9 on: May 15, 2019, 02:26:58 PM »
Brett,

He said he didn't have a copy of the plans "or anything." And it sounded like he had the completed wing, perhaps reused out of an earlier airplane. Maybe an ARF with no plans. If I understand correctly what you are suggesting, I think he's going to be unable to interpolate or even trace the root rib.

Dave

Offline Matt Spencer

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 3379
Re: Wing Hole Cut Out
« Reply #10 on: May 15, 2019, 07:28:44 PM »
Getting it level to mark the centerline ,
Often a block of wood , or two , DRESSED - cut to length , will fit in the engine bay & or tank compartment .
Something like a 2 x 4 .

If theres no protrusions , there you are . Put it on the bench , and its LEVEL . Of course if its electric . . . VD~ S?P .

Slide a soft block under the rear while its held down level , then traquilise the cat and lay that over it to hold it down without marking .

Another block , piece of cardboard , cut to the ' wing level height , or even a ruler , will then get the centerline dialed in .

Offline Motorman

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 4546
  • Millville NJ PDQ Flying Clown Country
Re: Wing Hole Cut Out
« Reply #11 on: May 16, 2019, 11:42:01 AM »
Success, I used the solder to get the shape then transferred to cardboard. not easy to get the solder to lay down. No cats were tranquilized in the making of this template.

Motorman 8)   
There will be a sunny day and we will fly our airplanes.

Offline Dave Hull

  • 2018 Supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 754
Re: Wing Hole Cut Out
« Reply #12 on: May 16, 2019, 12:23:49 PM »
Sounds like progress!

I usually build in my garage. I have a barstool to sit on when I have to sit down to think. There was a neighborhood cat that would come by most evenings. If the garage door was open, he would saunter down the driveway, peek around inside the garage, and then jump up on the stool to supervise. He'd usually stick around watching for 5 or 10 minutes to be sure I wasn't slacking, and that I was doing a good job. Then he'd jump down and head off to the next project. I never asked him, but I bet he would have held parts for me while the glue was drying. Cool cat. Miss him....

Divot

Offline badbill

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 373
Re: Wing Hole Cut Out
« Reply #13 on: May 16, 2019, 01:30:52 PM »
Success, I used the solder to get the shape then transferred to cardboard. not easy to get the solder to lay down. No cats were tranquilized in the making of this template.

Motorman 8)   

Looks like it turned out great, good job!  y1
Bill Davenport
AMA 28141


If some is good, and more is better, then too much is just right!


Tags: