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General control line discussion => Open Forum => Topic started by: Peter in Fairfax, VA on July 01, 2020, 10:36:26 AM

Title: How to measure wing thickness.
Post by: Peter in Fairfax, VA on July 01, 2020, 10:36:26 AM

What is a good way to measure wing thickness that uses common tools?  My typical caliper does not have long enough "teeth."

At present, I am setting the wing on a surface, ideally a hard surface, then balancing a small level on top of the wing, while juggling a ruler to measure between the level and the hard surface.  The result is between unsatisfactory and fair, but never excellent.

thanks,

Peter

Title: Re: How to measure wing thickness.
Post by: Brent Williams on July 01, 2020, 11:10:59 AM

Outside calipers.
(https://images.homedepot-static.com/productImages/15285098-5770-4c37-9423-ffcb6872e2bc/svn/general-tools-calipers-452-10-64_1000.jpg)

Title: Re: How to measure wing thickness.
Post by: Avaiojet on July 01, 2020, 11:55:12 AM

Take some scrap .125 balsa 2" in height and cut a length for the top and bottom of the wing with a few inches sticking out at the LE and TE.

Pin a couple of vertical pieces at the ends keeping both the top and bottom pieces parallel and the end pieces square at 90 degrees.

Slide the thing over the wing and have the top piece pivot on the two pinned end pieces.

When it touches the wing top and bottom, CA the pieces.

Remove it from the wing. If the top and bottom pieces are parallel, the distance between them is the thickness of your wing.

Works for many things. n~

Title: Re: How to measure wing thickness.
Post by: John Park on July 01, 2020, 11:55:49 AM

It will be easy enough to make up a crude but serviceable pair of outside calipers (from, say, 1/8" ply and a bolt and wing-nut) to handle any size wing you like.  The accuracy won't be to engineering standard, but should be 'near enough for jazz', as we used to say.

Title: Re: How to measure wing thickness.
Post by: Dan Berry on July 01, 2020, 12:01:49 PM

Two squares along the lines of a framing. Lay one onto the other to form a 'U' shape. You'll get a direct reading.
Use two squares, not two nerds.

Title: Re: How to measure wing thickness.
Post by: Peter in Fairfax, VA on July 01, 2020, 12:19:17 PM

The "two framing squares in a U shape" technique worked.

Title: Re: How to measure wing thickness.
Post by: Wayne Collier on July 01, 2020, 12:42:45 PM

Go buy a cheep plastic set of calipers at Harbor Freight or similar retailer. Carefully CA some long balsa extensions onto the sides of the jaws. Lot’s of kinds off material could be used for jaw extensions but soft wood can be adjusted with sandpaper. Don’t use much pressure or the extensions will bend and cause bad measurement.

Actually if you clamped a speed square or tri-square to your workbench with the rule vertical your level method would work pretty good.

Title: Re: How to measure wing thickness.
Post by: Dan McEntee on July 01, 2020, 12:48:19 PM

I would just get out the plans and measure with a ruler.
Type at you later,
Dan McEntee

Title: Re: How to measure wing thickness.
Post by: Peter in Fairfax, VA on July 01, 2020, 01:39:06 PM

Dan,

Plans?  That would involve building, correct?

/s

Peter

Title: Re: How to measure wing thickness.
Post by: Dan McEntee on July 01, 2020, 03:27:28 PM

Quote from: Peter in Fairfax, VA on July 01, 2020, 01:39:06 PM

Dan,

Plans?  That would involve building, correct?

/s

Peter

   Well, yes and no. I have models that I didnt build but I have the plans for them. I think the only airplane I have that I dont have plans for is the Top Flite Score, but I own a set of odd ball cheap long jaw calipers so that if I really needed to know how thick the airfoil is I would get those out. I just dont remember where I got them or why I have them.!!