travel board airfoil patterns

[mike20papa]

I've been thinking to make my own "travel boards" for aileron throw on my A model.  The airfoil given is: "NACA 641-415"  I thought I would google this and easily come up with a drawing that I could plot out.  Like most NACA airfoils... No such luck. I believe the nomenclature used in my '59 manual may not be standard, but even then, no reference even in older texts.  However, it may be that it is actually a standard NACA 6 digit airfoil that translated would be a NACA 64,1-415.   The six series airfoils are considered complex and to be plotted from NACA data,  Also, that the 641 is a variation of a 64 series airfoil, designated typically as 64(1) ... Way over my head... Anyone out there an aeroengineer or run into this before,  Never knew Al Mooney may have even been into modifying NACA airfoils for special application.  Who was this guy..some kind of genius!?   Thanks for any help.

[KSMooniac]

I'm an aero engineer by training, but make my living on the structures side of the discipline.  

Having said that, I doubt the Mooney airfoils were modified from the NACA standard collection at that time as there wasn't a good method beyond just cutting and trying to analyze changes.  Years ago I stumbled across some websites that had normalized coordinate values for standard NACA airfoils.  Searching might find them today.  You would need a CAD program to plot the coordinates and turn them into an airfoil, and of course scale them up to fit a particular wing station.  I'm not familiar with the A wing, but if it is similar to the later models the problem is slightly more complicated... the wing root uses one airfoil while the tip uses a different one, and they're blended over the span.  So, you would need both airfoil definitions (coordinates) and plot them in CAD and create a surface between them, then make a cut/extract at the aileron/flap wing station where the travel boards go.  Then you would need to figure out where the hinge point is, and plot that rotational scale to measure the deflections.

Al was still a genius, though!

[cliffy]

Why not ask to make a paper copy of the boards at/from an MSC that has them?

 

[carusoam]

Al was a genius.  His 20th design was pretty cool.  It comes in various forms from wood wings to all aluminum, NA to TN, short body to Long Body..!

Have you searched around here for the drawing?  Somebody has posted a similar project that they were working on.

Best regards,

-a-

[Guest]

With enough demand for them why don't you guys pool your money and buy a set for the group?

Clarence

[Yetti]

---

Closest I could find was a 64(1)-112

http://airfoiltools.com/search/index?m[textSearch]=&m[maxCamber]=&m[minCamber]=&m[maxThickness]=&m[minThickness]=&m[grp]=naca6&m[sort]=1&m

---

=3&m[count]=73

[RLCarter]

Skyjump did a set for the newer birds and uploaded the scans Travel Boards

[mike20papa]

I have the CAD capability, plotter, etc to make these IF I can get a hold of the airfoil profile.  I have a set of wood wing drawings at home, I need to go through these and see if the drawing is in there.  Thanks all for the help.  It is interesting that the wing is the same airfoil, all models A thru M!

[Hank]

I think the wing is the same for all models, M20 - M20V.

[carusoam]

The tail feathers moved back and got wider over time.  The rudder travel increased a bit and got longer too...

The wing got a few adornments on the tips, landing and taxi lights in the leading edge, some variations of speed breaks, and a few different fuel tank mods. Twisted wings, hydraulic and electric flaps...

gotta love that wing! It is the device that provides the speed and efficiency that is Mooney.

One day it will be constructed of composite materials similar to the original wood (nature's composite).

Best regards,

-a-

[M20F-1968]

The wing is the same up to the present day, except for fuel tank configurations and positions and wing tips.

John Breda

[M20F-1968]

I am looking to make a set of travel boards.  I can make a set for my self by hand, or could have them commercially made if there is enough interest by other owners.  Please PM me if interested in getting involved in this project, with an indication of which model Mooney you have, and which of the 3 travel boards you would like.  I will in turn investigate options on having them made.  Naturally, in everything involving fabrication, the more you make at a time, the less expensive each piece becomes.  If I made them by hand, I would make them from wood and my expense is really my time.  If I had them made, I most likely would make them from aluminum but could look into other substances as well. 

John Breda

[RLCarter]

Aluminum would be too pricey, fiberglass or a plastic/poly-carb could be cut by water-jetting which are everywhere now. Laser cutters aren't as easy to find but they are around and can do wood as well. Just seeing photos of the travel boards, I would think you could get 20 sets if nested correctly from a 48"x96" piece of material.

[N601RX]

The original ones are 3 or 4 pieces riveted together and the wood is varnished.  A simpler and cheaper method to produce several sets that is completely automated is to cut them from sheet aluminum or plastic and engrave the markings on them letting them be just one piece. 

I have a coworker who has a CNC router that will accept 4'x12' sheets of aluminum or plastic.  It can cut and engrave them all in one step.  If someone has an accurate CAD file I can get him to cut a set and see how they turn out and get an idea on the time/price required.

[mike20papa]

Yes...if we only had that airfoil section!  My old set of wing drawings unfortunately is lacking these.  I wish the present Mooney folks would honor the work of Al & Co. and pass on the drawings for the A model thru the J to the Smithsonian - where they belong.

https://airandspace.si.edu/collections/archival/technical-drawings.cfm

I see the M-18 Mite dwg.s are there..I wonder who provided them, and when.

[carusoam]

I was just at the A&S museum, yesterday.  Wish I knew who or how to ask..?

I need to go back for some unfinished business.  The place is quite large with a lot of stuff.  They have a Continental engine cut open to view operating valves when you turn the prop disc...

Best regards,

-a-