Best NACA foil for daggerboard?

Ticktack

Member
Hello All, I purchased an aftermarket daggerboard & out of curiosity, I made a plaster template of the foil shape which indicated the max thickness is at about 50%!
I was wondering if someone a lot smarter than me could recommend an NACA foil that I could use to give the board a more desirable shape?
I looked at the class rules but nowhere could I find any specs. addressing the actual “”shape” of the board, only the dimensions.
Thanks so much!
Tom
 
You'll want a symmetric foil so... a common one for this would be a NACA 0012.

Problem is - a NACA 0012 is too wide at a 9.5" chord to fit in the daggerboard slot.

A NACA 0009 will fit, or a NACA 0012 with the thickness chopped down 27/32"
 
You'll want a symmetric foil so... a common one for this would be a NACA 0012.

Problem is - a NACA 0012 is too wide at a 9.5" chord to fit in the daggerboard slot.

A NACA 0009 will fit, or a NACA 0012 with the thickness chopped down 27/32"
Awesome, I’ll look at the NACA 0009, I wonder if the official Sunfish board is similar to it?
Thanks again!
Tom
 
Awesome, I’ll look at the NACA 0009, I wonder if the official Sunfish board is similar to it?
Thanks again!
Tom
You'll want a symmetric foil so... a common one for this would be a NACA 0012.

Problem is - a NACA 0012 is too wide at a 9.5" chord to fit in the daggerboard slot.

A NACA 0009 will fit, or a NACA 0012 with the thickness chopped down 27/32"
Wow, the NACA 0009 is a good looking foil,
This is very exciting for me! How could I get it sized to the 9.5” chord needed with the Sunfish board?
Thank you So much!!
Tom
 
If not identical - it's pretty close.

Sunfish%2BDaggerboard%2BSpecs%2B1980%2B1993.png
 
Wow, the NACA 0009 is a good looking foil,
This is very exciting for me! How could I get it sized to the 9.5” chord needed with the Sunfish board?
Thank you So much!!
Tom

www.airfoiltools.com has excellent plotting tools and low Re data for a bunch of NACA airfoils. Linked here is the plotting tool for the NACA 0009, where you can change the cord length and export a pdf template or set of coordinates that are properly to scale. Now, manufacturing a board with the exact airfoil would be more tricky and nothing easy comes to mind. I'm sure some other folks can make suggestions for this part!
 
3D print a negative half section about an inch wide and use it as a template.

Here is a quick thrown together negative half of a NACA 0009 if you have access to a 3D printer:


This is a great idea! @Ticktack let us know how it comes out if you decide to give it a go.

@aborgman Do you happen to work at Umich Aero? I think you helped my 405 team last fall with getting that huge blue DC power supply out of Gamba's lab for our project. Small world! :D
 
3D print a negative half section about an inch wide and use it as a template.

Here is a quick thrown together negative half of a NACA 0009 if you have access to a 3D printer:

T
3D print a negative half section about an inch wide and use it as a template.

Here is a quick thrown together negative half of a NACA 0009 if you have access to a 3D printer:

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3D print a negative half section about an inch wide and use it as a template.

Here is a quick thrown together negative half of a NACA 0009 if you have access to a 3D printer:

aborgman, Thank you so much, that is exactly what I was looking for. I’ll see if I can get that printed & will let you how it turns out!
Tom
 

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