Frequentcrasher

Hi there,
Could anyone send me a dwg file of a 66-012 airfoil?
jsmartin*sasktel.net (replace the asterisk with a @) This is just so I don't get spammed.
Thanks,
Jeff

DonStegall

My Feedback: (1)

Do you want it in template form with skins and leading edge? What chord length do you want? Basically what is the purpose, so you get what you need?

Frequentcrasher

All good questions, Don. I need it to CAD a quickee wing to mill some plugs for composite wings. I'll make my own molds from those. Skins aren't necessary, but full airfoil shape is, ie. leading edge being there. 9 7/8" chord. I appreciate your call for clarification. I'm new to doing things like this in a computer world, so if there is anything else you think I need. Let me know. I would have normally just made a mold from one of my existing wings, but no survivors are trim free. Apparently this CNC stuff is the way to go anyway.
Thanks,
Jeff

Ed Smith

You will also need the wing thickness to make a legal wing. The true airfoil at the stated chord may need tweaking to give you the correct wing thickness.

Ed S

DonStegall

My Feedback: (1)

Check your email for it in DXF format for a 9 7/8 chord with no sheeting and no leading edge.

I did not add any additional negative sheeting because it comes out to 1.1859875 which is real close to 1 3/16 … By the time you add the joint, it will be thick enough.

Note that the CompuFoil 2000 generated figure is not perfect. If you are going to use CNC, you need to get the polars and get a perfect representation. CompuFoil 3D may be better, but I don’t have it.

AllanU

Jeff

I have a couple of templates/cad files if your still looking. The 66012 for 11.25% for us CPPRA flyers and the 66012 for 12% as well as 12.25% to get the 1 3/16 thickness( a little too thick but...) Let me know if you want them. You may need to adjust them to get the right thickness if your building a mold etc but its a start.

What are you making Jeff? New weapons for the season?.


Al

DonStegall

My Feedback: (1)

Al,

You should only need to go to 12.25% if you are using a 9 5/8 or 9 3/4 chord. 9 7/8 comes out fine at 12.01. I highly recommend against going to 9 5/8 or even 9 3/4 with a perfectly sharp trailing edge. By the time you trim the molding flashing, you will be a little under those sizes. At 9 5/8 there is no room for tip design. So you can't get nice Vortex style tips. I made the mistake of using 9 3/4 on the Smasher and it limited what I could do with the tips.

Another mistake I made on the Smasher is that my wing is a little over 1 3/16 not counting the wing joint. By the time you add two layers of 1.4 ounce and two layers of .7 ounce plus the glue used on the seam, you wind up with some additional thickness. Some people trim the bagged halves before joining to make this less of an issue, but for epoxy molds you will possibly damage the flanges.

Frequentcrasher

Thanks, Don! I really appreciate you taking time to send me the file. I'll be fine for American thickness and the drawing is already done. I should be able to do a nice tip at 9 7/8". Thanks for the advice as well.

Hey Al, I hope you're wintering well. We're dying over here. I thought I'd get ahead of myself and make a wing mold. It might not see a wing this season, but the fuses are coming out better. I would like one more quickee when the season rolls around. Any word on you guys hosting yet?

Ed, always nice to hear from you. Like Al stated, we only need 11.25% of chord here in the prairies, but I thought if I plan on going through the trouble of making a mold, I might as well make it thick enough so that if I do ever go to a race down south, I'll be legal.

Thanks for the help,
Jeff