After seeing the gorgeous ripmax alliance in the latest se modeler, and noticing what I think is too much weight for a 8 cell sp480 machine, ( 27 oz!), I have decided to make my own pink foamie knockoff that will use a mag mayhem DD with apc 7x5 on 8 cp2400 cells.

I'm confident that it will weigh around 35-37 oz as I've built similar sized and equiped planes like this before and they are always under 40 oz.

I have gotten to the part of the design where I have to choose and airfoil but am unsure what airfoil " proper " pattern planes run.

I'm assuming that it'll be full symetrical, but I'm hoping for a specific recommendation. I do have profi so I can make just about anything.

Can anybody help me out here?

Thanks,
Dean in Milwaukee

From the weight you mention, the plane won't be large.. practically any smooth curve top and bottom will work,about 12 to 15% thick, high point about 30%, rounded leading edge.

Thanks for the advice.

Your right that it won't be large. 38" span and 315 in/sq.

I built a similar size and weight plane, (but very differnet looking!) with 40 span and 350 in/sq and e205 airfoil and it was a real floater. Launch was very easy and landing flare hung on forever.

Becouse of that experience, and my desire for this to be a faster plane than the last ones 55 mph, I'm going to try a smaller wing.

The alliance looks pretty sleek, but we'll have to see how fast my copy actually goes.

I am hoping to have enough speed to transition into good vertical.
The mag mayhem should be pulling 25 amps with a 67 mph ps.

Dean

Hi Dean
Sounds like a neat little project. The guy who might be able to help is Scott Black, who hangs our hereabouts on occasions. He did a baby version of the "Caprise" FAI pattern ship that went very nicely. I've got his plan in CAD format and I recall he used a NACA 64A010 airfoil - you can do that in Profile.

Scott seemed happy enough with the low speed handling of this, so it seems like a good one to consider.

Heck, if doing a PF model, you could probably build and fly two or three sections in a week! Good luck with her.

Hey thanks Dereck! This was exactly the kind of info I was hoping for, a known good performing profile.

You are right about being able to knock out a lot of wings in a short period of time. Same thing with the fuse. It is nice to build on someone elses hard work though and cut down the steps you need to get a good one.

Dean