Kit #903,Chipmunk and Dihedral set

[Balsa Pilot]

Greetings to all (again)

I have just pulled the Chipmunk out of the cupboard and have notched the fuselage, ribs, and bulkheads. That being completed I was reading the plans and they say to use an 11/16ths" dihedral. After searching the plans on both sides for any indication of a dihedral set, or a handy balsa indicator ( I admit my math skills are way below par), do any of you know how to figure the angle of the root rib that is required? The wingspan of one wing is 7 and 15/16ths" or, 8" close enough, from tip to root.
This model is intended to be a flier, so the dihedral is fairly important. Also, should I build a nose block?, and what is a good rubber/prop combination to use? I already have 6" red props in the drawer.
Does anyone know how I can make my own rubber lube?

Back to the shop!

Thanks for the help(again)H

[Coloradoken]

A little trig is needed. If you think of a triangle with a base length of 4 inches (root to wing tip) and height of 11/16 inch (dihedral), the rise over run or opposite divided by adjacent length is 11/16 divided by 4 would be the tangent of the required angle. In this case tangent is 0.17188, which corresponds to 5.76 degrees. Got it?

[Balsa Pilot]

thanks Ken, that makes it easy!

[davidchoate]

I suck at math so I would need a protractor. I do not believe being off 1/16" or so on the dihedral will make a difference on a plane so small. But it is important to be equal on both sides. As for the prop and rubber all I know is get FAI rubber.I do mostly RC so I can only say that weight,balance, and perfectly aligned surfaces is crucial to all of the possible versions. I never did the Chipmunk, but did do the T-34 as a Rubber flyer, and it did way better than I hoped. The Bird Dog was My best Rubber Motor Flying Plane. Mitch is who You need to get advice on setup.