Quality Props?

[KnifeEdge51]

Now I've done it. I've entered the Science Olympiad. :D I've got some good ideas for making and cutting ribs (steam formed 1/16), and a few other ideas. But I'm lost when it comes to the prop. I need to use a commercially available plastic two-blade prop. Who makes a high quality plastic prop that I can use? Thanks!

Nick R.

[Bob Chiang]

Peck Polymers http://www.peck-polymers.com/ is one of the most common suppliers for rubber props. Check the rules: I think you can balance it, but not scrape it to reduce weight.

With respect to the ribs: typical sliced ribs are weak near the leading edge, so steaming is a good idea. Another method is to make a form for the airfoil, and laminate two sheets of 1/32" balsa to the airfoil shape. Then slice ribs from that stock.

-Bob Chiang
Ithaca, NY

[KnifeEdge51]

Thank you, Bob. The rules so state that I can scrape the prop to reduce weight. Lucky for me, eh?

I have also been thinking about lamination, in general, lately. However, I do not know how to perform this technique. It sounds like a very strong, yet light, way to produce a structure. Perhaps a search is in order?? :) Thanks again!

Nick R.

[Bob Chiang]

Hi,

These web page have lots of hints and tips for building free flight.
http://www.mindspring.com/~thayer5/modelhp.html
http://groups.msn.com/FreeFlightOnline/_homepage.msnw?pgmarket=en-us
http://website.lineone.net/~raynes.pk.mac/start.htm
http://www.windysock.net/


I can't remember if they have anything about laminating. The more common use for laminating is to form curved outlines for wing tips and tail surfaces.

I like building models with wing ribs made of a sliced top member (either from sheet stock or the laminated and formed stock we've been talking about) and a straight stick for the lower member.

[Bob Chiang]

Rearwin Speedster with sliced ribs and laminated outlines

[KnifeEdge51]

Very nice! Thanks for the links. I'll dive into those right now and see what goodies they contain. :D

Nick R.