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General control line discussion => Open Forum => Topic started by: Bob Porter on November 15, 2011, 05:54:25 AM

Title: How to scale up a model? .46 or maybe .60 size Bi Slob?
Post by: Bob Porter on November 15, 2011, 05:54:25 AM

I would like to build a .46 or maybe even a .60 size bi-slob.  Can you gentlemen give me some rules to use to decide how to up size the design?  Do I double the wing area for double the engine? Or is it some exponential formula?  And do I then just expand every dimension by the same multiplier?

I'm sure some of you have already made a bi-slob on steroids, any recommendations?

Bob in New Orleans

Title: Re: How to scale up a model? .46 or maybe .60 size Bi Slob?
Post by: Larry Renger on November 15, 2011, 08:24:10 AM

A linear change of wing area with cu.in. capacity is a fair guideline.  To get the % size increase to plug into a copier, take the square root of the ratio of the areas. (Or the displacements!)

The BiSlob is a .35 size plane, so sq.rt.(.60/.35) = 130%