weight watchers

On the "high end" of various weight suggestions, flight characteristics will likely be so poor that building that heavy of a plane would only be an exercise in frustration for the beginner.

>400 sq in 25-32oz,

The above "max" would be more suited to a design with coupled flaps. That much weight for a sport plane without flaps is such that performance is generally going to be inhibited (let's aim for 22-29 ounces for unflapped stunters this size).

>500 sq in 32-38oz,

On the bracket above, I'd allow up to 42 ounces for a flapped model design, but the "38" would seem to be too high for an unflapped plane. (What size is a "Medic", anyway?)

>550-600 sq in 35-42oz,

Again, with coupled flaps, up to 48 ounces should still work fine. The only "unflapped" designs that large are specialized combat planes (unless the Fancher "Doctor" fits in that size range, in which case I'd say to shoot for a 39 ounce maximum).

600-650 sq in 45-55oz,

Those numbers look dead on.

>650-700+ sq in 50-65oz.

I have never dealt with that size plane (not my own, nor any belonging to modelling acquaintances). No opinion.

Kiwi

It's fun in the wind though!

Hi Nils!

Build one of the Brodak Profile kits. I don't think there is much of anything you can do to build them too heavy. Especially if you cover the wings with $ or Ultra coat and paint the fuselage and stab/elevaor with one of the moderately fuel proof enamels - Rustoleum, or the Top Flite matching color paints.
Doing it that way might not be the lightest possible weight outcome, but it won't be overweight either.

If you are shooting for a certain weight objective, by weighing the components against someone else's known weights, it gives you an idea as you progress as to whether or not you are going to reach your target. If people say simply "keep it light", how do you know what is light? If they say "shoot for 46 ounces", how do you know you are getting there? If they say, "Shoot for 46 ounces or less and here are my component weights and my total", then you have something to go by.

If the builder says 2 ounces for the tail and you have 4, then you know to build another and not use that one. (Unless he had to add tail weight in the end, and then the nose was probably too long.)

Use these weights as a guide, and you will know how close you are going to be.

And, as for ordering wood, we usually order about two or three times as much as we plan for a project. Order contest balsa (4-6 pound weight) if this is what you need. Weigh it, mark it, and use it accordingly. Just remember, if they cut it from a 5 1/2 ounce density log, one side may be heavier, one side lighter. So the wood you get may actually range from 4 to 7 1/2 pound density in reality. Use the heavier wood in places where it is needed (8 pound density 1/32 wood is just as strong and just as light as 4 pound density 1/16 wood for skinning a foam wing, for instance, and will soak up less dope in the finish process. We, also, purposely use 7 to 8 pound wood for fuselage sides, and maybe a little heavier for flaps (less twist).)

In the end you will use all of the wood, and you will have other wood for other projects that come along. But if all builders weighed all of their components, and used these against a guideline, they could see how close they are coming while they are building and not have to wait until it is too late.

And, as a side benefit, if your first tail assembly weighed 2 ounces, and you worked out a method to build it just as strong that weighed 1 1/2 ounces the next time, you will have a way, again, of determining which method of construction is better.

Leonard Neumann

I don't really have anything to base this on but my guess would be that the Tanager at 40-42 oz with a stock Fox 35 would be marginal, maybe 45-48 oz max with the stock FP 40, may be OK at 52 oz or even more with Leonards 40 profile special, ST 46, LA 46, etc. It has plenty of area so the effect of weight would also seem to be a function of available power. With the 40FP mounted per plans, mine was siqnificantly nose heavy-if you forsee this you can save some trimming weight by making adjustments as you build. In other words, if I were to do it again, I would shorten the nose maybe 3/4 or 1 inch, or move the wing forward some. The hazard to doing this is you may wind up tail heavy which is much more difficult and requires much more trim weight to correct.

Good luck with the Tanager.
Jim