Mr Akimoto's Fabulous Flying Advice for Novices!

| >(I'm not really sure how many G's that plane is capable of. Given | >enough speed, three seems reasonable.) | | Its WAY more than that ... (kinda Scary when you think about it) The | max G-load is proportional to the SQUARE of the speed ratio. To run | some typical numbers Say the stall speed is 20 mph (probably high | ... even for a durathing ... ) Lets say you have a really crappy | engine on it and max level speed is 40 mph ... in that case (40/20) | squared = 4 , so 4 Gs (24 lbs)

Interesting. I'd never heard of that, but it makes sense.

Though I doubt a Duraplane 40 stalls at 20 mph. Probably faster.

At some point, even with enough rubber bands, the wing won't be able to handle the stress and it'll fold. If it stays in one piece, you might be able to land the plane -- it depends on just how much new dihedral you got, and how symmetrical it is.

Also, the (# Gs x the total weight) formula is a little bit unfair, because the rubber bands don't have to support the weight of the wing itself. But the general idea is still valid.

| I have seen wings and fuselage part company in the air several times, | and it sucks.

Dunno -- it's really cool to watch, as long as 1) it's not aimed at you, and 2) it's not your plane. The wing flopping down is really quite funny.

| (as an aside, if this does happen, input the controls for a spin, | sometimes the offset rudder and elevator can get the wingless fuselage | to do a "maple leaf" type autorotation. If you have time, vary the | throttle to try to get it going, otherwise just go to idle, but do try | the spin ... at that point you have nothing to lose.

I had that happen to me once. It was a Pico Stick. I was a few hundred feet up, and I did a loop, and the wing folded, and half broke off. And then the other half broke off. And then the stab broke off, leaving only the vertical stabilizer left. Which proceeded to autorotate at about two rev/s, and land very gently. A while later, the other three parts (left wing, right wing, horizontal stabilizer) landed.

This happened at the local (non-RC) park. I had quite a crowd watching it, and they were all sutiably impressed. Several thought I meant to do that :)

In any event, if one of the stabilizers (horizontal or vertical) hadn't come off, I suspect it would have made a lawn dart and there would have been nothing I could do about it. Yes, moving the sticks so both controls are at their maximum angle would slow it down (and therefore are a good idea), but I don't think it would stop it from being a lawn dart.

I wish I'd had that on film. It was cool enough that I'm tempted to try and force it again -- maybe someday when my Slow Stick gets so ratty that I'm ready to replace it, I'll weaken things and see if I can force it to happen. And make sure it gets filmed ...

(as an aside, if this does happen, input the controls for a spin,

Now that I hadn't thought of. Not that I'll remember or practice it sans wing. :) mk

---------------------------------------------------------- This is all interesting to me since I am evidently way under on the rubber bands. I converted a 40 size Big Stik from screws to rubber because I destroyed the wing in a wreck. I tie two rubber bands together so that they don't pull so hard across the new Styrofoam wing. I use three of these paired bands to a side, plus a pair crossing. Haven't had a problem yet.

I don't know what type of rubber bands you use in the US, but I have flown for a number of years using 40 size models and never used more than three bands per side usually in a cross configuration.

After each flying session I wash them through with detergent such as washing up liquid and then store them in a light tight container with talc.

Most bands last a full season with no problems, and there have been times when I've had no breakages for over two years.

I do a test stretch of the bands before each flying session and this usually shows up any weak bands - they break when stretched to about twice the length needed to hold the wings in place.

Malcolm

I would NEVER reuse rubber bands. The cost of an entire bag of rubber bands is a heck of a lot cheaper than just one of my planes. Just the damage done by UV is bad enough, add fuel into the mix and I just can't imagine......

BTW, I usually use 3 bands per side on my 2M gliders with 2 of them in a cross configuration. At the end of the day I snip them loose and throw them away.

Jim

the "standard" most used band here is the #64 which is about 1/4 inch wide, 1/16 thick, and 3-1/2 inches long. (loop length)

Now I KNOW that there are much heavier bands, and if that is what you are using, you are probably applying as much or more rubber than I do.

Rule of thumb for #64 bands (the way it was taught to me) is two (2) bands per pound of all-up weight with the last pair, or an extra pair crossed.

YMMV mine doesn't

In all my years of flying R/C, I've never seen a model crash because of using too many rubber bands. I can honestly say that I have lost count of the models I have seen crash because of too few rubber bands being used. Bands are cheap. Use a lot of them.

Ed Cregger

I agree that bands are cheap - relatively.

Over here, the standard is to use a minimum of three bands per side. I don't know of anyone who uses more than this. Band size is usually 1/2" wide - length according to the wing chord.

With some lightweight gliders, I have seen people fly with only one band each side - not my choice, I always use three i.e. a total of six.

In thirty plus years of flying R/C models - power and glider, I have NEVER seen a model crash because of wing band failure, and using my system have rarely had a band fail in use. Many have succumbed to my stretch test.

Malcolm

A half inch wide band is a husky rascal.

Many American glow sport flyers have used #64 rubber bands as a standard for many years. When flying a forty to fifty size sport model, I use 14 to 16 rubber bands total.

Lighter, less powerful models that I fly usually run at least 8 to 10 rubber bands. I always try to err on the side of safety.

If what you are doing has worked safely for you, who am I to tell you to do things differently?

Ed Cregger

Hi Ed,

I have no idea what a #64 band is like.

If I used smaller bands than my "normal" ones, I would probably add more. As it is, I buy a 1lb box of bands from a stationery supplier and they last me for a long time. I get lengths so that when stretched across the wing they are extended by about half their nominal length.

My local model shop sells white bands in packs of ten - similar size and thickness, but much more expensive than the boxes I buy.

Often two bands per side will support the model - especially when new - and the third is added for insurance.

As other posters have indicated, I replace those which are showing any signs of wear, and my "stretch test" makes sure that any failures occur before they get onto my models.

Malcolm

I found out many years ago that cutting up automobile or truck or trailer inner tubes into rubber bands of approximately 1/2 inch width gives me enough to fit almost any size wings within my stable. And I only use about 6 (2each side and 2 crisscrossed). They last indefinitely, and have never broken in all the years of use. Might generate a few wise ass remarks from fellow fliers, but so what?

Olin McDaniel, AMA 30932

Big Snip >

As a Yorkshire man, this is one of my favourite sources of wing bands.

Sadly though, when I use them to retain a diesel engined power pod, they react with the fuel and leave dirty black (or red) marks on the wing - a small price to pay methinks.

Malcolm