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Our plane weighs around 5.3 grams and it's WAY to light to be able to compete, is there anything we can do to make it heavier or do we have to start over?

Nesh wrote:Our plane weighs around 5.3 grams and it's WAY to light to be able to compete, is there anything we can do to make it heavier or do we have to start over?

I've heard clay ballast can be used, though you'll need to be careful not to negatively affect the balance. I don't know whether it has other downsides though.

Nesh wrote:Our plane weighs around 5.3 grams and it's WAY to light to be able to compete, is there anything we can do to make it heavier or do we have to start over?

This is good! You can use the extra mass to start playing around with the plane's center of gravity to adjust its flight pattern. Also you if things break you have some buffer for extra glue/wood mass from repairs, so definitely don't rebuild!

Like mentioned by others, definitely don't start over! There's a few things you can do to get it up to the minimum weight:
Attach extra balsa wood to the motor stick to strengthen it further, while also adding weight. Add clay ballast, as mentioned by Unome - clay doesn't stick as well after a while, so I prefer to use sticky tack. Make sure to add this at the center of gravity, if your plane is perfectly trimmed - you can check this by seeing how far down the motorstick the plane balances on your finger or a pen. If your plane is still stalling or diving, use the sticky tack to move the COG forward or backward to make it fly smoother - this will take experimentation.

Ok, thanks.

Nesh:

I agree with the others. Last year we were ending up about 1/2 gram light, and while that gave some ballasting, we had to move the wing around to adjust flight characteristics. this year, with revised design and improved building, the kids made their second plane come in under 4g. Having 3g of ballast really allows flexibility. It also means that if we have to do repairs, or stiffen things up, we can do so without fear of getting too heavy.

So, get to the gym and get tuning! Watch for any area that becomes too flexible, and then otherwise just use sticky tack as ballast.

Coach Chuck

Don't rebuild until you need to, but 3 grams under is 2.5 grams of STRENGTH you are giving away and you'll likely need to rebuild sooner. Don't just build as light as possible, it is possible to get far lighter than this. Build to target, maybe 5-10% under minimum, not 40%. I'd target .25 to .5 gm under minimum for these planes.

Jeff Anderson
Livonia, MI