Ballast???

[Rick Schwemmer]

Okay, as I have rad most of the posts so I could catch up with all thew guru's here, I came across the thread weight and bell crank location. Glad to see there is still some humor in thew world today. I do have a question as some pilots are looking for the zero ounce stunter. Has anyone built a ballast tube to their planes? I mean if the plane is too light just add ballast right? Different weights for different flying conditions.

Or do your planes fly better light or heavy?

Just curious.

[Gerald Arana]

Hi Rick,

There is a thread about the "Tucker Spl." by Ted Fancher. Its about weight and adding ballast to make it do a better square corner.

Check it out, Jerry

PS; Light isn't always a good thing! (Especially in the wind) 

[Brett Buck]

Okay, as I have rad most of the posts so I could catch up with all thew guru's here, I came across the thread weight and bell crank location. Glad to see there is still some humor in thew world today. I do have a question as some pilots are looking for the zero ounce stunter. Has anyone built a ballast tube to their planes? I mean if the plane is too light just add ballast right? Different weights for different flying conditions.

Or do your planes fly better light or heavy?

   Ballast has certainly been used in stunt planes.

   What you want depends on the issue you want to resolve. Nearly every airplane that has won the NATs in recent years exceeds the "How I won the 1975 Podunk Turkey Shoot" 12 oz/square foot MAX!!! advice, some by a huge amount. People can either learn from that, or not.   

     Of course it depends on using modern powerplants the way they were intended, if you don't, then you are going to have issues. 

   There are rather extensive discussions on the topic, I would suggest availing yourself of the archives on the topic. It was used as "bait" in the other thread, to which I no longer care to rise.

     Brett

[Ken Culbertson]

Okay, as I have rad most of the posts so I could catch up with all thew guru's here, I came across the thread weight and bell crank location. Glad to see there is still some humor in thew world today. I do have a question as some pilots are looking for the zero ounce stunter. Has anyone built a ballast tube to their planes? I mean if the plane is too light just add ballast right? Different weights for different flying conditions.

Or do your planes fly better light or heavy?

Just curious.

As a former sailplane enthusiast I know the value and effect of of ballast. I have suggested that in a thread a while back when I discovered that my 65oz ship flew better at 70oz after the repairs following my attempt to turn a 10' hourglass corner from 9'. But, sailplanes do not do square 8's often.

My experience is that properly powered heavier ships fly better up to a point.  That point seems to be when you can't overcome the inertia quickly enough in a corner to prevent it from skidding and that is more a function of center of lift and wing loading than absolute weight.  I have a gut feeling, based on absolutely zero scientific evidence, that adding ballast to bring a plane UP to an optimal wing loading would be good.  What is optimal and where to put it is above my pay grade.

Ken

[Jim Hoffman]

Build light, straight and stiff.  Pay great attention to hardware weight and finish weight.  Weight adding is easier than weight reduction mods on a finished airplane .

There’s generally a reasonable range of weights for a given design.  Any ballast weight additions would need to best occur at the CG. 

I personally have added ballast weight to one model in my 40+ year modeling career.  There are a myriad of trimming adjustments to be considered before adding weight. 

[Chuck_Smith]

Build it straight, build it light.

The Lift to Drag ratio L/D is baked into the aspect airplane's geometry, mostly aspect ratio. When you add weight the L goes up by that amount and the D accordingly.

Mass can be helpful when flying in bad air. The airplane won't maneuver any better, but it will be less susceptible to gusts.  If you've ever flown a really light ship in really bad air you know what I mean. You can be flying level and the doggone thing will sometimes jump 2 or three feet with no warning.

The other thing - bigger is almost always better. Wings are lighter than fuselages, and the larger the wing gets the lower the loading usually gets.

And for windy conditions - in my experience a tapered wing beats a straight wing every time. Calm air, not so much.

All IMHO and YMMV.

Chuck

[Brett Buck]

Build it straight, build it light.

The Lift to Drag ratio L/D is baked into the aspect airplane's geometry, mostly aspect ratio. When you add weight the L goes up by that amount and the D accordingly.

Mass can be helpful when flying in bad air. The airplane won't maneuver any better, but it will be less susceptible to gusts.

  In the Tucker Special experiment, and others, adding 1/2 pound of weight to a 38-ounce airplane *greatly improved* the cornering.

   Brett