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Old Dec 29, 2012, 08:31 PM
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R2R
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United States, FL, St Johns
Joined Nov 2009
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Ballast Use: How much do you use in what conditions and why?

I got the green light to attend a few nearby contests this winter and spring, so I spent some time over the last couple of days installing a ballast tube in my Sapphire and cutting some ballast rods. They are 5/8" diameter steel.

3 1/2" x 5 oz
5 7/8" x 8 oz
9 7/8" x 14
15 1/8" x 22 oz

The tube is rolled fiberglass with a blind nut epoxied to it and the aft-end sealed off. (Thanks to the personal stash of a great vendor/fellow RCG'er for that one and another one to be installed in my RES!! ) In the tail boom the tube is epoxied to the tail floor with a piece of foam wedged above and epoxied to tie everything in. At the forward end of the tube, it is glued to the hardwood dowel cross-brace on top and to a 1" diameter dowel that is glued to the fuse floor. The front of the dowel is also epoxied to my servo tray. A #6 screw will lock the ballast into place, screwing down into the blind nut into the dowel. The forecast is for 9MPH winds tomorrow, so I should get the chance to try out the lighter weights.

It was very timely receiving my Model Aviation this month. The excerpts on how the Masters use ballast was super interesting, especially JW's comments on Max LD to wind speed in marginal lift conditions and D.Hobby's comments. What I got out of it was that, both tune ballast using thermal activity as the overriding factor, while still keeping in mind wind speed. Seemed a little more concrete/systematic than what Dave Thornburg has captured in Old Buzzards.

I have never used ballast, so I can't offer any personal experience; how much do you all use for certain situations and why?

Allan
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