Archive of the Yahoo! Groups mailing list for the Bug hand-launch glider 2002-2018

From: Lee Teicheira <leet1@...>
Date: Sunday, August 14, 2011 2:02 AM
Subject: Re: [BugHLG] Re: Optimum weight for a Bug.
Hey John With today's radio gear, getting under 3 ounces (85g) is pretty easy. The bug was designed around the Hitec HS-50 servos, 555 receiver and a 3x50ma nicad battery. That is (was) about 1.7oz (48g) in radio gear. Therefore, the fuse had to be built short, and as light as possible to properly balance the plane without adding tail weight... You do build your tail feathers as light as possible, right? My current micro system of choice is a Castle Creations Berg 4L receiver, Dymond D47 servos and a 2x120 mah LiPo battery. This gives an all up radio weight of 0.85 oz (24g). This is the only (good) 72mHz combination that I know of that will run on 2 LiPos without a regulator. Many of the 2.4 gHz receivers will also run on 2 LiPos without a regulator, but you still want the Dymond servos. Most servos will go to sleep on more than 6 volts, and never wake up... As a side benefit, this also allows for a stouter fuse. Better added strength in the nose, than added lead to balance. You also might (should) lengthen the nose a bit to help with the balance with this light of a radio. Maybe as much as an inch (or more) if you keep you tail light. Did I mention that you should build your tail feathers light? Like 4-5 pound wood, sealed with 1-2 coats of clear Varathane that is wiped on with a rag, and *immediately* wiped off. Check eFlight for 7.4v 120mah 2S LiPos and charger. They use them in their small RC planes. With this radio, a 3oz Bug is easily obtainable. Just keep your tail light, and don't waist all the weight savings with lead. My current Bug project is rocket launched and weighs under 90g with a spent rocket motor casing (10g for the motor casing) on board.... I have mentioned this Bug before. It's almost finished. It keeps getting preempted by other projects. I will post pix when it is flying. And a thinner airfoil is probably a good idea at these reduced weights. Even though it won't reproduce true, AG35 blended to AG36 might be a good place to start. FWIW, my first Bug was 102g. Built with 5-6 pound balsa, Ultracote Lite (NO Monokote, way heavy), 2 x GWS Pico servos, GWS pico receiver and 4 x 110 NiCad (it's what I had on hand), and NO lead needed to balance. Flys very nice, but a lead sled by today's standards. Lee *Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us.* -*Bill Watterson* On Sat, Aug 13, 2011 at 2:38 PM, gldrgidr <gldrgidr@...> wrote: > Matt, > I think you are just bragging about how light your bug is. Most of the > rest of us are doing our best to get the weight below 115 grams. > It does seem that some ballast would improve your bug's performance in the > wind. The designer's bugs were about 3.5 oz.(99g), so anything up to that > should work. > > For those who have increased the span to 34 inches: > The stock area is 163 sq.in. and the new area is roughly 198 sq.in.. > At 65 grams, Matt's bug has a wing loading of 2.0 oz/sq-ft. > At 99 grams (designer's weight) the wing loading is 3.1 oz/sq-ft. > At 120 grams(4.2oz) for the 34" wing, the wing loading is 3.1 oz/sq-ft. > > Forgive me. I tried to figure the load in metric but it gave me a headache. > > John > > > --- In BugHLG@yahoogroups.com, "Matt" <mattmidair@...> wrote: > > > > Hi guys, > > Has anyone experimented in adding a touch of ballast to improve > penetration in a breeze? My DLG bugs are very light (60 - 65grams) and > perform very nicely in dead clam hot South African air...but they just dont > penetrate if there is anything more than the slightest air movement. I've > played with a bit of nose weight wothout much improvement, but its just > occured to me that some ballast mite just be whats needed. Any thoughts? PS: > maybe a thinner wing??? > > > > > > > ------------------------------------ > > Home Page - http://groups.yahoo.com/group/BugHLG/ > > Yahoo! Groups Links > > > > [Non-text portions of this message have been removed]