Radio Controlled Soaring Digest April 2005 Issue
Issue Contents:
A memorial to Jef Raskin March 9 1943-feb 26 2005. Jeff was a talented scientist musician composer conductor and sailplane enthusiast. His RCSD articles are summarized.
Alexander Lippisch designed early gliders including flying wings using models vs. wind tunnels. The Storch and Delta series were the result of his work. The Storch I (1927) The Storch IV is shown in 3 views. It was launched by a bungie cord and hand tow.
Torey Pines and other California flying sites are described.
Dave Describes how to cut a highly tapered (2:1) foam core wing using a cutting bow and a drop arm foam cutter. The bow should be 2X that of the core in length. Instructions for getting good results. Template plotting software available from myweb.cableone.net/regdave/index.htm
The Hobie Hawk design is over 20 years old but is a favorite model of many modelers. It was ahead f its time. A robust design models came in a number of sizes up to a 10 span. www.hobiehawk.com carries the story and pictures. Designed by Hobie Alter a sailboat manufacturer 10 000 to 14 000 sailplanes were sold. More at www.hobiehawk.com
A study of sheer load in the spar of a wood wing is discussed. A truss structure is very effective but has a high part count. Sheer webs are practical alternative. Vertical shear web grain if it is stronger may be true due to its adhesive bond to the spar cap. If the rib is split it should be securely glued to the sheer web or the wing will be weak. Avoid holes in the sheer web. Reinforce any required holes.
The relationship between flying speed the depth of a wing and Reynolds No: is graphed with the appropriate equation considering air viscosity and density.Another equation graph relates model wing loading to the coefficient of lift Cl and airspeed.
Years ago a pair of index fingers was all that was needed to set your CG. Todays high performance ships will need a precise setting of CG. The #69 3054 Multiplex CG tool at $42 can do the trick. The max capacity is 10 kg (22 lbs). CG range is 30 to 150 mm.
April 23 24 is the date for the Golden State RC Race. South Bay Soaring Society sponsors the event also LF Level 3 4 and 5 XC goals can be met.
Sportube Travel Part II. A 3M model in a Sportube is 6 long too long for most sedans and SUVs. If you have other passengers and luggage attaching them to the roof with a HandiRack is a good option. A HandiRack consists of 2 bladders to prevent the loads (like the Sportube) from shifting on the roofs surface damaging the paint. HandiRack costs ~$60.
The Sportube has become the standard way to send your model with you on the air travel. Plane Pack has been good for protection for models for years. Gordy asked for a special version to work with Sportube. The new design uses foam pads and individual pockets for parts. The new product is tube socks. Other features accommodate walkie-talkie and hardware. An official TSA lock on the Sportube has ended vandalism to the Sportube and Model. Plane Pack is ~$150On Page 10 Jim (producer of Plane Pack and Tube Socks describes his products and how he got into the business.
Judy Slates is remembered. She passed away March 10. Editor since 1990 through Aug 2004 she built and flew her own RC Sailplanes and enjoyed talking with anyone at the field. She leaves a big hole in our lives. Comments from other contributors such as Bruce Abell Ed Wilson Gordy Stahl John Durstine Tom Nagel and Greg Vasgerdsian.
Cover photo is of Richter R/c Alula being launched on a windless day in Switzerland.
Radio Controlled Soaring Digest April 2005 Issue
