File: 02cronenwett.lt1.doc
[Headline: Tim Wescott’s TUT timer]
If you fly with electric power, the motor will start when you move the throttle stick with “down the line” electronic controls or 2.4 GHz controls. If you have two or more motors, they will start simultaneously because the speed controls receive the same signal from the receiver.
When I fly my electric-powered B-29, all of the motors start at the same time, which is not realistic. I wanted the four motors to start in sequence and then shut down in sequence, but still be controlled by the same throttle stick.
I read about an electronic timer that Tim Wescott designed for Howard Rush, who flies Control Line (CL) Aerobatics. Tim’s Universal Timer, or the TUT timer, that Howard uses, starts the electric motor, slowly ramps up the rpm to get a smoother takeoff run, and then lets the 8-minute timer control the rpm during the flight. At the end of the flight, the TUT timer puts the motor to full power and shuts it down for landing.
Although I was not interested in Howard’s TUT timer, this information prompted me to call Tim to ask if he could design a TUT timer that would start and shut down the four electric motors on the B-29 in sequence.
Using the same board, Tim wrote a program for what I wanted. Now when I start the motors, they start sequentially, which is more realistic. The timer controls the motors’ startup and shutdown. During flight, the throttle stick controls the motors’ rpm.
I don’t know if the judges will give me more realism points for this, but it is cool to watch the motors start and shut down sequentially. On YouTube, there is a video on my channel titled “B-29 start sequence for electric power” that shows what this looks like when I start and shut down the motors.
If you fly a twin, trimotor, or quad electric-powered CL model, the TUT timer can be used to start and shut down the motors. It was designed and tested on my Tactic 2.4 GHz transmitter and receiver.
The TUT timer has several modes: motor start, flying, and motor shutdown. The pilot has full control of the motors during the flying portion. The TUT timer controls the startup and shutdown of the motors at the start and end of the flight. The TUT timer plugs into the receiver and then all of the speed controls plug into the timer.
Using the same 2.4 GHz receiver, transmitter, speed controls, and motors that I have been flying with during the last year, I was able to install the timer. Now when I start the motors, the TUT timer takes over and starts the motors in sequence with a 5-second delay between each during start and shutdown.
If you are interested in a TUT timer, contact Tim.
Broken Arrow Contest
The Lafayette Esquadrille CL Club in St. Louis has hosted the Broken Arrow Control Line Scale and Stunt Contest for 27 years. Buder Park has been a CL flying site since the 1960s and has two paved circles and a speed cage. This is one of the premier flying sites in the Midwest and worth visiting. Details about it are on the club’s website.
Sport and Profile Scale are split into two categories, allowing pilots to bring two Sport Scale models. The Military and Non-Military categories receive separate awards based upon finish. A P-51 Mustang in civilian paint would be entered in the Non-Military category.
There were four entries in Non-Military Sport Scale. Grant Hiestand flew his 1/3-scale Spacewalker with a sound system from Model Sounds Inc., based in Canada. The electric-powered model has a speaker that duplicates the sound of a Continental engine as in the full-scale aircraft. These sound systems are linked to the throttle channel, so the sound matches the power setting at startup, in idle, and at full power.
John Rist from Harvest, Alabama, flew his Extra 300 with a 1.20 four-stroke engine and a smoke system to a third-place finish. I flew my RV-4 to a second-place finish with electric power and flaps. Frank Beatty placed fourth with his Arrow Active. Controls used with the Spacewalker, RV-4, and the Extra 300 were 2.4 GHz, while Frank used three-line controls for throttle.
The Military Sport Scale category had two entries. Frank Beatty flew his Hawker Fury to a first-place finish. His well-trimmed model is flown with three-line controls for throttle. Lou Matustik placed second with his Messerschmitt Bf 109 with electric power and 2.4 GHz controls.
All three entries in Profile Scale were in the Military category. I flew my B-29 to first place. The electric-powered model spans 96 inches and uses 2.4 GHz controls. John Rist flew his electric-powered Lavochkin La-5 with 2.4 GHz controls. Mike Schmitt flew a P-38 with three-line control to third place.
Check out my YouTube channel for a flight video of Grant’s Spacewalker, John’s Dornier Do 335, and my B-29. There are also videos that show how to hook up and use 2.4 GHz controls for CL Scale.
With four entries this year, 1/2A Scale continues to be a popular event. Frank Beatty placed first with a beautiful D.H.89 Rapide with Brodak engines. John Rist flew a successful flight with his third-generation Do 335 (see the April 2014 “CL Scale” column) and earned second place.
Sometimes the first model built has technical problems that need to be worked out. John resized the model and discovered the best fuel tank and engine configuration to make the model work.
Tim Pansic placed third flying a Focke-Wulf Fw 189. Ed Palacios was fourth.
The 1/2A Scale category seems simple, but getting these small motors to cooperate for 10 laps and fly level is harder than it looks. The 1/2A event seems to encourage people to build models that you don’t normally see in Sport and Profile Scale.
The Rules Have Changed
If you plan to attend or host a CL Scale contest this year, read the revised rules for the 2015-2016 rule book. Revisions include Sport, Profile, and Team Scale.
Consider joining a friend and entering Team Scale at the 2015 Nats. Both the pilot and the builder of the model have to be present to enter Team Scale. You can take an existing Sport Scale model and have a friend fly it.
Designer Scale has been eliminated, and Authentic Scale and 1/2A Scale have been added as official events. Line diameters have changed, so look at the updated table to see if your lines meet the updated diameters. Contact MBS Model Supply for bulk line if you need to roll some new ones.
I welcome contest reports, contest flyers, pictures, and any projects you are building and flying. Now that we are into the colder months, have fun building that new Scale model and getting ready for the next flying season. The Nats will take place in less than six months!
Land softly![dingbat]
SOURCES:
Tim Wescott
(503) 631-7815
www.wescottdesign.com
MBS Model Supply
(785) 256-2583
www.mbsmodelsupply.com
Lafayette Esquadrille CL Club
www.lafayetteesquadrillecl.wordpress.com
Model Sounds Inc.
[email protected]
www.modelsoundsinc.com
National Association of Scale Aeromodelers (NASA)
www.nasascale.org
