RADIO CONTROL ELECTRICS - 2003/06
Bob Kopski 25 West End Dr., Lansdale PA 19446
Meet announcements
- 7th Eagles Electric Fly-In
- Date: Saturday, May 17, 2003 (rain date Sunday, May 18)
- Location: Hope, New Jersey
- Sponsor: Flying Models magazine; held in memory of Chuck Gill (The Aeroplane Works)
- Events: Electrics of all types invited, including Free Flight. One planned event: Elexaco (a timed event; rules allow any aircraft with aspect ratio ≤ 8, powered with a ferrite Speed 400 motor on a 7-cell 250–350 mAh pack).
- Contact: Joe Beshar, 198 Merritt Dr., Oradell NJ 07649; Tel: (201) 261-1281; Fax: (201) 261-0223. Request driving directions and printed info from Joe.
- Inaugural NIRAC Indoor RC Championship (National Indoor Remote-controlled Aircraft Council)
- Date: Saturday, May 31 and Sunday, June 1, 2003
- Location: Oakland Yard Dome, Waterford, Michigan (approx. 240 x 300 ft, ceiling ≈ 82 ft)
- Events: Six events planned; trophies to third place.
- Info & preregistration: www.nirac.org
- Contacts: John Worth ([email protected]) for local lodging and Saturday-night banquet; NIRAC President Bob Wilder ([email protected]) and Vice President Bob Aberle ([email protected]) for general info. Preregistration recommended.
- Loudoun County Aeromodelers Association 4th Annual Electric Fly-In
- Date: July 26, 2003
- Location: LCAA flying field at Banshee Reeks Park, Leesburg, Virginia
- Info: www.lcaa.org
- Contacts: Brian Allen, 47036 Berwick Ct., Sterling VA 20165; Tel: (703) 430-5849; E-mail: [email protected]. Alternate contact: Ron Anderson, 115 Sue Ann Ct., Sterling VA 20164; Tel: (703) 444-3215; E-mail: [email protected]. A detailed mailer is available.
- 2003 Northeast Electric Aircraft Technology (NEAT) Fair
- Dates: September 12–14, 2003
- Manager: Silent Electric Flyers of Long Island (SEFLI)
- Notes: Expected to be the largest E-meet in the country; last year more than 290 pilots attended. The meet site is Peaceful Valley Campsite in Shinhopple, New York (campground setting with the flying field in the middle). If you can make only one meet this year, this is the one.
- Info & preregistration: www.neatfair.org
- Campsite info: www.peaceful-valley.com
Nuts & Volts airborne video (park flyer)
Nuts & Volts (a monthly electronics hobbyist magazine) ran an article in its February 2003 issue by Phil Blake describing an airborne live video system installed in a park flyer (Great Planes Escapade ARF). The onboard camera and transmitter operate on 900 MHz and reportedly require an amateur radio license. If you don’t get the magazine, see www.nutsvolts.com or check your local library—the article is worth a look.
Chokes — reader feedback
I’ve written about chokes in recent issues and reader reaction continues to arrive. Reports have been uniformly positive. One letter came from Bob Pearsall (Radio Control Boat Modeler), who fixed glitch problems on an Astro 25-powered, 45-pound RC electric tug and on a friend’s Douglas 4 seaplane, both of which had previously been considered unsafe to fly. He also reported a similar improvement on one of his own airplanes—“radio glitches are a thing of the past.” If you haven’t tried chokes yet, see the September 2002 and February 2003 columns for details. Cost is low, time investment is small, and results can be decisive.
Pack dischargers — DUMP'R
Discharging packs can be a nuisance when you have charged packs but no flying time. A reader sent information about the DUMP'R pack discharger by Power Research Products (PRP). Key points:
- Discharges nearly all 4- to 18-cell NiCd/NiMH packs.
- Discharge current: ~0.5 A (constant).
- Built-in cutoff: ~0.9 V per cell equivalent (e.g., a 12-cell pack stops at ~10.8 V).
- Self-contained; powered by the pack being discharged (no external power needed).
- Rotary-switch selects cell count (4–18). Push-button start; unit discharges until cutoff then shuts off to prevent overdischarge.
- Small enough for a flight box; costs about $35.
- I’ve used a DUMP'R trouble-free for a full season and plan to make more.
In the March 2003 column I noted some chargers (for example, the Astro 110 Deluxe) can both charge and discharge. My Deluxe is installed in the minivan and I don’t like removing it, so I needed a more portable solution for multiple park-flyer packs—hence the DUMP'R.
I know many readers enjoy electronics projects related to E-aeromodelling. I’m testing interest in publishing the DUMP'R design and construction info. If there’s enough interest, I’ll see about sharing the design; for now I have no drawings or detailed text to distribute.
Multimotor installations
Last month I began discussing multimotor installations, especially twins. Beyond twins, trimotors, quads, and more are feasible and relatively easy with electric power. You don’t have to worry about losing one side and synchronization as much as with glow engines, and the combined sound can be very pleasant.
The four-motor (quad) installation is probably the next most popular after twins. The familiar wiring choices apply: series, parallel, or combinations. Pure series: all four motors in series requires roughly four times the cell count of a single motor. Pure parallel: all four in parallel implies roughly four times the current draw. Both extremes can be impractical. Consider a compromise: series/parallel combinations.
A common approach is to make two series pairs and wire those pairs in parallel (effectively twice the cell count with cells of twice the capacity compared to a single motor setup). Example: a single Speed 400 might use seven cells of 1.0 Ah. A series twin would use 14 cells of 1.0 Ah. A quad using two series pairs (paralleled) would use 14 cells of 2.0 or 2.4 Ah—comfortable and workable while keeping wiring and power demands reasonable, and still using a single ESC, arming switch, etc.
Wiring detail to consider: avoid pairing the two left motors as one series pair and the two right motors as the other pair if you can. Instead, wire the two inboard motors as one series pair and the two outboard motors as the other series pair. This may add some connector complexity but provides redundancy: if one motor/propeller fails on one pair, you’ll still have one motor operating on each wing, retaining lateral balance and easier control.
Closing
This column marks the halfway point of 2003 columnwise and the start of the summer flying season—my favorite time of year.
Please include an SASE with any correspondence for which you'd like a reply; everyone who does so will get one. I do not use e-mail for this purpose.
Many safe summertime E-landings, everyone! MA
Transcribed from original scans by AI. Minor OCR errors may remain.
