Radio Control: SPORT/AEROBATICS
Ron Van Putte
Frosty
Those of you who read about the freezing temperatures here in the South around Christmas might not have been too sympathetic, because it was probably even colder where you were. However, the cold temperatures really hit us hard here, since we aren't used to it. It got down to 13°F where I live, and the little bayou in back of my house froze over. You should have seen the local seagulls and ducks trying to land on the ice!
A few hardy souls went flying, but they were mostly transplanted Northerners who knew cold-weather tricks: keeping their engines warm in their cars or in the car exhaust and squirting lighter fluid into the engines to start them. I don't think anyone went so far as to put hand warmers in with the receiver battery packs, but it really wasn't cold enough to warrant that. It makes us appreciate the warmer weather we have most of the year.
Hinge-slotting technique
Back in the December 1983 column I described several methods for installing hinges. Donald LeBoeuf (Belle Chasse, LA) wrote to acknowledge that article and noted he used to have problems cutting hinge slots all on the same line. He reported a method that assures all slots will be cut on exactly the same line. A Dremel drill press and a Dremel cutoff wheel (the wafer-thin cutter that breaks so easily) are required.
Procedure:
- Use a Du-Bro centerline marker to mark the centerline on a surface such as an aileron, then mark the hinge positions.
- Lower the drill press table to its lowest position and lock it tightly.
- Place the aileron on the drill press table so the centerline will strike the Dremel cutoff wheel.
- Adjust the height of the motor so the cutter will strike the centerline exactly.
- Turn the motor on and recheck the height adjustment — some motors have considerable end-play and the motor arbor moves when the motor is turned. Ensure the cutter strikes the centerline when the motor is running.
- With the alignment confirmed, cut the hinge slots quickly and accurately.
Finishing the slot:
- The slots may not be quite deep enough after cutting. Use an X-Acto No. 11 blade inserted in the slot to the proper depth, and a broken-off coping saw blade to remove balsa from the bottom of the slot to the required depth.
- Elevators, horizontal stabs, vertical fins, rudders, and trailing edges of built-up wings can be prepared this way prior to installation.
Safety and checks:
- Check the Dremel motor end-play before beginning. If it has a lot of end-play, it can be reduced by disassembling the motor and installing proper-thickness washers on the motor shaft.
- Wear safety glasses when cutting slots.
Additional tips:
- Thin cutoff wheels can be substantially strengthened by dropping one or two drops of Jet Zap, Hot Stuff, or a similar CyA (cyanoacrylate) adhesive on them and allowing it to soak in.
- I like to use an X-Acto No. 27 saw blade to open up hinge slots. The No. 27 fits the X-Acto medium-size handle (No. 3) and leaves a slot that’s a perfect fit for most hinges.
- I'd still like to see someone come out with plastic inserts (plasticserts) or blind nuts to help keep screws from vibrating loose in high-vibration environments. Such a product would rank up with innovations like the original steel clevis, the Ball Link line, and EZ connectors.
Fuel mix-ups at the field
I extracted a goodie from the Davison Aviator News (Davison, MI), edited by Don Parks. In the September 1983 issue a column on field activities reported the following about Bill Hill:
Bill came to the field with his model, radio, fuel, and flight box and was ready to fly. He filled the tank and tried to start, but the engine wouldn't run. He changed the glow plug and tried again, but it still wouldn't run. He did notice the fuel was sort of foamy, but since he had just filled up with fresh fuel he wasn't too concerned. When nothing worked, he yelled for help.
Inspection of everything looked OK except the fuel. It appeared to contain water — and possibly other chemicals. The fuel was the right color, but that was the only resemblance to glow fuel. After questioning where he stored his fuel, Bill realized he had also stored 10 gallons of a pink liquid (in a similar container to glow fuel) that is used for winterizing the plumbing of mobile homes and RVs. He had apparently mixed up the containers: he now had only nine gallons of winterizing fluid left, and he learned the hard way that glow engines will not run on antifreeze. The antifreeze also was not compatible with glow fuel pumps and totally ruined his new Du-Bro fuel pump.
A similar local story: our club fuel was based on Klotz KL-100 oil and was bright red, so we nicknamed it "strawberry soda pop." One day a member couldn't get his engine started; we discovered he was trying to run on strawberry Kool-Aid. His wife had mixed it in the same kind of container he kept fuel in (an old milk jug), and he took it to the field thinking it was fuel. He rushed home to make sure his wife hadn't fed any of his fuel to the kids. We all learned a valuable lesson.
Battery care reminder
If you own or have access to a battery cycler, be sure to cycle your dormant radio system several discharge/charge cycles this winter to prevent having weak batteries next spring. Several of us learned the hard way about peculiarities of nickel-cadmium cells when they first became available for R/C. Cells left unattended on the shelf over winter often went bad by spring, ruining winter-built airplanes. Do us a favor and don't let it happen to you.
Ron Van Putte 111 Sleepy Oaks Rd. Ft. Walton Beach, FL 32548
Transcribed from original scans by AI. Minor OCR errors may remain.
