This video was a nostalgia trigger for me — back in my youth, I built model airplanes, and of course they were driven by the ubiquitous Cox .049 engine.
The video makes them sound more reliable than they actually were. The coil was easily fouled, and trying to get the dang things started by repeatedly turning them over would make that worse. Yes, there was an art to tweaking that needle valve, but when you had a finicky engine optimizing the fuel mix was a process that could kill it, and then you’d spend ages trying to get that fouled up engine restarted. I envied those people who had the nifty motorized starters — I was just using the spring on the engine to get it going.
I still remember the “brap” noise when you tried to start them, and that rewarding but obnoxious mosquito-whine when it finally caught.
You can’t get them anymore. They’ve all been replaced by easy, quiet, smooth-running electric motors. Good.
Oops, apparently you can still buy them. But why would you?
My brother had a cheap control-line airplane that had one of those. I think he got it running twice, and then crashed the plane badly enough that we could never get it running again. It was frankly kind of surprising that something like that would run at all.
OMG yes. 1971, nine years old, I got one of these as a hand-me-down (literally, from the loft). I bought fuel and battery and spent hours trying to start it with the in-built spring, and then learnt that the glow-plug often burns out. I bought a new ‘plug, swapped it in, but my luck was out: I flicked it over and it fired first time, whipped round and near took my finger off. The joy, amazement and indescribable pain are etched vividly onto my memory. Now in retirement, I sometimes forget which day of the week it is, but recollecting my first engineering ‘mend’ brings tears still, though now of happiness and pride. Thanks for the reminder.
I fly R/C airplanes and my club has a number of members that also fly control line planes, including the plastic Cox models. Every year we have a vintage aviation day that gets a good showing of these models. I have a picture from a couple years ago of something like six or so 60-80-year-olds huddled on the runway around one of these trying to get it running long enough to fly it. It was quite amusing.
The Cox plastics still have a pretty good following and models can go for premium dollars on eBay depending on the condition.
I had one of those around 1962; P-51 Flying Tiger
Cracked it up the first time I “flew” it by crossing the control lines. “Flying” it on the school basketball court didn’t help the landing.
If you want to fly a drone further than batteries last (like, blowing up a munitions dump deep inside Russia) I suppose you could rig a small, reliable engine to continuously charge the battery while an electric engine handles propulsion, including temporary energy spurts to counter headwind. Combustion engines are most efficient at a specific rpm.
Wow, PZ, great article and great perspective. Brings back memories. They used to call them the ‘baby bee’. They screamed when running. You had to be careful to not cut your finger off with the prop when it started. And YES, electric motors.
@5 birgerjohansson wrote ‘Combustion engines are most efficient at a specific rpm.’
I reply: yes, the torque curve and power curve of infernal combustion engines coincides at maximum at only one point in engine rpm. However, most electric motors have full torque at stall.
For some inexplicable reason, I use to collect these little gas engines. I have a couple Cox 049s NIB along with a book shelf filled with an assortment of brand-new O.S. engines (for larger scale RC airplanes). There’s even a spit-shined, “vintage” weed-whacker engine from the early 70s!
For the love of god, dennyk, why?!
Anywhere in America between ’55 and ’85?
I call bullshit. I know plenty of people who grew up in America between those years and no one ever mentioned these toy planes.
I had a control line plane with one of those engines. I later built a control line plane (with rather longer lines) that used a Fox 15X. Got it tuned perfectly on one memorable flight. Calculated that it was doing 90 mph on 52′ lines.
For the dyslexic nostalgic, here are the Beach Boys performing 409