Cliff Bastow Posted May 24 Share Posted May 24 Just a reminder that electric models can bite , this was my little comet racer which slipped its restraints and bit me! 2 Quote Link to comment Share on other sites More sharing options...
john davidson 1 Posted May 24 Share Posted May 24 is the comet all right? Quote Link to comment Share on other sites More sharing options...
Cliff Bastow Posted May 24 Author Share Posted May 24 Broke the prop that’s all thank goodness! Quote Link to comment Share on other sites More sharing options...
Don Fry Posted May 24 Share Posted May 24 Love bite. Think of a big one. I fear big ones, especially big electric one ones. They chew until the gristle or bone, burns it out. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted May 24 Share Posted May 24 I fight an almost hopeless battle against folk at my club - particularly when connecting batteries with their arms through the prop arc. Apparently they're quite safe because they have a throttle cut set. If you don't mind, I'll post your picture to our club group... 5 1 Quote Link to comment Share on other sites More sharing options...
Cliff Bastow Posted May 24 Author Share Posted May 24 Yes I don’t mind, many electrics nowadays won’t arm until the throttle is opened fully and then shut of again. My injury was my fault because I did not restrain it properly whilst running and the model slipped out of the restraint. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted May 24 Share Posted May 24 9 minutes ago, Martin Harris - Moderator said: I fight an almost hopeless battle against folk at my club - particularly when connecting batteries with their arms through the prop arc Same here, an endless battle,,, Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted May 25 Share Posted May 25 16 hours ago, Martin Harris - Moderator said: I fight an almost hopeless battle against folk at my club - particularly when connecting batteries with their arms through the prop arc. Apparently they're quite safe because they have a throttle cut set. If you don't mind, I'll post your picture to our club group... What amazes me is when people rest the model in their lap with the prop in their crutch area and plug in the battery! It's all very well saying I have the throttle cut switch ON but try telling the ESC when it has a glitch and sends power to the motor despite what the Tx says! 1 Quote Link to comment Share on other sites More sharing options...
Brian Cooper Posted May 26 Share Posted May 26 Electric power is the most dangerous of all the options for powering our aircraft. Sadly, many people seem to regard it as something clean, safe and friendly. . . It isn't. A different (higher) level of safety consciousness is required when handling every aspect of electric models. 4 Quote Link to comment Share on other sites More sharing options...
payneib Posted May 26 Share Posted May 26 Electric models are more likely to bite. I/C models have an audible alarm that tells you when they're dangerous. 4 Quote Link to comment Share on other sites More sharing options...
PatMc Posted May 26 Share Posted May 26 Electric power of models is no more or less hazardous than any other power source. The primary causes of most accidents are the same no matter what method of power is being employed & all in the brain of injured party. 4 Quote Link to comment Share on other sites More sharing options...
john davidson 1 Posted May 26 Share Posted May 26 Tuning needle valves is perhaps more dangerous, too near the spinning prop, that is why many engines began appearing with remote valves. Speaking from experience ---needed a hospital visit years ago after touching a prop when reaching for the needle . I fly solely electric now and I am very careful and try to follow a safe routine, 3 Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted May 26 Share Posted May 26 Agreed - the biggest difference is that there is absolutely no need whatsoever to get your hands anywhere near to an electric prop, but it's typically built into the operation of a propeller driven by an IC engine, whether it be adjusting the needle vale, flipping the prop to start or turning the prop to prime the engine all of those operations brings you hands into contact with or close proximity to the propeller. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted May 26 Share Posted May 26 All I can say is I have many times in the past hand started a Gipsy Major in a Tiger Moth. Stand in front of the prop. call "ignition off", rotate it to the start of compression, reach up with both hands to the prop blade, finger tips over its trailing edge, call "contact" and pull down smartly. Make sure both your arms swing down and away along with a side step back. A 6' 4" diameter wooden prop with a sheet copper leading edge and 130hp behind it teaches you great respect. If it starts it doesn't bite, it can kill! The confidence of youth and a lack of imagination certainly helps. 😉 I agree entirely about the dangers of an electric driven prop. I own 35 electric powered planes and none of them require the wings, or anything else, apart from a battery hatch to be added after the battery is connected. Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted May 26 Share Posted May 26 I have also, very relutantly, hand swung a Gypsy Major in a Tiger Moth into life. It frightened the life out of me! One thing.I was told not to do was to curl my fkngers over the props trailing edge! "Press on the blade" I was told as if the engine kicks your.finger tips will still be with you. I never volunteered to hsnd swing a Gypsy ever again! Quote Link to comment Share on other sites More sharing options...
J D 8 - Moderator Posted May 26 Share Posted May 26 The press on the blade method is how I start my Mills .75 and PAW 1.5, only one finger used though. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted May 27 Share Posted May 27 I was in Simon's camp - the confidence of youth coupled with careful study of an excellent article in Pilot Magazine by Brian Lecomber on the subject helped steady my nerves - although I was given to understand that using only one hand was best practice in order to use the other arm for counter-balance. By starting from a slightly stretched stance, you used your natural momentum to step away from the prop arc as you completed the swing. I've never forgotten the advice to "whip off the starboard beetle-crusher" to give a (frequently) stuck impulse magneto a sharp tap with - and the total avoidance of the word "on". Mag switches were either set at "off" or "contact" in order to avoid confusion on the all too common occasions when one of our gliding club's Chipmunk's batteries failed to crank its Gypsy Major. For some reason - probably due to being right handed - I never fancied doing the same to the more awkwardly lower set opposite rotating engines in the Super Cubs - fortunately I was never put in that position. 1 Quote Link to comment Share on other sites More sharing options...
John Lee Posted May 27 Share Posted May 27 Further thread drift of a happy memory. I used to be well practiced in hand swinging many full size aircraft engines so one day when I heard a shout of 'Anyone give me a swing' I was more than happy to wander over to give assistance. The crier turned out to be 'Ginger' Lacey, one of the top scoring pilots of WW2 in a little home built aircraft. It was a privilege to give service. Quote Link to comment Share on other sites More sharing options...
David P Williams Posted May 27 Share Posted May 27 Drifting further - like you John I was well practiced on Gypsies, Tigres, Lycomings (didn’t like them, they seemed more likely to bite and went the wrong way round as Martin said). I got a ‘Swing please’ call and it turned out to be a Stearman with a 9 cylinder 450hp Pratt & Whitney and an 8ft prop. Bit nervous, but it turned out to be straightforward. My only injury in 7 years of this was when compression testing a Lycoming. This involves holding the prop while compressed air is applied to each cylinder in turn. The prop slipped and whacked round into my leg. Very impressive bruise. Quote Link to comment Share on other sites More sharing options...
Keith Billinge Posted May 27 Share Posted May 27 The intersting thing about brushless electric motors is if you try and stall one by say...... feeding your fingers into the prop. As it slows, due to the resitance of said fingers, the electrical resistance of the motor goes up and the circuit (Via the ESC) compensates by instantly drawing more current and adding more force to the spinning propeller. This is due to Ohm's Law (V=I x R). Stalling an IC motor by feeding fingers in, is actually safer beacause onece you've stalled it; it generally stops. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted May 27 Share Posted May 27 6 minutes ago, Keith Billinge said: Stalling an IC motor by feeding fingers in, is actually safer beacause onece you've stalled it; it generally stops. So are you trying for the Darwin award ?. 1 Quote Link to comment Share on other sites More sharing options...
PatMc Posted May 27 Share Posted May 27 3 hours ago, Keith Billinge said: The intersting thing about brushless electric motors is if you try and stall one by say...... feeding your fingers into the prop. As it slows, due to the resitance of said fingers, the electrical resistance of the motor goes up and the circuit (Via the ESC) compensates by instantly drawing more current and adding more force to the spinning propeller. This is due to Ohm's Law (V=I x R). Stalling an IC motor by feeding fingers in, is actually safer beacause onece you've stalled it; it generally stops. That's a much repeated fallacy. The motor will stall at about the same point as an ic engine would & the ESC will detect no feedback telling it to send the next power pulse. 2 1 Quote Link to comment Share on other sites More sharing options...
Phil Green Posted May 27 Share Posted May 27 4 hours ago, Keith Billinge said: As it slows ... the electrical resistance of the motor goes up... Er... No 🙂 2 1 Quote Link to comment Share on other sites More sharing options...
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