Wiltshire Flyer Posted October 24, 2014 Share Posted October 24, 2014 The other day I decided to pop just a little but of fuel into engine on my spitfire as it's new and I wanted to let it soak it in. so I went to the shed and got my fuel, I then took it into the lounge and poured a little into the cap and drizzled a little into the piston head and spilled some, I called my wife to pass some kitchen roll whilst I tried to stop more falling on the carpet with my hand that obviously didn't work lol. it got me thinking, if that had been normal petrol, I would not have done it, I would have waited till the next day and done it outside. So why did I do it with the model fuel? Which let's face it is just as dangerous as petrol! i came to the conclusion that it's because it lacks that pungent smell of petrol. silly it may sound but I think that's what it is, growing up whenever I was near petrol that smell reminded me of the danger of the stuff, but with model fuel although to some extent it does have an odour I have not treated it with the same caution. Don't get me wrong, I have never been completely lax with safety when using it, but I didn't regard it as being as dangerous as I now realise it is. its made me a little more aware if anything I am doing regarding modelling and I'm sure you'll agree it's not a bad thing! Anybody else have a tale of complacency that led them to be a little more careful? Quote Link to comment Share on other sites More sharing options...
Pete B Posted October 24, 2014 Share Posted October 24, 2014 Great idea for a thread, WF.... The first indication I had that I had soldered an XT60 connector with reverse polarity to a new 60A ESC was when I plugged it in and the ESC emitted the magic smoke and let me know in no uncertain terms that it wasn't going to work any more.... You only do it once.... Pete ps I'll move this over to 'Incident Reports' as it could become a useful reference work on what not to do... Quote Link to comment Share on other sites More sharing options...
cymaz Posted October 24, 2014 Share Posted October 24, 2014 One golden rule I forgot " always cut away from yourself". I was paring some balsa wood and I thought," I will just clean out this corner of a fuel bay". Then oops Stanley blade between thumb and finger Narrowly missed the joint socket but the blade nearly came out the other side....10 stitches later. I'm sure everyone has a finger in prop story! Quote Link to comment Share on other sites More sharing options...
IanN Posted October 24, 2014 Share Posted October 24, 2014 I think everyone will have some examples of this. Two of mine (related) that spring to mind I'd taken my Tx when we went to my parents last xmas to check that I could set the buddy function up with my Dad's gear on his electric foamy Wot4. We started in the garage but it was cold so we moved indoors. I said "best be safe and take the prop off" so we did. During the messing round and setting up process the motor suddenly burst into life - the spare channel I'd selected to use on my Futaba Tx didn't have the throttle reversed. A bit embarrassed at that but secretly smug we'd removed the prop So what did I do? A couple of months later, I was making some Tx changes at home in the shed with the model in my hand but I hadn't removed the prop. Same result. Motor burst into life but this time the 11x7 at max rpm instantly sucked everything lightweight and within reach into the prop. Result? An absolute whiteout blizzard of shredded balsa shavings, pieces of paper, etc etc. That only lasted a couple of seconds before I cut the throttle but I was lucky. It would have been incredibly easy under the sudden unexpected thrust to lose grip of the model and get a severe mangling A seriously scary moment and I hope I'll never do that again Quote Link to comment Share on other sites More sharing options...
Jon H Posted October 25, 2014 Share Posted October 25, 2014 I can think of a number of situations when testing engines that caused me some shock. The first came when I was bench testing a saito 450 3 cyl radial. I made the mistake of over priming it and flooded the cylinders, so I took the plugs out as normal flipped it about and put it back together. I noted that it was still a little hard to turn over signifying slightly over primed but I knew it would clear after some vigorous flicking....well, I few flicks later and with a loud bang one pot fired (without glow attached) and the 22 inch prop cracked me across the back of my hand. 'oh darn that hurts' said I. After this I removed the plugs again and spun it with a starter before trying again to start it...imagine my dismay when upon attempting to start it the no2 cylinder blew out the puddle of fuel that had accumulated in the exhaust bend and promptly ignited it. With the entire test bench ablaze I did not have long to rip the tank off it and cover it with a towel before the whole thing went up! It should also be noted that I have had about 5 fires when hand starting large 4 strokes, so be aware. The other test bench drama involved a laser 300v when it pulled the mounting screws out of the test stand. needless to say, it was rather intimidating seeing an engine with that amount of power rearing up towards me. Edited By Jon Harper on 25/10/2014 09:59:28 Quote Link to comment Share on other sites More sharing options...
cymaz Posted October 25, 2014 Share Posted October 25, 2014 I have had a TT130 fs back fire. It shattered the aluminium spinner...never did find the lock nut! As it happens the plane was pointing into an open field and I was behind it, as I always am, when it was running. Quote Link to comment Share on other sites More sharing options...
Levanter Posted October 25, 2014 Share Posted October 25, 2014 Only last weekend I was testing the controls of Jemima using a transmitter. This was very exciting as it is my first electric and plan build. I used a very small electric motor which I already had but the model is light so I am hopeful for when the maiden comes. I wanted to see how much thrust was being generated with the motor installed. I was very, very careful and pleased to see that there was plenty of oomph, the throttle control worked perfectly, no vibration but surprising quite a loud whine from the motor and prop. This was indoors mind, as I don't have an outdoors. Then noticed that the rudder control was reversed. No problem, I have servo reversing switches (Dx4E) and in the slightly dim light of the entrance hall I read the switch labels not bothering to go and get my glasses (there's the complacency bit). Here is the stupid bit that shocked the living daylights out of me. You've got it, I reversed the throttle instead and like a arrow she hit the front door with the most appalling racket no doubt confirming to my neighbours that a complete lunatic lives in flat 4a! Fortunately I realised my error quite quickly but not before the tips of the three bladed propeller started melt with the heat friction and a very distinct part of a circle had been carved into the front door. In that I was very lucky, no injuries to person, a very slightly bent prop shaft but not sure how I am going to explain this to my long suffering landlady. I am going to keep the scar on the door as a reminder of what NOT to do. This was a brutal but invaluable lesson on the differences electric and i.c. because generally speaking i.c. engines don't spontaneously burst into life. Another lesson for me though was that I should test flight controls with the motor disconnected and / or the propeller removed. Motor testing should be in a class off its own. In my work, which often deals with the after effects, the biggest precursor to complacency is success. We call it the Big C and it can be a killer in many senses of the word. Quote Link to comment Share on other sites More sharing options...
Dave Hopkin Posted October 25, 2014 Share Posted October 25, 2014 Testing the channel set up in the shed, elevator yep fine, Rudder, yep thats fine, ailerons yes they are fine, throttle... the world vanished into a total whiteout of balsa dust as the 500 Watt swung the prop.... off cuts of solartex sucked in and shredded, small tools vanishing in the propwash..... thankfully I had a firm grip on the model and nothing serious happened but it was close.......... Using a needle file to open up a hole in a small part, part firmly gripped in left hand, file being worked in the right, happy days.... Oh wait.... why is there a really bad stabbing pain in my left palm? what is all the red stuff coming from? Yep you guessed, stabbed the base of my thumb with the point of the needle file - man that hurt! Quote Link to comment Share on other sites More sharing options...
Malcolm Blake 1 Posted October 25, 2014 Share Posted October 25, 2014 I remember 60 years ago I was building my first model, a Piper Cub. I had covered the wings with nylon and was doping them on the living room table. As I worked along the wings I was moving them across the table and the already doped end was getting nearer and nearer to the open fire. Suddenly that end ignited and I had no option but to continue feeding the wing fully into the fire. There ended the building !! Quote Link to comment Share on other sites More sharing options...
Terry Walters Posted October 25, 2014 Share Posted October 25, 2014 Complacency? No that'll never creep up on me. Terry Quote Link to comment Share on other sites More sharing options...
Stevo Posted October 25, 2014 Share Posted October 25, 2014 trying to tune a Saito 50, inverted. The engine was off and on several times... An I lost on of the two spinner screws. (Plastic stock spinner). So - assembled it with just one. Started her up, and, on 1/2 throttle, the poorly fastened spinner decided to go solo, and as I was kneeling down, hit me in the right thigh, around 2" from the Crown Jewels. It stung but over the next day of so, the bruise was well over 6" across, and I don't bruise easily! Quote Link to comment Share on other sites More sharing options...
John Privett Posted October 25, 2014 Share Posted October 25, 2014 My worst "complacent" accident was about 20 years ago. Having got back into the hobby after a few years out I was back to a reasonable standard with a .40 powered trainer, but got a bit complacent about restraining the model in the pits whilst starting the engine. So on the fateful day, I started the engine and left it gently ticking over while I reached round to pick up the transmitter. At this point the neckstrap slipped against the throttle stick and nudged it open. The ticking-over engine responded instantly and the model accellerated towards me. (That was another bit of complacency - still being in front of the mode!) Instinctively I held out my left-hand to stop the plane hitting me. CRUNCH... And OUCH. The prop hit three fingers, one of them twice. It could have been a lot worse I guess, but it was bad enough. Somebody supplied a cloth to wrap around my hand, and we quickly packed away my gear and I drove home to inspect the damage. On arriving home my wife took one look at the blood-soaked rag around my hand and drove me straight to Epsom A&E where I spent hours waiting to be patched-up. "Superficial cuts" is what they wrote on the form. Well I suppose compared to some of the things they deal with there they probably were "superficial", but it's not the way I'd have described them! I turned up at work the next day with - much to the amusement of my colleagues - three enormous bandages on the fingers of my left hand. Though they're faded somewhat now, I can still see the scars on the fingers. And since then I always restrain my models! Quote Link to comment Share on other sites More sharing options...
Willyuk Posted October 25, 2014 Share Posted October 25, 2014 What I have learned is that if I follow the guidelines in the BMFA handbook, then these sorts of problems rarely occur. I learned this by poo pooing the Handbook and making lots of mistakes, then I studied what it said and bingo I feel much better equipped now. I will probably still get complacent but at least I can't say I wasn't warned! Toddle pip Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted October 25, 2014 Share Posted October 25, 2014 yes-I have to admit throwing my zagi off the cliff face without switching on......or as mentioned elsewhere on the forum--- going home leaving all my gear at our field...yee- gazooks ....I hear you say ... ken Anderson....ne...1 complacent dept Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted October 25, 2014 Share Posted October 25, 2014 don't use a bungee strap as a model restraint. Just don't. Quote Link to comment Share on other sites More sharing options...
flyeruk Posted October 25, 2014 Share Posted October 25, 2014 Just today,started myWot 4, hand round, from the front,to take off the glow starter,just caught my hand on prop.Lucky that i had some gloves on,but it gave me a shock. So easy to become complacent, Quote Link to comment Share on other sites More sharing options...
Peter Jenkins Posted October 26, 2014 Share Posted October 26, 2014 I changed servos from Hitec to Futaba on an F3A model as the Hitec centreing was not up to the job. I set the whole thing up in my shed where I had to have the wings off. All the throws were set up to be identical to the original setup. I did my control checks as usual - well I've flown this aircraft umpteen times - and took off. Immediately I was airborne I realised the ailerons were reversed! I managed to fly around for 6 minutes trying to work out if I could train myself to fly with reversed ailerons. Then tried to reverse the servos (got one done and then the sub trim setting meant that the aircraft started to roll so lost my nerve to move to the second servo and reverse that and just set the original servo back to where it had been. None of my buddies flew JR so they were unable to help with the unfamiliar menu. As I only had enough battery power for a further 2 mins I tried a highish landing approach, which went OK and overshot from that. The next time round was for real. All went well till around 10 ft from the ground when a gust tipped one wing up and training took over - yep rolled her to wings vertical just in time to hit the ground with the wing tip! Moral - when you do your control checks even if you have changed nothing on the aircraft always consciously check the sense is correct. It's ever so easy to end up seeing what you want to see. The other thing to watch out for is having a chat with your mates as you assemble your aircraft - another opportunity to think you've done everything right when you have been distracted. I now make sure I don't talk to anyone when I'm assembling an aircraft and doing control checks even to the extent of saying "sorry, can't talk at the moment" to anyone who approaches me while I'm so engaged. Quote Link to comment Share on other sites More sharing options...
Wiltshire Flyer Posted October 26, 2014 Author Share Posted October 26, 2014 So glad to hear I am not the only one to not notice the ailerons were reversed! on the maiden of my FMS LET13 I had them reversed! Luckily I was in a soft cornfield otherwise it could have been a problem 😮 Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted October 26, 2014 Share Posted October 26, 2014 For me I think I would replace complacency with stupidity.....the end result is usually the same.... Quote Link to comment Share on other sites More sharing options...
Dave Hopkin Posted October 26, 2014 Share Posted October 26, 2014 Posted by Steve Hargreaves - Moderator on 26/10/2014 12:30:46: For me I think I would replace complacency with stupidity.....the end result is usually the same.... I place most of the blame on Shed Gremlins..... little blighters they are Quote Link to comment Share on other sites More sharing options...
Chuck Plains Posted October 26, 2014 Share Posted October 26, 2014 Posted by Dave Hopkin on 26/10/2014 13:25:40: Posted by Steve Hargreaves - Moderator on 26/10/2014 12:30:46: For me I think I would replace complacency with stupidity.....the end result is usually the same.... I place most of the blame on Shed Gremlins..... little blighters they are Stupid shed gremlins!! They sometimes accompany me to work! But I'm too new to RC flying and planes to be complacent yet. So apart from cutting myself with my hobby knife or grabbing toe wrong end of the soldering iron. The Injury Time thread was initiated by my lack of experience. I don't think I'll do that again. Quote Link to comment Share on other sites More sharing options...
Fylingdales Flyer Posted October 26, 2014 Share Posted October 26, 2014 Complacency crept up on me when I completed my first electric model after many years of I/C. I had finished my Junior 60 and decided to test the radio installation prior to going to the flying field for the maiden flight. The aeroplane, minus wings, was sat on the kitchen table. I switched on the transmitter, then the aircraft power system. As the receiver was powered from the BEC the motor electrics were live, and the propeller fitted. I waggled the rudder, checked the movement of the elevator and then, well I'm sure you know what comes next... Yes, with the transmitter in my left hand my brain reverted to I/C mode and shoved the throttle forward! All hell broke loose as the Axi 2820/10 went to full power and the fuselage leapt off the table. Luckily I was stood to one side but unfortunately my right hand shot out instinctivly to catch it. I caught the whirling propeller which chewed my hand and right arm. I was just able, through the shock and pain, to retrieve the Tx, which I had dropped, and shut it down. The injuries, though severe enough, were not as bad as they could have been, no permanent damage, apart from scarring. The blood spatter though was spectacular, even reaching the tailplane. The incident didn't put me off electrics, in fact I have now almost completely moved over to electric flight. I am, though, very wary of 'live' electric models. I fit an arming plug in the battery leads and only use Jeti ESC's with a switch fitted. As an aside, after a Lipo accident burned down our local model shop in Whitby, I decided to use only LiFe batteries, as I do not trust myself not to become complacent with Lipos. Graham Edited By BayNavigator on 26/10/2014 16:24:53 Edited By BayNavigator on 26/10/2014 16:25:17 Edited By BayNavigator on 26/10/2014 16:27:00 Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted October 26, 2014 Share Posted October 26, 2014 Very interesting and valuable thread this. What I find amazing is how many folks have recounted what is basically a very similar tale of an electric model "firing up" on them in the workshop. My own "stupidity moment" was very similar. I was putting together a Tiger Moth - it was my first electric model. Initially I set it up as "one servo wing" with the two aileron servos connected via a Y-lead. I'd done all this very carefully - prop off etc. and all was OK. Then I decided - hell no I'd rather have it as a two servo wing with the servos on separate channels. So I rewired the wing and turned on. Only one aileron worked. Well of course, dummy, I'd not actually changed the Tx over had I? So I go into the configuration screen, click "Two servo wing" - and life suddenly became very very exciting.... I was stuck in a small room with an unfettered chain saw! Paper, bits of wood, small tools etc were flying everywhere, the model was doing an impersonation of a demented Tasmanian Devil! Lucky I not not injured at all - but I was certainly shocked and had to sit quietly to calm down. What had happened? Why had it suddenly erupted into life? I hadn't touched the throttle! Well it was a Futaba system and, as anyone who has used Futaba with electric power will know, you pretty well always have to reverse the throttle on the Tx. And I had done that. But when I reset to a two servo wing - everything else gets reset to its default value automatically! So my "reversed" throttle was promptly "un-reversed". Moral of the story? Never, ever, work on an electric model in the workshop with the prop on. That's why we always preach this. A moment's lack of thought - a secondary effect you haven't thought of - and wham, you suddenly have a big, potentially very serious, problem on your hands. These days I'd go even further. I won't work on an electric model even at the field if it has a prop fitted unless it is properly and securely restrained - no matter how minor the adjustment I am about to make, even just altering the throws. Once bitten,...etc. BEB Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted October 26, 2014 Share Posted October 26, 2014 Almost a carbon copy of BEBs experience for me.... Also on Futaba...I went to reverse the rudder on a "live" model (Ch4) but hit Ch3 instead (throttle) so the model went from zero to 100% power in the blink of an eye....shot across the workbench chewing up paper & balsa bits as it went, flew across the workshop & smashed into the shed wall where upon it fell to the floor & thrashed itself to death. Again like BEB I was not injured & count myself very lucky... This was a small model with maybe 150watts.....it leaves me cold to think what a 1kw plus model with a 15 or 16" prop might do in a similar situation.....hands...fingers....face..... So if you only take ONE thing away from this thread let it be that you MUST remove the prop from an electric model before doing ANYTHING to it whilst it's "live"....... here endeth the lesson... Quote Link to comment Share on other sites More sharing options...
Levanter Posted October 26, 2014 Share Posted October 26, 2014 It is some consolation to see that I am in some esteemed company. My carelessness is equal to the very best. Quote Link to comment Share on other sites More sharing options...
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