Mark a Posted April 24, 2014 Share Posted April 24, 2014 Out flying my Seagull PC9 today third flight in about a minute after take off the model became very twitchy so straight away landed and as I was taxying back to the pits I lost all control and the aircraft ended up in the long grass at the edge of the strip. With the model back in the pits checked everything but couldn't find any fault so I decided to change the flight battery and turned the model back on and the power went off even with the main switch in the on position and then it came on again. Turned out to be a dodgy switch which when wiggled only slightly would interrupt the power to the receiver. I feel lucky I got the model back in one piece all for the sake of a switch worth a few pounds so check your switches folks. Quote Link to comment Share on other sites More sharing options...
Ultymate Posted April 24, 2014 Share Posted April 24, 2014 If you check around you'll find there are regulators / switch combinations that will fail "safe" ie should they fail your radio will stay live till you disconnect from your power source Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted April 24, 2014 Share Posted April 24, 2014 Switches are very much the weak link in our systems now. I don't know why the suppliers continue to sell these really cheap flaky switches - well I do, its because we keep on buying them! As well as the "fail safe" type that Ulty refers to you can simply buy a better quality switch - which I do now having had similar experiences with the standard cheap wafer type. BEB Quote Link to comment Share on other sites More sharing options...
Shaunie Posted April 24, 2014 Share Posted April 24, 2014 As you say BEB, we keep buying them! The problem lies in the fact that we buy them in good faith expecting them to be reliable! You can buy "heavy duty" of course but that usually means a slightly bigger but still rubbish switch. I don't know what the answer is apart from only buying switches from major brand names. So saying I may be tempting fate but I've never had trouble with a receiver switch so far. Some hints for others:- It is worth a look inside the switch to see if both poles are wired in parallel. Personally with my I/C models I always fit the switch inside the fus and operate it with a control rod as a switch full of used oil is never a good idea. I have had good results using miniature toggle switches from RS Components, they have one with a security toggle that you have to pull up before you can operate it which helps prevent inadvertent operation. Shaunie. Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted April 24, 2014 Share Posted April 24, 2014 One switch that I use has a light come on when switched on- should the switch fail, I assume this will not come on? CS Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted April 24, 2014 Share Posted April 24, 2014 Mark, I'm guessing that you're flying the electric PC9, and your ESC has the switch on a fly lead. My routine is to cut the switch off and throw it away, and then connect the flight pack just prior to flight. Depending on your individual ESC, you may need to solder the resulting bare wires together. FWIW None of my models have any switches at all. tim Quote Link to comment Share on other sites More sharing options...
Glenn Stratton Posted April 24, 2014 Share Posted April 24, 2014 Mark a, was the switch from a major brand or a ebay special! Like the sound of your switch, you have a part number for it Shaunie? Quote Link to comment Share on other sites More sharing options...
Plummet Posted April 24, 2014 Share Posted April 24, 2014 Something to beware of... Heavy duty switches are designed to carry heavy currents. Some of our applications use tiny currents. Some heavy duty switches will have contacts that are somewhat liable to corrosion, or greased, but friction and the arcing on switching clean them. Light currents do not cause arcs, and the contacts foul up and become intermittent. This is why many small switches have precious metal contacts. On another tack... The NiCad battery is gone. Now we have NiMH in its place. With NiCads we had to beware of the dreaded Black Wire Disease*. I had a case when the disease had spread from a NiCad, along the -ve wire, through the connector and on to the switch, which stopped working and fell apart. Are NiMH cells subject to Black Wire Disease, or is their electrolyte different. Plummet * Black Wire Disease - slight electrolyte leak from a cell wouls cause electrolytic corrosion on the -ve wire. This would cause crystals to form around the wire, along which the electrolyte would wick. Thus the corrosion would spread along the -ve wire. The corrosion would cause the wire to become brittle. It's not friendly! Quote Link to comment Share on other sites More sharing options...
Shaunie Posted April 24, 2014 Share Posted April 24, 2014 I think this is the one:- **LINK** Bit more than I remember them to be. I'll try and have another look tomorrow. Shaunie. Quote Link to comment Share on other sites More sharing options...
reg shaw Posted April 24, 2014 Share Posted April 24, 2014 I always fit two switches to my outsidey models. Like someone mentioned previously, the switch is the weakest link in the system. Have them switched separately too, ie. not on the same 't' shape wire through the fuselage since you'll never know if one has failed 'til the other one does! Ian. Quote Link to comment Share on other sites More sharing options...
GrahamC Posted April 24, 2014 Share Posted April 24, 2014 I've also seen what look to be quite good switches with an LED in a nice chunky case which on closer inspection turn out to be very small poor quality switches buried inside a flash case. I have wondered about wiring two switches in parallel for a degree of protection from failure. Quote Link to comment Share on other sites More sharing options...
Glenn Stratton Posted April 25, 2014 Share Posted April 25, 2014 Thanks Shaunie, like RS but found their website daunting! Looks like they've got a bit more user friendly since I last looked. Personally I prefer to have peace of mind having spent time and money on my model, and if the quality of the part is good then happy to pay, to a point! Ian, can you expand on your method of switch wiring for me please, not sure about *on the same 't' shape wire* bit! Quote Link to comment Share on other sites More sharing options...
Mark a Posted April 25, 2014 Author Share Posted April 25, 2014 Hi Guys The model is IC and the switch has been in the model about a year and yes it was an e-bay special. Just ordered a few new ones better quality and plan to change the cheap ones as and when I come to fly each model in my fleet. All my fail safes are set and tested but of course if the receiver has no power the fail safe won't kick in. Mark. Quote Link to comment Share on other sites More sharing options...
Ultymate Posted April 25, 2014 Share Posted April 25, 2014 I don't know whether you're confused here, the "failsafe switches" I mentioned have nothing to do with your radio failsafe Quote Link to comment Share on other sites More sharing options...
Mark a Posted April 25, 2014 Author Share Posted April 25, 2014 Posted by Ultymate on 25/04/2014 10:05:03: I don't know whether you're confused here, the "failsafe switches" I mentioned have nothing to do with your radio failsafe Not confused will look into a switch that fails safe, who am I again. Quote Link to comment Share on other sites More sharing options...
The Wright Stuff Posted April 25, 2014 Share Posted April 25, 2014 Can I ask the obvious silly question? Why is a switch required at all for a receiver powered by a LiPo powered ESC? In the NiMH case, the battery lives in the plane and is charged in situ, so fair enough - but I don't see the point otherwise. My E-Flite Hurricane came with a receiver switch, when none of the Parkzone planes (to my knowledge) have one. Why would I want to power the ESC/motor but not the Rx? Quote Link to comment Share on other sites More sharing options...
reg shaw Posted April 25, 2014 Share Posted April 25, 2014 Posted by Glenn Stratton on 25/04/2014 07:38:08: Ian, can you expand on your method of switch wiring for me please, not sure about *on the same 't' shape wire* bit! Hi Glenn, some modellers have the switch mounted internally, with a bent wire from it to outside the model or in the cockpit. When using two switches, don't have the same wire doing both switches as you'll never know one has failed until the other one fails. Doing it separately means you can power up each switch independantly at the start of each flight as assurance they are both working. On the battery pack, one switch is as normal, the other is wired to the big leads or even y leaded from the normal lead. At the Rx end, one switch into the normal Rx port, the other switch into any other channel, y leaded to a servo port if there isn't any spare ports. Ian. Quote Link to comment Share on other sites More sharing options...
John Lee Posted April 25, 2014 Share Posted April 25, 2014 Posted by The Wright Stuff on 25/04/2014 11:18:41: Can I ask the obvious silly question? Why is a switch required at all for a receiver powered by a LiPo powered ESC? In the NiMH case, the battery lives in the plane and is charged in situ, so fair enough - but I don't see the point otherwise. My E-Flite Hurricane came with a receiver switch, when none of the Parkzone planes (to my knowledge) have one. Why would I want to power the ESC/motor but not the Rx? The only silly question is the one that is not asked. The following is an extract from the instructions of my E-flite 60 amp ESC that explains it all: "Radio System Power Switch The ESC is equipped with an on/off switch intending to cycle the power to the receiver/radio system on and off. This helps to prevent the radio system from being powered on and arming the ESC prematurely (before you are ready) when the battery is plugged in, making it safer and more convenient to handle the model before (and after) flight. However the on/off switch is for short term use only (like when you are at the field). This is because even if the switch is in the off position, when the battery is connected, some power is still being used by the ESC. It is critical that you always disconnect the battery from the ESC when you are done flying........" Quote Link to comment Share on other sites More sharing options...
stuey Posted April 25, 2014 Share Posted April 25, 2014 On my Seagull Sea Fury I have fitted two HD switches in parallel. I have added an extra output lead to the Sub-C receiver pack, one output lead into each switch, then the switch output lead into a spare port each end of the connector section of my Spektrum AR9000 RX. This in effect creates a ring main, so if one switch fails the other one is there to take the load. I switch them on and off in sequence to prove them as ok before flight. Quote Link to comment Share on other sites More sharing options...
The Wright Stuff Posted April 25, 2014 Share Posted April 25, 2014 Thanks John, I do see there is a logic to that. I have to admit that I hadn't read the 60 A ESC instructions - I assumed it would be the same as the 30 A instructions albeit with a few different numbers! Interesting that HH supply the switch with the 60 A ESC, but not the 30 A one. Live, learn and feel stupid! Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted April 25, 2014 Share Posted April 25, 2014 Certainly the quality of the typical Rx switch seems to have come down over the years......even the "official" Futaba one I bought recently felt pretty flimsy..... Quote Link to comment Share on other sites More sharing options...
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