New Model, first adventure into petrol

Forget the magnetic switch for now Simon. The Rxel unit - larger red socket plugs into a battery supply, eg: Nimh pack 4.8v. the smaller red plug is connected to the ignition module. The two other leads are the led ignition on warning light and the other plug goes to spare switched channel on you receiver, eg gear switch. You can then kill ignition with that switch. Also if the receiver is not switched on then neither is the ignition.

I think the magnetic switch Frank had there he planned to pull the key out when he wanted the ignition ON, I suspect but it is not necessary though. Some of my planes have ignition switches and some don't. Personal preference! The receiver will switch it on and off for you anyway.

Thanks Phil.

I thought you might say that.
Kevin did say the same about the switch, but i was worried it had to be there..

Simon

Re-your PM. You can use one or many as you like receiver batteries. On bigger planes it is favoured for two Lipos, 7.4v (through a regulator) or Life (6.6v). In other words wire up as any other of your aircraft. For ignition you want a smaller battery (ignition doesn't consume many milliamps) maybe a 4.8v nimh pack which i am sure you must have lying around. This battery then powers the ignition via the Kill Switch. The Kill Switch is optically isolated so there is no connection between the two circuits. The ignition circuit's on/off signal is derived from your preferred channel on your TX. Being an aerobatic plane without retractable gear, use the gear switch (ch5) or assign one of your choice that is not used.

Hope that helps.

Not sure where Frank put the ignition module but needs to fairly close to the engine and locate your receiver well away from it. (Stray HF interference).

Sorry Simon did not read all your message. Busy with soldering iron and microchips.

I have scribbled a schematic that may help you below. Personally I use two 2100 Life RX packs from HobbyKing UK ,Y-leaded together. That gives me 4200maH capacity. Switched off by a heavy duty switch with LED, that reminds me to turn off. At the end of the day though unplug them.

Ignition LED! Place it so it is visible on the outside of the fuselage. I usually bore a 5mm hole then push gently the LED through till the little lips stop it. Hold it with a blob of UHU or silicon sealer. If you have the LED bezel that should come with th e kill-switch, then drill out to around 6.5mm for the bezel and then push LED into it. Blob it with UHU.

PhilF51 wrote: Sorry Simon did not read all your message. Busy with soldering iron and microchips.

I have scribbled a schematic that may help you below. Personally I use two 2100 Life RX packs from HobbyKing UK ,Y-leaded together. That gives me 4200maH capacity. Switched off by a heavy duty switch with LED, that reminds me to turn off. At the end of the day though unplug them.

Ignition LED! Place it so it is visible on the outside of the fuselage. I usually bore a 5mm hole then push gently the LED through till the little lips stop it. Hold it with a blob of UHU or silicon sealer. If you have the LED bezel that should come with th e kill-switch, then drill out to around 6.5mm for the bezel and then push LED into it. Blob it with UHU.

Phil - your practice of connecting two batteries in parallel is not ideal because it does not provide power failsafe. It is better to feed each battery via its own switch and an independent isolation diode. Either by constructing your own with a heavy duty switch and a Schottky diode such as this
www.maplin.co.uk/p/mbr1535ct-15a-schottk...rier-rectifier-n13cc
or splash out and buy a Powerbox failsafe switch.
www.nexusmodels.co.uk/powerbox-systems-p...sor-sparkswitch.html

Personally, i think that all models ITRO 7kgs and above should have a dual failsafe power supply.

Hi Kevin. I have considered a Shottky diode set up, got quite a few 5a animals but decided I did not want the voltage drop of 0.7v plus I would have to knock up a circuit board to mount them and make up fly leads, plug ins. I may do in the future but I have no issues at all. Spektrum Powersafe RX do not offer battery redundancy, still internally paralleled. Best and expensive option is Powerbox or similar.

Or of course I make my own powerbox up - regulator and fast switching battery monitor Now there is a thing to do when it's raining.

Hi Phil & Kevin.

Thank you both for your kind assistance, I am going to have a look at the switches that came with the model and see what I can do.

I am getting my head round this now :blush: :oops:

Simon

Hi Guy's
Help !!
Roto engine on the model i have bought from frank has a Walbro carb on it.
I have fitted the tank tubing as advised, set up linkage etc, etc, ready to start engine first run (it has never been run been in storage since 2014)
Got fuel in tank engine will not pull fuel up, disconnect fuel line from carb blow into vent pipe fuel supplied to carb pipe.
Put carb feed back on pressurise tank slightly no fuel to carb, take off carb pipe pressure to tank- fuel at carb.
Take off carb from engine, remove fuel feed pipe and cover blow in pipe ok, put cover back on can't blow through pipe.
Seems like the inlet of the carb is blocked, take out low and high speed jets still can't blow through ?

Any suggestions

Ta
Simon

You may already know this, but the Walbro has an integral pump with in/out valves (formed by gasket flaps) and it will ONLY pump gas when it receives pulses emanating from the crankcase through a tiny hole parallel to the inlet manifold. You cannot blow fuel into the carburetor like you can with a glow engine.
If the motor is dry then look for a blockage between the crankcase hole through the manifold to the carby..

Thanks for the info I have now got it sorted, needle valve stuck in think, got fuel through now.
The carb was as dry as a bone too

Ta

Simon