Rotec Radial and keyed ignition switch

[jtpitkin06]

Here is one solution for a powered “on” system.

It uses one generic automotive key switch and two toggle switches.
System has the safety of being off with the key off or removed.

You can jumper the IGN and ACC terminals on the keyed switch to have two contacts feeding the ignition selectors. The ACC terminal could also have a separate feed from the battery bus to eliminate a single point failure.

The “Mag” switches (really ignition selector switches) are turned on for engine running. The selector switches receive power from the keyed ignition/starter switch. Individual ignition be selected off for checking operation of the other side during engine run-up.

John Pitkin
Greenville, TX

[N213RV]

I appreciate all the help.... I have attached the wiring schematic for the ACS key switch. It has provisions to run left mag, right mag, both mags, and a spring loaded start just like an automobile. I've used this on all the planes I've built or helped build (KitFox is now the 6th). I really like it.

The switch grounds to turn the mags off, or opens the ground to activate the ignition. This is standard for mag operation.

The Rotec has 1 mag (which will work fine with this switch) and it has one electronic ignition. The issue is, how can I use this with the electronic ignition? It seems like it would work opposite of what I need. I'd like for it to unground the electronic ignition when off, and ground it when on...

Seems like the addition of another relay might work?

Thanks for all the help!

[N213RV]

So in other words, the mag is open circuit to turn on, and it appears the electronic ignition has to be closed circuit to turn on.... My switch only accommodates open circuit to turn on from my understanding.....

[paulc]

A good customer tipped me off about this thread

Its Paul from Rotec here, we have six guys and girls in the office. We always reply. Check you have the right email. paul@rotecaerosport.com or rotecengineering@bipond.com or rotecadmin@bigpond.com there are many.
Anyway, the R2800 ignition using two separate toggle switches is easy. One contact closed to earth will KILL the mag side (typical P lead set up). And one contact closed on hall electronic side to feed power to the auto coil will make it HOT (so the reverse contact of mag side).

BUT if using a traditional mag switch (key style) this will have two contacts that both go open to make both hot. That's fine for the "P" side of the Rotec but wont work on the Hall side. So what you can do is have the second P contact connect to a normally closed 12v mini auto relay, they are common. So when the second contact on the mag switch is open contact (hot) the relay will be closed contact and switching power to the Hall side. Its a simple circuit.
Also remember, radials including the Rotec should be cranked on the starter with DEAD mags for a few turns before flicking the mag switches hot. This gives you one last chance to avoid HL! This is super important, a HL will stall the starter motor every time. But if the engine fires on a HL its all over So make sure to pull the start wire from the mag key switch and mount a separate starter button that is independent from the mag switches. The method is of course done after the regular hand propping with the two lower intake pipe drains cleared of any oil.

Please always contact the factory first before pulling advice from forums. Some of the "FREE" advice I see given is scary. Not this forum though, these guys are tops!
Paul.

[N213RV]

Hi Paul,
Thanks for the reply. I had been emailing with Cuinn who responded to my original note sent to you, but he must be busy as he was not yet able to respond to my follow up emails. This is exactly what I was looking for so thank you for the help!

-Mike Kraus