RE: TwinJet to Rocket Propelled/Ever been done?
I use the Jomar switch its electriclly isolated from the receiver and uses a seperate battery pack (two or more 50 mAh cells). Don't use a standard 9 volt it will not fire composite ignitors and questionable on Estes nichrome solar ignitors. Always use NiCad cells they have way more kick. The Jomar switch keeps your Rc servo from being effected by the air-start or vice-versa. Weight of the xtra battery pack is small , can be used to offset the rocket motor weight. Test out your system on the ground first to ensure it will fire the ignitor. For composites I use the Quick-Burst brand ignitors.