Setting up first Tri-copter

Hello, My grandson and I are asking for help to set up our first Tri-copter build which consists of a Turnigy Talon Spektrum DX8i with an Orange R820X V2 receiver we are using an Arducopter 2.8 with Ublox Neo-6M GPS. I have previously built an X450 and set it up with my old Turnigy 9X TX. But since then I am now on a Mac and the version of APM is different to the old one I had used, none of the screens look familiar to my windows 7 version apart from the map and compass😊. I’ve flashed it but cannot successfully calibrate enough points on it within the 60 second allowance, also I keep getting vocal messages about pre arming? or not armed. also not sure how to wire up as the RX has a label saying CPPM which I have never used before and currently it’s wired as I have previously done which is PWM. I have only recently purchased the Spektrum DX8i and it seems a bit complex although flying planes with it is great I would like to do some aerial photography with the Tri-copter. If anyone could give us some connection diagrams (TX -Arducopter and on) useful links or information to help us along I would be much obliged I have gleaned that the servo is powered from output 7 but not sure how that is setup from my DX8i?. I’m afraid at my age none of this comes easy, my grandson is better but not really the age to have this kind of experience although he’s proving to be a good pilot and we get much pleasure from sharing this hobby. Apologies if it’s me being an idiot but, if you can help it would be great

Sorry about the mistake but the voice message I get is “Pre-arm check R/C not calibrated” I hope that makes more sense to someone? Thanks

That sounds like you have not gone through the setup wizard correctly, in particular the R/C calibration process was not successful, so I suggest you go though that again. And if possible it would be best if you can get onto a PC as I find mission planner to work much better for APM

Thanks for your reply Alex, I unfortunately made the mistake of downloading the free windows 10 upgrade and APM doesn’t seem to work it kept crashing so that’s why I’m using it on Mac. Maybe I should un-install it and try a new download? Have you tried APM on windows 10? Also can you tell me the outputs will be 1,2,4 and 7 for the servo? what about the connections from the receiver to the Arducopter which to which? Thankyou and I’ll let you know how it goes.