Building a QAV 250r and QAV x can I just download Inav firmware to Flight controlled and not have to have a GPS antenna and say aDJI nav trying to understand this new to fpv never built drones or flown and building two right now one for me and one for son. Please explain as for my 250r for my son I just ordered a DJI Nav from getfpv so he could have the return home feature which will add weight that I would like to get rid of. If I understand this correctly I would just purchase say a KISS flight controller and download the Inav firmware which is free and I could eliminate the GPS antenna and return the DJI nav system to getfpv? and I could do the same for the QAVX that I am building which is too small to add a gps Flight controller this way the QAVx would have a return to home feature as well with no added weight? or am I way off here someone please help me understand. Thanks very nice QAV by the way Kevin kevinJLsheridan@gmail.com I have also been looking for some help with these QAV builds and have posted below what I could use help with on some FPV forums with no luck so if someone could assist I would surely be grateful! New to this sport, never flown or built before, I am sparing no expense in building two drones so I want to get this right. I am currently ordering parts to build my son a QAV 250r and I ordered a QAV x for myself. Below is what I have ordered for parts and I need some help with eCalc configurations to give me some specs on what I am building. I am looking for optimal prop size and pitch with the motor and size I chose along with optimal ESC to handle the motors on a 4s 95c 1300MAH Luminier battery. OEM Lumenier QAV X and QAV 250r will have PRO Tmotor F40 2600KV motors, Kiss 30 AMP ESC, 4s 1300 MAH 95c Batteries, 5045/3 Props. I seeking to get out of the 250r to 80-90 MPH and my QAV X to 95-100 MPH if not faster with decent fly time! My eCalc configurator shows that I am not even close to desired MPH and fly time for both QAV X and QAV 250r and shows my ESC’s, (KISS 30 AMP) are too small and I, need a bigger AMP ESC’s, it also shows my Pitch is way off and shows low MPH for both QAV’s. (I could be entering the wrong information based on lack of experience which is why I need your help) Can someone configure both QAV’s for me and let me know the following a) What optimal ESC and Prop size/Pitch would be for both build configurations and what prop would you suggest? b) What Max Speed will be for both QAV’s QAV 250r for my son and QAV X for myself? c)What is the fly time for each? d) What is your experienced opinion about the Motors ESC, Battery and Prop selection I choose for each the QAV 250r and the QAV X builds. Is there a more efficient, more powerful lighter better combination you would have gone with to make each QAV sick performing drones? if so what would you have chosen? Please email me product info and why you would have gone that route so I can research and change products before I build. e) What is it you would do to maximize each QAV with the Motor, ESC, Battery and Prop to get the most out of each QAV. You can email me at kevinJLsheridan@gmail.com or text me at 989-359-1026 I will be building these QAV’s this week and parts are arriving daily so time is off the essence and I need an experienced FPV Drone builder to help. Best regards, KevinJLsheridan@gmail.com