Hey VF, just a quick note on the prop set-up. there are 2 plastic washers included with the APC prop and the instructions do not make mention of them. ( I also used this same prop on my PIGI3D) Anyhow make sure you use the bigger of the 2 and you will have to hand tighten it as it is a little tight so it will screw down like a nut.so in step 15 there is 1. 3x3 screw 2. 12x5 washer 3.spinner base (4. plastic washer) 5. prop ( also be sure to shave off and lightly sand and plastic flashing so the prop sits flush) 6. 12x5 washer etc...by putting the washer in your prop will be much more stable and will not have to reley solely on how tight the M5 nut it for stability. This kinda works out cool that I can add hints to the post as I'm building as my PC and workshop are all in the same room !Later man and hope this helps