SANDRO SPEC RACE WHOOP
Introduction
This race whoop is the result of many build iterations and experimentation. It follows the principle of simplify and light-weighting. No big, motors, no external receiver and no bulky vtx's. This build comes in at 5-10grams lighter than commercial offerings and you will see and feel much easier this makes it to fly around a tight track.
PArts List
Build Details
Frame
Betafpv 75mm frame, you can use the more generic ones you find on aliexpress, but they are alot weaker IMHO. The betafpv frame is heavier however. PAY ATTENTION TO MOTOR MOUNTS some motors have a different mounting pattern, the combinations I've listed will work.
Motors
Not all 0603 size motors are made equal, the racerstar BR0603B are rubbish!!! The BR0603C look ALOT better but I haven't tried them yet. I have tried 0703 also, I think they are not worth the weight and power consumption penalty. I am HappyModel SE0603 19000kv with 1mm shaft.
Flight Controller
Crazybee F3, keep it light with an integrated receiver. I have also tried the 'f4 whoop pro' , but it seems to not be available anymore. The BetaFPV F4 board is also another option, but note it incurs a small weight penalty
Propellers
Standard 3 blade whoop props. I have also tried the betafpv 4 blade props, they corner better but have less top end. the HQ whoop propellers are also extremely good, but very expensive.
Battery
Keep it LIGHT! I am using 300mah 3.7v packs. If you just want to fly around casually you can use 450-550mah packs, but the performance is significantly worse. 300mah gives you just about 2 mins of racing at the pace you see in the videos below, 3:00-3:30 if you fly around slowly. 450mah gives you 3 mins of racing and up to 5 mins of casually putting around.
Flight Controller
'Standard' AIO 25mw. At the moment am using the AKK BS2. I don't use a canopy as I like to run really high camera tilt, so I make a custom mount and cage from zipties, yes really, it works really well. See picture.
Software
On the Crazybee f3 you must run 8k/4k with dynamic filtering ON. Also very important, at the time of writing there is a bug with telemetry, so if you turn on telemetry your FC will randomly crash. Turn it off for now.
MIN IDLE must be set to at least 7, even go as high at 8 or 9 if you want. Too low and you will washout in corners and dive recovery will be poor. This stops dsyncs.
MOTOR TIMING set to medium high or high, confirm when you spool up the motor in Betaflight (with prop) you get minimal sputtering at high throttle, this is very important to prevent help with preventing dsyncs.
Flight Style
A note on flying style; I am flying full out in the video, throttle pinned for a lot of it, fly it more gently and it will fly like a normal whoop. I also fly acro, not level. You need high camera tilt to fly a high pace with any whoop. KEEP. IT. LIGHT. my AUW with battery for this quad is 31g
Final Notes
A note on vibration, vibration is a killer and will sap your power. Make sure your props are down as far onto the motor hub as they will go. This helps a lot. For most props the fit is too tight to get them down without damaging the motor. Buy a 0.9mm drill bit and ream out out the inside of the prop where the shaft goes until they fit snugly and can go all the way onto the motor shaft.
You can test for vibration in the props by holding the quad and blowing on the propeller to spin it up, you will feel if there is excessive vibration.