Parts
Every class of build has one component that sets the ceiling on everything else. Change that part and the whole aircraft changes; change the others and you mostly change the price.
What actually limits a build, by class
The table below is the short version of every build sheet on this site. The column on the right is the part that stops you from getting more out of the aircraft, and it is the one worth spending on first.
| Class | Sets the ceiling | Spend here first | What you get |
|---|---|---|---|
| Freestyle 5-inch | ESC current rating | Motors and props together | Punch and 40 seconds of flight |
| Long range (5–7 inch) | Battery chemistry and capacity | 21700 pack and a GPS module | Radius, not top speed |
| Cinewhoop (2–3 inch) | Duct clearance and camera weight | Ducts and a soft mount | Footage you can use without stabilisation |
| Racing | Frame durability and weight | A second identical frame | Finishing races |
| Whoop (65–75 mm) | Motor bell straightness | A bag of spare motors | Consistent flight, not speed |
| Ultralight | Arm thickness | A spare arm set | Surviving a crash you can walk to |
Motors: KV is a decision about battery, not power
Motor KV on its own tells you nothing. What matters is KV multiplied by cell count, which gives the no-load RPM the motor tries to reach. A 1750 KV motor on 6S and a 2600 KV motor on 4S turn a 5-inch prop at almost the same speed; the 6S build draws less current for the same thrust, which is why it flies longer and runs cooler. If you are choosing between the two, pick the higher cell count unless your frame is too small for the pack.
ESCs: buy the current headroom, not the firmware name
The useful question is what the aircraft draws at full throttle plus 30 percent, because prop wash spikes are real and a 5-inch freestyle quad that pulls 38 A in a straight line will spike past 50 A in a hard corner. BLHeli_32 and AM32 both do bidirectional DShot, which the RPM filter needs; the practical difference is that AM32 lets you run 48 kHz PWM on small motors, which removes a lot of audible whine on 2 to 2.5 inch builds.
Props: pitch is the throttle-limiting factor
Going up in pitch raises top-end thrust and current together, and it costs flight time at every throttle position, not just at the top. A 5.1x4.6 prop against a 5.1x4.3 on the same motor is about 4 A and 35 seconds of flight. The exception is ducted builds, where the duct recovers some of the tip losses and a lower-pitch prop is the only way to keep the current inside a small ESC.
VTX and link: two separate budgets
Video and control have nothing to do with each other and should be budgeted separately. On 5.8 GHz analogue, 25 mW is enough for a race course and 800 mW is enough for 3 km with a patch antenna; digital links want more power for the same distance and generate a lot more heat. On the control side, 2.4 GHz at 250 Hz is the default for anything flown within a kilometre, and 915 MHz at 100 Hz is what you move to when the aircraft starts disappearing behind terrain.
Build parts on file
- 5in-freestyle-baseline Frame - Apex EVO 5 in, 5 mm arms, 220 mm motor-to-motor · Motors - 4 x 2207 1750 KV, 12N14P · ESC - 4-in-1 55 A, BLHeli_32 flashed to AM32 2.17 · Flight controller - F7, 30x30 mm, ICM-42688-P gyro · Props - Gemfan 51466-3 (5.1 x 4.6 x 3) · VTX - 5.8 GHz 800 mW, SmartAudio 2.1 · Receiver - ExpressLRS 2.4 GHz, 250 Hz packet rate · Battery - 6S 1300 mAh 120C LiPo · Camera - 19 mm micro analogue, 1/1.8 in sensor
- 7in-longrange-cruiser Frame - 295 mm deadcat, 6 mm arms, aluminium camera cage · Motors - 4 x 2806.5 1300 KV, 12N14P · ESC - 4-in-1 60 A, BLHeli_32 32.9 · Flight controller - H7, 30x30 mm, dual gyro · Props - HQProp 7x3.5x3 · VTX - 5.8 GHz 1000 mW with a 40 mm heatsink · Receiver - ExpressLRS 915 MHz, 100 Hz packet rate · GPS - M10 module with a 25 mm ceramic patch, mounted on a mast · Battery - 6S 3000 mAh Li-Ion 21700 pack · Camera - 19 mm analogue plus a 4K action camera on a soft mount
- 3in-cinewhoop-ducted Frame - 155 mm ducted cinewhoop with replaceable ducts · Motors - 4 x 1404 3800 KV · ESC - 4-in-1 45 A, Bluejay 0.21 at 48 kHz PWM · Flight controller - F7 25.5x25.5 mm with a barometer · Props - 3x2.5x3 ducted, low pitch · VTX - 5.8 GHz 400 mW, on-board or 20x20 mm module · Receiver - ExpressLRS 2.4 GHz, 150 Hz · Battery - 4S 850 mAh 95C LiPo · Camera - on-board 4K, 1/1.7 in sensor, 25 degree tilt
- 65mm-whoop-indoor Frame - 65 mm plastic whoop frame with a 1 mm carbon brace · Motors - 4 x 0702 27000 KV · ESC - all-in-one 5 A board · Flight controller - integrated 1S AIO, 25.5 mm mounting · Props - 31 mm 3-blade, 0.8 mm hub · VTX - 25 mW integrated, raceband · Receiver - ExpressLRS 2.4 GHz, 50 Hz · Battery - 1S 300 mAh HV LiPo · Camera - integrated 1/4 in analogue, 120 degree lens
- 5in-racing-lowslung Frame - 215 mm race frame, 5 mm arms, aluminium standoffs removed · Motors - 4 x 2207 1960 KV · ESC - 4-in-1 50 A, AM32 2.17 · Flight controller - F7, 20x20 mm, no barometer · Props - 5x4.3x3 race props, hand-balanced · VTX - 25 mW raceband with a whip antenna · Receiver - ExpressLRS 2.4 GHz at 500 Hz packet rate · Battery - 6S 1100 mAh 130C LiPo · Camera - micro analogue, 1.8 mm lens for a 130 degree field of view
- 4in-sub250-longrange Frame - 185 mm ultralight, 3 mm arms, no camera cage · Motors - 4 x 1804 2450 KV · ESC - 4-in-1 35 A, Bluejay 0.21 · Flight controller - F7 20x20 mm with a barometer · Props - 4x2.8x3, balanced · VTX - 5.8 GHz 500 mW, 20x20 mm · Receiver - ExpressLRS 915 MHz, 100 Hz · GPS - M10 with a 15 mm patch, mounted on a 3D printed mast · Battery - 4S 850 mAh Li-Ion 18650 pack · Camera - micro analogue, 1/3 in sensor