The Toolbox — Charts

Drone & Rocketry

Rocket motor classification, HPR certification levels, drone frame/prop sizes, motor stator reference, flight controller sizing, and FPV VTX power guide.

Rocket Motor Classification

Each class doubles the total impulse of the previous. HPR certification through NAR or Tripoli required for H motors and above.

Class	Total Impulse	Avg Thrust	HPR Level	Notes
A	1.26–2.5 N·s	~2N	None	Beginner — small model rockets
B	2.51–5.0 N·s	~4N	None	Small rockets, higher altitude
C	5.01–10 N·s	~8N	None	Mid-power entry, Estes C6
D	10.01–20 N·s	~15N	None	Larger model rockets
E	20.01–40 N·s	~28N	None	High-performance LPR / MPR entry
F	40.01–80 N·s	~55N	None	Mid-power rocketry
G	80.01–160 N·s	~110N	None	HPR threshold (H starts HPR)
H	160.01–320 N·s	~220N	Level 1	HPR Level 1 certification required
I	320.01–640 N·s	~440N	Level 1	HPR Level 1
J	640.01–1280 N·s	~880N	Level 2	HPR Level 2 certification required
K	1280.01–2560 N·s	~1760N	Level 2	HPR Level 2
L	2560.01–5120 N·s	~3500N	Level 2	HPR Level 2
M	5120.01–10240 N·s	~7000N	Level 3	HPR Level 3 certification required
N	10240.01–20480 N·s	~14000N	Level 3	HPR Level 3
O	20480.01–40960 N·s	~28000N	Level 3	HPR Level 3 — commercial launch sites

Drone Frame & Prop Size Reference

Frame size is measured motor-to-motor diagonally. Prop size should match frame size for optimal efficiency.

Frame Size	Prop Size	Cell Count	Notes
65mm Whoop	31mm	1S	Indoor micro
75mm Whoop	40mm	1S–2S	Indoor/outdoor micro
2"	2 inch	2S–3S	Micro freestyle
3"	3 inch	3S–4S	Micro/mini freestyle
3.5"	3.5 inch	3S–4S	Sub-250g builds
4"	4 inch	3S–4S	Mid-size freestyle
5"	5 inch	4S–6S	Standard FPV — most popular
6"	6 inch	4S–6S	Long range, efficiency
7"	7 inch	4S–6S	Long range cruiser
10"	10 inch	4S–6S	Heavy lift, cinematic

Motor Stator Size Reference

Motor designation format: XXYY where XX = stator diameter in mm, YY = stator height in mm. Larger diameter = more torque. Greater height = more power at same KV.

Stator	Diameter	Height	KV Range	Typical Use
0802	8mm	2mm	10000–19000 KV	1S whoops, ultra-micro
1102	11mm	2mm	8000–15000 KV	1S–2S micro whoops
1104	11mm	4mm	5000–9000 KV	2S micro builds
1303	13mm	3mm	4000–6000 KV	2S–3S micro quads
1404	14mm	4mm	3000–4000 KV	2S–3S 2.5" builds
1506	15mm	6mm	2500–4000 KV	3S–4S 3" builds
1804	18mm	4mm	2400–3000 KV	3S–4S 3" builds
2004	20mm	4mm	1800–2500 KV	3S–4S 3"–4" builds
2205	22mm	5mm	2300–2600 KV	4S 5" — classic racing size
2306	23mm	6mm	1700–2500 KV	4S–6S 5" freestyle
2207	22mm	7mm	1700–2400 KV	4S–6S 5" freestyle/racing
2306	23mm	6mm	1500–1800 KV	4S–6S 5" long range
2407	24mm	7mm	1700–2100 KV	5S–6S 5" high performance
2806	28mm	6mm	1100–1500 KV	4S–6S 6"–7" long range
3115	31mm	15mm	700–900 KV	Heavy lift, cinematic

Flight Controller Mounting Size Reference

FC mounting hole pattern measured corner to corner. Must match frame stack mounting holes.

Mount Size	Typical Use	Notes
16×16mm	Micro/whoop AIO boards	All-in-one FC+ESC, 1S–2S, limited expandability
20×20mm	Micro to 3" builds	Stack or AIO, 1S–4S, most common micro size
25.5×25.5mm	3"–4" builds	Intermediate size, good feature set
30×30mm	4"–5" builds	Standard stack mounting, full feature set
45×45mm	5" and larger	Large format, maximum features, heavier

FPV Video Transmitter Power Guide

Range estimates are approximate in open air with omnidirectional antennas. Actual range varies significantly with obstacles, antenna quality, and receiver sensitivity. Operating above 25 mW on 5.8 GHz without a HAM license violates FCC Part 97.

Power	Est. Range	Legal Status	Notes
25 mW	~300m	Part 15 — no license	Indoor, proximity flying
100 mW	~800m	Part 15 — no license	General FPV flying
200 mW	~1.2 km	HAM license required (Technician+)	Extended range
400 mW	~2 km	HAM license required	Long range FPV
600 mW	~2.5 km	HAM license required	Extended long range
800 mW	~3 km	HAM license required	Maximum typical VTX
1000 mW (1W)	~4 km	HAM license required	High power — check local regulations