Hey everyone. I've been looking into building a drone obviously and am confused with a lot of the numbers and abbreviations. I want to buy the "BrotherHobby Returner R6 2207 2550kv" but I'm not sure which esc, Fc and lipo are compatible with these motors. Also what does 2207-2550kv mean?
I need help with parts
- Thread starter Screecher
- Start date
wafflejock
Well-Known Member
Motor specs are given as bell (part with magnets in it) diameter and height so 2207 is 22mm diameter and 07mm height in general a bigger motor has more mass and so more inertia and changes speed less quickly but with larger magents and more copper windings can have more torque (ability to swing bigger props at full speed or in general overcome any counteracting turning force). 2207 is a good size for 5" props anywhere from 1804 to 2307 might be available but 2206 or 2207 I think is most popular and pretty decent for 5". There are much bigger motors like my 6374 for esk8 and other big flying machines that spin bigger props or wheels.
The second number kv is the rpm per volt applied typical range for 4S is around 2300kv-2600kv (2450kv I think is the sweet spot on 4S). Depending on battery voltage you might go lower kv if using higher voltage like 6S.
For simple example a 100kv motor spins 100rpm when you have 1V (volt) of potential at full duty cycle (full speed ahead). If you go to 2V it's 200rpm.
With our quads using 2300kv motor and 4S (4 x 4.2V = 16.8V fully charged), can in theory spin at 16.8 x 2300 = 38,640 rpm. Speaking of that always test with props off spoke with a co-worker last night who had 16 stitches from a quad accident.
wafflejock
Well-Known Member
Oh also regarding ESCs blheli32 based ones are fairly modern the competition to blheli is basically kiss. BL-Heli S is a bit older but was open source the new 32 bit ones are proprietary firmware (but work with any FC). For specs anything rated for the voltage you want (usually rated for 2-6S) and usually 20A is enough but can check motor max current draw to be sure, 35A rated ones would be safer higher rating is just more overhead for heat dissipation. Max current is always a tricky thing because it depends on how long you are pushing a lot of current or maxing the throttle vs momentary blips.