see also: AntriebsTheorie, en/MotorCurves

MK3638 & MK3538


Version V2

  • 4 holes for propeller mount
  • for direct propeller mount

where to buy

The Motor is custom made for MikroKopter only. You can buy it here

Plate for direct carbon propeller mount here


This motor has long wires (52cm), a short shaft and a small clipring. So it can be mounted directly on the aluminium arm.

Technical data

Voltage Lithium:



max 20A

Current max. (60 Sek.):

25 A


760 Rpm/V

Wire resistance:

0,11 Ohm

Phase resistance:

0,07 Ohm

No-load Current:

0,65A @ 10V

Num. magnetic poles:



10" - 14"

Max. Efficiency (g/W):


Electrical power:

max 350 W

Thrust max.:

max 2200 g

Weight (only motor)


Weight incl. cable and adapter



h=38 d=35 mm

Shaft diameter:

4 mm

Mounting plan

Thrust over current

MK3638 16V (4S) 12" Carbon

MK3638 4S 14" Carbon

MK3638 4S 15" Carbon

Different props

Same curve in higher resolution:

APC Propellers

13x6,5 APC

EPP-CF (chopped fiber)

How to read the curves

With this curves it is easy to estimate the needed current and even estimate the flight-time.

You can read the needed current for each needed thrust


The total weight of a MikroKopter (4 Rotors) is 1400g -> so each motor needs a thrust of 350g for hovering (1400g / 4 = 350g)

Current needed for 350g with the 13x6,5 APC - Propeller? -> 1,8A

Current needed for 350g with the 12x8 APC - Propeller? -> 2,4A

The total current for all four motors would be 7,2A (4 * 1,8A) or 9,6A (4 * 2,4A)

Flight time

You can estimate the flight time with this formular:

Time = 54 * Lipo / Current

(54 because we estimate 10% losses -> 60 * 0,9)

In case we would have a 3300 Lipo (3,3Ah), the Flight time for the 13x6,5 would be:

Time = 54 * 3,3 / 7,2 = 24,7 min

The same for the 12x8 Prop:

Time = 54 * 3,3 / 9,6 = 18,5 min

That is a different of 33% in flight time!

See also: FlugZeit

Rotation direction

Clockwise (seen from above)


  • A = gray
  • B = blue
  • C = black

Counter-clockwise (seen from above)


  • A = blue
  • B = gray
  • C = black

difference MK3538 vs. MK3638

The technical data and weight are the same for both types.

Compared to the MK3538 the MK3638 has laser engravings and bigger ball bearings. The bigger bearings make the motor more silent.

Also the shrink tube (cable protection) is longer.