I've spent far too long this evening researching whether it's possible to clone a Starship; for my own amusement and/or to terrorise the neighbourhood. A Starship delivery robot, that is, not the SpaceX Starship.

Starship robot

Amongst other detail there's a fair bit of info on the basic specifications knocking about:

  • Weight: 23kg empty
  • Payload: 10 kg
  • Battery: 18.5V 8000 mAh
  • Runtime: 2 hours / 6 km
  • Speed: 3 km/h nominal; 6 km/h max
  • Motors: brushless
  • Wheel diameter: 200mm (derived from Dimensions.com)

Utilising the calculation elaborated in this Medium post and Robot Shop's motor sizing tool, I reckon the six motors need to rotate at about 80 rpm, with a torque of about 1 Nm and power of 6 W each if I consider a similar weight. I can sort of get there with a geared DC motor something like this economy variant from Active Robots and can probably get even closer with a bit more research.

But I note the above spec lists use of "brushless electric motors." If the brushless motors are anything like those i used in aircraft then they'll turn at a high rpm. Unlike DC brushed motors, I'm struggling to find (m)any turnkey brushless motors with a gearbox ready-attached and then opening up a whole world of pain to find the right combination. Is brushless + gearbox a normal use-case, or am I going down blind alley?


1 Answer 1


Yes, brushless and grearbox is a normal usecase. Due to the popular application of using brushless motors on drone propellers other applications are harder to find. The keywords "Brushless Planetary Gear Motor" gives me plenty good search results.

  • $\begingroup$ Excellent. That's just the search term I needed. Thanks @50k4. $\endgroup$
    – Mat
    Dec 13, 2020 at 21:50

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