Tutorial:Making a Breaking ground Propeller

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The Breaking Ground DLC introduced rotational parts; specifically, motors. Thus, one of the most common craft/subassemblies build is rotors, which can run entirely off of electricity. However, the motor exert a huge amount of torque, more than what an individual reaction wheel can counter. Thus, all Breaking Ground propellers are w:Contra-rotating propellers, using two motors that spin opposite each other to cancel the torque.

A few things to note:

  • Lay off of the auto-struts and rigid attachment. Autostruts can make parts not spin.
  • Wings provide better lifting capability compare to a similar size control surface
  • Use snap to ensure both motors are inline. (Default "c")
  • Use the micro adjustment to offset and rotate the parts precisely. (Default "shift")
  • "Absolute" positioning and rotational is recommend

There are two methods to do so:

  1. given a base component, one is mount on top by node, while another is mount radial to the base component, and then use the tool to move (offset) such that it's above the other motor.
  2. Motors attach node-to-node, with the "base" motor made unpowered and spin opposite direction of the powered motor. The end result is that both end of the power motor would spin freely, spinning the rotors in equal and opposite directions) (valid as of 1.0.0 Breaking ground)


  • Length: 15–30 minutes
  • Difficulty: Advanced
  • For version: Breaking Ground DLC


  • 1x Octagon strut
  • EM-32 Standard Motor
  • Basic fins


Create the first motor

  • Place the Octagon Strut
  • Attach the the first motor node-to-node
  • Symmetrically-8 Radial attach basic fins to the motors
  • Use rotational tool such that the fins are parallel to the flat end of the motors
  • Click on offset tools. Click on one of the two side fins, and then move it such that it is at the top or bottom axis, with the black-line vertical and the widest part at the outer radius.
  • Click on the rotational tool. Click on the now-top fin (does in the last step). Without using the fine-snap adjustment, rotate it clockwise by 45 degrees, or 3 clicks.
  • Set first motor to rotate in clockwise

Create the Second motor

  • Holding down the copy shortcut (Default "alt"), copy the first motor-assembly; the fins should be attached on the copied motor
  • Attach the second motor radially onto the octagon struts. If the program created symmetrical coppies, use x to cycle through it so there is no symmetry. Make sure the orientation of the second motor is the same as the first motor
  • Use rotational tool such that the fins are parallel to the flat end of the motors
  • Click on the rotational tool. Click on the now-top fin (does in the last step) of the second motor. Without using the fine-snap adjustment, rotate it counter-clockwise by 90 degree degrees, or 6 clicks.
  • Put your motor in counterclockwise

Create action group

  • Using action group, assign "1" to toggle motor power


  • Create a simple test platform by using a Rovemate, Mk2 lander can, etc, and attach 4x medium landing gears such that it is stable. Disable steering.
  • Mount the motor to the rear node. Offset the landign gear as needed.
  • Load it onto SPH and Activate motor. If it works, your test platform should just go forward.