I am working on a project that requires remotely switched LEGO valves, and I tried many designs I found, and none of them worked due to the valve causing too much resistance. Does anyone have a remotely switched valve design that fulfills the conditions below?

  1. It must be tested and work.
  2. It must use only PF motors.
  3. It must not use 32449.
  • 3
    Why the ban on 32449 (thin liftarm length 4) ? Jan 30, 2020 at 6:43
  • @MichaelVerschaeve Because I do not have it and don't want to wait for one to be shipped. Jan 30, 2020 at 15:19
  • 2
    I just think that your question would be more relevant to others without this restriction, see point 4 of meta.stackexchange.com/help/how-to-ask. Also, even if a presented design contained the forbidden element, you surely can replace it with an alternative element ? Jan 30, 2020 at 15:58

1 Answer 1


I tried many designs I found

A quick Google search resulted in the following designs. Have you tried them all?

Sariel's Autovalve:enter image description here

Philo's pneumatic valve:

enter image description here

Sariel's Servo Valve:enter image description here

Tamas Juhasz's small autovalve with compressor:enter image description here

Technic-Dragon's Compact Pneumatic Autovalve:enter image description here

Bonus entries, not using exclusively PF motors, but could be adapted to:

Conchas' Micromotor valve:

enter image description here

Pneumatically controlled valve from the B model of 8868-1: Air Tech Claw Rigenter image description here

  • 2
    I have my doubts about a couple of these designs. When under pressure, the valve switch takes quite a bit of force to turn. I think a couple of these designs don't have sufficient gearing down to work unless there's no significant pressure yet. Jan 30, 2020 at 14:12
  • 1
    @MichaelVerschaeve I haven't tried any of them personally (except for the 8868), but provided links to their respective websites and forum threads, where comments might be left to indicate such problems and their solutions.
    – zovits
    Jan 30, 2020 at 14:14
  • 2
    @MichaelVerschaeve The first Sariel autovalve is not super reliable - in my experience, the small liftarms can get stuck in certain positions. The servo valves definitely have more than enough torque. The micromotor valve is definitely questionable, not to mention that it requires a sensor and probably takes 5-10 seconds to flip state. Pneumatic autovalves are pretty common in air-powered creations.
    – MindS1
    Feb 3, 2020 at 20:37

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