I've decided to try my hand at building a working LEGO Concrete Block Making Machine, as shown in this picture:

enter image description here

with the idea being that the machine will be controlled by both manual and automatic input. The machine will be controlled by a pneumatic air system using various cylinders.

The manual control is the easy bit, as it's just a bunch of levers next to each other. The problem comes in the form of the automatic system whereby the Technic controller needs to be able to control a pneumatic valve bank in order to run the machine.

My question is this, does LEGO make an electronically controlled valve bank? If so, where can I find one? If not, what would be the best way in accomplishing this?

  • What do you mean by "Technic controller" ? One of the many remote controls lego has released, a recent example of which is Powered Up Bluetooth Speed Remote Control Unit ? Or one of the several programmable bricks, a recent example of which is Powered Up Large Hub ? Or something else ? Commented Oct 4, 2023 at 11:44
  • Apologies. I meant the RCX Controller V1.0.
    – GipsyD
    Commented Oct 4, 2023 at 11:47
  • 3
    LEGO pneumatics are not really precise. You might want to consider using mechanical operation with linear actuators.
    – Alex
    Commented Oct 5, 2023 at 5:19
  • @Alex, by linear actuators, you mean things like mechanical pistons? The type that doesn't use hydraulic or pneumatic?
    – GipsyD
    Commented Oct 5, 2023 at 15:36
  • 3
    Yes, mechanical pistons without any sort of pneumatic or hydraulic stuff. I mean this small linear actuator, bigger one and the largest.
    – Alex
    Commented Oct 5, 2023 at 19:10

2 Answers 2


I don't know of any electronically controlled LEGO pneumatics.

However it's not too hard to get the needed functionality. I see two main parts to the equation :

Controlling the pressure in the system

LEGO have released several pumps over the years. A recent example is Pneumatic Pump Small (6L) V2 with Reinforced Cylinder. A pump like that can relatively easily be driven by a regular motor (by transforming the motor's rotary motion into a linear back and forth motion - using a cam mechanism eg.), which in turn can be controlled by your controller of choice.

Note, you can make this as complicated as you want, with features to protect your motor from overload, to more evenly generate pressure, etc. Many examples of varying complexity can be found on the internet.

Controlling the direction of air flow

LEGO have released several switches over the years. A recent example is Pneumatic Switch with Pin Holes and Axle Hole, which has a convenient axle hole to allow it to be driven by a motor. Ideally a servo motor, but a regular motor can be made to act like a servo motor if needed.

Some example solutions (mostly using the older style switches that didn't have an axle hole) can be found in How to motorize a LEGO Pneumatic valve?.

  • Thanks Sander. Really appreciate the detailed answer. I have a design for pressure regulation, but the directional air flow is something I will most definitely check out. I had no idea parts like this existed. I just have one question though. These designs are calling for LEGO Power functions, can the controller/receiver be programmed for automation?
    – GipsyD
    Commented Oct 5, 2023 at 15:25
  • @GipsyD : no, Power Functions does not include a programmable brick. Most designs you'll find will indeed use more recent generations of motors, but it should just be a matter of adapting the designs to suit the different form factor of your older 9V motors that can be controlled by your RCX Controller. Alternatively, you can control Power Functions motors (apart from the servo motor afaik) with your RCX Controller by using the right extension wire. Commented Oct 6, 2023 at 5:22
  • That's a win all things considered. Thanks for the link. Got some planning to do.
    – GipsyD
    Commented Oct 6, 2023 at 10:16

There were a few sets with pneumatics and compressors available from the early '90's, my sister had the 8868 Air Tech Claw Rig which came with a 9V motor to keep the compressor working to provide the pressure to move the various parts around

Compressor and Pneumatics Diagram

Sadly though as you point out, the switching was at that time all manual.

  • 1
    The B model of that set did feature valves that were actuated by other pistons though. Still not electronically controlled (and technically not even controlled at all, as it ran automatically in a loop), but a neat and unique feature.
    – zovits
    Commented Oct 7, 2023 at 15:17

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