Video Presentation

How it works

The engine is powered by a single pneumatic cylinder, which acts on a crankshaft to power the flywheel with 5:1 gear ratio, and an other crank to operate the switch accordingly. The flywheel helps to overcome the deadpoint of the switch, where no air goes in or out the switch, by bringing to the system inertia. The sliding connecting rod mechanism to operate the switch helps to reduce this moment to the minimum by having a large displacement of the rod comparing to the needed movement on the switch. It results in a pneumatic engine which runs smoothly at max 100rpm with any unmodified switch or cylinder, in a lovely steampunk design, powered by 2 pumps as the air supply. Speaking of the air supply, this creation is available in three versions  : no pump (you need to have your own air supply), 2x LEGO pump and 2x LEGO pump in handpump (better grip).

You can read the full review of this model on my blog.

How to build ?

You only need the parts and the instructions. You can purchase the PDF instructions on this shop which contains the partlist at the end, and you can check on Rebrickable (2x pumps in handpump) or in the instructions preview below.

The instructions are delivered in three different versions :

• No pump (you need your own source of air : compressor of bike pump / 2-3 bars)
• 2x Lego pumps
• 2x Lego pumps in handpump (better grip)

If you do not have the parts, you can purchase the complete kit from retailers :

• Using Genuine LEGO Parts : This model is available at Buildamoc, in a complete package including LEGO Genuine Parts and PDF instructions (2x pumps in Hand Pump)
• Using non-Genuine LEGO Parts : This model is available on LesDiy Store in a complete package, including parts (alternative bricks from China) and PDF Instructions. (2x pumps)

About this product

Instructions preview