11/10/19

-Sorry I had to repost this. It got flagged for having someone's brand name associated with it. A much better designed inline 2 and 4 are in the works and will be posted when they are ready.

Edit as of 4-16-19:
-Revised the cam ends, making them shorter so the 50mm bolts fit deeper.
-Revised the flywheel hub to have a collar that prevents the bearing from pushing down it
-Added crank spacers to keep the connecting rods centered
-Added a small amount to the diameter of the piston so it could be sanded more to fit the cylinder, giving less scratchiness
-Shortened the crank_gear by 1mm to allow tolerance for the crank in the block

This is a small 4 cylinder air engine I designed and built using 3D printed parts and store-bought bolts and springs. I have assembly instructions for sale that will walk you through the steps.

To see more about this engine and a video of it running, check out my instagram page @CompressedCreations

I apologize for the parts not being faced correctly to print when they are uploaded to a slicer but just turn them to the correct orientation and it'll print. I used 3D Printer OS to slice all my files and include the specs in the instructions.

**Some basic knowledge is needed, I refer to things by their name and if you do not know the general terms associated with engines it may be difficult to understand. Example, "sand the cylinder walls to match the piston." It's not super deep but is not for someone with no engine knowledge.

Engine Specs:
~1000 RPM @ 1psi (lung pressure)
Max RPM is unknown but probably about 5000
21.5 CC's of displacement
Bore: 19mm
Stroke: 19mm

Required tools for assembly:
-Sand Paper, 200+ grit. I recommend closer to 400
-1.5mm allen wrench
-Small phillips screwdriver
-Razor blade (Xacto knife recommended)
-Small amount of epoxy/super glue

Parts Required:
-M2x16mm bolt (10)
-M2x50mm bolt (2)
-1mm rod ~25mm (4)
-3mm rod ~18mm (4)
-M2x22mm bolt (4)
-M4x15mm spring (4)
-M2x12mm bolt (8)
-M2 nut (14)
-6mm airsoft bb (4)
-8mmx2mm O-ring (4)
-5x11x4mm bearing (4)
-.25" brass tube (1")

This is a lot of different parts and it can get expensive to order them all. I found all the cheapest buying options for the parts needed and it would cost over $70 to buy it all due to the minimum quantities they are sold in and shipping from various places. I have full part bundles and instructions for sale here: https://compressedcreations.bigcartel.com This will save you time and money and ensure you get the exact parts that I used to successfully build this engine. I will also cut all necessary pieces to the closest spec possible if you purchase it from me. I charge $21 for all the necessary parts and $2 for 3-5 day shipping, hopefully making it much more stress-free and affordable for people to build this engine.

This engine is a really fun desk toy but was designed with the intention of also being able to power things. I integrated an axle connection in the flywheel so it can power things and you can also print your own replacement flywheel and bolt it to the universal hub. The engine doesn't actually need the flywheel to run so it can be removed if wanted. It also does not require the engine stand, it is optional but is a nice way to display the engine. The hub has four 1.8mm holes in a 8x8mm square to accept M2 bolts. If you want to make something like a propeller or any other kind of drive component you can design the object with this bolt pattern and attach it to the crank output on either side of the engine.

It puts out decent torque at just 1psi (lung pressure) but is very strong when connected to an air compressor. The problem with an air compressor is it may not be able to supply the volume of air this engine can take so 30psi from the compressor may drop to 3psi by the time it gets to the engine.

If you build this please send me a video or link to it! I'd also love to see it ran at insanely high pressures to see what it can handle.

I hope you enjoy this model and please contact me with any problems or questions at [email protected].