Garden Railway Forum

Here's a LEGO vacuum engine I built, "vacuum" referring to a readily available power source, a vacuum cleaner - it has nothing to do with a flamelicker. (Look up Lego Vacuum Engine on YouTube, they get pretty impressive, I'm talking v16s and stuff.) Anyway, this one here is a double acting single cylinder, it's very smooth. I'm thinking I could make 2 of these and mount them on a frame with a compressed air tank made from a 1-liter soda bottle, and have a "live air" LEGO fireless...

This looks really interesting. What kind of speed/power does it make?

I'd guess about 800-1000 rpm, I made a transmission for it and it was unable to turn it so very little power, but there are some pretty powerful ones out there. However it runs nicely and I could use a longer stroke for more torque.

I'll have to take a slow-mo video and count the revs myself as I don't have a tachometer.

I took a slow motion video of it and trimmed to 16 seconds, then counted 80 rotations in groups of 8. Since the slow mo video is 4x slower that gives us 80 rotations every 4 seconds or 20 rotations per second, which equates to 1200 rpm. Of course, it would be faster with a more powerful vacuum.

Maybe something like this:

Here's a gif of it running, watch the blue thing