Harmonic Hyperdrive

Harmonic Hyperdrive is a gearing contraption that achieves a 300 to 1 gearing ratio. It is a combination of a strain wave gear, also known as harmonic drive, and the Grinder Gears. The mechanism has two sets of cycloid drives, one with a gearing ratio of 26 to 24, and the other 25 to 23. The resulting gearing ratio is 25x24/2=300 to 1.

Harmonic drives are best known for their high accuracy, not any slack or backlash, and high reduction ratios. The reduction ratio of a Harmonic Hyperdrive is proportional to the square of the reduction ratio of the equivalent harmonic drive. So it can achieve even higher gearing ratios while keeping the number of gear teeth limited, and the size of the teeth not too small.

After seeing the YouTube video, Dr. Ingolf Schäfer of Harmonic Drive AG told Oskar that they had conceived a similar (same?) concept in the 1990's. However, only some lousy sketches are left. It is unsure whether they ever prototyped it. The reason that Harmonic Drive never pursued the concept that there is no market for gear drives with such extreme reduction ratios.

Watch the YouTube video.
Read at the Shapeways Forum.
Read more at the Non-Twisty Puzzles Forum.

Please order a 3D-printed do-it-yourself kit from Shapeways at this page (check with Oskar about screws), or contact Oskar directly if you are interested in obtaining a fully colored, and assembled sample of this gearing contraption.