Grabcad

Knive grinder reverse engineered

 * https://drive.google.com/file/d/0B_CjXV72cuE_UDc2eUh0YmwzakE/view
 * https://www.youtube.com/watch?v=ZAnhqDf-l2c
 * https://grabcad.com/library/handheld-grinder-reverse-engineering-model-1
 * https://grabcad.com/library/upgrade-to-handheld-grinder-5-items-1 Upgraded version
 * https://www.youtube.com/watch?v=ZSi8LJIIYFU
 * https://drive.google.com/file/d/0B_CjXV72cuE_NDlfVjBzSTQtRmc/view

worm gear
https://grabcad.com/library/worm-gear-reducer-6

https://grabcad.com/library/multistage-reducer-visestepeni-reduktor-1 worm bevel gear reducer  solid files

planetary
https://grabcad.com/library/planetary-gear-box-3

https://grabcad.com/library/three-stage-planetary-gearbox-with-two-output-shafts-amination-tutorial-1 solid files

https://grabcad.com/library/worm-dual-planetary-gear-unit-with-a-capacity-of-60-kw-type-rcpg-2 planet worm gear combo esigned to power the chassis of the rotary excavator in coal mines. Analytical calculations of all gear and worm gears are made with Kisssoft gear design software. For 3D Designing and 2D drafting drawings are used Autodesk Mechanical Desktop and Solid Works

Grinder
https://grabcad.com/library/upgrade-to-handheld-grinder-5-items-1 hand held grinder.

https://grabcad.com/library/v-belt-grinder

mechanisms
https://www.youtube.com/user/thang010146 200 short clips on various mechanisms