<br> [MAS.865](../../index.html) > [Mechanisms](../../Mechanisms) > Gears ### Best sources for these things: - [SDP/SI](https://shop.sdp-si.com/catalog?brand=sdp) ### Involutes ![gearanimation](gearAnimation.gif) #### Layout: Gear Trains: ![Trains](train.jpg) [Planetary (aka epicyclic)](http://www-mdp.eng.cam.ac.uk/web/library/enginfo/textbooks_dvd_only/DAN/gears/epicyclic/epicyclic.html) ![Planets](planet.jpg) [Rack and Pinion](https://github.com/fellesverkstedet/fabricatable-machines) ![rp](rack.jpg) #### Main concerns / design guidelines: [Tooth Shear](https://www.geartechnology.com/articles/0815/Tooth_Flank_Fracture_-_Basic_Principles_and_Calculation_Model_for_a_Sub-Surface-Initiated_Fatigue_Failure_Mode_of_Case-Hardened_Gears/) ![shear](shear-1.jpg) ![shear](shear-2.png) Friction ![friction](friction.png) Backlash ![backlash](backlash.png) #### Fancy Things Preloading (CNC Router Parts R&P) ![cncrp](cncrp-rack.jpg) Helical-Cut Gears ![helical](helical.jpg) Harmonic Reducers ![harmonic](harmonic.gif) Cycloidal Reducers ![cycloid](cycloid.gif) ### Resources: [Spectacular Notes on How / Why Involtes Work / Are](http://www-mdp.eng.cam.ac.uk/web/library/enginfo/textbooks_dvd_only/DAN/gears/home.html#top) [See Particularely](http://www-mdp.eng.cam.ac.uk/web/library/enginfo/textbooks_dvd_only/DAN/gears/meshing/meshing.html) [NASA Gearing Doc](nasa-gearing.pdf) [Involute Gear DXF Generator](http://hessmer.org/gears/InvoluteSpurGearBuilder.html) #### Particular Implementations [Gorgeous Mill / Cast Microrobotics](http://lcamtuf.coredump.cx/omni/) [TDPD](https://gitlab.cba.mit.edu/jakeread/tdpd)