Parametric Bearing Gear Toy

thingiverse

A Parametric Gear Toy Based On The Parametric Spur Gear Using Small Bearings The parametric gear toy is based on the popular [parametric spur gear](https://www.thingiverse.com/thing:3336641), utilizing small bearings to provide smooth motion and precise control. Four gear teeth counts and bearing dimensions are adjustable parameters, allowing users to customize their design to suit specific needs. The default settings produce a gear ratio of approximately 3 from the outside to inside gear, using MR104-2RS (4mm ID x 10mm OD x 4mm W) bearings that are press fit into the gear assemblies and onto the frame shafts. For those who prefer a bearing-less design, see the [parametric gear toy](https://www.thingiverse.com/thing:3336663). This design exposes several top-level parameters related to gear teeth and bearing dimensions: * `TOP_GEAR1_TEETH` - tooth count of right gear (default 35) * `TOP_GEAR2_TEETH` - tooth count of top middle gear (default 16) * `TOP_GEAR3_TEETH` - tooth count of bottom middle gear (default 33) * `TOP_GEAR4_TEETH` - tooth count of left gear (default 24) * `TOP_GEAR_HEIGHT` - height of all gears (default 5mm) * `TOP_GEAR_SCALE` - tooth scaling for process margin (default 0.925) To address material shrinkage and printing accuracy discrepancies in the gear teeth, this design incorporates a parameter called `TOP_GEAR_SCALE`, which ranges from 0.0-1.0 and defaults to 0.925. This parameter scales the width of the gear teeth along their reference diameter, where 1.0 is the nominal width. If binding or slop occurs, users can adjust `TOP_GEAR_SCALE` to compensate. In addition, this design exposes several top-level parameters for bearing dimensions and press fit: * `TOP_BEARING_BORE` - inner diameter of bearings (default 4mm) * `TOP_BEARING_DIAMETER` - outer diameter of bearings (default 10mm) * `TOP_BEARING_HEIGHT` - width of bearings (default 4mm) * `PRESS_FIT_SOCKET_CLEARANCE` - socket margin for press fitting the outer diameter of the bearings into the gear sockets (default 0.01mm) + The socket diameters are increased by this amount * `PRESS_FIT_SHAFT_CLEARANCE` - shaft margin for press fitting the shafts into the inner diameter of the bearings (default 0.05mm) + The shaft diameters are increased by this amount The press fit clearance parameters may require some adjustment to achieve an effective press fit of the bearings. GitHub: https://github.com/vsergeev/3d-gear-toy/tree/master/parametric-bearing-gear-toy Design on A360: https://a360.co/2EI4bxf