20:1 Planetary Gearset Servo Drive InMoov Hip Joint by mayaway

Last crawled date: 3 years ago

I reused 6) Planet.STL, 1) Ring.STL from https://www.thingiverse.com/thing:2335266
The input and output shafts are HEX and 14mm (heavier)
I re-designed the Carrier (now InputGearPlate) to keep the gears of the two stages from binding on each other and make what used to be the SunGear a part of that plate.
The gearbox is very quiet and runs smooth if you grease everything up.
I'm using HS-5805MG Servo for the drive. The pot is removed & used for external feedback. The servo is altered for continuous rotation. I've also ported wires to the motor contacts so I can drive a slave in the robot ankles, creating the effect of parallelogram legs. The gearbox is 20:1 so torque increases dramatically.
I've enlarged the sun gears for less play. Scale if needed based on your print results.
There are brackets for mounting the assembly to my current InMoov & legs setup. The output shaft is held firm so the gearbox itself produces the output motion. The big pin inserts into the rest of the part of the hip joint which allows for flexion and extension at the hip. I've built a set of legs for my InMoov which I will publish once I have her walking. My plan is to use this in my InMoov's hip & ankle joints for lateral weight shifting, an absolute must if the InMoov is to walk. I am a retired PT and know quite a bit about the human gait sequence.
Let me know if the images and video provide enough info for assembly.
Video: https://youtu.be/tiQeYsx9oTM
Hardware:
6) M4 x 10mm Hex Cap Screws - Gears
6) #8 x 5/8" Sheet Metal Screws - Covers
10) Large Servo Screws (from Mega's) - Servo, Servo Wheel, HipPlanetPotBar
2) M3 x 20mm Machine Screws - Servo Riser mounting
1) Small 6mm machine screw - HipPlanetPotArm
2/6/18 Considering design changes to make the assembly more compact and the drive and output shafts heavier. Will upload as needed & post notes of changes.
2/18/18 New shorter and adjustable version of HipPlanetPotArm & HipPlanetPotBar - print both with support.
2/19/18 Combined three parts (Carrier, Separator, Sun Gear) into one: InputGearPlate
2/20/18 Revised covers to lessen input/output shaft play. Am testing inner bearing surface for input sun gear... we'll see.
2/27/18
Yep - the inner bearing surface on the input gear is a good addition so InputGearPlate and SunGear are both new.
For High torque output applications the OutputGearPlate_v2.stl is replaced with OutputGearPlate_v2.stl along with a cover to match, Cover-36mm v2.stl and HipPlanetMount_SQ.stl
To tighten up the backlash even more I've scaled the Planet gears 4% larger.