Mini CH3-R spec opinion needed

Lynxmotion Legged Robots
1

hello everybody.

planning to make mini CH3-R like hexapod but powered by micro servos with 2,5kg stall torque.
need specialists opinion is it have any chance for success?
main materials is aluminium alloys and glass or carbon fiber parts.
accu (2S lipo 2-2,2Ah) weight around 0,15 Kg, servos 0,015kg each. BEC 0,056kg both.

including PDF with drawings
Draft1.dft.pdf (37.4 KB)

2

That looks like a cool walker. From your drawing I gather that your femur is 5cm center to center? So I’ll assume your tars is also 5 and apply a worst case scenario: Bot supported on 3 nearly outstretched legs. Then you’d have something like 2.5/9 = .27kg of support per leg. You could support about 810g. From the parts you listed you’re already at 476g. If you can keep your structure less than 300g it would probably be ok.

Also you could try this:

leg load.png
leg load.png819×460 2.36 KB

The red line represents the force on the leg. If you keep the distances, represented by the purple and yellow lines, as equal as possible in your gait sequence then you can keep the loads on your hip and knee servos close to equal and support more load.

3

Perhaps the Robot Leg Torque Calculator Tutorial can give you a start to the equations.
robotshop.com/robot-leg-tutorial.html

Very nice design. Take three legs, lift them up and add them as dead weight, and spread the legs out a bit. This will help you calculate if the torque produced servos in the shoulder are enough to support the load.

4

i’m afraid that 300g would be only screws lol. joking. will use M2 screws shoud be fine. probably carbon fiber only must be for the flat parts.

thanks you both for a clue