Summary

This Spider Rover can be simply clicked together with one and the same lock washer type. No screws required. Just in case you want to do more extensive research with it, you can add a motor (pulley is in the files)

https://www.youtube.com/watch?v=7VCwuc3o3bI

Motor replications will be listed here:
Александр Александрович: https://www.youtube.com/watch?v=Y7xACFmR0Vk
Justin Wilcott: https://www.youtube.com/watch?v=LswDA3t8Rc0

Instructions

added piece count requested by pcav:

1x deck_base.stl
1x deck_bottom.stl
1x deck_middle.stl
1x deck_top.stl
6x leg_arm_bottom.stl
12x leg_arm_middle.stl
12x leg_arm_upper.stl
6x leg_control_al50_delta-30_r1_s1.5.stl
6x leg_gear.stl
6x leg_gear_washer_fix.stl
6x leg_pin_bottom.stl
6x leg_pin_middle.stl
12x leg_pin_upper_middle.stl
6x leg_shell_big.stl
12x leg_shell_small.stl
6x leg_shoulder.stl
76x lock_washer.stl
1x optional_motor_belt_pulley.stl (only for motor)
1x worm_gear.stl (not scale, motor) or worm_gear_scaling.stl (small scaling)
1x deck_bottom_worm_gear.stl (bearing, motor) or deck_bottom_worm_gear_dummy.stl (no bearing, no motor)

To put together one leg as shown in the picture use from the complete part list:

1x leg_arm_bottom.stl
2x leg_arm_middle.stl
2x leg_arm_upper.stl
1x leg_control_al50_delta-30_r1_s1.5.stl
1x leg_pin_bottom.stl
1x leg_pin_middle.stl
2x leg_pin_upper_middle.stl
1x leg_shell_big.stl
2x leg_shell_small.stl
1x leg_shoulder.stl
1x leg_gear_washer_fix.stl
8x lock_washer.stl