Originally shared by james wolf I have been thinking about making a simple crawling

[james_wolf]

Originally shared by james wolf

I have been thinking about making a simple crawling bot. I needed to come up with a design for part of it that could operate 2 opposing legs with just one servo. I thought this design might work.

The setup pivots the black plastic post that is attached to the lower half of the servo with a box. This keeps the two horizontal pieces in line and allows the “feet” to move up and down with just a rotation of the servo. It is strong, friction free, and maximizes the servos strength.

I came up with a design one day, drew it out in SketchUp, and 3D print it at home in less than 2 hours.

3D printing allows you to iterate through an idea so quickly. When I realized that one of the pieces got measured wrong, I changed it in the design, and reprinted just that part. Turn around time = 40 minutes.

The same essential design could be used to represent almost any muscle movement on a robot. The next step is to use a second servo to rotate this one. Both servos combine to make a single segment on a multi-segmented robot (think centipede).

Want the files?
STL (3D print file)

ServoLegDesign.stl

SKP (SketchUp file)

ServoLegDesign.skp

[Tristan_O_Brien]

I made something similar to this from mechano years ago. Used 3 sets to make a 6 legged walker. Using a chain in a tripple looped 8 got the legs to offset on each step. 3 servos for the three sets of legs. All controlled off 1 pin. And one servo for the “twist”. So total of two pins from a micro. Could only go in straight lines though…

[Alan_Weber]

Put these in some rock 'em sock 'em robots!

[james_wolf]

this is the last video I did of it in action:

but right now it is even better than that, I will prob post a new video later this week when I get the new changes complete (includes the ability to turn)