Conductive Graphite & 3M Ear_Plugs = Sensor

A project log for TriMaxGripper & Linear Servo Actuator (GM)

3D Printing a Positional Servo Actuator

chiprobotchiprobot 06/25/2014 at 20:550 Comments

Just had my delivery of Conductive Ink & 3M Ear_Plugs !!!!!

I have started to make some custom Resistance Force sensors to fit to the push rod end of the actuator.

They will be used a a Force Feedback system so i will be able to calculate pushing forces..

The video of how I made them can be found Here :-

Its a messy job "2 by 2 Hands of Blue" however the results are promising - just have to design 3D printed housing for them.

This is the first "Stab" at creating some sensors.....

Here is a test of the foam sandwiched between two halves of a finger tip and lined both sides with copper foil for connectivity.

The resting resistance is circa 700 Ohms lowering down to 300 Ohms on compression.

Starting to take shape :-

Compression Chamber test print No.1 

I need a Pull sensor and not a Push sensor so my first idea is to create a sliding piston type (the 3M Plug only alters slightly in diameter on compression meaning that it needs little clearance with the side wall)

Have to process 3M earplug and the Galvanised screw should be a Nylon one (or maybe not - have to test after ink is dry)