Pen Mechanism

To make it draw I needed a platform held between the drive wheels.

This platform has to be held exactly central to the wheels and move with the wheels when raised and lowered.

Rather than use a servo, I wanted to control the lifting and lowering of the pen using just one wire. (on/off)

I have done an Instructable on the Pen Lifter.

Testing that the pen is in the centre between the wheels.

After adding the pen mechanism to the robot (I want it to be able to draw on the floor). I found that I had no clearance for the robot to drive over low obstacles (floor rug).

So I needed to fit a mechanism to rise the pen platform.

I found another nice little geared motor with an M3 threaded bar, on eBay.

With this I made a lifter to rise the Pen and sensor platform.

I made circuit boards to control the pen lifter and platform lifter.

Both the Pen Lifter and the Platform Lifter work in the same way. (single wire, on/off)

Making a circuit board to control these two motors, means the program does not have to wait for the motors to compleate there task.

If you like what I have done, or want to know more.

Please leave a comment below.