Robotic Drawing Arm - Part 1

This is going to be the first post of an ongoing project. For a little bit of background, I've been working on a fairly complicated robotic project over the last few years, basically a 16 servo, 4-legged walking robot. eventually I'll have a series of videos and blog posts for that.

In the course of accumulating supplies for that robot, and going through different prototypes I ended up with a handful of extra parts, and I've always wanted to make a robotic arm that could draw. I'm still learning computer programming, so I realized that if I created the code to move and control a simple 2-piece arm, I could use a good portion to control the leg of the walking robot when I get to that point, since it's a very similar setup.

Here is a snapshot of the design in progress. It will be run by two main servo motors, and a smaller one to lift and lower the pen. the design of the main base plate, and the first link of the arm is about 75% done, but I have not started on the pen holder, and the tray to allow it to switch pens/markers.

Initial concept for the robot arm.

Initial concept for the robot arm.

Top view

Top view

Detail of first joint/servo.

Detail of first joint/servo.

As you can see I'm digitally designing the robotic components, and will have them laser cut, but I started off building a base for the arm tonight, since it's a set size.

 

BasePlate1.jpg

I picked up a sheet of 12"x12"x1/4" plywood and a few pieces of 1/2"x1/2" wood strips. I cut the strips to have a 45deg bevel at the corners to fit together, and then using wood glue and a nail gun, stuck it all together.

BasePlate2.jpg

I got a piece of thin black core mat-board and cut it to size to fit over the plywood. I wanted a surface that would be nice to draw on, so when the drawing paper is adhered or clamped down, the robot can have a smooth surface.

That's as far as I've gotten so far. The next steps will really be to finish up the digital design and get the pieces laser cut. I'll post an update when I get the model complete and have a parts list of everything I'll need.

Let me know in the comments if you have any questions.