In this Instructable, we see how to design, 3D-Print and test components of a Robotic Hand.
If you like any part of this project, please vote for it and then email the link to everybody you know!
I enjoy writing programs. I love building things. I don't build robots for a living, but I do design them for fun and research.
My team and I are considering building a robot for the DARPA Robotics Challenge. And today, we're looking at hands.
We need a realistic, reasonably priced robotic hand platform to test some ideas with. When I shopped around, I found a lot of really good models that I didn't have the budget for yet. I wanted to see what could be designed using mostly 3D printed parts. I'm happy to share our experiences with you here.
For this hand design, we want to be able to try lots of different types of servos, tendons, sensors, and control software. I'm choosing to design the palm and fingers separately in an interchangeable and modular way, so the design can evolve with the project.
In this Instructable, I'll be focusing on the design and build of the fingers. I'll spend a little time showing the palm design and talk briefly about the plan for tendons and servos. The design was made using mostly OpenSCAD, and we debug some of the control systems in V-Rep in a later instructable.
If you are already familiar with OpenSCAD, you can skip ahead.
If you like, you can jump directly to the printed fingers.
Let's get started!...
Step 1: The tools to get you started...
The Tools Used:
Brain (I had one that I wasn’t using for anything else at the time...)
Some paper and a pen
My own hand (I had one handy)
Digital calipers $9-$20 from Harbor Freight
Computer (Linux, Mac, or Windows)
The Software Used:
OpenSCAD Programmatic 3D Modelling Program
MiniMagics STL File viewer
STL View by ModuleWorks
(Search the Android Marketplace)
3D Printing Service Used:
EngATech.com (ask for Tim)
How to Make it REAL:
While you are waiting for your download of OpenSCAD to finish, place your hand on a sheet of paper and trace the outline of your hand on the paper with the pen. (Starts out easy, right?)
I placed a dot on the tracing at each location I thought I’d want a hinge or joint of some kind; at each knuckle of each finger and the thumb. Afterwards, I used the digital calipers to measure (in millimeters) and make notes on the drawing of things like the width of each finger at the location of each joint.
I also measured the distance between joints, the overall length and breadth of the palm and wrist. Taking measurements from the paper tracing turned out to be much simpler than measuring with the calipers directly from my hand. I was able to measure more carefully, and got better results, I think.