School project – mechanical hand
This article will have an overview of our school project (term 2/6). There are three heads on my group. Our goal with this project is to make a mechanical hand which can move it fingers like a real human hand, electronically controlled. Even point at, pick and crush things!
Before we decided what project we wanted to do, we had several ideas. A sensor based 4wd vehicle to mention one of them. After setting our goal on making a mechanical hand we did our research on google search/images. We only found a single hand (image below) which seemed something we could do in our time, among many other professional vendors.
It is required by us to setup a budget and plans for the rest of the project. All groups in my class needs to be finish by week 21 when the presentation is.
Me and my group are finish developing the hand and making it. We also got our plans for each week ready. Luckily, we reached our milestone for this week, were we wanted to figure out signal’s need for the RC-servos.
The hand is going to be drifted with five Futaba 148S servos, they cost about $19 each and provide 4.1KG of torque with 6.0v and a twist time of 0.19sec/60 degrees. So far, our budget is on $94, but it may increase by a few bucks due to some small components we might need.
We are still working on the sinew/rod’s before installing servos. We might just clean it for all welding points as well.
We have now figured out the servo signals and created a physical servo controller. We are using the 555 timer, two actually, because we had an issue with only using one. It didn’t create a stable output before 30 seconds after start. The
surrounding components, capacitors and resistors are our variables, changing the signal length.
The circuit’s for this hand is so complex, that we decided to program it all into a Altera card. Logic scheme will be available later when we have completed the project.
|School project – Mechanical hand|
Video of hand in action.
Many have asked about this hand and how to copy it. I have compiled a list of the material used for our hand.
- Stainless steel. One large tube for wrist/arm. Small tubes for fingers and a plate for the hand.
- Bicycle wire and bicycle tube used for bicycle breaks.
- Sikafleks, a glue like compound.
- 5 x servos
- Altera DE II
- Misc. wires
Even though this hand is made this way. I recmmend you to skip the Altera board. Its FPGA based and overkill for this application. You would achieve your goal quicker with an Arduino.