Introduction: Extendo Hand
Second Prize in the
Instructables and RoboGames Robot Contest
Sometimes wish I had an extendo hand to help me reach things that are just a little too far away. For instance, picking plums off of the trees around here in Santa Clara, they are usually just about 12 inches too far away for me.
This is totally ridiculous, I know, but here it is...
here's my boyfriend Greg picking plums with it:
Step 1: Stuff You Need
a wrist brace (you can find these at Safeway made by Ace bandages)
5 spring type door stoppers
some wood and some screws
5 large washers with holes big enough to fit your fingers through
some eyelet screws to guide the string through
Step 2: Attach the Fingers
attach the door stoppers to a small chunk of wood which will act sort of like the palm of the hand.
I tried a couple of different directions for the thumb, but straight up at 90 degrees seemed to be the best idea.
Step 3: Attach the Tendons
first tie the strings to the tip of the door stops underneath the rubber end caps.
then secure the string to the "knuckle" part of the door stopper with cable ties.
attach the eyelet screws to the wooden palm and guide the strings through them.
Step 4: Attach the Hand to the Arm Bone
attach the palm to a long stick of wood to be the arm with screws.
attach the wrist guard to the wood at the other end with screws also.
Step 5: Adjust the String Length
put your hand inside the wrist guard and tighten it down with the velcro straps. You may need to add some velcro to the backside of the wood for it to grab onto.
carefully connect the large washers to the tendon strings and align them so the inside holes just reach the tips of your fingers.
Step 6: Now Go and Grab Some Stuff!
The fingers aren't too strong though, they keep shifting to the sides a little. And it needs some padding under the knuckles and on the finger rings if you're going to use it a lot.
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Please be positive and constructive.