Foil Capability Switch

Step 9: Other Uses - Foot Switch

We worked with a six-month old who had arthroglyposis.  She could not move her arms but she could move her legs.  So that she could play with adapted toys, we did several things for her.

First, we made a pad (as in the main instructable).  Next, we covered one of her little shoes with hot glue and then covered it in foil.  One clip goes to the pad, the other to the shoe.  She could activate toys by kicking her foot against the plate.

We also took her soft socks / baby booties and sewed the loop side of a piece of velcro to the sock.  We hot-glued the hook side of velcro to a strip of aluminum foil that had been folded over a couple of times.  This made a wide variety of adjustments possible, and allowed us to experiment with a lot of different configurations.

Comments

[juiceman74]

I had my 6 graders make games and type writer application with similar switches.  We used Picoboards (I bought individual boards for $70).
10x for the great contribution.

BTW - do you have an idea how to make a spindle switch that turns on with centrifugal force?

[spark master]

use a top that light up?

[juiceman74]

what kind of top? I didn't understand you.

Thanks for the reply.

[spark master]

kids toy that lights up on spinning similar to or a duplication of a tilt switch. ballbearing is in a slide as it spins the force pushes the ball bearing into the end (cup) and it shorts the edges ligting up the top.

you could do same I guess.

short plastic tube seal one end at switched end embed two (or six every other one is half th eswitch , so no matter how the ball goes in it works) wires either side of tube mounted at upward angle , as it spins ball moves up shorts the leads, like a mercury switch.OR Use two pieces of printed circuit board in shape of a Vee at the action end and it should work quite nicely

If it has to work in any position while spinning it must be spring loaded so the ball can move freely ONLY when spun.

Duncan used to make tops that lit only when spinning , if the top has an on off switch and is not spin activated the switch won't work. Those switch quite a bit of rotational speed to function.

[spark master]

sHADOWWYND 'S CONCEPT OF ARMS THAT FLY OUT AND MAKE CONTACT IS BETTER , SINCE YOU NEED A MORE INVOLDED SYSTEM TO GET THE SWITCH FROM INSIDE A SPINNING OBJECT TO DO SOMETHING OUTSIDE THE ROTATING BODY. iT CAN BE DONE , JUST NOT EASILY

[shadowwynd]

I assume (you could do it the opposite way also) when stopped, no contact between conductors.  When rotating with enough force, contact is made between conductors.

My first thought would be to look at a couple technologies:

Tilt Sensor (anti cheating) for pinball machines
http://electronics.howstuffworks.com/pinball-machine4.htm

Steam flyball governor
http://www.history.rochester.edu/steam/thurston/1878/chapter3.html

In the first, gravity normally separates the contacts when the machine is upright, contact is made when tilted.  In the second, the governor is placed on a rotating shaft.  The balls get further apart the faster the shaft goes. 

If the direction of shaft rotation is perpendicular to gravity, a couple options come to mind.

First, you could make the pinball tilt sensor, but connect the plumb bob to a vertical rotating shaft with a spring.  Use a slip ring to transmit electricity to a collar that is soldered to the spring.The spring will be partially mounted on the vertical shaft.  When the shaft is stopped, the spring will hang straight down due to gravity.  When the shaft is in motion, the weight will move sideways, the spring will bend sideways, the spring will contact the ring, thus closing the circuit.

You could also make something similar on the edge of a flywheel.  A contact spring bends outwards when the wheel is spinning and touches a contact plate, then returns to an upright position when stopped.

If you can find a glass-tube mercury tilt switch (from old A/C control units, etc.) that would make an easy tilt switch also.

You could have a weight (non-conductive) attached to a spring in a tube or track.  When the rotation is stopped, the weight is near the center.  When rotating, the weight slides down the track and presses a button (commercial switch).

You could have a piece of metal in a nonconductive track, attached with a spring to the center of the rotating object.  When there is no rotation, the spring keeps the metal near the center.  When rotating, the metal slides down the track and bridges two contacts, OR the metal weight is electrified and thus is the other contact.

These would also work if you had a horizontal rotating shaft, but you would need to make sure the spring is stiff enough that it does not touch due to gravity, only rotation.

[juiceman74]

Shadowynd, Thanks for the interesting ideas.

I'm in the direction of the more simpler suggestions you gave. In the attached picture I've drawn my idea. I still need to check it out.

Kid's toys use a spring that bends with force with spin and creates contact with another meta which short circuit.
What is the idea behind the horizontal rotation shaft?

[foobear]

very interesting