dbmoura wrote:The solution to switch the solenoid can be done by a simple and well positioned push button next to the glasses. Is someone testing or had this kind of idea? For me sounds nice the mechanism operating the shutter at the end, when the printed material achieve the proper pressure against the glass. Any contribution I would share it here documented in 3D via Sketchup.
How about placing a small white colored profile piece / clip, which will slide between the glass panels so it can be placed above the bottom and inner margin of the book. The clip has small and thin switches attached underneath to contact the book pages when it is pressed against the glass. The clip can be made of a plastic / aluminum connection or finishing profile. See the profile shape at http://www.salomons-metalen.nl/en/products/89/aluminium/profiles/finishing-profiles
and the illustration below:
I found two ideas for having thin switches underneath the clip for activating the solenoids or servos mounted without damaging the pages:
1: LilyPad Buttons
Two LilyPad Buttons placed under the clip. The button closes when pushed and opens when released (momentary push button). Dimensions: 8x16mm and thin 0.8mm PCB. Maybe it can be setup with two 5v solenoids parallel using conductive thread which is thin enough for under / or in the gap between the glass.
- LilyPad Buttons from http://www.sparkfun.com/products/8776
- Conductive thread from http://www.sparkfun.com/categories/204
- Solenoid small 5v from http://www.sparkfun.com/products/11015
- Servo from http://www.sparkfun.com/categories/178
2: Conductive Fabric Pressure Sensors
Two small fabric sensors placed under the clip. It will switch with the pressure between the paper and the glass. By minimizing the conductive surfaces on either side of the piezo resistive material, the sensitivity of the sensor can be adjust.
- DIY sample http://www.instructables.com/id/Flexibl ... re-Sensor/
- Velostat by 3M from http://www.lessemf.com/plastic.html
- Conductive thread from http://www.lessemf.com/fabric.html
- Conductive fabric from http://www.lessemf.com/fabric.html
In the DIY sample neoprene is used but is not necessary in this design. One can use any fabric or material as a base substrate, as it is not a functional part of the button/sensor. Fusible interfacing is a fabric glue that comes in sheets and is fused with heat from an iron, one can also use double sided sticky tape. Instead of conductive fabric contacts one can also use aluminum foil. Even the spacer material can be made from a material other than foam. Anything thick enough to keep the two conductive contacts apart when they aren't pushed together.