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Primer

This is an open hardware project based on the Michael Peshkin Lightboard from Northwestern University:

https://sites.google.com/site/northwesternlightboard/

Concept

A simple design that allows a lecturer presenting to a camera to write as they would on a white board but facing students.  This eliminates the need for complicated computer generated graphics. 

Differences between the Duke Lightboard and the original Peshkin Lightboard

The Duke Lightboard focuses on smaller, lighter construction the goal of eliminating the need for many studio accessories.  As a result, the design is somewhat portable and reduces the need for complicated lighting arrangements.  The three key technical elements are the use of an electronic "flipper" to mirror the video, the use of a custom designed LED clip, and the exclusive use of bolt-together 80/20 aluminum framing as opposed to a welded steel frame.  A project goal is also to create a design that is simple enough a lower level technician could build it.  It was also desirable to use common, easily sourced components for the construction.

The electronic flipper processes the reversed image as opposed to shooting the camera through an actual physical mirror as spec'ed in the original design.  This eliminates complication and geometry from the design as well as increasing the light input to the camera.  The LED Clip is also a key element.  The design holds cheap 3528 sized LED's on standard 8mm strips precisely up to the glass.  The design is extremely light and includes framing for a second LED strip that can illuminate the face of the lecturer without the need for industrial studio lighting.  The second Subject LED Strip is set to a warm 3000K temperature which is more appropriate for human skin.  The clip can be reproduced using simple extruding or 3D printing technologies.  The use of 80/20 components considerably reduces the weight of the final product while making it easier for someone who does not have access to a welder or other metal working equipment.

Design Evolution

The project progressed through two stages where a small prototype was built to test various concepts while providing an example instructional development teams could use in designing course concepts and material.

Prototype

Bill of Goods for Prototype (3'x2') Lightboard

Standard Fabrication Components
ItemQntyEst. Cost Link
80/20 - 24" 15 Series sections2  http://www.amazon.com/80-20-SERIES-T-SLOTTED-EXTRUSION/dp/B001F0F14E/
80/20 - 36" 15 Series sections4  http://www.amazon.com/80-20-SERIES-T-SLOTTED-EXTRUSION/dp/B00BL104NU/
80/20 - Inside Gusset4  http://www.amazon.com/80-20-Series-4-HOLE-INSIDE/dp/B001IA12YE
80/20 - 7-Hole Tee Joining Plate2  http://www.amazon.com/80-20-Series-5-HOLE-JOINING/dp/B001IA4PQ6/
80/20 - Leveling Feet4  http://www.amazon.com/80-20-Inc-Series-Leveling/dp/B006YVZ04A/
80/20 - Inside Corner Brackets4  http://www.amazon.com/80-20-Series-2-HOLE-BRACKET/dp/B001IA4Q7Y
80/20 - 5/16 Button Head Bolts30   
80/20 - 5/16 T-Nuts30   
60 watt power supply1  http://www.amazon.com/LEDwholesalers-Waterproof-Transformer-3-prong-3204/dp/B003WOIVRU/
8mm - 5m 6000K 3528 8mm LED Strip1  http://www.amazon.com/HitLights-Density-Flexible-Adapter-included/dp/B005ST2I9O/
8mm - 5m 3000K 3528 8mm LED Strip1  http://www.amazon.com/HitLights-White-Double-Density-Flexible/dp/B00710K0DE/
LED Strip Connector2  http://www.amazon.com/dp/B00JJ4SRSA/
Custom Fabrication Components
LED Clips24$5.99 http://www.thingiverse.com/thing:307144
1/4 Tempered Glass    
     
     
     

 

Bill of Goods for Desktop (6'x4') Lightboard

Standard Components
ItemQntyCost PerCost TotalLink
80/20 - 72" 15 Series sections6$40.11$240.66http://www.amazon.com/80-20-SERIES-T-SLOTTED-EXTRUSION/dp/B001F0I3FI
80/20 - 24" 15 Series sections2$14.67$29.34http://www.amazon.com/80-20-SERIES-T-SLOTTED-EXTRUSION/dp/B001F0F14E/
80/20 - 24" 15 Series sections2$21.03$42.06http://www.amazon.com/dp/B00BL104NU/
80/20 - 5-Hole Tee Joining Plate4 $31.20http://www.amazon.com/dp/B001IA4PQ6
80/20 Inside Corner Bracket2$2.95 http://www.amazon.com/dp/B001IA4Q7Y/
80/20 - 45 Degree 15 Series Support2 $47.00http://www.amazon.com/dp/B006YVZ4UU/
80/20 - Caster Mount4 $74.60www.amazon.com/dp/B00J0934RI/
80/20 - Casters4 $124.00http://www.amazon.com/dp/B006YVZ2IO/
8mm - 5m 6000K 3528 8mm LED Strip2$22.95$45.90http://www.amazon.com/dp/B005ST2I9O/
8mm - 5m 3000K 3528 8mm LED Strip2$22.95

$45.90

http://www.amazon.com/dp/B00710K0DE/
LED Clips24$5.99 http://www.thingiverse.com/thing:307144
Dimmer4$2.99$12.96http://www.amazon.com/dp/B003L4KKF2/
     
150 Watt DC Power Supply1$68.00$68.00http://www.amazon.com/dp/B00IHZ9ME0/
Terminal Block1$7.99$7.99http://www.amazon.com/dp/B0055HOK7C/
Total  
Custom Fabrication Components
3/8 Low Iron Tempered Glass1$1026.89$1026.89 
     
     
     
Fuse block2$2.25 www.amazon.com/Fuse-Block-Full-Molded-3AG/dp/B00E3X6MGQ/

Studio Lightboard Construction

80/20 Primer

This version of the Lightboard makes heavy use of 80/20 T-Slot extruded aluminum.  T-Slot uses special nuts slid into slots then tightened to make a joint.  Joint pieces come in a variety of shapes and sizes for various applications but the concept is the same.  The special nuts (called T nuts) in this project are either single, double, or triple length.  Note that using double and triple T-nuts where possible makes construction easier.  An example is demonstrated in the video below.

80:20.m4v

LED Clip Primer

This project uses specialized clips to hold the LED strips precisely to the glass and provide subject lighting for the presenting lecturer.  The clips are easily manufactured with 3D printing. The LED strips must then be inserted into the LED clip.  This is demonstrated in the video below.

LED Clip.m4v

Principle Construction

Construction Of The Frame

InstructionsDiagramExample PhotoExample Photo
 Construct left and right side frame by joining 1x 72" 80/20 extrusion to 1x 80/20 24" extrusion with a 5-hole T-Joining Plate, build two of these T shaped structures
Add supports for left side of frame by joining 1x 45 degree 15 series support to the T shaped structure created in step 1.  The 45 degree supports have their own joints built in 
Add 5 hole corner bracket to what will be the back side of the left and right frame  
Add rear bracing by first taping the bottom 24" 80/20 1515 section.  Add a pivot nub to
Add 5 hole T-Joining plate to the bottom of the frame at the same location as the vertical 72" piece of 80/20 1515
Add corner gusset to the middle and top of the frame near the centerline of the holes you had cut in the glass.  Subtract 3/4" for the center line of the 80/20 1515 crossbar we will be adding.  
With both the left and right side of the stand complete, join them together at the bottom with two pieces of 72" 80/20 1515 acting as crossbars.   
Attach 2x 45 degree 18" or 12" supports to the inside of the two frames and against the bottom, center crossbar.   
Insert 4x 5/16 T-Nuts into the remaining 2 72" 80/20 1515 crossbars, latter these will support the glass.  With the side containing the T-nuts facing forward, mounting them as cross bars to the structure.   
Tap the top crossbar and top of the right and left sides of frame.  Add a right angle connector.   
At this point you should have a completed frame.  Stop to check all connections and make sure everything is secure and tight  
Attach the stand offs to the glass and insert a 2" 5/16 bolt.  We found it best secure them with super glue to they don't fall off during assembly. The insert of the stand off should be in the glass as to prevent metal on glass contact.  Standoffs may be sourced locally or custom stand offs can be used.  If using the 3D printing,
Lay the stand down and put soft material over the frame (such as a towel).  With several people helping, place the glass over the frame and secure it, making adjustments to the top cross bars as necessary. Bolt the glass to the frame, DO NOT OVER TIGHTEN
While stand is laying flat, attach casters and caster mounts to the bottom "corners" of the unit.  BE SURE TO LOCK THE WHEELS.  With everything attached, stand the unit up raising it evenly from the top corners. Be careful not to apply torsional force or twisting motions.  
    

 

Schematic For Studio Lightboard Glass

Studio Lightboard Power Consumption

Light ArrayPer LegArray Total
Top33.8 watts101.4 watts
Left21.75 watts65.25 watts
Right21.75 watts65.25 watts
Bottom  
Total231.9 watts

 

 

Cleaning Methodology

  • Wipe Lightboard clean with a traditional whiteboard eraser
  • White residual power from Lightboard with a clean, dry paper towel
  • Use a thin mixture of Dawn dish detergent in a spray bottle and mist the surface of the glass
  • Use a squeegee to wipe the cleaner off

 

 

 

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