Digital Assembly

Keywon Chung, Marcelo Coelho and Scott Greenwald

May 18, 2009

Disc Punch Press

The final milled parts and the punch pressed discs.

Detail of the positive part.

Detail of the negative part. Cylinder for cutting hole got bent.

3D Models for Disc Punch Press

There is a 0.001" offset between positive and negative parts.

Rhinoscript 3D parametric punch press (.RVB)
Rhino 3D punch press model (.3DM)
Rhino 3D punch press model (.DXF)

3D Models for Printing Snappers

Rhinoscript 3D parametric part (.RVB)
Rhino 3D part model (.3DM)
Rhino 3D part model (.DXF)
May 11, 2009

Male and female parts for punch pressing the tiles

In this design, there is a 2 mil offset between parts A and B.
This was designed to be used with 1/16 balls.
(Offset was later reduced to 1 mil).

May 4, 2009

Part Size

final ball diameter = 1/16"
part width = 6/16" = "1/3-inch part" (0.375")
thinner: 0.02" = 1/3 of the ball diameter
thicker: 0.04" = 2/3 of the ball diameter

Conductive Parts

Material: Blue Shim Stock

- Upper layer (thin): Shim Stock Strip Blue Tempered Spring Steel, .020" Thick, 6" X 25"
- Lower layer (thick): Shim Stock Strip Blue Tempered Spring Steel, .042" Thick, 6" X 25"
- Balls: Low-Carbon Steel Ball 1/16" Diameter, Grade 1000, Packs of 500

Non-conductive parts

- Upper layer (thin): White Delrin Strip .020" Thick, 12" Width
- Lower layer (thick): White Delrin Strip .040" Thick, 12" Width
- Balls: Clear Extruded Acrylic Ball 1/16" Diameter, Packs of 500

Part Fabrication

1. Flow balls into the holes of a base layer.
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. . .

Alternative: Vacuum pickup
. . .
. . .

2. Put a thin/top layer upside down over the base layer and the balls.
. . .

3. Apply glue
. . .

4. Put a thick/bottom layer
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5. Cut parts
. . .

- How to keep parts in place? Do we need tabs?
- Spacer + tabs?

Placing with Vacuum Tip

. . . vacuum engine
We need a bigger tip to cover the center ball area
. . .

Size 14 syringe tip, cropped short
. . . syringe tips
. . . vacuum tip
. . . digital assembler syringe
. . .

April 27, 2009

1. Part design

Goodbye GIK, hello snap tiles: two-layer parts with epoxy and balls (Part PDF spec)

 - Conductive tiles and insulating tiles
 - Triangle vs. cross: zig-zag, no shear lines?
 - Balls vs. pegs: chamfered edge
 - Cut them in sheets, connected by tabs
 - Alignment rods for multiple layers
 - Flow spheres over the layers
 - Final dimensions: 50 mils? 
 - Tool for cutting shim stocks: alternating teeth?

2. Pick and place

Vacuum pen: Press the button with linear gear (Mount PDF spec)

Motion sequence:
 1. Button press
 2. Move pen down
 3. Button release
 4. Move pen up
 [move x-y]
 5. Move pen down
 6. Button press (extra force down here would be useful...)
 7. Move pen up
 8. Button release

Press-fit force at step #6
How to hold the piece down as it's released...?

To do:
1. laser cut and assemble conductive and non-conductive parts
   a. can we cut a single material by etching smaller different depth holes?
   b. can we bake the parts together so they will stick?
   c. what kind of glue would work and at what scale

2. figure out suction cup mechanism
   a. valve 
   b. suction cup itself
   c. how will the suction cup press the part into place
   d. pump

April 13, 2009

1. Cam prototype

2. Parts design

Options: GIK, miniature Legos, or custom part

- Custom part design
[Need picture/video here]

- George Popescu's GIK page, paper draft
- 1/10mm size, SOIC scale
- Metals and functional materials >> Neil strongly suggests 2D parts (use new lasercutter)
- Start with a bed of lattice
- No meterology(sp?) on the printer
- We can start with 2 grooves (4 is more than we need)
- 90-degree rotation: 2 heads vs. 1 rotating head
- Spacers
- Circuitboard fab: killer app, counter 3D printers
- George's GIK assembler has 4 blades - 1. Building 2. Detecting errors 3. Removing errors 4. Rebuilding removed parts

- GIKs cut in two sizes: 0.272" for 5/64" thick acrylic (perhaps supposed to be 1/16") and the other 0.365" (7/64", approx 1/8" thick)
- Empty space - solder leak?

March 31, 2009

Rhino drawing of stamper parts

Stamping Machine for Lego Assembler from Marcelo Coelho on Vimeo.

March 17, 2009

Early work

2D Assembler
3D Assembler
1. 2D Assembler

- what process(es) will it use?

For robust design with that reduces the number of motions necessary per part assembled, we use three principles:

  1. Periodic Juxtaposition: Use a sewing machine-like head in combination with a platform moving at constant speed (as opposed to a jerky-arm model)

  2. Part Aperture: For small numbers of parts, we propose columns of feed stock parts with individual apertures that release parts in coded order. For large numbers of parts, we propose a cylindrical array of part columns with a fixed aperture that releases parts in a coded order

  3. Funnel Queueing: Once release from their apertures, parts slide into funnel that queues the parts for placement by the pecking element. Introducing a funnel eliminates the need for a 2-d coded motion that selects the desired part from an array of feed stock.

- what will (and won't) it be able to do?

In this case, "2-d" refers to the motion of a platform which supports the part. We assume that snap, adhesive, or other bonding can be initiated mechanically by the pecking element.

- what are the benefits (and disadvantages) over current practice?

By separating oscillation from translational motion, we achieve a robust design.

- what are the system components?

Feed stock, apertured array, funnel, pecking element, 2-d platform

- which parts exist, and which will require development?

Aperture, pecking element, and funnel need design.

- what will the workflow be from design to output?

Geometry file in, aperture coding out.

- what consumables will it need?

Ordered feed stock parts.

2. Universal 3D Assembler
Two-part process
  1. Make multi-layer pieces: Operand layers (glues, resin, magnet, copper etc.) and coded dimples optional

  2. Assemble the pieces: Achieve multiple configurations using robotic arms and syringed functional materials
Part 1. Make multi-layer pieces:
Combination of printer/copier + iron + bandsaw
Part 2. Assemble the pieces:
Achieve configurations A-F. Robotic arms pressfitting + injection syringe
Can do:

Can't do:

Which parts exist, and which will require development?

how much will it cost?

How fast will it be?