Fab@Home:Heated Build Base

From Fab @ Home

1 Plastic Tool System Part 2 of 5: The Heated Build Base
2 Assembly
- 2.1 Aluminum Plate Fabrication

Plastic Tool System Part 2 of 5: The Heated Build Base

In this part we will build the Heated Build Base. Plastic printing onto this surface will minimize warping. It will be wired up in part 3.

On Hand Assembly Tools and Parts for Plastic Tool

Soldering iron for soldering
Needle Nose Pliers
Wire Strippers
5/64" hex Driver
18 AWG wire
Awl / Center Punch
Hammer
Metal File
Drill Press/Cordless Drill
#27 Drill Bit
Band saw / Hack saw with metal blade
Exacto Knife / Scissors

Bill of Materials

Plastic Tool System BOM

Acrylic Parts

You can download the DXF files for the Plastic Tool System here and cut them out on a laser cutter:

Plain DXF Files
Cut compensated for Epilog Helix 35W laser engraver DXF Files

You can also use Ponoko to cut out all of the acrylic parts for the Plastic Tool System for you here

SolidWorks 2009 assemblies and part files of the Fab@Home Model 2.0 with the Plastic Tool System
Also contains laser cutting layouts in Solidworks 2009 drawing files.

Fab@Home Model 2 CAD with Plastic Tool System in Parasolid Format

Assembly

Aluminum Plate Fabrication

This can be accomplished by either using the heated build base engineering drawing, or the following procedure:

Remove the Z Table Support Plate from the Fab@Home. Square it up against the corner of the aluminum plate as pictured. With a Sharpie, mark the edges of the plate as well as the 8 indicated holes.
[1x] .125" thick, 12" x 12" Aluminum Plate
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Using an Awl / Center punch and hammer, mark the 8 holes. This will help with drilling later.
Cut along the 2 lines you have drawn using a Bandsaw or Hack saw with metal blade. De-Burr all edges with metal file
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Drill out the 8 holes you have center punched with a #27 drill bit. De-Burr all holes with metal file
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Adhere the Kapton film to the surface of the plate (Chose the side with the least defects)[1x] .005" thick, 12" x 12" Kapton Film
Use a 10mm shaft from the Fab@Home to help smooth the film onto the surface, this reduces air getting trapped under the surface
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Cut away excess Kapton film from edges with exacto knife / scissors, as well as the 8 holes. Poke a hole into any bubbles and flatten the katpton.
Cut two 1m lengths of 18 gauge wire and strip both ends. Solder one end of each wire to the leads on the 6" x 6" heater in order to extend them. Wrap connections in Kapton Tape.
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Flip the plate over an adhere the 6" x 6" heater to the center of the plate with pressure.
[1x] 6" x 6" Heater 10W/sqin - adhesive backed
Align the heater so that the leads exit from a side with the holes furthest apart (holes are not symmetric on plate). What we want here is when the plate is mounted on the machine, the leads come out the side or back, not the front
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Cut a 5 foot length of K type thermocouple wire. Strip each end as shown. On one end twist the wires together to make a thermocouple
[5 ft] K type thermocouple
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Tape the twisted end of the thermocouple with kapton tape approximately 5mm from the heater as pictured. Tape down all wires and edges of heater as pictured.
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Trace the Z Table Support Plate on the Ceramic Insulation, including marking the holes. Cut out the square of ceramic insulation along the edge lines you have drawn. Cut out 14mm square notches where the 8 holes are marked as in the picture.
[1x] Roll of Ceramic Insulation
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Tape this cut ceramic insulation to the bottom of the plate with loops of kapton tape as pictured. Ensure that the ceramic is in the proper orientation (clearance for holes)
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Attach to Fab@Home Z axis using 8 ceramic standoffs. Remove acyclic build tray and guides. Thread 8 #6-32 from the bottom of the Z table support plate, then thread the ceramic standoff on those screws.
[8x] 1" length #6-32 ceramic standoffs
[16x] 1/2" length #6-32 screws
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