[0: Safety disclaimer]

These instructions are meant to give you a hint for the assembly process.
Do this at your own risk. Always take the proper precautions when working with
tools and hazardous materials. E.g. wear goggles, gloves and a respirator mask when working with fibre glass
and/or 2K-Epoxy. If in doubt, read the product safety sheets.
We are not responsible for injuries or damage caused by following these instructions.

[1: Print the parts]

All files are available as binary STL files (unit: mm). Standard ABS printed parts work well,
resolution is not critical.

For an overall view of the assembled structure see the STEP file in source:/trunk/hardware/cad_export_step

[2: Rework printed parts]

Use a thread cutter to rethreaded all tap holes. Depending on the
printer accuracy you might want to regroove all holes using a standard drill or a reamer.

[3: Cutting fibre glass rods]

Cut the rods to the following lengths & sand down the ends in order to buff the sharp ends.

  • projection area:
    • 2x 84mm (side, upper)
    • 2x 69mm (side, lower)
    • 1x 244mm (top)
    • 1x 260mm (bottom)
    • 2x 151mm (cross, lower)
    • 2x 136mm (cross, upper)
    • 4x 600mm (holding rods)
  • projector & lens assembly
    • 8 x 170mm

[4: Assembly]

[4a: Projection area & camera holder]

In this step we assemble the projection area & the camera holding structure.
Before glueing any parts lay down and connect all rods and the holding elements
in order to arrange all parts in the right way.

Afterwards disassemble the structure and use common 2 component epoxy glue to
connect the parts permanently. Make sure the side for the projection area is planar.

Remove the camera casing & replace the standard C-mount with the M12 mount. Attach the
camera PCB to the camera holder using 4 screws. You might have to add washers lateron to adjust the
field of view.

[4b: Lens & projector holder]

The next step requires the lens, two fibre glas rods (170mm) and the lens holder print (lens_holder.stl).

First use the epoxy glue to secure the rods in the holding element. Afterwards apply a small amount
of glue on the holding structure and place the lens into the structure.

Once the glue has dried slip the projector holder (pk201_holder.stl) onto the two rods DO NOT USE GLUE.
Now attach both side structures (holder_side_panel_left*) to this base and fixate them using M3 screws (shown red).

Now connect the six T-connectors (t_connector.stl) to both sides using M3 Screws (show in cyan). Do not tighten them yet.

Mount the projector holder & the projection screen holder to the Helmet using the helmet T-connectors ( t_connector_helmet.stl).
Make sure to check the projection area and the camera view during assembly.
Onye you found a suitable mounting position markt the t-connector positions on the helmet and drill 3mm holes
through the helmet (do not wear the helmet during this procedure).

Place shims on long M3 screws and fixate the connectors from the helmet inside. DO NOT USE GLUE on the fibre rods, you want to have them adjustable. Temporary fixation is done using tape.

[4c: Innertial Measurement unit]

Remove the X-IMU from the original casing and place it in the
3D printed case (ximu_holder.stl + ximu_holder_endcap.stl). Use three screws to close the case.

Attach the IMU on the principal head axis using long M3 screws and shims.

[5: Counterweights]

In order to have a well balanced helmet we add additional counterweights (metal bars) at the back side of the helmet.