Building Details

Please get your proposal approved by following the instructions in the proposal guide before continuing on this page.

Now that your proposal has been approved, it’s time to get started with building your project! First, double-check the limitations so that your project will be able to fly at Apex.

Preparing the Box

• The styrofoam box will be a protection and insulator for your electronics.
• Use a light yet durable styrofoam container.
• Add some duct tape around the corners so it doesn’t break upon landing.

Mounting the Electronics

Keeping the electronics firmly positioned in the payload ensures they are kept intact and operational throughout flight. We recommend mounting them to an internal structure using screws. Using screws allows the electronics to be removed if they need to be serviced and reattached. This can be done with battery holders and PCBs, provided they have screw holes.

Drilling Mounting Holes:

• Place a platform snugly fit inside the box using a sheet of styrofoam, balsa wood, or plastic.
• Take measurements and place marks on four holes at where the mounting positions of the PCB are.
• Attach nylon or metal standoffs to elevate the PCB above the base (reducing vibration and potential damage). Standoffs can be screwed into rigid materials like wood or plastic from below. Metal standoffs can be heated and embedded into styrofoam with hot glue to hold.
• The platform can be affixed to the payload using hot glue, duct tape, aluminum tape, or even velcro.

Wire Management:

• Tie down and bundle wires securely using small zip ties.
• Supply wires with enough slack to avoid tension but not enough that they catch.
• Taping and/or hot gluing these wire bundles to the walls before flight can also be helpful.

Securing Batteries:

• We recommend using a battery pack that can be screwed down, allowing batteries to be easily replaced. Before flight, tape the batteries down into the holders as well with duct tape for extra security (if the battery holder doesn’t have a screw down lid).

Power Switch:

• Everyone will need to mount a master power ON/OFF switch to the outside of their payload box. This will make sure that we can seal the payloads up the day before, and turn them on easily just before launch. This can be either a simple SPST rocker switch (which we can secure in the ON position for flight with aluminum tape) or JST SYP connectors that can be connected together to power on the payload.

Mounting External Components

Certain components like GPS modules, antennas, or cameras must be mounted outside the payload.

Cut small holes:

• Cut small holes for wire pass-throughs to the exterior. This can be done carefully with a drill bit by hand by twisting it through. Heating it up a little can help, just make sure not to burn yourself!
• Leave the holes no larger than necessary for the passage of connectors to prevent heat loss.

Antenna Mounting:

• Keep antennas at a distance from metal parts to prevent interference. Secure any antennas to the inside or outside of the box.

Camera or Sensor Mounting:

• Mount cameras externally by sticking the lens out, and the camera body in.
• Provide the lens of the camera with an unhindered view by clearing out adjacent styrofoam.

Sealing Openings:

• Seal holes with spray foam to keep moisture and cold air out.

Tethering and Rigging

In order to travel up to the stratosphere, your payload boxes will need to be attached, one after another, in a long daisy chain, referred to as the “payload train.” This means each payload will hang from the payload above it, and so on.

We will be rigging these payload boxes up using a method designed to minimize the stresses put on the payload boxes themselves. We also want to make sure that a structural failure on one payload doesn’t cause payload further down the line to break free.

As a result, all payloads will need to keep the center area of their payloads free to allow for the insertion of the flight tube at the Apex pre-launch event. This will be ⅜” vinyl tube that gets inserted all the way through the center from the payload, in through the top and out through the bottom. If you leave enough space, we can also wrap PE foam insulation around the tube on the inside of your payload.

You should start building your project by May 1st to allow for shipping to Apex before the launch. Details on shipping your project and the launch are on the launch info page.

Again, if you have any questions, ask in the #apex channel on the Hack Club Slack!