There are several ideas on how the brackets should look like. We are here going to make suggestion on how it can fit the Arduino board.
The drawing to the right shows the bracket with dimensions and placements of holes before it is bent. The material you can use for the plate is 0.5-1 mm aluminium.
The plate is bent inwards on top and outwards on the bottom. Where to bend the plate is shown on the drawing.
Remember holes for strips to fasten the battery.
To make the CanSat easy to turn on and off, a switch is recommended to be placed between the battery and the CanSat kit. But remember that the switch will be a weak link during launch campaign.
In the figure below is shown an example of how the CanSat could look like.