Northern Star Nerf Target

This is a rotating / reactive target for use with Nerf and nerf-style blasters.

You might be able to use it with airsoft and similar toys, but that hasn't been tested.

It functions quite similar to a “Texas star”, but since it was not designed in Texas let's not call it that.

The targets drop off the arms when a dart impacts them.

This starts the whole thing swinging, as the weight is now off-balance.

Great for practicing your aim on moving targets.

All parts *should* be oriented correctly for printing, but as usual make sure to double-check!

You need to print one of the front plates, 5x “arm”, 5x “target_mount_a” and “target_mount_b” and 5 targets.

For people using aluminium-channels instead of the printed arms I would also suggest printing the drill-guides.

To build this you need the following extra hardware:

• 1x 608-type ball bearing
• mounting hardware for your location of choice
   
• 10x M5x10 screws
• 5x M5x10 magnet responsive screws
• 10x M5 nylock nuts
   
• 20x M3x20 screws
• 20x M3 nylock nuts
  alternatively 10x M3x15 & 10x M3x20 screws, 10x nylock nuts
• 5x 10x5mm (OD x height) N52 magnet
   
• optional: 5x 15x10x1.5mm aluminium u-channel, at least 55mm each

For the bearing for the rotation mechanism in the front-plate I'd recommend getting the “ZZ”-type; they roll much smoother than the “RS” or regular bearings.

The front-plate can be mounted directly to a wall; might even look like a weird kind of clock.
Use a sufficiently long screw / bolt to secure into a stud and add some kind of spacer (like a stack of washers) between the bearing and the wall.

You could also mount the front-plate to a post or on a stand so you could move it around and store it away.

Just make sure that the bearing (and targets) can spin freely.

The arms were originally designed just as templates for testing and determining the final length of aluminium u-channel to use; they are however surprisingly sturdy and can be used instead of the aluminium, although I do not have any knowledge about their long-time durability.

Guides for drilling the mounting holes into the u-channels are in the “guides” folder, for people like me who hate to measure...

Each arm requires one piece of u-channel (W*H*T: 15x10x1.5mm) at least 55mm long (200+mm recommended), 2x M5x8 screws and 2x M5 nylock nuts to mount to the front plate.

2x M3x20mm screws and 2x M3 nylock nuts are required to mount target_mount_a into the channel; you'll also need a strong (N52) 10x5mm magnet to hold the targets in place.
Firmly press the magnet into the open end of target_mount_a (mallet to the rescue) until it sits completely flush.

The targets themselves are screwed with 2x M3x15+ screws directly into the target_mount_b piece; alternatively use M3x20 with (again) nylock nuts to secure them even more securely.

The other end of target_mount_b needs a magnetable (?) M5x10 screw; this can be used to “calibrate” the strength of the magnetic force by screwing it more or less deep into the part.
If the screw actually touches the magnet the targets are most secure.
By increasing the distance between magnet and screw you reduce the holding-force of the magnet and thus of the target.

The target plates are 5mm thick and the mounting holes are 7mm apart (center-to-center), just in case you want to design your own.

The printed targets are sturdy enough to withstand even modded blasters (within reason); they are not strong enough for overpowered blasters (like double-spring caliburn).
The whole magnet mounting system is probably strong enough to hold wooden plates of the same size; doubtful that metal plates would hold.

If you want to use horrendously overpowered blasters with these targets I would suggest cardboard as it is the cheapest to replace.
Also it might show cleaner, rounder holes…

The whole construction is not strong enough for use with regular guns. Don't do it!