4th Doctor's Sonic Screw Driver

I liked this model because it was broken out into several different parts which made it easy to print, paint, and finish without a multi filament printer, and the spring action was an added bonus.  However some of the pieces were just to small and flimsy to be practical. 

I increased the thickness/size of the halo, and rivets holding the bullet.  I also adjusted the size and shape of the bullet to better match the screen version of the screw driver. 

Like the original you'll need a around a 6mm spring for the movement. It doesn't need to be exact.  The diameter just needs to be somewhere between the diameter of the handle and the slider.  Also unless you have really good faith in your printer printing very small parts I would skip the war sonic rivet all together and instead just get the shortest 3mm flat head screw you can find and glue it in place.

Assembly is pretty easy the only tricky part is the halo.  I removed the outer holes on the upper part of the halo where the you would slide the two short rivets through on the old model.  So glue the two short rivets into the bullet.  Once dry add a small drop of glue (if you want it will actually hold itself in place without it) to each of the two holes in the halo.  Position the bullet so one rivet is in place then slowly and gently rotate it until the other rivet slides into it's place.  You may need so gently squeeze the ring a bit so it flexes to give you the movement you need. Once that is done the rest is easy.  You can slide the neck through the bottom hole on the halo to glue it to the bullet and then glue and slide it into the central rod.