For my stage show I needed something with a “WOW factor”, and an automatic crossbow would be amazing.
But to be able to make it open automatic at stage I needed a spring mechanism. This cheap umbrella open automatically when the release button is pressed. Hmm, I can definitely use this.
Because of the mechanism I had to redesign the prop, so it could move freely along the axis. That means that the awesome horns that swirl around the extended ” arms must be tweaked.
Let’s go! I started by stripping the umbrella and adding cardboard details as a skeleton and a little foam to build up the form. After every bit I added I tested to see if it could still be opened and closed.
Thin foam strips (2 mm) were added to created the ornamented details.
YES! I can still close it.
To keep it lightweight and cheap I used cardboard to create the scales of the horns.
The only part of the bow where I have used worbla is the skull face on front, since the form was so organic. The worbla sheet was sculpted by hand to get the shape I wanted.
More movement tests
Then I need to slap some paint on it and add a few LED
In the end the prop turned out great! And if you want to see it in action, here is a youtube video of the spring effect.