You're always unlucky with DIY projects because your temper gets the better of you, or at least that's what you tell your audience. This also explains the bandage you wear on your arm.
Now pull out a drill, your expression changes, taking on a somewhat diabolical look. And then drill right through your arm!!! - If you want, you'll bleed a lot of (theatrical) blood.

This new shocker from Andrew Mayne is simple to perform and can be built in half an hour.

You will need €10 in material costs and an electric screwdriver for €20 from the hardware store.