Off the top of my head, if you wanted to build a shutter which is "all your own work", the simplest kind to make would be a guillotine shutter, which is basically a piece of thin wood about 5 or 6 times as long as it is wide with a hole in the middle. This runs vertically between two wood rails, to fire it, you first raise it so the hole is higher than the lens and hold it in place with a releasable detent. To release it, you then disengage the detent, the shutter drops, either by gravity or driven by a rubber band, etc. the hole in the wood passes the lens and comes to halt beneath this. If you can find a Victorian photography book from the 1850s or 1860s, you might even find some working drawings, since there were no commercially-available shutters at this time and people made their own.
Originally Posted by Surly