Controlling a mechanical shutter with an electromagnet

Question

I'd like to drive a pair of mechanical shutter / apertures with an electromagnet. For those curious, we're using a shutter from Edmond optical. For the particular application, I'd like to design a compact actuator to drive it. (I had considered just hacking a camera lens with a shutter, but couldn't find one that was large enough for my needs).

So at present I am thinking about attaching a neodymium magnet to the lever of the shutter and then using a series of electromagnets to push it between open and closed. Which all leads to my first question: how can build compact electromagnet?

It seems like the steps involved are to find a solenoid and then to drive it with a decent voltage difference. I wonder if anyone could recommend a good small solenoid for such purposes. Does it make more sense to roll my own with an iron core and insulated wire?

My second question is more open-ended: can you think of a better way to drive such a shutter? How would you design the shutter motor?

UPDATE: in response to comments:

@tyblu the shutter needs to be open or closed in about 500 microseconds (but exactness is not important).

@bt2 a solenoid is interesting, are you thinking of hitting the lever and letting momentum carry it across to the close position?

Answer 1

You could use a servo with a linkage arm to close the shutter. I'm looking at doing this right now, except I need to precisely control the aperture. A servo will give you (relatively) precise position control, and it's fairly easy to interface with.

If you need to close the shutter very rapidly, then your best bet might be a solenoid. I wouldn't, however, recommend building your own. There's plenty out there that'll do the trick and probably work better than you can design - it'll also save you time. You'll need to use a spring to restore the shutter to the open position. You might try searching Digikey.com to find some.

Answer 2

As was already stated if you want to be able to control how open it is then you will need some kind of linear actuator and a mechanical linkage to the lever that opens and closes the aperture. If you are just alternating between totally open and totally closed then an electro-magnet may work. A Google search for linear actuators may provide you with what you are looking for.

Answer 3

You need to rethink your requirements. Opening and closing a mechanical shutter in 500 microseconds is an extreme demand. Most mechanical shutters take several times as long to open completely. The shutters in SLRs achieve sub-millisecond exposures by opening partially and moving the opening across the frame so each portion "sees" light for a brief interval, but the overall exposure takes longer. Extremely fast opening and closing times are the domain of electro-optical shutters.