I'm asking around on a few forums, as my searches have not turned up what I am after.
I'm looking for some sort of actuator, with a travel of about 120mm. It doesn't need much force at all, and will only ever be fully open or fully closed.
My searches have turned up linear servos, which don't have the length of action I need, or micro and miniature actuators which are eyewateringly expensive and overkill, since I need 8 of them.
They will be operating shutters, a simple piece of thin metal sandwiched between a 3D printed housing and a metal plate (obviously with a little room to move), and will just open and close with a switch. I can run it through an arduino to use PWM stuff like servos, but something that just trundles open and closed with just a high or low from a digital pin would be preferable.
The leaves it will be operating are 120mm x 17mm, and will be arranged about 12mm apart, as per the pic. They will be pulled to the left on the pic, to reveal whats beneath. The actuators will mount behind the black box.
What is the RPM on those little motors? You probably need gearing.
I don't see any feedback in your picture. An encoder on the back of the motor often works well. I can't tell from your description if you need any intermediate position between fully-open and fully-closed. If not, then you don't need the feedback.
Paul_KD7HB:
When something does not move the distance you require, levers can give the multiplier factor to get the distance.
Paul
And you can drive them with cheap auto door lock actuators. No built-in limit switches for position feedback but you can compensate by controlling the extend/retract times. Throw is about 1".
6000rpm on the little motors at 6v (3000 at 3v). They are just ordinary 6v DC motors, with a limit switch I will put at either end (I've not put a limit switch at the far end on the diagram, they will be mounted on the bit the whole assembly mounts to)
I don't need any intermediate positioning. Just open or closed.
I want to avoid the complexity of driving stepper motors and servos, since they only ever need to be either fully open or fully closed, so there's no need for the additional complexity and cost. the motors I found are £3 for 10.
Belt drive is a good shout, but more expensive to achieve.
Adding levers etc will be tough, as it is more complexity and space is limited.
Then you don't care about slip. A rubber wheel pressing on the shutter will work fine and will be cheaper and easier than the long screws. But you lose the gear ratio that the screw drive provided.
I care about slip for the aesthetics - the operation needs to be nice and smooth and steady. I think a wheel directly onto the shutter would be too fast. But a cracking idea though!
I have a 3D printer so no problem on printing parts. I really like the wheel idea though for the simplicity...
