Door open/rattle mechanism

[BigRez]

Hi All -

I have two vertically mounted foam doors, about 2.5' x 5' (WxH) that I'd like to have quickly open and close about 2".  They're very light so a small electric motor (or servo?) should suffice for the movement.  My problem is coming up with a good mechanism to move the doors.  They are mounted on a display and I'll have only about 2" clearance between the back of the door and the wall.

I have a couple ideas, one using a single servo to push/pull both doors, but wanted to know if someone has done this or something different and could share.

Thanks all,

mike

[JackMan]

Depending on how "fast" is fast, servos should work but I would think you'll have to use 2 so the linkage can be attached close to the hinge side of each door. It's gonna be hard to use a single servo and get 2" of movement quickly.

[JonnyMac]

Even light foam doors have mass that creates inertia that can easily strip gears. I would check Servo City for a heavy duty servo, or, I think a better idea would be a small cylinder. Maybe the doors can be sprung shut hand have a small cylinder pull them open with ropes and pulleys.

[bsnut]

I have to agree with Jon on this. I think small cylinder will work better using a 3 way valve for control over the cylinder. Or, try a used handicap door operators which are designed to handle heavy loads and you can find them on EBay.

[BigRez]

The cylinder would be best, but I cannot use one in this application.

Maybe I should rethink the opening of the doors to just rattling them a little bit. It just needs to appear as if something is behind the doors.  They are pretty light doors, about 4lb each.

Hadn't thought of using springs to close them. If I do that, maybe just a motor pushing on the doors would work.  Might be back with more questions...

Thank you

[JackMan]

Yeah, 4 lbs. each might be bit much for servos. I think a motor with a cam and spring load the doors might be a better approach.