next topic »

[on:]

I'm in need of a bit of help..

Attached is a 3-part cross-section of what I want to have happen.  Basically, it's a square wooden box, with a lid (the shaded part) that sits on top, and fits down into it.  I need it to go from Position 3, then either to Position 2 and remain, or Position 1 and remain.

The easiest way I can think of is to have some sort of string/cable attaching to the lid in 4 places at the part that sticks down, then attaching to the center of the lid, and then attach to a motor(or other mechanical device) that rests on the base that would pull on the 4 strings. But I'm not sure that's the best option?

Part 2 of this, ideas to keep the outside faces of the lid (in position 1) to not get scratched going from Position3 to Position1, as the outside faces will be finished/painted?

If anyone could be of any help, I would greatly appreciate it.

[Reply #1 on:]

Fit springs under the lid edges so that the lid is biased towards position 1  (ie held up).

Then via a small servo motor fitted with a winch drum (thick shaft) get a cord wound around the drum to pull down on the centre of the lid and set the servo to stop at the desired positions.

I used this type of action to drive a robotic finger to operate a digital camera shutter button (total of 3 positions)

[Reply #2 on:]

I can't see your drawing: take a look at "most useless machine" on you tube, easy ways to open a box lid.

[Reply #3 on:]

Hope this helps

1. Springs on the sides and motor pulling the string (Jackrae's idea)
2. Motorized platform (Think of this as scissorlift)
3. Rack and Pinion

Sorry for the bad drawing.

Thanks, BTF

[Reply #4 on:]

 How big is this box? How much weight does this box need to support or lift?

[Reply #5 on:]

The box is simple, just 6.5 inches square, made of 1/8 inch pine (or similar - not built yet) and only needs to support its own weight.  It's a purely aesthetic function.

btfdev, I think I like the scissor lift idea the best, as it seems the most reliable, cheapest, and probably easiest way to get the job done.

And now that I think about it, I had planned on using the 'lid' as the access panel, so the lift still allows that option.

Thanks for all the suggestions, and I'm still open to others!

[Reply #6 on:]

Here's another idea:

The black lines are extra supports you need to build. You have a small winch (blue), and the string (green) goes over the floor supports, then connects on the bottom of the lid supports.

[Reply #7 on:]

2 shafts with 4 cams, shafts are linked together and operated by a servo.
cover is just floating on the cams.

2 shafts with arms and links, shafts are linked together and operated by a servo.
cover is retained by the links.