Need to make a thing rotatable, with fixed stops

[Scott Winners]

Imagine a clock on the wall that can be adjusted to have either the 3 or the 9 pointing straight up, as well as the 12.

My best idea so far is to use a disc of plywood with through holes at 9-12-3 and a suitable lag bolt to hold both the rotating plywood disc and the item of interest also mounted to the plywood disc. One fixed hole in the wall at 12, and then a bit of dowel to keep the item in one of three possible alignments.

Thanks

[Jamie Buxton]

How firmly do you need to hold the thing in its various positions? When I just need a detent, I use rare earth magnets -- y'know, those disc-shaped magnets. With the right size, they can hold your thing well, but you can bump the thing away from a position and on to the next one.

[David Bassett]

What size & weight is your thing? Smaller, (i.e. easier to support), would open up your options.

[Scott Winners]

I am basically wanting to mount a video monitor, say 15-20" diagonal onto an IV pole. When the patient needs to be left sidelying I can rotate the monitor 90 degrees and roll it to the left side of the bed. Two hours later, rotate the patient to right side lying, rotate the monitor back through upright and then another 90 degrees, roll the monitor around to the other side of the bed...

All I really need is a working scale model to take to leadership. My manager does a lot better with tactile examples. If I can get some of the heavy lifting out of the way for the guys in the hospital shop (we have a really nice wood shop and a well equipped metal shop down by the loading dock at my home hospital); then the folks in the shop can get to a working prototype faster. If I can include a full scale (I guess it is a vertical turn table) rotating mechanism, the folks in the shop can move straight to cable management and so forth.

I will call my local medical equipment loaner place tomorrow to see if they have an IV pole in good working order. A couple U bolts and some 3/4 plywood scraps should put me in business for a full scale prototype. I do know who to talk to in IT to get a wireless receiver mounted so the item will only need 120VAC for cabling.

[Scott Winners]

This is not a thing I have any intention of seeking patent for or quitting my day job. If you want to make one or a thousand of these, go bananas with my blessing. I think I have a big enough piece of UMHW to put an anti seize disc between the fixed and rotating plywood turntable halves.

[David Bassett]

Scott,

a regular dart board weighs 10-12 pounds and is about 18" in diameter. To even out wear they are regularly rotated. Traditionally they used a nail or screw head in a u-shaped bracket, but there are more sophisticated (complicated) brackets available. Some allow any angle and would work for the mechanical part of your problem. Others are indexed and wouldn't accommodate your 90-deg rotations, (dart boards are rotated in multiples of 36-degs,) but might provide an idea your shop could modify.

Another thought is that small monitors are common on TV & movie sets. (You see them in behind the scenes shots.) They are often clamped on light stands and other supports, so the must be products the production companies buy that might work for you. Other than scrolling around the B&H Photo Video or Adorama or equivalent websites, I don't have any idea how you'd find these.

Good luck!

[Jamie Buxton]

Considering the use, I'd avoid a design with loose parts - which might get lost.

[Jerry Bruette]

You could use retractable spring plungers to lock it in position.
https://www.mcmaster.com/spring-plungers/