I'm trying to select a TV for my bedroom, and the way the room is set up, my bed is separated from the rest of the room by a shelf. Kind of studio-style. My desk is facing the shelf, too, so I'm wanting to set up a TV on the shelf that can be turned to either face my desk or to face my bed depending on which side of the room I'm using.
I'm definitely open to any help in selecting a TV, but more importantly, I'm having trouble finding a mount for the TV and being confident that it's a good selection (and value).
So far, the most promising mount I've found is this one--the main thing that sets it apart from the rest is that it rests on top of a shelf rather than being a "ceiling" mount that hangs. But it's more than a hundered dollars where as the hanging stands I'm finding on Amazon are ~$50.
The shelf itself is a 48" * 18" shelf that's adjustable, has up to 5 platforms, and is 72" tall. Each shelf is rated for either 200 or 250lbs as long as the weight is distributed evenly, and I've actually put all of my weight on some of the shelves in the process of assembly so I reckon it can hold a TV and a mount.
Regarding the TV I want to mount, I don't have one yet. I'm assuming something in the ~48" range will do more than well enough for me, in bed I'll be practically right next to the TV, where as at my desk I'll probably be about 3' from it. I want it to display in 4K, and having support for some HDR color would be nice too. I'm primarily going to use the TV to watch movies/videos, but I will also occasionally use it to sit back in bed and play games on it. I don't think my hardware (GTX 1070) can push AAA games in 4K, but I also really enjoy playing older games (PS2/Gamecube, mostly) and oversampling them way up to 4K and beyond.
A lot of the cheap ceiling mounts look as if they tilt at the mounting point and also have an extra hole to lock it in squarely from the ceiling. I see no reason why this couldn't be flipped 180* to use on a shelf. Since this would require a drill to mount on a shelf anyway, you could just add a hole with a bolt to lock it in place if you choose one without a way to lock it at 90*.
The wider the 'base', the more stable it will be. If the shelf isn't particularly thick then you might want to add a square of appropriate size (wider than the base) along with washers to distribute the load. This could be added under the shelf to hide it. Without washers the bolts (I wouldn't trust screws in thin material, particularly in MDF) can easily pull through and send the TV crashing to the floor or your lap. If you put a reinforcement piece the same exact size as the base then it can create a cookie cutter effect. People mounting roll bars to sheet metal in vehicles this way have lost their lives.
If the shelf is not made from solid wood or plywood, but some type of compressed wood/MDF then I would recommend adding reinforcement on the underside of the shelf to span the length side-to-side. That goes double if you are in a humid environment. Having the weight centered on the shelf, even if it is much less than the maximum recommended weight, can cause it to sag over time. I have added strips of wood to shelves like this many times, similar to how some tables and countertops are built.
Do you think steel or aluminum bars or sheets (which can be had pretty cheaply) would do enough in terms of reinforcement? I think those would be easier to disguise under the fabric wrap I was planning rather than thick pieces of wood. The shelves are made of some sort of compressed wood, though I'm at a loss as to what exactly. It has a nice sawdust smell rather than any unpleasant glue/chemical smell, for whatever that's worth.
The thing that really spooks me about using a ceiling mount 'upside down' is I just don't think I can convince myself they're designed to handle the wear and tear of being turned 180 degrees once or twice a day while also supporting weight and being upside down 24/7.
if i were you i would wall mount using these going through the stud. and use a wall mount on a arm. the main reason is large tv's fall easy and break easy so mounting to the studs themselves is the best way. if you use a 18 in wide shelf it may be fine or it may someday fall and at 72 inches it wont survive.
Angle steel/aluminum would work. You don't need a ton of material, it just needs good design. If you lay a board on edge it is much more resistant to sagging than laying it flat, and shelves lay flat by design. Think of a soda can, how it can hold the weight of an adult standing on it yet easily folds in when dented on the side. The material being very minimal and flat is extremely strong in one direction. Angle stock would give you strength in one direction, and a surface to put screws through to attach it to the shelf. It might be fine for the short term without any reinforcement, but long term those things tend to sag.
As far as the swivel it is really up in the air depending on what you end up buying. Going online and not being able to examine the design first hand is problematic. There isn't any way for me to say 'this one works' since I have no first hand knowledge with it. My guess is that something made to hang from a ceiling, and the large number of these mounts I see in doctors offices and such, would be that if they were seriously fragile we would have heard a huge public outcry about it by now.
The only thing I can think of is to hunt down unboxings and installations on youtube that mention specific models that are currently available and assess them for yourself. You could try looking locally, but I doubt too many places have them set up for people to play around with. Buying locally at a place with a good return policy is another option. The desktop mount you linked to really doesn't look any different from a couple of the cheaper mounts on Amazon, so I guess you are just paying extra for something that is advertised to work as expected instead of gambling.
