3M Under-Desk Computer Tower CPU Holder, Width Adjust from 3.5″ to 9.3″, Height Adjust from 12.5″ to 22.5″ to Fit Most CPU’s up to 50 lbs, 360⁰ Swivel, Steel Construction, 17″…

I recently converted my desk to a adjustable height desk to allow me to stand. One thing that you quickly find in moving to an adjustable height desk is that all of the rules for what is acceptable in wiring changes…it is impossible to have a computer sitting in the floor and have the monitors/keyboard/mouse all change in distance from the computer without having a nightmare of cables and risking breaking components in the computer.

I bought this and was able to attach it to the bottom of my desk without too much hassle. It is great that it rotates and slides to make it easier to access. I find that the main bracket is a bit flimsy though, I am not sure how much my tower weighs…its a common “quiet” Corsair case that is sold everywhere and has standard high-end components in it, but it doesn’t have 8 hard drives or anything overly “heavy”.

I would be greatly concerned by using this mount if you do not have the cables coming out of your tower supported (e.g. video cables could be heavy enough to cause great problems). In my use case it is fine as all cables and wiring had to be zip tied to the desk in order to move with the desk at it raised/lowered.

Overall the mount is fine, but it could use a slightly stronger frame and it would be nice if it had some rubber pads to isolate from metal-to-metal contact to cut down on noise. The plastic bracket that “clamps” on could also have a better design, perhaps if it had longer and softer rubber nubs it would help hold the system more securely and further isolate noise transfer through vibration. I will be adding some sorbothane spacers to help reduce noise.

I had to buy a new under-desk pc holder recently as my latest PC case is right around 9″ wide, and most of the PC holders out there (including the one I used to use) max out around 8-8.5″ in width.

This holder comfortably accommodates my new wider PC, and its sliding track and rotating feature are convenient. Ideally, the adjusting knob and piece that hold the PC on the outside edge would feel a little sturdier, but as long as you’re not wheeling your desk down a bumpy hallway or experiencing a 9.3 earthquake, this holder will “hold” up and keep your PC in place.

Not bad for the price. My computer is a bit wide and it seemed to lean a bit. Then I realized that the rack has 4 screws to release it from the rotating top so that it can be shifted to the left or right depending on the width of your computer. I shifted mine one set of holes to the right and now it sits more evenly. Still not perfectly centered but definitely more stable. I wish the holding arm on the left were metal instead of plastic.The top part of the arm is the only part that it is contact with the computer since the arm is bendable and bends out a bit when you try and get it snug. I have a fairly large/heavy computer and it feels perfectly stable in this rack. I did notice that it is best to reach back to the side-arm tightening knob when pulling or pushing the computer along the track. If you pull or push on the computer itself then this thing will wobble all over the place and I imagine is a good way to break it. They should have put a handle on it. I also installed mine further back under the desk than the instructions stated and when pulled all the way out still extends past the front of the desk by a few inches which is all I want. When pushed back fully, it leaves just enough room so that the cables are not smashed against the wall. I would suggest doing some major measuring (taking to account the depth of your computer) before installing this unless you want to be disappointed. There are rubber pads on both side, but none on the bottom.

I really wanted a five-star product. But here is the issue. I have a 9″ wide by 19″ tall desktop PC. The flange that goes underneath the computer only extends 5 1/2″. This means there is tremendous pressure on the dust filter and metal mesh on the bottom of my PC when I would prefer that this flange extend the full 9 inches.
Second, in order to get the PC into the unit, I had to either take off its rear foot or give the whole PC another inch of space to hang down. It was quite a pain. Third, the plastic arm that drops down to hold the the PC in place against the flange coming down on the other side only contacts the PC near the top. No contact at all any further down. It looks bad and looks precarious. Fourth, it would be very helpful when mounting my PC in the unit to remove the plastic holding arm. But you cannot do this and reassemble it with the PC in place. But this seems to be an oversight because parts are all machined to accept a 5 1/2 long bolt that could fit into the knob currently attached to a 5/8″ or so bolt. The longer bolt would allow you to put the plastic holding arm in place after placing the PC on the metal flanges.

And amazing as this may seem, this being 3M, the assembly instructions were pathetic! As I messed with trying to get my PC mounted, the whole unit rolled totally out the front and fortunately, I caught it! Nothing I noticed in the instructions told me to secure it in place IMMEDIATELY lest the PC can slide out and fall to the floor.

Anyway, it is all in place now. I will look into getting that 5 1/2″ bolt I mentioned. I would love to extend that lower flange all the way across the base of my PC, but that may be quite difficult.

Updated: The Holder as designed did not work for my desktop. It was not secure. But I got the holder to work by replacing the outer bracket with a common 15″ Rubber Bungee Cord (e.g. https://www.amazon.com/ROBLOCK-Heavy-Duty-Crimped-Securing-Canvases/dp/B085Q2Z7G7/), a chain, and a third bungee hook. Why the chain vs. trying to use a 20″ to 21″ bungee? So you have the flexibility to choose degrees of tightness for the bungee. And mine it tight!