I have a USB hub that has a large number of wires that are coming into it. This is HDMI cables, VGA, USB cables, power and Ethernet. The USB hub connects to laptop using a USB-C. This USB-C cable is actually very short. I need to be able to connect this cable to laptops of different sizes that I have. This includes laptops used for personel use and also work.

In order to keep the desk area neat, I am going to mount the USB hub onto the back of the desk. Therefore, the USB hub shall be out of sight. Its USB-C cable will stick out on the right side of the desk, near the floor. I can place the laptop there and connect it to this hub.

I have decided that to prevent damage to the USB hub, I will not fix it at a single location. This means that it will be easy to connect it to different laptops of varying sizes. I believe that I need something like this to make this work:

enter image description here

The USB hub shall be mounted onto the piece of wood "confined to the rails". This gives it a single degree of freedom, to be able to move vertically. The USB hub is like 4cm while the rod in the diagram is about 40 cm. Maybe I don't need to cover the entire 40 cm.

Now my question is, what exactly do I look for in the market that will form the rails and the top and bottom end? I can't use the rails sold for use with drawers since they are too long and the center piece in this case is actually like 4 cm high. Ideally there could be a thin metal rod that is serves as the rail but I don't know. What do you think?


Here is image of the type of USB hub I am referring to:

enter image description here

1 Answer 1


You could I suppose drill the rail so you could pin the block in place at each position; even using a piece of dowel would do, no need for a metal pin1.

But there's a much simpler solution, think marking gauge:

Marking gauge examples

As you can see, you could attach the block to the rail in any of the ways that the two parts of a marking gauge lock together.

Now my question is, what exactly do I look for in the market that will form the rails and the top and bottom end?

The rail can be cylindrical, so you'd buy dowel or metal rod/tube2, or rectilinear in which case you'd buy or make a narrow board. Then you'd just glue or nail/screw (or both) wooden blocks to both ends.

Note that if you go with a side-locking mechanism the moving block would not need to be confined, but being confined would give the advantage that the block wouldn't have a tendency to fall off when the locking mechanism is loosened.

As you can see from the images, the locking mechanism can be just a dowel (shaped or tapered), a basic wedge, or more commonly a screw-in mechanism of some sort3.

1 Although this can be as simple as a common nail, with or without the head cut off.

2 Or steal the wood or tubular metal handle from something like a broom or mop, even buying new this can sometimes work out cheaper than buying commercial dowelling (especially hardwood).

3 If thumbscrews are not cheaply and easily available a perfectly serviceable equivalent can be made from a bolt/machine screw and a wing nut.

  • You have really solved my predicament. The solution was obvious but I was just lost and confused. Thanks man.
    – quantum231
    Jan 28, 2023 at 11:30
  • No problem! It's easy to not see obvious and simple solutions until you have numerous projects under your belt, and/or have read enough to have seen many solutions to many problems. I probably wouldn't have thought of this 9 or 10 years ago!
    – Graphus
    Jan 28, 2023 at 16:56

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