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Background

I am looking to increase the versatility of a desk by allowing the monitor to raise and lower, using a manual mechanical solution (i.e., no electric motors). I am trying to make adjusting the monitor height be as quick and effortless as possible, while eliminating the risk of "dropping" the monitor.

The situation is depicted here:

Monitor Stand

The items involved in this problem include:

  • a monitor of ~12kg, with dimensions of 449.6mm x 690.2mm x 83mm;
  • a single post of 10cm in diameter, made from 5mm thick steel; and
  • an arm of ~3.1kg, with a maximum extent of 37cm.

The extensible arm provides a great deal of motion. The post is notched at the bottom, resting on a type of halved joint, and secured at the back of the desk by thick wood slats.

The monitor needs to have about two feet of motion so that I can stand while working. (Lifting the entire desk would be much [$10k] too costly!)

Problem

As described in this physics answer, the compressive force and the moment conveyed to the post are fairly significant. I'm looking for a solution that would allow the monitor to raise and lower and lock, even if it meant having to retract the monitor close to the post while adjusting the height.

To raise the monitor with the current situation requires unscrewing the post, hoisting it, and reattaching the screws. This is both dangerous (for the monitor) and time-consuming.

Post and Track

The faceplate welded to the post has 10 threaded holes drilled into it (barely visible in the above photograph). I think I need a two-piece sliding track mechanism. One piece attaches to the post and the other attaches to the extensible arm. The logistics resemble:

Sliding Track Mechanism

Question

What type of sliding track mechanism would allow the monitor to raise and lower without much effort, time, or potential for accidentally dropping the monitor onto the desk?

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Dave Jarvis
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  • -1 because I believe that building adjustable height desks and computer monitor stands should be off topic here (computer desk isn't really part of the home), even though a prior question on this topic was very highly rated. – BMitch Aug 28 '13 at 11:54
  • -1 because not only do I think this is borderline off topic, but also because it's been asked before, twice, and there was another similar question focused specifically on the driving mechanism. I also think this type of question is too broad, since everybody that reads it could potentially offer up there own valid design. However, the question was presented in a very nice way, so good job on that. – Tester101 Aug 28 '13 at 12:27
  • Spend $15.68 USD: http://www.monoprice.com/products/product.asp?c_id=109&cp_id=10828&cs_id=1082808&p_id=5400&seq=1&format=2 – Jason Aug 28 '13 at 14:38
  • @Tester101: The driving mechanism is closest to my question. The other two are about raising desks -- as you can see in the picture, raising the desk is not a realistic DIY option: the desk weighs over 250 lbs. – Dave Jarvis Aug 28 '13 at 15:05
  • @Jason: Thank you for the tip on a prefabricated solution. That particular solution would cause the monitor to sit too high in its lowest position, but would work great for raising. I would also be uncertain of whether the prefabbed tube could support the weight of the monitor when extended from the post. Great starting point, thank you! – Dave Jarvis Aug 28 '13 at 15:14
  • @DaveJarvis NO. The point of this Question and Answer site, is to ask a question and get an answer. Sometimes multiple answers are given, but only one can ultimately get the check mark and be accepted as the answer. – Tester101 Aug 28 '13 at 15:34
  • @DaveJarvis This site is a game. You score points by asking good questions, and providing good answers. You get a bonus if your answer is correct. When you ask a question, you're setting the rules for that round of the game. When you ask questions with this in mind "so that I could select the design most likely to work in this situation.", you're asking people to play a game where the rules can constantly change. They call this game "I win", and only the winner likes to play that type of game. – Tester101 Aug 28 '13 at 16:02
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    The opinions of our star moderator may not reflect the collective opinions for the DIY.StackExchange.com site. Feel free to come by the chat room to express YOUR take on what the site is, should or could be. – HerrBag Aug 28 '13 at 16:34
  • Did you complete your project? I'm currently working on something similar. My approach to the problem is using a hydraulic piston that works something like lift support pistons on a vehicle's trunk/hood. Anyways, you have final picture or link to your solution? – Justin Nathanael Waters Jul 15 '19 at 05:37
  • @JustinNathanaelWaters - I've added an answer. Instead of raising the entire desk, I used two independent arms that can raise and lower the monitor and keyboard. – Dave Jarvis Jul 16 '19 at 02:01
  • **Definition of transmogrify -

    transitive verb : to change or alter greatly and often with grotesque or humorous effect** - Modifying your stationary post will probably be grotesque and/or humorous looking. So transmogrify at your own risk. or buy one that is made for the job.

     – Alaska Man Jul 16 '19 at 18:24

3 Answers3

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This is a bit out there and seemingly off track, but please bear with me.

We have a premium shower system which includes a shower head holder on a vertical bar: Hansgrohe Croma E 75 3-Jet Wallbar Set, 24" Except our showerhead is much more substantial than in this photo and exerts fair bit of torque on the slider assembly. So much so that we barely have to tighten the slider.

As a result, we tend to leave it fairly loose so we can adjust it with one hand and only a little force by providing relief of the showerhead torque. It then slides easily up and down.

Perhaps that adding a single ring to glide closely around your post could use the same principle. It would be about 10.2 cm interior diameter, probably 5 mm thickness, and about 2 cm high. Weld to one side of the ring a vertical bracket to attach bolts to fasten the monitor arm. Diagram of collar around post with bracket to attach to monitor arm
I don't expect any artistry awards, but maybe this is clearer?

wallyk
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Start by attaching two rack gears to the post.

enter image description here

Next fabricate a halved trolley.

enter image description here
Rear Trolley
enter image description here
Front Trolley

You'll need a couple pinion gears that can mesh with the rack gears.

enter image description here

And a couple pins to allow the gears to spin.

enter image description here

Next assemble the trolley. You can use cotter pins through the gear pins to hold everything together You'll probably want to use 4 cotter pins for each gear pin. One on the front of the front plate, one on the back of the front plate, one on the front of the rear plate, and one on the back of the rear plate.

enter image description here
Cotter pins not pictured

Finally, install a spring loaded release pin (held in place using a C-clip), that will lock the trolley in place.

enter image description here
Spring not pictured

When you want to raise/lower the monitor, pull out the release pin, move the monitor, then let the release pin spring back locking the monitor in place.

For a simpler design. Go take a walk through your local hardware store, and pay close attention to the mechanisms used to raise and lower the table on drill presses.

Tester101
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  • @DaveJarvis Wheels would probably work. I used a rack and pinion, because I thought then you would be able to add in a hand crank of some type. The hand crank would allow you to crank the unit up and down, which would be less effort than lifting the entire weight of the monitor to move it. I just didn't add the crank in the model because I'm lazy. – Tester101 Aug 29 '13 at 12:02
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The solution I finally went with was a combination of DIY and off-the-shelf:

Monitor, Post, and Arm

The arm came from SpaceCo. The bottom bracket shown in the picture at the bottom of the post leads to another extensible arm affixed with a 24" keyboard platform, also by SpaceCo.

Dave Jarvis
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