Is building a computer chassis out of pure LEGO dangerous?

I have been looking and reading about creating a computer chassi out of pure LEGO parts (Ive seen a bunch of cool projects on the web that has done that), but then I stumbled upon this Reddit thread:

Where the author asked:

It's ok building a PC case with Lego bricks?

Temperatures issues? Melting plastic? Breathing the air of plastic that almost melts?

Where the most upvoted comment (14 votes) wrote:

The only possible problems you'd have is:

• not having grounding between components
• causing EMI radiation due to improper shielding.

I am not a pro-pc builder, but these sound like serious problems.

Is it dangerous (as in for my life, toxic fumes, or computer, or worse, the house gets burnt down) to create a computer chassis out of pure LEGO plastic parts?

I rather take facts than speculations, as this is actually a serious hazard question.

5 Answers

The ABS plastic used in Lego bricks starts to melt/produces fumes at around 80 degrees Celsius.
There is some softness, malleability starting as of 50 degrees Celsius which causes the bricks to loose their "grippy-ness" when stuck together and which can deform the bricks, especially if they are load-bearing.
50 degrees Celsius is easily reached inside a PC case. CPU cooler, video-cards, even hard-drives will run that hot.

Lego themselves recommend that you can put Lego in a dishwasher for cleaning, but you should keep the temperature at no more than 40 degrees Celsius.

So you really have to make sure the bricks don't make direct contact with the hot parts inside the computer and that there is really good airflow to get hot air away from the bricks.
(I have seen some people use small wooden blocks as spacers between the Lego and the hot stuff.)

Grounding is not an issue. The grounding through the power-supply should be enough.

EMI emission might cause some disturbance on other electrical equipment (old tube TV's or radio's), but isn't really harmful.

Seeing as how all the concerns about building a computer case with Lego bricks are about how the temperature would affect the plastic, my guess is that you'll be fine provided that the case is large and well ventilated so as to not let any excess heat build up.

Okay, as for not having grounding between components... I don't really know what they're talking about- isn't the power supply connected to all the components? Isn't the power supply grounded? If you're really worried about it, mount the motherboard to a metal plate you've taken out of another case before you put it into the lego case.

EMI radiation because of improper shielding- okay, I suppose there's a SLIGHT possibility this could be a problem but it is really HIGHLY unlikely, as most components are they themselves shielded (DVD drive, hard drive, etc.) and I really don't think the motherboard puts out very much (if really any at all). That being said, the worst thing that could happen is that your computer would maybe screw with your tv's picture if it got too close but I HIGHLY DOUBT IT.

Also, just so you know, I once made a computer case entirely out of clear plexiglass. I imagine plexiglass to be roughly the same as lego bricks with how it responds to heat and whatnot and I NEVER had ANY problem with the plastic heating up or anything.

I mean, think about it- all the heat from the computer is put into the air inside the case, via heat sinks and the like. Nowhere is the heat ever transferred to the case because no one wants a case you cant touch. Just make sure you design your case with airflow in mind- you should have an intake fan, an outtake fan and the processor fan. Unless you plan an open-air type case, in which case you could probably just get away with the processor fan.

You could look into watercooling if you're really concerned about the heat.

Also, my plexiglass computer case worked perfectly and I never had any problems from the absence of a "shared ground" (which really isn't true anyways) or from emi radiation causing interference.

I have built a lego pc case (see ) without any problems with heating (btw my graphic card is a GTX 560 Ti). As you can see in the pictures, I have 2 big fans on the back side and big open holes in the front so the flow of air is bigger than in most of normal cases (I will say below 70$), I have also some removable methacrylate plates on top, in case I'm gaming in summer

I have notice that in my old metallic case the motherboard was isolated to the body of the case with around 8 plastic pins (it was a cheap case) and I dont remember it had a single screw. Also the power supply has its own grounding to the electrical network, so I dont think this is neither a problem.

About EMI radiation I aslo HIGHLY DOUBT IT since normal metal cases use to have many holes which are not radiation save, and I also live in a flat with signal from 10 wifi networks and 4 cellphones (my point is the radiation I'm exposed to is, I hope, small)

I also have my PC under my flat screen TV, and I do not notice any problems in the image from the TV, but true is that radiation will affect more to old tube TVs.

Other problem can be dust I solve it with 2 cleaning per year, one important before summer. I have notice that the dust use to stay around all fans (main fans of the case, CPU fan and cooler and graphic card, and also in some cables inside the case, but my case design keeps big open places and good air flow, so my intention is that the dust go in and out, and just some is absorbed by internal fans and coolers)

The computer will at shut off due to over heating before Legos Evan have a chance to even soften as long as you don't forget to put a fan or 2 in there you will be fine