Hello,
I am working on my first rig, 3 1080ti duke.
Iv been looking all over for tutorials on how to build a decent case, most youtube videos either post wrong measurements or dont state the materials needed 
I would really appreciate some guidance for an easy yet reliable guide to build a case for my first rig. Super newbie here.
Another question i have, is arent aluminum or metal cases dangerous for having all that electric stuff on it?
Thanks alot!
If you are only going to run 3 cards buy a case, corsair carbide 740, im running this setup my cards have 50 deegres and 66 deegres and is producing 770 sol per card. If you are looking to have an open rig i have seen multiple ikea builds 
not nice but working
Spend less than 10 dollar, get the air-cooled cards 10-15 Celcius lower with OC… build yourself a metal rack…
Go to hardware store, ask for the metal shelving rod, its long and L-shaped, it comes in 10 feet long per rod… and some bolts and nuts…
In my place, 1 unit of 10 feet rod cost around 2.5 dollar, i bought 3 of them,ask them to cut to 2 feet each…
Bring them back home, put them together as cube with some elevated placement for GPU… I can make it smaller, but i want the gpu as far as possible from each other…
Assemble all parts, put GPU as far from each other… Put them in a corner or somewhere with good ventilation, plug them in, jump the power… and connect using Teamviewer, and just forget it ever exist in your house… everything is through Teamviewer…
my 1070 only get as hot as 67 C, fan cooled at 80%, OC-ed on hottest day, no air conditioning just ceiling fan, ambient is 27-35 C…