Prototype 12L mini tower

[phaelax]

I've been following mini-itx advancements nearly 10 years now but only finally managed to put an actual build together. My original concepts for a case were no longer relevant as they relied on a thin-mini board utilizing Intel graphics. So now I'm making a mini tower, which I thought would be the smallest case out there containing a GPU and water cooling until I started looking at these custom build forums. Yall showed me up and I haven't even finished yet!

I'm calling this a prototype because I honestly don't know if I'll like it when it's done. I'm using acrylic which is a new medium for me and outside my comfort zone. Wood is likely to increase my overall dimensions by about an inch on each side and I didn't want that. I'd prefer metal, (metal fab and welding was my military profession) but I don't have access to all the same equipment at home that I'm used to. So let's try something new!

My original design was 7" x 12" x 8" (WxH) but after actually laying out the components I'm widening the box to 8" and possibly extending the depth due to the PSU I bought. It's about 1.5" longer than the old seasonic I measured in my early blueprints.


Parts:
Gigabyte GA-Z270N-WIFI
250GB Evo 960 NVMe
32GB DDR4-2400 Ballistix
EVGA GeForce GTX 1060 6GB
SeaSonic 650w Prime Titanium
Corsair H55 cooler
(Additional HDD TDB)

The PSU is overkill, I know. I went to the store to buy a smaller one, but the website was incorrect about their stock, so I grabbed this one.


Motherboard tray

Initial layout

So far so good.

I didn't take a close enough look before cutting.The 4 holes are not all the same *facepalm*

I drilled holes to place the standoff screws on the thicker acrylic sheet (this will be the case side) which the motherboard tray will set on. And then the last screw snapped as I was screwing it in!

So I had to drill out the hole again (luckily brass is soft and drills out easily). Although, putting in a new screw then gave me another problem, the acrylic cracked!

The screw at least feels secure and everything lined up perfectly. This is actually a horribly planned build because I'm basically making it up as I go. Normally I'd have everything pre-measured but this I just sorta line parts up, make a mark with a sharpie, then cut/drill.

On a side note, always wear eye protection when cutting acrylic. Trust me, a hot piece of plastic in your eye doesn't feel good! But my jigsaw does cut the acrylic easily and leaves a nice clean cut. My table saw blade would likely be too aggressive for this material. The back of the case is actually polycarbonate, not acrylic like the rest will be. It's also only 0.093" compared to the 0.22" acrylic.



I'm open to suggestions on working with acrylic, such as best way to glue it together?

 

[robbee]

I'm open to suggestions on working with acrylic, such as best way to glue it together?

Regular glue won't work as it doesn't attach well to acrylic. You'll need a special kind of glue that dissolves the surface of the acrylic to melt the two pieces together. I've used something called 'Acrifix' once, and it did the job pretty well.

 

[phaelax]

After googling Acrifix, I came across this stuff. Also waiting on my power switch and usb header to come in the mail. Couldn't find any place in town that sold that kind of solvent. And with radioshack gone now, I'm finding I have to buy a lot more pieces for my projects online.

Another question is, how easily does acrylic bend? I have a heat gun and was thinking about trying it on a piece of scrap.

 

[msystems]

So it cracked from the pressure of inserting the standoff? Seems like it should be drilled out more, and perhaps you can put glue in the threads or something to help.

 

[matt3o]

Use polycarbonate instead of acrylic for the structural part (like the motherboard plate). PC bends where acrylic breaks.

Apart from that, why are you placing the PSU on the right? wouldn't it better on the left of the motherboard so it doesn't interfere with GPU cooling?

 

[robbee]

Another question is, how easily does acrylic bend? I have a heat gun and was thinking about trying it on a piece of scrap.

Bending is easy, bending the exact curve you need is hard. Two pieces of advice I wish I knew before attempting:

- Bend first and adapt the other pieces to the bend you come up with, this way you can hide small mistakes
- The plate will deform if you bend the material. There's a formula to calculate the deformation, but you might still have to cut the acrylic again after you made the bend:

 

[phaelax]

why are you placing the PSU on the right?

The view you're looking at is actually if the case were on it's side. The PSU is on the bottom. My Antec case is setup a similar way and I haven't had any issues with heat. The PSU will suck air in from the bottom of the case. I have considered adding a piece above the PSU to block it off from the rest of the case (aside a small hole for cables) to help block possible heat, but honestly I don't expect it to get warm at all.
It is a bit close, I'll admit. If it doesn't work out, I suppose I could swap a water block onto the card instead. Only one way to find out!

I attempted a bend with a piece of scrap. I think maybe I heated it too fast because while I got a good bend, it ended up with lots of bubbles. I do have an idea for making bends with a very short arc length using a jig. I'll find out tomorrow if it works.

Project is still on hold until my glue arrives in the mail! In the meantime, I've begun another prototype with a modified layout. (the GPU will pull air from the side unobstructed while the radiator heat is blown out from the top. I'm making this one out of wood because it's quick and easy for me. If I like it, I'll invest in some aluminum.

On a side note, I did try my router with a 1/8" straight bit. It spins too fast apparently as it didn't so much as cut the acrylic as it did melt its way through.

 

[matt3o]

The view you're looking at is actually if the case were on it's side. The PSU is on the bottom. My Antec case is setup a similar way and I haven't had any issues with heat.

that makes sense

I attempted a bend with a piece of scrap. I think maybe I heated it too fast because while I got a good bend, it ended up with lots of bubbles. I do have an idea for making bends with a very short arc length using a jig. I'll find out tomorrow if it works.

I've seen bending acrylics with UV. The bent comes out super sharp. But looking at the interwebs it seems heatgun is good enough.

On a side note, I did try my router with a 1/8" straight bit. It spins too fast apparently as it didn't so much as cut the acrylic as it did melt its way through.

I've been able to CNC acrylic, you need a good new end mill to start with, then it's all about speed. You have to go as fast as possible to avoid melting. The following is a keyboard plate I've done on acrylic

 

[phaelax]

Bent a small piece of scrap and watched my heat more closely. This is probably the tightest corner I can do, which is well enough for me.

 

[phaelax]

So I had a small mishap. When I was cutting a sheet, I cut into my work table which jerk the blade and messed things up. It also threw my guide off which I didn't notice immediately. Suffice to say, the top of the case is now rather ugly.

Here's my "jig" for bending.

Slow heat and let gravity start the bend on its own for me.

Bent the other side. The radius of the bend isn't quite perfectly matched with the first one.

Progress so far. It should actually be about half an inch taller, but I cut it trying to fix the mistake I mentioned above. Hopefully I didn't create any clearance problems for the future. Definitely no room for a future ODD now. The side will be cut off so I can make the side panel separately. I made the bend first before cutting so I had leverage to make the bend and thought I'd have more like matching the radius of it with the other side.

Right now I have mixed feelings about this project. I don't think at this point the end result is going to be something I'll want to display. I need some metal to work with!


Below is the other prototype design I mentioned. This is just made from wood to see if I'd like it or not. The silver pieces will wrap around the whole thing and repeat all the way up.

 

[robbee]

For such tight bends, you might want to look into heating up a resistance wire for bending. This tutorial is pretty clear on the subject:

 

[phaelax]

That's pretty cool. I would consider making that if I thought I'd be working with more acrylic in the future, but aside from this case I have no use for it.

I've got the base and the back panel glued up. I've cut the top piece twice now and somehow it doesn't fit either time. Just wasted some good size chunks of acrylic I played around with sanding the stuff so I think I'll be safe to oversize it the 3rd time and sand it down after it's glued up. With my belt sander, I think I can trim it without hitting the sides of the case.