Acrylic Radiator Housing

posted Oct 9, 2012, 6:04 PM by Andrew Stock   [ updated Oct 9, 2012, 6:04 PM ]
Hello again!

I've been a little lazy about posting... mostly because I'm spending all my time either playing with my equipment, or playing ON my equipment... (WoW is a big time consumer right now with the recent expansion... )

Anyway, as was mentioned before, I finally got the spare funds to buy all of my Acrylic needs, so that got ordered and delivered. Here's what I got:


First of all... some plastic working tools! Polish, glue, applicators, bits... the works. I've never worked with acrylic before, so I figured I might as well get all the right tools. 

Also, the acrylic itself... it's all cell cast, so it's better for machining. It also has the nice paper masking, as opposed to that annoying plastic film. There's some opaque black 5mm, some opaque white 5mm, clear 5mm, some opaque black 1mm, and a custom cast acrylic tube (whose purpose should be obvious. )

Next, I worked on cleaning up my template from before... now I'm down to laser sharp edges and true corners... it's about as good as it's going to get:


Once cleaned up, I put the double sided tape on it again, re-attached the clear "demo" that I cut originally, and ran it through the router one more time. 

Once that was done, I moved on to trying to line up the holes that I would need to put in it so that I could put screws through the fans, then acrylic, and into the radiator. 

I kinda eyeballed this time around, threw it into the drill press, and came back with something passable... but not super accurate. I put the housing back on the radiator, then traced around the edges that I would need to expand to get the hole completely centered:

One more pass through the drill press...

... and now all the screws fit. Unfortunately... the screws I have are about 3mm too short to actually catch on the radiator threads with the acrylic and fans in place... so I am going to order some more from MDPC-X that will fit correctly (if I would just wake up in time to catch their hours... ) Here's how it will look, anyway:

Anyway, I went on to repeat the whole process (skipping the photos this time, as I've already been there done that with the demo piece of acrylic... except...

Whoops.  Two lessons learned from this mistake... 

1) Don't get excited and feed the router too quickly. It will catch, and detonate your carefully crafted piece, only inches from being done. 

2) Always cut the most intricate/fragile pieces first, then go back and do the simple large cuts. In this case, I traced around the outside first and then went back and did the inside... that's when the thin little piece broke. The second time through, I did the inside first while there was still plenty of support from the extra material around the edges, then went back and did the outside a little more slowly. Strait passes seem much less likely to catch, so it was a bit cleaner that way, and less likely to explode. 

Anyway, I went on to cut two more (successful) pieces like the one pictured above without any other issues. After that, I went on to try and think of a better way to cut out the screw holes so that I wouldn't be 'eyeballing it' anymore... which wouldn't be possible anyway, considering i'm making the actual housing out of opaque black acrylic. 

I settled on re-printing out the piece from Sketchup and laying it on top of the actual radiator. taping it in place, then punching screws through to make sure the digital representation I made lined up perfectly with the physical one... and it did.  After that, it was just a matter of putting the same paper template on top of the acrylic pieces that I needed to cut, and marked through the holes in the paper with a pen. Easy enough...


Here's how the pieces all come together, before drilling and assembly:

And here's the channel at the bottom that I was originally planning on making. 

As I looked at it physically and thought about it, I changed my mind on how best to fabricate this...  Instead of one 5mm sheet that the radiator sits on, and a second 5mm sheet that the housing bottom rests on the bottom of the case on, I changed it to buying some 1" thick clear acrylic "blocks" that I will set at the front, back, and center or something like that. I'll drill some channels through it so that the wires can pass through as well. This will allow me to accomplish a few things:

1) I was originally planning on just gluing all this together, but then I thought it might be a bit troublesome if I needed to remove the radiators from the housing for one reason or another. Then, I thought about tapping the acrylic and screwing it together... but it seems to me like the acrylic will eventually crack and the threading will give way. No good, it has to be more durable. So I landed on these little things called "Heatfit machine screw inserts" that you can force into a hole drilled in the acrylic with a soldering iron, then you can use machine screws for that clean "metal on metal" fastening. Putting the thick 1" acrylic blocks down there gives me plenty of room to drill and insert these fittings. Now I can use the blocks on the bottom to hold the two sides together using metal screws, and I can also secure the radiator housing to the bottom of the case, too. 

2) It greatly reduces the complexity of the piece, lessening the chance that something will be crooked or wonky. 

3) It will provide a better base for the whole unit, which is actually pretty heavy. I was a little concerned about the acrylic glue seams giving way down the road... but now it will be a non-issue. 

Anyway, I ordered the 1" thick acrylic, and I am looking for the best place to order the fittings from...

Moving right along, I went on to drill the holes for the screws in the sides of the radiator housing using my drill press:

Not bad, actually pretty centered. I originally attempted the cuts with a 1/8" drill bit, which fit the screws perfectly... but I found the fit to be a little too 'snug', and I would have to be inhumanly accurate with the hole placement to get every one just right. With this many holes in a rigid piece of acrylic... yea... not going to happen. I decided to relax the hole size a little and go with a 5/32" bit. The hole will be completely obscured by the head of the screw and the fancy washer around it (love those brainwashers), and it makes screwing the whole thing together so much easier. 

I did have one screw hole that was just a touch off, so I ended up using my trimming bit for my dremel in the drill press to shave a tiny bit away from the edge of the hole... it worked great, whereas the regular bit didn't want to trim away at an existing hole's edge. +1 for these bits when working with acrylic. You can see the difference in the flutes one on the right, how the cutting edge faces outward, as opposed to the strait bit on the left which is for cutting strait down.

Anyway, that's all for now... I've ordered the additional acrylic I need, and am actively searching for a good place to find the heatfit hardware... hopefully I'll find that tomorrow, with any luck from somewhere local so I can just go pick it up. 

I also plan on working on the reservoir housing tomorrow... that should be fun!