Need advice on first scratch build

Hi all

I was originally thinking of building my case from wood, as I haven't got any experience with acrylic but having looked at it a bit more, it seems it probably won't be any cheaper or easier and will be a lot heavier with wood, so I'm planning to use acrylic/aluminium/polycarbonate now. I'd appreciate any advice from some experienced modders as it's all very new to me!

I want a split level case, with the PSU, HDDs and DVDs on the lower level and the motherboard on the upper level. I originally thought of having the whole case transparent but now think I'd prefer the lower, more messy level, to be hidden (I think it might need to be aluminium for strength anyway) with just the upper level on display. I've knocked up a couple of sketches in Sketchup. I've probably had to re-start them about 50 times because I keep realising I need it to be bigger and can't work out how to extend it, so it's actually taken me a long while just to get to these rough outlines!

I recently dismantled an old case so plan to use the rear panel and motherboard base from that. I actually shouldn't have removed the rivets joining those two parts as now I have to rivet them back together but that will still be quicker and easier than trying to mark out the holes for the motherboard supports and secure the rear panel to the acrylic (not to mention more stable). Once joined, I plan to screw the motherboard tray to the acrylic and have another piece at the rear on the outside, which will be screwed to the base and help support the metal rear panel.

This is the lower level. I haven't decided on the air vents for it yet. I could have the one on the left panel (passive) just for the PSU (Antec CP-850) or it could supply air for the HDDs as well, drawn over them by a fan on the rear panel. Otherwise, I could move the rear vent to behind the left HDD and have another vent on the right panel, with one a passive intake and the other a fan exhaust. The white strip on the right of the PSU is meant to be a right angle strip, which I intend to put on both sides to stop the PSU shifting and putting strain on the screws attaching it to the rear panel.

However, I was also thinking it would probably be a good idea to have some handholds on the sides of the lower level, to make it easier to lift and move the thing safely. I'm not sure if it was made of poly or acrylic whether this would be strong enough to bear the weight or if the screws joining the side panels to the base and uprights might crack through, which is the main reason I'm thinking of using aluminium for the lower level now. I'd also have to seal off the handholds on the inside (with a plastic box over them internally for instance) as otherwise air/dust will get in. I could of course just screw handles to the outside but they'll stick out, requiring a wider space for the PC and also looking a bit naff, unless I can find/make some funky looking ones.

If I did this, there wouldn't be room for air vents on the sides, so I'd put two (passive) intakes on the front with a divider between them as shown below, one feeding the PSU fan and the other feeding the fan on the rear panel, drawing air over the HDDs.

I might yet decide to put one HDD above the other, which would let me reduce the width of the case a bit. I generally don't like doing this as then the heat rises from the bottom one and makes the top one run hotter but it's probably not sufficient to worry about, just seems a bit unfair on the top drive ;)

After a while (doh!), I realised that to be able to secure the upper level to the lower level posts, I'd need to move everything on the upper level in a bit, thus leaving an edge outside the uprights which would rest on the lower uprights, allowing me to screw the upper level to them. To avoid this lip being left on show though, I'd need to use some spacers attached to the upper level uprights, so that the side panels can line up with the outside edge of the case but still be screwed to the uprights.

The 111mm protrusion on the front panel (furthest away in this picture) is for a 5.25" USB,SATA,Audio bay. I did think of putting it on the lower level but figured as it's plugged into the motherboard it makes more sense to keep it with that so that I don't have to unplug all the leads when separating the two levels. The bay is not actually this deep but I have to allow for the cables, which I will bend and run under the bottom of the upper level and then bring back up at the edge of the board where the connectors are. I also had to move the motherboard over so that it's 24-pin power connector isn't obstructed by the bay's cables.

There'll be a passive 120mm intake on the front panel, above the bay, feeding the fan on my TRUE rev.c and a matching 120mm exhaust fan on the rear panel. On the left panel (right in above picture), there'll be at least one passive intake feeding the fans on my graphics card's Accelero Extreme Plus II http://www.arctic.ac/en/p/cooling/vg...ii.html?c=2182. All intakes will be filtered of course.

I want both side panels (maybe front as well) on both levels to be removable for ease of access, so I plan to screw those to the uprights and maybe into the 5mm thick base as well. I've also been thinking about having the sides and front panels all joined so that they all come off as one. For any power switches, etc I could have these attached to a small piece of wood/acrylic joined to the base, with the front panel lying over this, with the buttons/lights showing through.

For the upright supports, I could use acrylic rods like these http://sheetplastics.co.uk/Acrylic_r...r_square_bar10 assuming they're available in suitable sizes (I think 10mm is too small to properly support the upper level) but if not, I can use wood. I'm not sure if they'd be rigid enough just screwed into the base (from underneath) though, or if I'd need to make some right angle pieces to attach the uprights to two edges and if so, whether they could be fairly low, as shown below, or if they'd need to be much higher.

Would 5mm thick aluminium/acrylic be suitable for the bases of the lower and upper levels? Obviously the lower level has to support the weight of both levels, whilst the upper level has much less to support.

I'm open to using whichever materials are most appropriate and easiest to work with and cheapest. I don't have any experience with any of these materials though and will probably need to buy some tools (I only really have access to a jigsaw, handsaws and a drill at the moment), so I need to bear that in mind and if I'd have to spend a lot on different tools for each material, it will probably get too expensive but as I'm not using any curved edges, I should be able to get all the panels cut to size at least, so mostly I'll just need to be drilling screw holes and fan/drive/switch holes.

I would not recommend acrylic be used as a major structural component unless it is well designed for the application to avoid stresses. I would also not recommend tapping and screwing things into it unless you've accounted for keeping stresses off the panel. Acrylic will crack if it is stressed, or a force is applied unevenly at a fixed point. Also, if you use countersunk screws it will be prone to fracturing radially from the holes due to the forces pushing outward.

I would recommend using aluminum sheet or MDF for the bulk of the structural components. Aluminum is easy to work with, as is MDF. MDF is super cheap and can take stresses that would shatter acrylic. Aluminum sheet can be tapped for threads, but should be drilled and backed up with a nut instead. Thread into aluminum channel is best. MDF can be threaded too, but I would recommend soaking the stuff with some cyanoacrylate glue to make the threads stiffer and don't rely on it to take a lot of force.

Thanks for that valuable advice, which will save me wasting time and money trying to use Acrylic.

It's only the upper level panels, mainly the front and lid and possibly also the sides that I want to be transparent and these aren't really structural/weight-bearing, so I could use MDF or Aluminium for the rest. What would you recommended as the best material for the transparent panels?

What thickness would I want for aluminium or MDF? Would one be considerably lighter than the other?

I do think that aluminium would be better for the lower level but I imagine if the corner uprights are wood screwed to the aluminium base they'd be the weak point, so I'll have to see if I can find some solid aluminium blocks I could use for those instead, something like this http://www.aluminiumwarehouse.co.uk/...duct_info.html

Hi, Welcome to the forum.

Just a few ideas, you could use bigger bottom supports to allow mounting the top pillars right in the corner to keep the vertical edge square which will allow easier mounting of the side panels, also you can mount HDD's on their side which will give you more room and eliminate the heat problem of stacked drives.

You can use ali profile instead of solid bar, I've used it a lot and it has useful slots in it that you can slide bolts into and use for attaching brackets etc. 8)

Hi Beta-brain

Thanks, that's a good idea about using bigger bottom supports that totally didn't occur to me. I guess if there's nothing available in the required size, I could just put two pieces of solid bar or ali profile next to each other, probably joined together for stability.

I did see that build and was very impressed and considered whether I could use ali profile for my frame as well but I don't think it would be economical as I'll still need aluminium sheet for the base, sides, front and back, so it's probably better just to use the sheets joined together by the corner supports to make the frame, although I'm certainly looking at using profile for the supports and anything else that might be appropriate.

I'm not so keen on the idea of putting the HDDs sideways, mainly because I'm not sure how I'd screw the bottom edge down! With them mounted flat, it's fairly easy to drill some holes in a piece of right-angle metal, which is screwed to the base and then to the HDD (with a rubber grommet in between the HDD and bracket to absorb vibration noise).

So it seems I can either

a) build an ali profile frame, somewhat like the one shown in beta-brain's post, then get a piece of ali sheet to lie on top of it for the base(s). Obviously I'd have to cut out the corners of the sheet to fit round the uprights and then screw the sheet down into the profile.

b) start with ali sheet and then get some ali profile or solid bars for the uprights and screw through the bottom of the sheet into the uprights.

Can anyone think of any pros/cons to either approach?

The obvious one with a) is that I'd be using more profile, so it would cost more. The main question with b) is whether the uprights will be stable enough with a single screw attaching them to the base. It seems obvious now that I think about it that I won't be able to screw into the edge of the base, as shown in the last picture in my first post, as even at 5mm it'll be too thin. So if a single screw through the bottom isn't enough to hold the uprights, perhaps I could use two right angle pieces like this.

This is upside down so you can see the underside of the base but one side has the red right-angle, screwed into the side of the upright and also into the underside of the base and through into the bottom of the upright and the other side does the same with the yellow right-angle, which on the underside of the base would have to lay over the red right-angle.

Take a look around on EBay for used/pre-cut/scrap aluminum extrusions. I know that 8020 sells stuff on there and it's a decent price. There are all kinds of angle support brackets that can go outside the extrusions, inside the extrusions or on the ends of the extrusions to produce any type of support you need. Another idea is that you can place your skin panels in the slots in the extrusion if you like that look. 8020 also now comes in black anodized.

Here's 8020's EBay "Garage Sale":
http://stores.ebay.com/8020incgaragesale

Here's 8020's catalog downloads page:
http://www.8020.net/downloads.asp

There are other manufacturers of extrusion, just throwing the 8020 out there as I'm more familiar with their parts than others'.

Yeah, it did occur to me to put the panels in the slots but then I wouldn't be able to remove the lower level ones without lifting off the upper level first, which would be a pain, so I'll have to work out how to screw them on the outside of the profile instead.

If I was to build the frame with profile I wouldn't need right-angle brackets to support the uprights anyway, they're only (possibly) required if I were to use sheet with the uprights secured to them.

I'm in the UK by the way but thanks for the links anyway. I'm sure there's some information I'll find useful in there.

You don't have to have the lowest panel (floor panel) on the ground it can also be mounted on right angle brackets like the other panels, you don't have to cut the corners to fit around the corner profiles as the side panels will cover it, you can make the panels the full width and bolt them on top of the angle brackets and then you can easily unbolt them and slide them out the side, that's how mine work ;)

Quote:

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Originally Posted by Beta-brain

You don't have to have the lowest panel (floor panel) on the ground it can also be mounted on right angle brackets like the other panels, you don't have to cut the corners to fit around the corner profiles as the side panels will cover it, you can make the panels the full width and bolt them on top of the angle brackets and then you can easily unbolt them and slide them out the side, that's how mine work ;)

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The reason I was thinking I'd need to cut the the base panels to fit around the corner profiles, is that otherwise the panel will not be able to go all the way to the front or back of the frame, as shown in the sketch below.

The base obviously has a thickness as well which I have to consider (this sketch is with it at 5mm)

What my concern is with this is that it might cause problems for attaching the PSU to the rear panel, as the last 20mm will not be resting on the base but hanging over the profile between the base and the rear panel. Likewise with the optical drives and 5.25" port bay, obviously the supports for these will have to be attached to the base panel and the screw holes on the devices are in fixed positions, which might mean that the drives can't be properly lined up with the front panel.

The motherboard on the upper level would probably be OK, it would just mean that the rear of the motherboard tray and thus the ports would be at least 20mm in from the rear panel but I don't think that would be a problem (it could even be looked on as a good thing, by keeping the ports away from the edge it protects them from getting knocked somewhat).

Perhaps the answer is to bolt the base panels to the front and rear profile and not have it the full width of the frame but then I have to consider whether the bolts might get in the way of the optical drives and motherboard. I can't see that I'd want to be able to remove the base panels though, if that makes things any easier, as the lower one will have components attached to it which can be removed individually if necessary and the upper one will have a motherboard tray attached to it and I would just unscrew the motherboard if I needed to remove it.

Obviously the case will have to be bigger doing it this way as well, as the base trays are raised up 20mm, which means the height of each level will have to increase (from 130mm to 150mm for the lower level and 200mm to 220mm for the upper level).

Unless your a design expert, which I certainly am not :rolleyes: once you have a basic idea of what you want to do you might find it easier to just get the parts together and see what does and doesn't work for you, it's almost inevitable that whatever you think is the final design will get changed in some way as you change your mind or think of a better way to do something, it's difficult to anticipate every problem that may occur in a build so you need to be flexible in your approach and be prepared to change things, it's all about modifying after all 8)

THAT'S A GREAT IDEA! Mmmm, maybe not :think:

Yeah, the problem is I can't really afford to buy a load of profile that I might not end up using or ali sheet and cut it to fit round the profile, only to find that layout doesn't work, so I need to work out the layout fairly accurately before I start buying parts.

I also don't have any idea what thickness ali sheet I'd need for the base and side panels either. 5mm costs quite a bit more than 3mm, so I don't want to get thicker than I need.

Perhaps the strongest solution, in terms of lifting/handles would be to have the base, rear and half-sides made from one piece of ali bent to shape but I don't have the facilities to bend it myself and the places I've come across only offer to provide cut, not bent, sheets. When I say half-sides, what I mean is the sides would be half-height, with the handles (or lifting cutouts) attached to those and the top half of the side panels would be attached to the front panel, which would all come off as one piece, which would allow enough access room. As I say though, it might be the best idea but it's also the least practical for me to make, so I'll have to concentrate on base sheet with profile uprights attached.

Yes, I appreciate the cost of materials you might not use I work to a tight budget myself, you can certainly save money by using 3mm instead of 5mm ali the thickest I have used in my current build is 3mm.

The open side door in this picture is 3mm and it's strong enough to make a door and mount it on hinges and bolt a gas strut to it, it flexed a little bit diagonally from corner to corner which is the longest length but that's only when pushing the door closed against the force of the gas strut which is quite a resistance to overcome, adding two strengthening struts cured that.

3mm thick is more than strong enough to use as a base panel of upper panel and will easily support the weight of the mobo, drives etc, and any brackets you want to bolt to it.

Thanks, that's great. So it sounds like I should be OK to use 3mm for everything except the lower level base, which I'll use 5mm for? The strength of the lower level sides needs to be where it's joined to the uprights/base so that they don't separate when lifting, not so much the thickness, so 3mm should be fine for those too.

Once I've worked out the exact dimensions of the case, I'll order the ali sheet and some profile for the uprights and see about attaching the uprights to the base sheets (got a big box of various sized brackets from Lidl for £4 the other day, which was a bargain as B&Q charge about that for two brackets!) and if that isn't working out, I can always buy some more profile and cut the base to fit on top of the profile, as in your design :)

1/10 scale radio control cars use 3mm aluminum for their chassis. 1/8 scale cars use 5mm aluminum chassis plates. i would suspect that if the 3mm holds up under the rigors of off-road r/c-ing that it should do fine for a computer case.

something you might think about before buying your aluminum, or at least before you start cutting anything is to make a complete build of your design out of card board and poster board and duct tape to make sure everything fits exactly the way you want before you cut a costly aluminum sheet too small.