Perspex?

[LethalCorpse]

Okay, so maybe this is a newbie lounge question (and feel free to move it if so), for I am definitely a newbie to case modding, but I have grand ideas which are definitely specific to the case mod forum.
My girl is the office manager for a laser manufacturing company (lucky me), and she knows that the lasers will happily cut wood or perspex to an impressive degree of detail - certainly fine enough for the bits and pieces of a pc box. She doesn't think it can cut acrylic, but I don't know that they've tried. I spotted an acrylic case a little while ago and was bloody impressed, and would love to build a completely transparent case. I figure if I muck around with the design long enough, working closely with existing steel cases for the critical measurements and acrylic cases for what works well with plastics, I can come up with something that can be built in 5-10mm perspex. What I want to know is, is perspex an appropriate material for building an entire case. Is it strong/heat resistant/noise resistant/<insert other materials selection critera here> enough? Also, does anyone have any other advice on how to go about it - methods for joining the non-removable and removable parts together, and joining the hardware to the box? Any creative input would be cool too - but no, I don't plan to bubble air through water at this stage.
cheers,
-Lethal Corpse

[[aE]-brent]

Have a look at these:
http://www.bit-tech.net/article/72/
http://www.virtual-hideout.net/artic...be/index.shtml

Both made out of acrylic.

I don't know that you need to get it laser cut though. You can usually saw and file it to what every you want.

I'm going to make a case out of perspex too (but painted). How your going to put it together requires a lot of thought, considering a lot of aspects. I was planning on using Glue for permanent joins, and screws for removeable pieces. But in my design i want asa few screws as possible.

Good luck

[Cnidus]

Perspex is actually just a brand of acrylic you do realise, chances are that bit of "perspex" is actually acrylic, the same thing (or very similar) just made by a different comapny.

Australian's happen to refer to clear acrylic as perspex, other countries remember it by a different brand (cant remember names).

[LethalCorpse]

*sheepish* yeah, I figured that out shortly after I posted, and hoped no-one else would notice. I always thought they were the same thing, but I did a bit of a trawl beforehand and found a few places apparently referring to them as two different things, so I thought they might have slightly different properties. Perspex, acrylic, plexiglas, it's all much of a muchness.
I saw someone talking about a guys bubble window earlier, and he said you should soak a bit of perspex in acetone overnight and then attach it, so you get one continuous piece of perspex. would this be wise for major joins, or would it be too unstable?
-LC

[whitetoeddog]

I think it would be too unstable, especially if joining at 90 degrees, a bit like melting the ends together (strong but brittle).

I saw someone talking about a guys bubble window earlier, and he said you should soak a bit of perspex in acetone overnight and then attach it, so you get one continuous piece of perspex.

One continuous piece, i think not, even with the best rejoining would not remove the join completely

[Duallayerformat]

Obviously you have never tried this method of joining. After joining a bit of plexi-melted-in-acetone perpendicular to another piece, (in kind of a T shape) and leaving it overnight, I then tried to break the join. After much straining I only succeeded in snapping one of the pieces. The join held strong. The only downside to this method is unless you are super carefull and use it sparingly, it tends to look like total shite. I used this method to put together a res (as in watercooling) and after 4 months there is no sign of any cracking or faulty joins (thank god).

Edit: Just to make it more clear, I glued 2 pieces of perspex perpendicular to each other using perspex melted in acetone as the glue.

[montyt]

What other methods of joining Perspex are there.
I too want to make a reservoir or two and would like to keep the clear properties of Perspex (not frosty)

I have acriliflex (from plastic factory) dear as elephant’s tusks (little tube 1/2 used and $30).

Will araldite be suitable for creating laminates (WC block top)?
And what can be purchased for edge joining (clear) acrylic for reservoir.

[Cnidus]

i seem to remember using chloroform last year at school for joining 'perspex' together, although i don't know the availibility of this stuff, and i wouldnt use it in anything but a well ventilated room (u can knock yourself out with it).

[Cyranos]

I used to work in an factory that made acrylic items and we used chloroform for minor jobs and where we needed to know there was no chance of the stuff ever comming appart we used Acrafix made by Rhom chemicals in germany. The acrafix if used properly left a nicer affect. Either way both are UV curing so getting a black light helps if you want to get it done faster (it still technically needs 24 hours to cure 99.5%)

As for cutting acrylic there are two ways, laser cutting and the other method which is done by shooting a jet of ultra high presure water through it.

But its acrylic, it is really really easy to work with, using a router, jigsaw or really anything you should be able to get the shape you want, just make sure you protect the acrylic (either the original covering or masking tape) and take it slow, otherwise you get chipping around the edges.

[titan]

acrylic is made from a base of acetone, which means that acetone is able to return it to its original state. Leaving a piece of perspex in acetone overnight will give you the liquid form of perspex, which can then be used to make joins. I don't know what Duallayerformat is talking about, because if you left two peices of joined perspex in acetone overnight you wouldn't end up with a join, you would end up with a liquid...

After joining a bit of plexi-melted-in-acetone perpendicular to another piece, (in kind of a T shape) and leaving it overnight, I then tried to break the join

[LethalCorpse]

What about designing the cutouts on the laser so that the pieces key together without glue or other adhesive? It may not look as good, but it may be a more stable join. I'm trying to figure out how you'd go about it so it still looks good.
-LC

[Cnidus]

If its thick enough drill holes into the side of the perspex (ie the depth), get some motherboard screw things (the brass hexagonal things that space the motherboard from the case) knock them in carefully, with a little epoxy/superglue). VIOLA instant thread for screws to attacch to.

I cannot claim this is my own idea, saw it in a tut.

[titan]

Originally posted by LethalCorpse
What about designing the cutouts on the laser so that the pieces key together without glue or other adhesive? It may not look as good, but it may be a more stable join. I'm trying to figure out how you'd go about it so it still looks good.
-LC

you could do a deep tongue-in-groove joint that would hold fairly well and still look good. That would need a router though.

[LethalCorpse]

Got bored and decided to play with paint. Did you know that MSpaint can be conclusively proven to be the worst graphics package available for technical drawing? Anyway, these are the results.

I thought more about the tongue in groove idea and figured the way to do it would be a finger joint. It could be done on the laser easily, just cut a square wave pattern into the edge of each piece to be joined. The fingers could be any length long - optimally 50-100mm - but the depth would be equal to the width of the acrylic. This would create a very good solid join - finger joints in carpentry are a pretty tried and true method, without resorting to dovetails, which really aren't appropriate for materials of this thickness. The glued surfaces are coloured in grey, you would also need to glue the faces these surfaces mate against. That's a downside of this method, the gluing could be a messy process. If you were careful, though, it would be possible to do it without a lot of runoff to mar the finish.

Second one I thought about, I saw on one of the models posted earlier, so it's probably proprietary. The method is to put a block, square or quarter circle, along the length of the right angle of the join and screw into it from both sides. Upsides of this are that it's not messy, and all the surfaces will be nice and shiny. If you use nice polished screws it's a pretty neat contrasting effect. Downside is it'd be difficult to line up properly, and I'm not sure it'd be as structurally sound as gluing. Might be best to glue the block onto one of the panels before screwing into it from both sides - I think this is what I'll do, for the removable panels at least. You'll also lose that width as usable space around the edges of the panels, so the parts will all need to accomodate this. The diagram is dificult to visualise, but I hope with the text you'll see what I mean.
Woddayareckon?
-LC

[ozzy7750]

i have just built a clear cube, similar to linears, but a bit more stuff added. i used IPS weld-on #16 as the adhesive, it dries completely clear, and very strong. i dont have time now, but i will come back to this thread, or pm me with any questions you have. i know a lot of things i would do differently if i was to do it again now.

i just have to sort out a couple of little things - holes for my drive cage mount, sealing my res with silicone, and attaching a couple of things and it will be finished. then i will take some photos and post them