Anyone made their own laser cut enclosures?

[Jasper C.]

As the subject line says, I'm looking at going the laser cut path because I can't find anything appropriate off the shelf, less-than appropriate is expensive, and it'd probably work out easier...

I was wondering if anyone here had tried it before and had any tips.  Ponoko offers the service and has a tutorial on the subject, though their details on tolerances hasn't been updated since 2008!  Looks like what I want to do is Sketchup -> Inkscape via converter -> Ponoko.

Cheers,
JC

[Antti Nissinen]

Hi Jasper, I have made a few laser cut enclosures and I still keep doing it, it's often very good mix of design, electronics and plain handcrafts, I love it.

I've learned that lasercutting is very similar to 3D printing in a way that the machines are a bit unique and there are few tips and tricks for all of them, ponoko's tutorials work well for their cutters and probably for the rest big expensive machines, but not so much for the 900$ chinese CO₂ cutter (obviously) anyway, there are good basics which should get you going with all of them.

There's also quite many choices how you want to build your box together and how it affects your design and the strength of the joints.

the handcraft style:

The easiest path I often tend to follow is using acrylic glue, I make my design using very simple big box joint for the edges. This is a very fast and good way to get your project done, but it's very easy to get messy with glue. Acrylic glue is very strong when you let it cure properly. I would avoid this method with wood (the simple joints), finger joints or a mix of glue and bolts is better option.

Finger joints:

I think the hardest method (and often best looking) is using the finger joints like this: http://support.ponoko.com/entries/491205-use-google-sketchup-inkscape-to-create-laser-cut-designs

it's a bit easier with wood using glue, but with acrylic it's very easy to crack it, if you don't shape your joint's right, I couldn't find the tutorial for this right now, but basically you should do a little teeth inside the joints

here's a picture I draw to demonstrate, I don't remember if there should be a opposite for the teeth as well, but try to find this tutorial if you are interested about finger joints with acrylic

nut's and bolts:

I've never done this because I don't like the look, but maybe some day when I find it handy. It's a good way to join the edges very strong without glue, it's also a good way to crack your acryl if you don't do the fine tuning: 

http://support.ponoko.com/entries/498833-get-the-best-results-from-interlocking-acrylic-designs 

http://support.ponoko.com/entries/20344437-laser-cut-project-box-tutorial <- maybe you've seen this, but here's a good tutorial using sketchup for modeling, there's also two different techniques used.

Hopefully this helps a bit, or at least to find the right path

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anacron

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[ChrisChong]

Hi Jasper

I've done a few lasercuts in my time as well (plus a lot of fancy joints thanks to my years in Industrial Design), and Stephan and I are actually getting one for minor commercial purposes (which should arrive this month). If you're interested and don't mind the wait, let me know more about your project and we can arrange to get it done for you - almost definitely cheaper than Ponoko!

Best regards

Chris

[Jasper C.]

Hi guys,

I've been looking into it a bit more over the weekend.  Will probably be going with the nuts and bolts way as I don't need it to look slick and for this application, strong is good.  Already picked up on the need for reliefs in internal corners.

How strong is the glue solution?  I know chloroform is supposed to work fantastic for that, especially since capillary action will draw it into where it should go.  Trouble is getting some, and it's *really* not something I want to work with.

Chris,

Thanks for the offer.  I'm looking at crafting a case for my router to which I can add a fan.  Heat is a problem for these cheap-ish things, and dust is a problem around my place.  Rather than Dremel out the existing enclosure I figured I'd put together something that I can slap a intake filter on.  Not sure what timescales you're working with.  It might take me a bit of time to get the thing sketched out, but I'd be interested to check out yours when it arrives.

May also do the same for a PSU box - I seem to have this mad proliferation of 12V devices.  I've already picked up a nicely efficient AC/DC unit and the connectors I'll need

Cheers,

JC

[Jan Detlefsen]

there are some scripts to help you design the interlocking box parts:

https://github.com/poundifdef/SVG-Box-Generator

http://www.thingiverse.com/thing:1541

http://www.frag-den-spatz.de/index.php?menue=/boxdesigner/menue.htm&page=/boxdesigner/fingerbox.html

http://boxmaker.rahulbotics.com/

[Antti Nissinen]

acrylic glue isn't really glue, it's a solvant and you are basically welding the acrylic parts together so it can be almost as strong as the cutted parts itself, there's also acrylic cement which is better for rough edges, but it really is very very strong bond.

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anacron

[ChrisChong]

Actually, my experience with acrylic glue hasn't been so awesome. Then again, it really depends on the thickness of the acrylic you're 'gluing' together. If it's thick, no problem. Otherwise, like any two weak joints stuck together, it's going to fall apart. You don't need chlorofoam btw, super glue *is* actually acrylic glue. It does the same thing - melts the plastics together and has some filler to make it hold. You might have to sand the edges to (ironically) make it rough first though.

What kind of acrylic thickness are you looking at for the housing? If you have thick acrylic, want really strong and really don't care abt aesthetics, then get some angled metal brackets and screw them together. Remember to use (preferably soft) washers tho - Otherwise you're going to get cracks around the screw areas..

/Chris

[Jasper C.]

My experience with glues hasn't been great either.  Of course it could also have been that the cuts weren't that straight which reduced contact area.  I'm under the impression there are two types of glue, the solvent kind that melts both surfaces together, and the cement kind (cyanoacrylate).

I was considering 3 mm thick acrylic, though I'm now thinking about 4 mm (which Ponoko stocks), just to accommodate M3 nuts and bolts better.  Strong is relative - I'd like stronger than my prior experience with glues, but it doesn't need metal reinforcement.  Pretty much "does not fall apart when held tightly".

[ChrisChong]

Actually, if it's just 'hand tight', a proper laser cut box could snap together with no problems, and would withstand quite some damage. You wouldn't need any glue, and could take it apart after. A 3 or 4mm acrylic would work just fine for that :)

Cheers
Chris