Case design software?

[parabuzzle]

So, I'm new to this game and I've been using Eagle CAD to design my boards but now that I have a product that needs a bit more "finish" then a simple project box, I want to design the whole thing including a custom case. I have a few questions of the more experienced here:

1) What software (that won't break my tiny bank) would be suggested for case design?

2) How do you deal with a board that has LED's and connectors that need to align in to holes in the case when the board is in Eagle and the case is in another program? Do you have to make a CAD representation of the final board too?

3) Any "gotchas" I should look out for?

Thanks in advance.

-Mike

[kizzap]

1) any CAD drafting software is suitable if you can get the correct information to whomever is going to make the case for you. There are a plethora of programs for drawing out there: Solidworks($$), PTC Creo($$), AutoCAD($$) are the big players that I can recall, but there are free versions out there. Sketchup (formerly of Google?) is one of the more popular ones. But as I said, it really depends on who you are going to be getting the case made by that really will influence how and what you design.

2) Mounting holes/clips are the most important thing to consider. As for holes where LEDs, switches, connectors, etc sit, generally the PCB layout guys and enclosure developers work in tandem to get the design down pat. Making a CAD version of the important information is a good way to ensure clearances, but isn't the only way. Lucky you can get the correct distances between components in PCB software so even just a sketch on a piece of paper is a good start to ensure that you get the correct clearances as needed.

3) The only "gotcha" I can really think of is the method of which the board is mounted into the enclosure. If you are not careful you can get interference between pcb components and the case which make the board impossible to get in.

Hope this is a start for you.

-kizzap

edit: Just an afterthought that I had. Consider if you can to have the board fit in a standard, mass produced case. There are some good, professional looking cases out there, that just need a little bit of common sense style thought, which can save hours in design and get your product finished. Hell if you get big enough a lot of those manufacturers are happy to help you out with customised enclosures if it comes to it.

[notsob]

Another 'free' pkg that has recently been made available is 'designspark mechanical' (never used it - but it may be worth a look)

[igeorge]

autocad has an educational program for free
you do not need to be a student
just do not use it for comercial purpose.
i have it and is great
the only limitation is that it print "Educational software" on the plot

[ecat]

1) Start by downloading the free demos to see which features you find most useful and which software implements those features in the most usable way.

2) Once you have a couple of index holes or alignment edges the rest of the cut-outs just follow the Eagle measurements. Well, that's the theory, you may need a prototype or two or cardboard cut-outs and printouts.

I recently had a play (http://www.e-cigarette-forum.com/forum/battery-mods/482340-another-dna-20-mod.html) with the lesser known Alibre Design (now Geomagic) , quite good once you get the hang of things. The cheap edition is around $150 but you must check the limitations that come along with all of these entry level products.

While checking prices I came across this very appealing deal on the Alibre demo: free 3d printing of your first model! http://touchstone3d.com/free-alibre-design-30-day-trial-and-3d-printing/

No matter which sw you start with, don't become disheartened if you find it an uphill struggle, all of these design packages appear to have their quirks and non-intuitive paradigms.

[Corporate666]

So, I'm new to this game and I've been using Eagle CAD to design my boards but now that I have a product that needs a bit more "finish" then a simple project box, I want to design the whole thing including a custom case. I have a few questions of the more experienced here:

1) What software (that won't break my tiny bank) would be suggested for case design?

I used SolidWorks but it's $$$.  Dassault (the company who makes it) also has a free CAD program called DraftSight.  It's very good and easy to use as far as CAD goes.

2) How do you deal with a board that has LED's and connectors that need to align in to holes in the case when the board is in Eagle and the case is in another program? Do you have to make a CAD representation of the final board too?

You most definitely want to model your board as well as your case - that is the biggest reason for CAD software, to allow you to see problems before you make parts, so better to make the boards and housing in CAD and check for problems

3) Any "gotchas" I should look out for?

#1 - tolerances, tolerances, tolerances.  Remember that a 3" by 2" will not be 3.000" x 2.000".  The board manufacturer will have a tolerance, maybe 0.050".  The case manufacturer will also have a tolerance.  And connectors, LED's and such will have size tolerances too.  And you will want to leave room for your board and parts to easily fit together and be easily assembled.  Personally I try to leave 0.020" around the board perimeter.  So a 3" x 2" board, I would make sure my housing was at least 3.040" x 2.040"

For checking fitment and to see if you made any mistakes, it is always a good idea to print out the parts at 100% scale on transparency sheets on your laser printer, then lay them on top of each other and see if everything fits.  I have been burned by this lots of times... like measuring from the board origin to locate a hole for a switch, then forgetting to account for that in CAD, and when I assemble the board, the switch hole is 0.040" away from where I expected it to be.

This technique works well for lining up multiple boards and such too - a great method for checking your work before getting parts made.

[nctnico]

The trick to make it easy to align leds, connectors, etc to a case is to choose their references in a smart way (IOW not pin one). For example the middle of a connector or a mounting pin. That way its easy to reference the placement on a PCB to a case. Then again determining the height is a bit of an art. The best thing to do is make a dummy from card board and see if it fits (if not repeat ad nauseam).

I recently had some front plates lasercut. I used a9cad (free) to produce the DXF files. Its pretty simple to use:
http://download.cnet.com/A9CAD/3000-6677_4-10296835.html

[afourtrackmind]

Trimble SketchUp. It's free. Once you get your head around it, as it's a very backward way to look at the world, you wish everything worked like it.
It was bought by Google to help crowd source 3d objects for google maps and they made it free.

It has a great online community and a great source of tutorials. It also has a 3d warehouse of free components that you import into your project so you dont have to spend 4 hours making a screw. There are actually quite a few electronics parts on there too, RJ45 connectors and such.  The warehouse is public so there is a bit of crap on there, but because you can edit it, a lot of the stuff on there is great start especially if you need it custom.

I've been using it to design chassis for rack mount amplifiers for the last year or so and I love it. It;s not the most pro tool out there, but I cant imagine using anything else. Its easy and quick. It can export to .dxf which, with a little effort you can load it into a 3d printer for prototypes and with some more work and thought, you send it to a CNC mill.

I love it. It's free and it' awesome.
Cheers,
Joel

[Paul Moir]

There's a place relatively nearby to me that has some free software for designing their cases:

http://www.protocase.com/

But I haven't had a need for their services yet, so I don't know what they're like.  Been around a while though.

[penfold]

Packages such as solid works are absolutely brilliant, but it very much depends on how your manufacturer operates to whether or not you'll actually get the advantages from it.

For many prototypes where i've used a local machinist and he has been perfectly happy to work from a sketchy 2d cad file for any spacing critical aspects and interpolate any further details from a discussion about what we're trying to achieve and this has always worked very well for low volume stuff.

I've also had jigs and prototypes 3d printed, for this purposes they really need a cad files that are representative of the final product and using solidworks has benefited greatly with the ability to import a PCB file and ensure the alignment and clearances before committing

And further to this, where I've had stock enclosures modified, a few 2d cad diagrams showing where we needed holes and spaces inserting for board mounting and holes in the lid for switches and indicators has done fine for them.

For 3d cad I can't say I've gotten along with any free offerings very well, and solid works or sketchup-pro have been the only options that avoid wasting too much time being a mechanical draftsman (which i am not).  For the 2d stuff, i've gotten along quite well with anything from libre-cad to autocad.

It all really comes down to what your manufacturer prefers, there is no point learning the ins and outs of a high end cad package if all the frills are going to be wasted, but on the other hand there is no point wasting prototypes by providing inadequate information or not being able to verify alignment when it is necesary

[afourtrackmind]

I agree solidworks is great, but have you checked the price? The last time I checked it was over $4000 in Canada and another $1500 per year subscription. SketchUp Pro doesn't offer a lot more than sketch up free. Even though sketchup pro is a bargain at $500, free is even better and I've not found any limitations in using the free version yet.

[penfold]

Well, I did kind of ignore the price, trying more than anything to put across the methodology I use when choosing which program I will use for a particular job.

I totally agree with the fact sketch-up pro offers very few useful additions but of course, being a commercial user I wouldn't want to suggest I was using sketchup free...

There is a package an ex colleague used to rave about that was somewhat cheaper than solidworks, I'll try and find out what its called

[hagster]

Before you start you need to have an idea of the manufacturing process you are planning in using and the number of parts you will eventually want. Do you just want some laser cut acrylic or a full plastic part.

If you're only ever going to make do with a 3d printed part there is not much to worry about. If you want to get a more professional vac cast or even an injection molded part you need to think about how the mold separates to release your part. You may also need to think about drafting angles and shrinkage. You may also need to have an idea of how the mold fills in order not to get voids.

Protocut and protomold are worth a look at for lowish number parts.

I use sketchup myself and it's not bad. The other one worth looking at is Designspark Mechanical. I have only tried this briefly but it looks very powerful and is unrestricted and free.

[parabuzzle]

Thanks for all the responses. I downloaded sketchup and their tutorials got me up and running in about an hour. That program is super easy to model in and all I really needed was my digital caliper and my parts. Pretty sweet.

Also thanks for all the pointers in the area of gotchas