Introduction: Cardboard BoomBox (quick 'n' Dirty Concept Modelling 2D Into 3D)

About: Black sheep engineer, Chartered, and very silly. Currently living in the UK. I have been fortunate to have lived, studied and worked in Hong Kong, Norway and California. I believe physical models help people…

So you've been working in Illustrator, or some other design package, designing something cool and you want to do a quick mock-up to test the scale and functionality out...

...The idea may be in the early stages (or too large) to warrant a 3D Print, so perhaps consider using cardboard?

Having worked in concept generation departments in a few companies now, as a Design Engineer, I can say that these sort of 'quick & dirty' prototypes can really engage a team to make a decision, highlight a few critical functional/aesthetic flaws - or even just have some fun, as with this unapologetically retro BoomBox designed and built with my friends at Bare Conductive.


You can just stick on some paper layout buttons - but in actual fact - Bare Conductive Paint (and the new Bare Conductive Touch Board on Kickstarter) allows you to make each of those black 2D buttons a programmable user interface - pumping out all sorts of sounds, via amazing surface-mounted speakers.


- Check out more Design Modelling ideas on my Instructables page or website.
- Take a look at the Conductive Paint and/or Speakers.
- Check out the UI/UX Controller Board - now on Kickstarter!

As well as helping some great friends out with this BoomBox, this is a pretty good demonstration of how to create impact quickly with a scale model. Sure you can add weight and other complexity later on, to make it more realistic, but really being able to feel the concept take shape in a matter of hours is really exciting for any creative team.

Hope the Instructable is clear and some of the design tips are useful.

Let me know how you get on!



Step 1: Print Out Your 2D Concept

1. Print out your design:

Typically 1:1 is a good scale if possible, though arguably architectural buildings should be smaller (though Shigeru Ban would perhaps say otherwise) - and sometimes tiny things can benefit from being scaled up, e.g. Sub-Atomic Structures.

Note - Don't trust a basic printer to print to perfect 1:1 scale!
You may find that when you do print, you may need to first draw a scale line in the programme you are using and then measure this when it prints - this can help you scale it up, e.g. by 102% to correct it if needed. Also, you can be quite economical about printing - as shown, there was no need to print a second speaker, as both were identical.

2. You will need:

- Cardboard. Ideally the 'single corrugated' kind. (Amazon Boxes are great).
- Scalpel.
- Ruler.
- Cutting Mat (large than your piece - A2 is perfect).
- Spray Mount Adhesive*.
- Glue Gun.
Suggested Design Modelling info on Tools/Links, here.

*Please use in well ventilated areas and put down newspaper to protect surround area, as aside from being bad to inhale the fumes, you will have sticky floors for ages and your parents/tutors/flatmates will hate you for it.

Step 2: Spray Mounting

Spray a little of the Spray Mount on the back of the print-out. Spray from about 30cm/1ft away. Moving side to side, evenly, all the time.-

TIP: DON'T SPRAY TOO MUCH - it will leave the cardboard tacky and costs money.
Wait 30seconds and see if it sticks, if it does (lightly), that's fine. If not, remove and spray a little more.

Cut out the front shapes. Duplicate as necessary.

NB - Spray Mount is not the same as Photo Mount. The latter is permanent, the former is more like a Post-It Note. If you have neither, you can use masking tape - folder back on itself to make a 'loop'.

Step 3: Create Sides of Boxes

Here I have given a general thickness to the Speaker walls (~80mm). I also eye-balled the same for the middle Control Unit (70mm) and Handle (25mm). Note the direction of the cardboard 'fluting', as this helps make for more aesthetic results.

TIP 1: First cut out a large strip of cardboard (e.g. 80mm), then use the speaker to measure (scribe) out the wall dimensions, as shown. It sounds like a trivial thing - but this sort of referencing (as oppose to endless measuring) is what makes the modelling fast.

TIP 2: The Handle is 25mm wide, but this is convenient as it is the width of my ruler. Again - saves time and is accurate.

Step 4: Pro-Cardboard Technique (how to Get Really Nice Edges on Your Models)

So, you can just simply glue things together quickly, if you project does not call for being too aesthetic - perhaps it's just about function, e.g. like this project from a friend at NASA.

However, if you are looking to do something for Industrial Design or a smaller scale, which people will notice, I have demonstrated a way to create a 'Lap Joint' in cardboard by carefully removing a 'fillet' of the corrugated card and one of the outer layers.

Check it out below:

EXTRA LINKS: And for more advanced joints, (e.g. rounded corners, etc.) see the fully series here.

TIP 1: Continue building up the box, one side at a time. Try not too add too many sides at once (as the glue will set too fast, or look messy). If you look closely, you will see which sides i have removed from which sides of the box - paying attention to the orientation of the corrugation/fluting:
- Front and Back Panels - plain (not cuts), for presentation.
- Vertical Sides - outer edges removed.
- Horizontal Sides - all the way round.
Again, this is as much about planning which faces are most visible and what the priorities in this respect. Granted, your first attempt may not be perfect, but it's a great exercise in learning how to think ahead before you cut the material - and will really train your mind when later trying things like CNC Milling or Lathe work.

TIP 2: If you make a mistake, you can re-heat the glue (carefully) with a heat-gun and re-align the joint.

TIP 3: If you are working on a part which you know will be likely to bend (i.e. load-bearing) like the Handle - try to build in some reinforcements with scraps of card, as shown. Do this before you apply the final surrounding strip of cardboard.

Step 5: Building the Boxes

To give a little more detail to the earlier pictures of me working:

PIC 1: Creating the 'filleted' edge of the cardboard as show, using the metal ruler (plastic will not work as well).

PIC 2: Applying the glue to the 'lap joint' created. Doing one panel at a time.

PIC 3: Holding the joint in place, while drying. Also worth pressing the edge down on the table - it avoid burning your fingers and gives a more even edge than trying to hold it. If you are doing curved edges, perhaps use masking tape to hold really complex assemblies. The key is to do a little at at time.

Step 6: Assembly

As shown, the BoomBox is nothing more than 3 Boxes and a reinforced Handle. Pretty simple.

Once you are happy with the layout, peel-off the print-outs and admire you handy-work!

I added a few details like the volume knobs, by using the Curved Joint technique, below.
Remember to leave a 'tab' to complete the cylinder!

Step 7: Pro-Tip: 'Shadow Gaps'

If you look at many appliances that sit on a desktop, they usually have little feat underneath. This gives a shadow underneath the product - and so when you are making a model, by recreating this effect, it adds a degree of realism, which although most people will not think they notice, will simply think it looks more believable.

You can finish these off with some of the strips you might have removed from the previous filleting, or could cut new ones out - it's worth noticing that cardboard usually has two 'sides', a really nice finish and a slightly rougher finish. You can either aim to build everything with one facing externally, or you can deliberately put the inverse to create a subtle contrast, without it being distracting.

Finally, I have added a 'service hatch' at the back of the BoomBox, to fit the electronics in. Frankly, you could meticulously plan all of the wiring out beforehand, but personally, I find it simpler to 'freestyle' this, to fit it as I need it. After all, it's only a cardboard prototype - it does not matter if the wiring inside is a bit rough!

Step 8: Painting With Bare Conductive Paint + Touch Board (User Interface)

So there we have it - a super fast prototype capable of being tested and admired by the retro-craving public of London!

As for painting - this is where I hand-over to the guys at Bare Conductive, who carefully painted the designs on the box and wired up their new Touch Board - pumping out tunes through the Surface-Mounted Speakers inside the BoomBox. Though frankly, this is where you can really go wild and explore all sorts of new user-interfaces with the paint. If you can do a 'Dot-To-Dot' picture, you can create a Bare Conductive circuit: Good Luck!

Please let me know what you think and post any of your projects inspired by this as well.

Best wishes,

Step 9: Thanks

Thanks for all the fun and excitement with the team at Bare Conductive!
Good Luck =)
Check out the video featuring the BoomBox in action! 

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