What’s That?: Adding Dead Weight

pinnacle_2

So I was working on a project that utilized the recording capabilities of the Pinnacle Video Transfer–a useful little widget that transfers a video feed directly to a storage device via USB.

pinnacle_0

And we had taken it apart in order to re-package it into a test rig where we didn’t have room for the housing (any excuse to take something apart). And I noticed this brick of fiberboard heat staked into one of the housing halves…

pinnacle_3

This added material doesn’t appear to serve any other purpose–the components don’t generate much heat and there’s no noise to dampen. My conclusion is that while the components on the PCB (other than the connectors) where not all that tall, the connectors were. pinnacle_4 So this drove the final thickness of the product. I guess when you’re spending $100 on a piece of video kit, you probably want it to feel somewhat solid in your hands. So this is a cheap way to add some “heft” to the product.

I wonder if this was the result of some early prototype testing where the test subjects complained that the product felt “cheap” or flimsy… I’m sure this isn’t the first time this “trick” has been used.

I’ve seen special grades of plastic where the resin was engineered to have an increased density to add heft and mass to the product (sometimes to mimic metal). For example, check out RTP’s high gravity compounds.

Let me know if you’ve had to add some dead weight or mass to one of your products to change how it feels in the hand of the user.

UPDATE: By the way, my little “discovery” inside this product wasn’t intended to reveal something deceiving or dishonest on the part of Pinnacle’s designers. I was merely pointing out something that I thought was rather interesting. I was just curious about it and whether other designers used similar techniques in their products.

So far, judging from the comments, it looks like this material might have been used to add some weight and possibly insulate the PCB from heat.

And one last thing: There was one *slightly* snarky comment posted on the Boing Boing re-post suggesting that (a) someone from IDSA–meaning me– was surprised by that piece of fiberboard and (b) was confused about its purpose.  The reality is that I was neither surprised nor confused. There are several possible explanations for this material’s use in this product (adding some heft, as I suggest above, is just one of them). I was merely pointing out these things to spark some discussions on some of the more obscure and interesting elements of product design (mission accomplished).

Thanks again for helping advance the discussion. Feel free to e-mail me other “What’s That?” items.

VERDICT: Okay, after numerous requests for me to actually weight the fiberboard, I finally did it. And this is what I found:

pinnacle_solution_1

That sucker was harder to get out of there than I expected–mainly because it wasn’t very rigid. It was actually denser than I remembered and appears to be less like a piece of fiberboard and more like a cake of sawdust impregnated with a dense wax or clay binder. It broke and crumbled as I pried it out with a screwdriver (after cutting out the plastic heat stakes).

pinnacle_solution_2

Here’s what the scale told me: The complete product weighs 133.1 grams and this little brick weighs 42.4 grams. So it makes up 31.8% of its total weight. Or, if you’re considering it as an add-on, it added 46.7% more weight to the unit (which weighs 90.7 grams without it).

pinnacle_solution_3

So I guess this little brick of material really did add a significant amount of mass to the product. It definitely makes the product feel more solid. But is it enough to help keep it from being pulled of the table? It doesn’t have rubber feet; that’s more of a friction issue. Does it prevent the product from being lifted up and flipped over due to the cables? Perhaps–it depends on the cables. I’m still curious about what this added to the cost of the unit…

Thanks again to everyone who commented.

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43 Responses to “What’s That?: Adding Dead Weight”


  1. 1 Jomichael in Plano August 17, 2009 at 4:31 pm

    Not just to make something feel “valuable”, but also for better balance in the hand and especially to help keep a relatively tall product from toppling over too easily. Add extra weight to the base and lower the center of mass.

    • 2 Warren Ginn August 17, 2009 at 4:59 pm

      Yeah, that makes sense for hand-held products which this is (sorta, but not really)… I too have added weights to bases (or beefed up the base casting). But I’ve yet to just chunk a slab-o-fiberboard into a product like this… It isn’t even that dense.

      That’s why I like taking product apart: you never know what you’ll find.

      ~w~

  2. 3 Mech Mark August 17, 2009 at 4:58 pm

    Looks to me like it is used to ease the assembly procedure. From your pictures I can see that the PCB is not held to the housing using any fasteners so I would imagine that the material holds the board in place. Using a sandwich method like this would reduce the assembly steps by eliminateing any use of tools.

    Please let me know if there is anything I missed as I cannot see all the details in these pictures.

    Cheers,

    • 4 Warren Ginn August 17, 2009 at 5:06 pm

      I thought about that, but the 4 tube-shaped bosses engage the 4 pins that pass through the PCB and trap it when assembled. In addition, the two T-shaped fingers further lock it down since there’s two buttons that are pushed on the back.

      Good thought, though.

      ~w~

  3. 5 CLe4R August 17, 2009 at 5:01 pm

    It also helps when the item will have cables plugged into it, as cables twist and pull. If the device is too light, it gets pulled right off the surface it’s sitting on.

    • 6 Warren Ginn August 17, 2009 at 5:11 pm

      I would agree if the fiberboard was denser… It really doesn’t add so much mass that it wouldn’t still get pulled off the table… I almost see this thing as an i-line dongle as opposed to something that sits on a desk. But maybe this was the best they could do given some cost restriction…

      ~w~

    • 7 mdh August 17, 2009 at 5:11 pm

      Exactly. Heft is a design consideration, making it harder to move around when a cable gets pulled too far.

      I taped a rock to my lightweight USB bridge for the same reason.

      +1 to the engineers, -1 to the suspicious commentariat.

      • 8 Warren Ginn August 17, 2009 at 5:26 pm

        I would be more on-board with this theory if the dead weight in question wasn’t a crappy little piece of fiberboard… But maybe that’s all it needed… Now I gotta go yank that thing out and weigh it…

        ~w~

  4. 9 crabcore August 17, 2009 at 5:03 pm

    shielding perhaps since this might be a sensitive device for RF radiation?

    • 10 Warren Ginn August 17, 2009 at 5:14 pm

      Yeah, we thought that, too… But there doesn’t seem to be any coating on the material. And it’s just fiberboard, so what kind of EMF or RF shielding can you get with that?

      Another good suggestion, though… I wonder if Pinnacle’s designers read my blog? :-)

      ~w~

  5. 11 Mark Costa August 17, 2009 at 5:20 pm

    Rather than changing the mass significantly maybe this is there to improve the acoustics? The top shell might sound thin, hollow and cheap without it.

    • 12 Warren Ginn August 17, 2009 at 5:29 pm

      Yeah, that seems to make sense… The thin-walled plastic case probably sounded too “tinny” and hollow when you held it on your hand.

      Nice.

      ~w~

  6. 13 jak August 17, 2009 at 5:24 pm

    I found a heavy weight in a car stereo amplifier.Value added?

    • 14 Warren Ginn August 17, 2009 at 5:31 pm

      It would be if that heavy weight doubled as a heat sink…

      ~w~

    • 15 FormerCarAudioFreak August 18, 2009 at 1:10 am

      The quality of a car amplifier, like computer power supplies, can often be judged by its weight. A heavier amp is almost always the more powerful and better built amp.

      I too have seen some cheap chinese amps with slugs of steel glued inside empty areas of the chassis to increase it’s weight. These are the same amps that claim to put out orders of magnitude more power than they can actually produce.

  7. 16 Guess August 17, 2009 at 5:36 pm

    Heat conductor ? Better heat conduction than air (or convection)…

    • 17 Warren Ginn August 17, 2009 at 5:42 pm

      Actually, this stuff would make a better insulator… But this widget doesn’t generate that much heat.

      ~w~

      • 18 Guess August 18, 2009 at 5:07 am

        Better insulator?

        Thermal conductivity:
        Air = 0.025 W/(m·K)
        Wood = 0.04 – 0.4 W/(m·K)
        Expanded polystyrene = 0.033 W/(m·K)

        (wikipedia)

  8. 19 Sean August 17, 2009 at 5:58 pm

    I took apart a Nintendo light gun for the original NES apart once. It had a hunk of brass in it for what I’m guessing are the same reasons here… weight/heft and/or balance.

  9. 20 Warren Ginn August 17, 2009 at 6:04 pm

    Boing Boing’s got more comments and theories about the purpose and use of dead weights in products:

    http://www.boingboing.net/2009/08/17/gizmo-with-a-weight.html

    ~w~

  10. 21 Frank August 17, 2009 at 6:05 pm

    The components themselves may not generate much heat, but what about the equipment it is often going to be sitting on? Perhaps they’ve had problems with overheating from below, and instead of bulky fans and so forth, added a layer of insulation. Just a thought.

  11. 23 Bryan August 17, 2009 at 7:18 pm

    The weight may be added to prevent the product from sliding about on the surface or even fall from the surface. Some products with empty weight, the weight of the cable would pull the product from a desktop.

  12. 27 cak August 17, 2009 at 11:13 pm

    This is just like a washing machine, so that when your wachine machine is on spin cycle, it doesn’t roam across the floor. I imagine the weight serves a same purpose in this device. I would be careful if you rehoused it without the weight, putting it on spin. You may need to hand you video feeds out to dry in the sun.

  13. 29 Sammy August 18, 2009 at 4:00 am

    No question about it, the weight was added to keep the device from moving when you attach a 3in1 cable. I’m using heavy duty cables that can easily move light weight video switchers.

    Even the 7 in 1 USB hubs need to be fastened on the desk with velcro, not to forget my UB502 mixer with some heavy duty guitar cables. There are bunch of other divices (temp gauge, USB fan etc.) that I have attached in place by using Bostik Blue Tack, those are just too easy for my cat to push over.

    For extra weight in some device of appliance, there is always a good reason; to keep it from moving. I learned that back in 70′s when I found a huge slab of concrete (on top) inside my front loading washing machine.

  14. 30 bomdobot August 18, 2009 at 4:00 am

    I remember buying a Chinese knockoff of an Apple iPod dock. It looked exactly like the original at 2% of the cost. The only problem was that when I removed the iPod, the iPod itself would lift up the whole dock with its connector.
    So I opened the dock up, taped a bunch of pennies into the inside and voilà – a perfect dock.

    I think the same was done here. When the box would have weighted next to nothing, you would be moving it all over the place when inserting or moving the audio/video cables.

  15. 31 teambob August 18, 2009 at 7:38 am

    This is fairly standard fare at least for prototypes. Although it is usually a lump of metal, not fibreboard.

  16. 32 jonathan August 18, 2009 at 11:27 am

    Hey Warren,

    Haven’t seen a “what’s that?” in a while, and this one was pretty neat. Great discussion in the comments as to the actual need for the fiberboard, and it seems that the engineers may have considered all these reasons, and if not, should probably read up on this site.

    Anyways, I’ve got some cool examples in my mind of products where weight is definitely a factor into product design. I had a chance to speak to the USA president of operations for Bang and Olufsen (seems like audiophiles care a lot about weight), and they intentionally select certain materials to manufacture their product.

    For instance, take the standard television/dvd/home theatre remote. While a usual remote is made out of plastic, designed with minimum wall thicknesses to cut weight and cost, a B&O remote easily weighs a half pound, probably more with batteries. Wonder why? They aren’t using “cheap-o” aluminum, they cast their remotes out of zinc!

    Anyways, B&O’s decision to use certain materials certainly has more behind it than weight (appearance, sense of durability, style, sense of quality etc), but weight is definitely something that plays a part in the perceptions of all these qualities. So while weight for the Pinnacle may be mostly for usability (so the device doesn’t skitter off your desk), Bang and Olufsen designs their remotes to be able to be thrown across the room, chewed up by your dog, and beaten against a would be home intruder, and still control your $30000+ home theatre

    jon

    • 33 Warren Ginn August 18, 2009 at 11:42 am

      Hey Jon, thanks for the comments. I too had an similar audiophile design experience with a manufacturer where we constructed all the different system components using aluminum extrusions and castings. The entire system probably weighed over 500 lbs – it was one huge heat sink. For pictures of these beasts, check out Viola Lab’s Spirito Preamplifier and Bravo Power Amplifier:

      http://www.violalabs.com/gallery.html#spirito

      http://www.violalabs.com/gallery.html#bravo

      ~w~

      • 34 jonathan August 18, 2009 at 5:54 pm

        Warren, those are some beastly amps and psu’s! 39kg and 57kg? And those are meant to be home units?

        Also, noticed you’re in the RTP! I’m originally there, but just finished school at Northwestern, but my brother goes to NCSU. I’ll definitely point him to your blog (aspiring ID/ME).

      • 35 Warren Ginn August 18, 2009 at 6:07 pm

        Yup, they were designed to go their living rooms… Apparently they’re really popular in Japan… Crazy, huh?

        Yes, I live in Raleigh and graduated from NC State School of Design (although I moved away for 13 years). Feel free to contact me directly if you like (see the about page).

        Cheers,

        ~w~

  17. 36 Peter August 18, 2009 at 7:02 pm

    I really think Pinnacle could justify dead-weighting that as a measure of desktop stability.

  18. 37 Peter Crandom August 18, 2009 at 7:10 pm

    I have one of these – the weight is quite key to allowing you to plug in cables – and not having it ‘walk’.

    Pc.

  19. 38 hinn August 18, 2009 at 7:22 pm

    How about more information, how much is the complete and the extra weight?

  20. 41 Jessica December 7, 2009 at 6:06 am

    Wow is that a brick inside. lol awsome :)


  1. 1 Heft – Is there a corollary in UX? | There4 Development Trackback on November 25, 2009 at 2:30 pm
  2. 2 Gut Check: 3Dconnexion SpaceExplorer « IDSA Materials and Processes Section Trackback on October 20, 2011 at 11:52 am

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