Hacker News Reader

Comment by Animats | Hacker News Reader

Case. Must have case. A bare board is not a consumer product. Consider just dipping the thing in Plasti-Dip, without submerging the connector. For a better feel, put the button on the solder side side, and put a thin piece of plastic U-channel sized to fit the board over the component side to give it a flat surface. Then Plasti-Dip. No custom injection molding, and the user can still push the button through the Plasti-Dip.

Other than that, great idea. It's how PayPal started.

View on HN

I agree. The problem is trying to do this at scale. I don't want to do it myself as it would be too time consuming and messy.

Without having the funds for injection/pressure molding, I haven't been able to find a good solution. Maybe there are cost effective services that would work like PCB potting or overmolding.

One service that I found that looks promising is Cavist:

http://cavist.com/

But I haven't gone down this route or found someone that has. I might do this later on.

Look for someone who's already encapsulated USB devices. They might be able to reuse an existing mold. That business is all tooling cost; per-unit cost is tiny.

But don't send the job to China, or your device will be copied, cheaper.

Considering the whole design is open source this is going to happen anyway.

+1 on the case being a must have. I'll put some shrink tube over the ones I just ordered to keep them from getting banged up. Looking forward to trying it out in a few days.

Shrink tube is a good idea. Low risk.

Good idea, but I see ads in that sector saying "Molds start at $4990".

I've seen people do things like this at TechShop. They carve a positive mold out of maybe a dense wood. Then use that to make an negative mold out of some pourable plastic like RTV. Then insert the device, pour in epoxy, and wait for it to cure. The negative molds wear out fast, but you can make more from the positives. There are lots of plastic options and books on this stuff. People use these processes to turn out stuff to sell on Etsy. All this is do-able, but usually messy.

Still, struggling through the process to have an MVP to show resellers is worth the trouble. If you get a big order, you can go out to Cavist or someone like them and have them produce in volume.

Here's an option. There are companies in China which sell standard enclosures for USB plug-in devices. They'll even throw in a color of your choice and a sticker. You'd have to redesign your board to fit their case, but that may be a lot easier than dealing with encapsulation.[1]

[1] https://www.aliexpress.com/item/1-pcs-szomk-white-small-usb-...

The problem is that the U2F specification requires users to approve authentication requests by pressing a button and none of the existing enclosures have a space for one. Entirely coincidentally, the company behind it (Yubico) already had a design with a button because their original second-factor proposal had no other way of knowing you want to authenticate. It's a little pointless on U2F but the spec requires it.

You could quickly drill a small hole in each case, in order to fit a tall button like this one:

https://www.sparkfun.com/products/8605

Also, there's some U2F devices that trigger the approval simply when they are plugged in.

You may want to consider something like this, even though maybe it would take too much time, it would look awesome.

http://runawaybrainz.blogspot.co.uk/2012/04/audio-crystal-cm...

Holy shit, that looks amazing.

Almost make me want to exchange my O2 for a clear CMOY :D

You may be able to use one of these

http://www.digikey.com/product-detail/en/bud-industries/USB-...

it looks rather cute! see: https://blog.adafruit.com/2011/03/04/part-finder-friday-clea...

board respin required...either position the button so you squeeze the enclosure to press the button (it flexes a bit), or drill a small hole (use a jig to get the drill bit in the right location

enclosure co's will also customize/drill holes for you but its probably easier for you to just diy!

Oh, nice solution. I thought he'd have to order USB device enclosures from China, but these are from Bud Industries in Ohio, the classic maker of electronic enclosures for 80 years, and orderable from Digi-Key. (That means the parts will be good quality and they will show up on time.) Get a custom sticker printed, and you'll have a good MVP.

One super cheap idea that might be worth considering: clear shrink tubing. You could put whole trays of them at a time in your oven, just make sure the tubing is the right length and lined up right.

You might even be able to get away with not cutting out a hole for the button, as it could be activated through the flexible tubing.

This was exactly my first thought, it wouldn't be as strong to protect it from breaking but it's still better than nothing.

Honestly I think you're fine right now. Think of this initial run as a market test. If you end up selling out your entire stock, tell friends and family that you need a small loan and work with someone domestic to get your enclosure done.

Polycase might be a good place to start once you sell out. They sell generic cases and will quote you on modifications to their existing USB case.

After that (if you continue to sell out), you're probably a real business. Keep the domestic machine running and hop over to China to explore driving costs down. Probably explore what type of software/service might complement your hardware to drive recurring revenue. Create custom single unit packaging and bulk delivery packaging for consumer selling and business selling.

I am considering buying one. Was your plastidip suggestion legitimate? Should I just hold the connector and dip it into the plastidip? Thanks.

It's serious, but there's the possibility that Plasti-Dip might get into the interior of the button and insulate it so it doesn't work. You need sealed buttons. Some surface-mount buttons are sealed.[1] Many are not. I was thinking more from the point of view of what simple manufacturing step could the maker add to package the thing. Shrink-tube sounds good, although it might hold the button down if shrunk too hard.

[1] https://www.omron.com/ecb/products/sw/24/b3s.html

The sealed switches sound like good idea for the plastic dip.

I've done the heat shrink before with good success. If the button gets depressed by the tubing a quick cut with a craft / xacto knife around the button works well.

I'm not trying to make it water proof, just survive being banged around by all the pens / keys / USB / cables / power blocks / change / assorted other detritus that lives in the pockets of my computer bag.

Heat shrink tube might be an option. Although I don't know how durable it would be over the long haul.

Potting would be great too but very messy and the button must stay above

Use a potting mold with a tube sticking through it and down to the button, and a button with a long plunger.

Just buy some Sugru and use that. Doesn't seem much of a problem.

I'd price that up before suggesting it.

It was a suggestion for the end user, not for the manufacturer, and as such it makes perfect sense.

Seems good, let these guys sell it as cheap as they can. If you want a coat buy Sugru when you order this thing, and have your case in any colour and shape.

Reply on news.ycombinator.com