DIY: How I Made a Mobile Phone Neck Strap Lanyard Case for $6

Or: how to make the perfect neck strap case for using a mobile phone with a smart stopwatch app as a full replacement for a handheld sports stopwatch.

In the following, I will show you a quick way to attach a low-cost, yet comfortable strap to an affordable, minimal, yet sturdy-enough smartphone case. Together these provide the perfect complement for utility apps that require you to frequently switch between using the phone and getting your hands free for some other activity. Comparable products are hard to come by otherwise, and everything but affordable.

If you just want to get to the step-by-step guide without any context information, check out the required parts and go straight to assembly.

For utility apps with frequent pick-up

If you are a regular smartphone user, most of your most frequented apps such as mobile games or chat applications make it quick and easy for you to handle them. You typically spend longer, continuous stretches of time using these apps: once you pick up the phone, you find your preferred hand and finger position on the device and its screen, use the app for a while and, once done for good, re-stash the phone in a pocket or put it down on a surface such as the table right in front of you.

Some utility apps, however — and stopwatch apps for sports are just one prominent example — require a different pattern of use: you pick up the phone in your preferred (often single-)hand position, make a few taps on the screen, then let go of the phone to use your hands otherwise, just to return to the smartphone moments later. When using a utility app on the go at the track, pool or somewhere else outdoors, there often is no proper surface to rest the phone on in between uses. So, you either constantly take out and re-stash your phone in some pocket — or you use a neckband (also referred to as a smartphone necklace at times). A smartphone neckband comes with added drop protection and ideally works in such a way that you can blindly pick up the device in the required or preferred hand position.

The ideal neckband for a smartphone

(Tap on an image to enlarge it.)

For quick and easy use, the ideal neckband is attached close to both bottom corners of the phone. Having these two separate points to attach a band to protects the phone from turning and the neckband from twisting, potentially multiple times, like straps love to do. A single point of attachment — such as the fifth-generation iPod touch devices even had built in (as shown in the picture), when used with a neckband instead of the accompanying lanyard loop — is prone to twisting in itself.

Furthermore, when carrying multiple devices around the neck, these are likely to get tangled up in nasty knots. The double-corner attachment makes sure that the screen of your Android device, iPhone or iPod touch always stays in front. Attaching the neckband to the bottom of the device makes sure that, when you quickly slip your hand behind the phone and lift it closer to eye-level, the screen that hangs upside down on your chest stares right at you in the correct top-to-bottom orientation (as pictured).

Smartphones do not come with a means to attach a neckband in the way outlined. In fact, most phones do not come with any hook to attach a strap to at all. There are products to screw a small metal loop on top of, for example, an iPhone's Lightning port — but those are highly experimental at best. If you happen to rely on frequent-pick-up utility apps and in particular, if you are a sports coach who wants to use a video, analytics or stopwatch app on site, this leaves you with few options: buy a dedicated case with attachment points and strap already included, or go with a do-it-yourself option.

Hardly any ready-to-buy options

As the creator of a next-generation stopwatch app to replace one or even several traditional handheld stopwatches for sports coaches, parents and other frequent or occasional timekeepers, I had a keen interest in finding a ready-made solution. Regrettably, my extensive research came up rather short. Waterproof cases that I was originally most interested in were expensive and came without a proper neck strap. They also are bulky and no good for every-day use, yet especially tough to get a device into and back out again. Simpler cases with a strap attached didn't have the required double-corner attachment; and some more affordable waterproof covers, on top, left the smartphone screen rather hard to tap.

That's why I started to look into my own solution, dropping the preference for a waterproof case. Recent iPhones are water-resistant on their own anyway. In my particular case, I acquired an iPod touch to let professionals try my high-end stopwatch app for a while, even when they didn't own the required iPhone themselves. (An as-good-as-new iPod touch plus case and strap came down to about $160, which, together with the smart multi stopwatch app, gives a much more capable stopwatch than even the most high-end handheld stopwatches on the market, which often go for as high as $200–300 — a similarly-priced dedicated printer, the frequent only export option that my stopwatch app with its Excel-ready export does not require, not yet included.)

Ingredients of a handcrafted neckband case

These are the just three simple parts I combined into a neckband and case that is not only affordable, but also quite easy to apply to a naked smartphone as well as take off again.

(Tap on an image to enlarge it.)

• A 0.5mm tinker/fishing line (polyamide/nylon thread) — I bought a roll on Amazon, but I only needed about 20cm (8in). If you have a piece of a similar fishing line at home (we almost all do, don't we!), use it. Just make sure the line is sturdy enough to not risk tearing it and dropping an expensive smartphone in the process. 0.5mm (0.45mm to be exact; about 0.02in) is plenty.
• A thin, transparent case — an inexpensive, soft silicon case for your phone model, reasonably sturdy, in particular when pierced.
• A neck strap — I took the strap from a handheld stopwatch that wouldn't work anymore. (In the process, I cleaned it in hot water with dish detergent to make it shine as new.) As an alternative, I also tried the neckband of an expired event badge, which did the job just fine, too. I even removed the single hook it came with, as this is no good in our case.

(Tap on an image to enlarge it.)

Minimal costs

This is what I paid for the parts:

Item	Cost	Shipping	Total
Semi-transparent silicon case	€3.95	€1.95	€5.90
Nylon thread / fishing line	€1.41	€2.05	€3.46
Neckband	already at hand

Prices in US-$ are almost the same. Even if you buy a new roll of nylon thread as I did, this is something you need at home all the time anyway — and if you can find a suitable piece at home or amongst a friend's assets, it costs nothing. For some sort of (pseudo-)neckband/necklace, you can use any strap you already have, for example from an event tag or an old photo camera, or simply make one yourself from an existing thread, thin rope, etc. Therefore, for all practical purposes, I consider neckband and thread as already-owned. This leaves me with costs for materials at €5.90 (US $6.30).

Assembling neckband and case

1. Drilling holes

I drilled two holes right in the middle of each of the case's bottom corners using a rather thin, sub-millimeter drill. I used holes as small as possible to affect the stability of the plastic case as little as possible. If you don't have such a thin drilling means available, asking your dentist for help at the next appointment is a good option: dentists have plenty of those drills, and a diamond dentist drill makes it through plastic just fine. (The plastic didn't leave any permanent residue on the drill.)

(Tap on an image to enlarge it.)

A simple needle will make it through the case just fine, too, I believe. I didn't go with that option, however, because the resulting hole may be prone to tearing uncontrollably when pulling on the case in use. This may result in dropping the smartphone, which I don't like to risk.

One thing I would do differently next time: I would put the holes a bit further toward the center. This will be slightly less sturdy; however, as you can see in the pictures, my final product has the neckband stand out beyond the long edges of the case, which is slightly in the way when holding the phone at the lower end. There is a limit to how far in you can put the holes, though, as it is undesirable to get too close to the gaps for the likes of headphone plugs. A softer neckband would mitigate the — really just minor — problem, too.

(If you look closely at some of my photos, you'll also notice that I drilled an extra set of holes on the wrong, top side of the case. My excuse: the first time I did this, I was really in a hurry catching a train and didn't think properly. Attaching the neckband at the top would make the phone be upside-down when quickly picked up with one hand — not what we want.)

2. Attaching the thread

I cut off about 20–30cm (8–12in) of the fishing line and checked that the resulting piece didn't have any prior damage, which would reduce the resilience of the thread against unwanted pulling on the device. I then put each end of the line through one of the holes in the case from the inside and looped it back through the same hole. Through the two resulting loops I then put the neckband from the dysfunctional stopwatch or, alternatively, the event badge. Then I locked both ends of the thread in a quadruple (or more) knot, pulling the whole fishing line somewhat, but not too tight. With the fishing line more tightly knit, the neckband becomes more rigidly attached to the case and tends to stick out to the sides even more, which is not what I want.

(Tap on an image to enlarge it.)

3. Final assembly

I now just made sure that the knot was about in the middle of the case, so that when I put the device into the case it would push out the knot at the center gap (usually for a power adapter) — so the knot wouldn't leave a bump, which I thought might contribute to having the device slip out of the case slightly more easily. The final structure is rather sturdy and the smartphone tightly embedded in the case, even with a bit of fishing line between case and device.

(Tap on an image to enlarge it.)

One more step (optional): cut out the button

There is an optional step if you want to use the resulting product with a stopwatch app such as the smart multi stopwatch for sports coaches that I invented. One significant aspect of this stopwatch app is its support for pressing a physical volume button instead of the (in my patented one-button multi-timing method) single, virtual time button. Many photo apps also take advantage of at least one of a smartphone's physical buttons. Naturally, the position of the button will differ on different devices — but you will easily adapt the following to make a physical button accessible more easily despite the neckband case:

The case hides the physical button behind a layer of plastic/silicon which, although somewhat flexible, delays the button press. For a precision stopwatch — and possibly a photo app, too — this is undesirable. Therefore, I liberally cut out the lower of the two volume buttons; that's the '–' button in the case of the iPhone. I used nail scissors in favor of a carpet knife that I also tried, yet which turned out to be too coarse and not quite sharp enough.

(Tap on an image to enlarge it.)

After finishing the first hole, I tried to reduce sharp edges on the case further by cutting the hole in the form of a crater, which is wider around the outer perimeter. Still, I made sure not to cut the inner frame (on the phone's screen side) of the case or leave too little material there — cutting this off would make the smartphone fall out of the case much more easily.

(Tap on an image to enlarge it.)

Your index finger will tell you when the cut-out is about right. Spending some effort on getting this hole to a comfortable level is worth the time for sports timing at least, as a stopwatch will require you to press this button quite frequently.

That's it. I was somewhat surprised that I didn't find a satisfying commercial solution at a reasonable price — but in the end, I am quite happy with the do-it-yourself solution I found myself. Questions, suggestions or comments? Get in touch.