The only limitation I've had using it is to remember to bring it with me. Often times I'd leave it at my desk, in the glove box or the pants I wore yesterday. So If figured the one thing I always have with me, which won't allow me to lock up, drive off or enter into without, my keys.
I'd used the materials before to repair a broken key fob for an older car and figured why not.
If you don't have one, go get one, they're free at the squareup.com website.
Step 1: Square Card Reader Fob Supplies
1. Square Card reader with standard 3.5 mm output
2. Some ShapeLock thermoplastic (could probably use sugru or oogoo though I've never used either)
3. Microwave or range to get some tap water up to temp if using ShapeLock
4. Cup of water (prefer ceramic or glass over plastic as the ShapeLock and heat won't stick as readily to a glassy surface)
5. X-acto like blade for making cuts and trimming any necessary material
6. Some non greasy lip balm to provide a release between the card reader and the ShapeLock
7. Q-tip for putting lib balm release on card reader and using cylindrical shaft to create through hole for key ring.
8. Long reach tweezers (not pictured) to pull out ShapeLock after it's been heated in hot water, can also use X-acto knife
Step 2: Square Card Reader Fob Prep Step
I first get some of my lip balm on my Q-tip and apply it around the white plastic base of the card reader. I don't put any on the silver or white bands of the 3.5mm male adapter at all.
Cut off one of the business ends of the Q-tip so we can use the bare end for reaming.
Now we're ready to start cookin'
Step 3: Square Card Reader Fob Step #1
Once the time has elapsed, you can either take the cup out of the microwave, or just leave it in. It'll likely be hot to the touch.
Place your ShapeLock directly into the cup of hot water and give about 30 seconds for the pellets to melt down and begin to attach to one another. You'll know the ShapeLock is ready for working when its appearance goes from the opaque white to a translucent clear.
When the ShapeLock mass is completely translucent, take it out of the hot water carefully, using long tweezers or the X-acto knife you have.
Step 4: Square Card Reader Fob Step #2
I'm just doing a simple bakers roll using my fingers to create a cylinder.
I want to do this relatively quickly as the ShapeLock is setting up and loosing its ability to be worked.
Once in the general shape, literally plug in your (lip balmed up) Card reader into one end of the ShapeLock and begin to pinch in around the area where the 3.5mm male plug is encompassed with ShapeLock.
Cut off any excess after creating room for the keyring through hole using your X-acto knife carefully.
On the end where your keyring through hole is, push the cut end of the Q-tip into the flattened end and gently ream it out to accept your keyring.
If your ShapeLock sets up before jamming the Q-tip in you can just use a suitably sized drill bit and drill it out, or just dip the Fob end into some hot water to melt the ShapeLock down to get you some more working time to push the tip through. Just the end though, not the whole thing.
Step 5: Square Card Reader Fob Step #3
Did you hear the little snap? Nice.
Now place the fob on your keychain and then plug in your Square Card reader and go get paid.
This doesn't have to be on a keyring either, you could make a pendant for a necklace, earrings (maybe) etc. get creative with carrying your reader.