This is a miband strap made from oogoo. Replacement miband straps are very cheap, and the materials for this project well exceed the price of one on amazon or ebay. So this is not a very practical project unless you happen to have most of the materials, or really want a custom-fit, closed strap for your miband.
The band in the picture was an experiment, and so I didn't document it thoroughly. I intend to recreate a new band, perhaps black this time, and document it with pictures to add to the steps.
We will be doing the following:
1. Creating casting material (I use the gelatin/honey casting material).
2. Use modeling clay to build up the top of your miband before casting.
3. Creating a cast from your miband.
4. Mixing oogoo (sugru could potentially also work, but it's too expensive for my tastes).
5. Casting the 'housing' part of the band for the tracker.
6. Casting the strap for the tracker (best if done at same time as #5).
7. Connecting one side of the strap to the housing
8. Connecting the other side of the strap to the housing (yes, each has to be done separately).
9. Strengthening the connections and smoothing out the final product.
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Step 1: Creating Casting Material.
You can probably use whatever you want, but I'm using this gelatin material used for prosthetics. Use whatever casting material you want, as long as it has the following characteristics:
1. It must be flexible in order to remove the oogoo material without damaging it.
2. It must not get stuck to oogoo.
You'll need less than 1 cup of casting material.
Step 2: Cover Miband With Clay
For my original (white) band, I didn't do this step, and the housing didn't fit the band very well after I added the cover. For the black band, I'll be using a simple clay to build up the top before casting.
just cover your miband with the same amount of clay that you would want the silicone to cover once cast. I recommend adding about the thickness of a credit card on top.
Step 3: Cast Miband and Let Cool
Heat your casting material up (I find that 3X0-second stints in the microwave does the trick.It helps to cut it up into small pieces with scissors.
To cast the band, I attached some butcher twine to my band and lowered it into the cast. You'll want your band to be closed to the size it usually is on your wrist. Err on the side of too large.
Step 4: Mix Oogoo
Before you do this, read through the rest of the steps to be sure you're not missing anything you need. Oogoo will set up in just a few minutes, so if you screw up, you 'll have to do another batch. The nice thing is that oogoo can be made in any size batch you want, but the larger, the easier to mix.
Oogoo sticks to everything when it's being mixed, but only to some things once dry. It will not stick to most food-safe plastics (water bottles, ziplock bags, etc).
I use an old mayo jar and a flathead screwdriver to mix mine. If you want to add color, I got some oil pants at the craft store that work really well and are very cheap. However, it's really hard to get the color exactly the same each time, which is why I will only work in black and white.
Step 5: Cast Housing of Miband Tracker
Now we'll cast the housing of the miband tracker. First, cover your miband with (a VERY THIN LAYER of) some sort of oil or vaseline to prevent the face from sticking to the oogoo. The black part doesn't stick, but the gray face does for some reason. Trust me, you don't want to spend an hour scraping silicone off the face of your tracker.
Fill the cavity with oogoo, then cover the face of the miband with oogoo. Then gently press the tracker into the cavity until it's at the right spot. Better to shallow than too deep here. If there's not at least 1-2 MM of oogoo on each side of the tracker, the oogoo will break instead of stretch, and your band will be useless.
Smooth off the top as shown (I find getting my fingers wet and rubbing them over does the trick) once the oogoo has set a bit more. Then leave it to cure for an hour (or more if you can).
Step 6: Cast the Strap
Ok, so here is where I cheat. Theoretically you can use this method to make a band of any shape or size you want. But I don't have big sheets of thick plastic lying around, so I used the backside of a magnifying ruler from the dollar store. This part is particularly difficult because if there are any bubbles in your strap, it will break easily. So take your time and do it right. It took me about 5 tries to get it to work for me.
Step 7: Connect One Side
Once your strap is cast, cut off the end of your housing and the end of your strap, and stick them together. You'll only need a drop of oogoo, so try doing this along with another oogoo project, or like I do, mix a tiny amount in a bottlecap with a toothpick.
We will be blending and strengthening this part later, but it's MUCH harder to remove excess oogoo than it is to add some later, so ERR ON THE SIDE OF NOT ENOUGH. You'll only be able to connect one side at a time, so let this cure at least an hour before moving on to the next step.
Step 8: Connect the Second Side
Once the first side is connected, the second side must be connected in the same way. It's much more difficult because 1) the entire strap will be under stress and 2) You want it to be the right size for your wrist.
IMPORTANT: ERR ON THE SIDE OF TOO BIG. It's relatively simple to cut a section out and oogoo them back together. It's more than twice as much work to add a section in.
Finally, the worst case for a strap that's a little too big will be that it's annoying or might slip off. If a band is too small and you wear it to bed YOU COULD LOSE YOUR HAND (tourniquet, anyone?)
Step 9: Strengthen the Connections and Smooth Out the Top
Now for your (possibly) final batch of oogoo. You'll want at least a teaspoon if not more. Gently stretch the connections apart and fill in the space with oogoo, and then smooth it down. Smooth out any other spots you want to touch up (fingers + water work well here) and hang to dry. You can repeat this process as many times as you want, so if something's not working, just come back to it later. Oogoo sticks to old oogoo just as well as new.
IMPORTANT: LET THIS CURE FOR AT LEAST A DAY BEFORE TRYING TO WEAR.
If you don't give your oogoo sufficient time to cure, it will be weak and likely break when attempting to put it on. Regarding putting it on, this stuff will not stretch as much as you might think, so I just roll mine over my hand. Use the excess strap material to get a feel for the band's resilience.
UPDATE: I was tired of not being able to see my notifications, so I came up with a way to cover the top with clear silicone! The steps are really quite simple.
1) Place your tracker in the band. Trigger an alert and use a permanent marker to make dots where the lights are. They might be a little off center, and that's okay.
2) Take a standard paper hole-punch and punch holes around these! It's okay if they overlap, and a regular single-hole punch (the kind that looks like a pair of pliers) does a suprisingly good job of making clean circle cuts in the silicone.
3) Cover the top of your miband tracker with scotch tape! Silicone won't stick to scotch tape, and the top of the miband tracker is flat enough for a good solid application.
4)Replate your tracer in the band. You should now be able to see the holes covered in tape. Fill in the holes with REGULAR silicone, and smooth out the top. I find a wet finger or an ice cube works well.
This will cure in just a few hours, and you'll have a clear, smooth window to your miband!