Apple Airpods Pro Deodorant Diversion Case

After waiting for the back order delay since October, I finally got my Apple Airpods Pro in early February. They were the perfect replacement (and definite upgrade) for my Bose QuietComfort-20 earbuds that finally succumbed to too many tugs on the cable after many years of dutiful service. I primarily use them at work in your typical office environment and while I never really worried about someone taking my Bose ones (especially being wired), the Airpods are much more desirable along with being very easy to pocket.

So, to primarily safeguard them from normal damage I wanted to put them in some type of case, but couldn't find anything that I liked that would also provide an additional benefit of safeguarding them from theft, since most cases don't serve to disguise them. In fact, most of the cases would actually draw attention to them as being the real thing because who would buy a case/cover for knockoffs.

The first few minutes playing with my new earphones, I made the connection to the size and shape being very close to that of your standard deodorant. Since the brand I use was not a match I went to our local grocery store and purchased a few that were close. And the winner was Brut Classic. In addition to being almost a perfect match in size and shape it also matches the solid white color of the Airpod's outer housing to the actual deodorant "stuff".

Thus began the latest installment of (in my wife's voice), "What are you building now instead of fixing [fill in the blank]?!"

TERMINOLOGY:

Throughout this Instructable I'll use the following terminology.

Shell = The green plastic packaging of the Brut deodorant

Housing = Referring to the housing of the default Airpods with no case

Case = The final product, (Airpods installed in the Brut deodorant modified shell.)

Supplies

Materials:

1.) Men's Brut Classic Deodorant

2.) Male to Female Lightning Extension Cable:

https://www.amazon.com/gp/product/B017CNQQ1Y/ref=p...
Description to search on Amazon if the above link doesn't work -
TechMatte Apple Pencil Charging Adapter for iPad Pro Male to Female Flexible Connector (3.5 Inches)

3.) Two Springs:

https://www.hillmangroup.com/us/en/Home-Solutions/...
From Ace Hardware they are #123 springs in the hardware aisle where you grab things one by one and put them into a envelope and write the price and quantity of the items

4.) 2-Part Quick Setting Epoxy Suitable for Plastics (Details appear later)

Tools:

Resin 3D Printer

FDM printer can be used as well, I would assume, but I use a FormLabs Form 2 printer and the provided .stl files were generated based on this printer's output.
(My experience with 3D printing is limited to the Form2)

Hand Tools Capable of Cutting Plastic
Wet Sandpaper (400, 800, 1600 Grit)
Clamp
General hand tools

Step 1: Charging

Note: The Airpods Pro come with inductive charging. The basic Airpods do not, though you can pay more for a version that does. (This Instructable is strictly for the Pro version of Airpods. The basic Airpod housing is completely different in size. Though I did wonder if a "Travel Size" deodorant could serve for their purpose.)

For the case I designed, I wanted to be able to charge them inside the case (whether inductively or via USB). Also for travel purposes, I wanted to be able to charge them with a standard USB lightning cable (That way you don't need to carry an inductive charger with you while traveling.)

Thus the two criteria that drove this concept and overall design:

Not inhibit inductive charging while inside the case
Charge via USB while inside the case

Additionally, I would have preferred to be able to plug the charging cable in while the case was standing upright, but several things prevented that, mostly the types of different lightning cables and adapters to choose from.

The cable I finally chose is actually for the Apple pencil. It allows the Airpod's housing to plug into the male side of the cable and is actually a bit too long, but works to route the female end to the outside of the deodorant shell to allow a standard USB lightning cable to plug into the final case.

Step 2: Ejector Need

The fit of the housing into the cavity of the shell, while very close, is obviously not a perfect fit, but even so has actually just about the right amount of friction to keep them held in place but not require an excessive amount of force to pull them back out. The draft (injection molding technique to allow parts to be removed from their mold) of the shell creates a gradually tighter fit the further the housing is inserted into the shell.

During the design and testing phase, I had to pull the Airpods out from the shell many times by pulling on the Airpods opened lid. Definitely not something you want to do too many times, but mine held up fine. However, once I figured out the short USB extension cable portion of the case's design, I realized that the additional friction of the lightning connector into the housing simply added too much. Extracting the Airpods from the case, by overcoming the friction of the housing in the shell AND to separate the lightning connector, was just too much force to apply to the opened lid. At some point, this would result in damaging the Airpods.

Thus some method of ejecting the Airpods from the case was required. I knew this would greatly complicate the design of the case, but I considered it a fun challenge.

(If anyone wants to make a simplified version, add layers of foam, cardboard, or similar material to the shell's cavity so the Airpods housing can be inserted just to the proper depth. This will work if you're not concerned with charging only by induction and have no plans of needing to take them out of the case. If you did need to remove them, cut them free from the shell or drill holes in the bottom and use screwdriver or similar to press them up and out.)

Step 3: 3D Printed Components

There are two parts that need to be 3D printed. They are:

"Airpod Sleeve" (Left Image)
"Airpod Pusher" (Right Image)

The Airpod Sleeve is glued to the shell and remains fixed in place, while the Airpod Pusher is allowed to translate vertically to serve as the ejection device. The two springs are used to keep the pusher in the extended ("not eject") position. (When ejecting the Airpods, these two springs are compressed and the pusher moves vertically with the two pusher rods pressing the underside of the Airpod housing to push the housing out of the case.)

Both parts have cutouts to accommodate for the extra length of the adapter cable.

The sleeve has openings for both ends of the adapter cable. They are sized to allow a slip fit of the connector ends and have corner relief holes to serve as pockets for the epoxy to flow into when ready to glue the cable in place.

Both parts only need minor post processing out of the Form 2 printer. Mainly, removing the support points and sanding smooth with progressive grit wet sandpaper. Make sure to test fit the pushers' two rods into the mating holes on the sleeve to ensure a smooth slip fit. On mine, the two rods on the pusher part seemed to have bowed inward (or maybe it was outward) on the final part. Not sure if this was just a result of the long tall print or possibly the post cure. If I were to do another iteration of the case design I would leave the rods off of the print and have them be pressed or glued in metal or plastic rods (versus being integral to the part).

(I printed both parts in a perfectly vertical orientation on the Form 2 to limit the supports.)

Step 4: Installing the USB Cable Into the 3d Printed Sleeve

First, insert the smaller male end of the connector into the 3d printed sleeve part. To get the exact right height, insert the Airpods to see where the bottom surface of the housing rests. You want the Airpods housing to be in contact with the sleeve and not "floating" above it when the connector is inserted. Once you establish the proper height, keep it in that position and add the epoxy into the four corner holes. (A toothpick worked well for this for the epoxy I used, since it was too viscous to wick into the holes on its own.)

Note: Super glue will not work for this. (I tried.) I used a Loctite brand two part 5 min epoxy.

Note: 5 Minute Epoxy does NOT mean it cures in 5 minutes. This generally refers to a "working" time, which is the point it starts to cure and should not be handled. Even this epoxy takes 24 hours to fully cure:

https://www.loctiteproducts.com/en/products/build/epoxies/loctite_epoxy_instantmix5minute.html

Allow that end of the connector to fully cure.

Lastly, epoxy the other end in place by using a toothpick or small screwdriver or tweezers to coax the cable out of the hole in the side of the sleeve as you push the larger end of the adapter cable until it is flush with the bottom of the sleeve. Epoxy in the same manner. Since this end just has a cable plugged into it the height is not really important but to have the most stability of the case when its stood on end a slight recess of the connector face on this end is recommended.

Step 5: Assembling the Internals

Assemble as shown in the pictures above taking note to align the cutouts in the two 3D printed parts.

Step 6: Demo of Ejector Internals

Step 7: Preparing the Deodorant Shell

Fully extend the length of the deodorant and break free. Discard as I did, or put in a plastic bag and use as intended. (I hate being wasteful, but this type (solid white from any brand) irritates my skin.)
Separate the threaded rod by pushing it down from the inside (or by pulling from the outside with a quick tug of some vise grips)
Remove the plastic at the bottom where the ribbed wheel was located as shown in the last two pictures. Dremel with a router bit works best, but an X-Acto blade will work too just take longer.
Thoroughly wash with hot water and soap to remove all traces of the deodorant material

Note: I roughed up the surface of the shell where the epoxy would be contacting (with 400 grit sandpaper). Another method to ensure a good bond, but I don't think it was necessary in this case (pun intended).

Step 8: Final Assembly

This is the hardest part of the whole project. And like I mentioned earlier if I were to do another iteration of the design I would change a few things to address this step since its easy to mess up.

Take the internal assembly from Step #5 and insert into the prepared shell
Insert your Airpods housing while ensuring a proper mating to the lightning connector
Open the lid of the Airpods and adjust as needed so the surfaces indicated in the first image above are perfectly flush to the shell. The overall design of the components should set this position, but it might need a minor adjustment. This step is critical to making the final case look deceptive since it will "hide" the separation line of the Airpods lid.
At this point you have to restrain the internal assembly by squeezing/pinching the shell so it cant move. Make sure it stays in the position set in the previous step. I used a wood clamp with large surface area to distribute the force broadly and not mar the shell's surface or decal. You want to apply the clamp approximately where the "CLASSIC" word appears on the decal.
Flip over to apply the same epoxy as on other steps to the areas shown in the second picture. Similarly to gluing the cable in place, I created corner pockets to allow the epoxy to run down to get a good bond line. However, at this point, the glue can run too much and possibly glue the ejector part to this part preventing the ejector from working. To prevent this, I removed the Airpods from the case, and then pressed the ejector to the "eject" position and stuck Q-Tips in the holes around the opening to hold it in the "eject" position while the epoxy cured.

Step 9: Demo of Final Case

I do my modeling in CREO (as much as I hate it for conceptual design like this, it's what I know the best and haven't had time to learn another tool like Fusion 360, which is on my goal list.) and if anyone wants the native files to manipulate further or would like a different format that CREO can export please let me know.

Enjoy and thanks for your time and interest in reading my Instructable.