Double Capacity MintyBoost with 4-AA Battery Holder Modification

Step 13 Prepare the Altoids Tin

Cut a hole in the Altoids tin to accommodate the MintyBoost USB connector. The bottom of the hole should be even with the bottom of the USB connector after you apply the foam tape. Here is how I accomplished this...

I measured the USB connector and then created a template out of thin cardboard. This allowed me to check the size of the hole for fit with the USB connector before attempting to cut the tin case. Once the template was made I used it to trace the outline of the hole at the desired location on the tin. Once I marked the outline of the hole where I wanted it I used a Dremel drill bit to make an initial hole and then a Dremel soft metal cutting bit to rough out the hole. Then I used some small hand files, one flat and one square, to finish out the hole. The images below show the progression of this process along with the tools used for each step.

I would like to find a rectangular hole punch to make this step easier in the future.

One of the benefits of making the hole this way instead of using tin shears is that the case is more sturdy and we can use it to sink off some of the heat generated by the MintyBoost as shown later.