The Battery Carrier Project

1.) What was the intent?

The intent of this project was to enable easy transport of Milwaukee Drill battery chargers and batteries.  The current system at the school is to lug them around one by one, which is inconvenient as I discovered during my drilling as part of the T - Track Wasteboard project.  The goal was to create something to organize the batteries and chargers in the tools cabinet, but also allowed for easy transport.

2.) How would the intent manifest?

Similar to the Laptop Stand Project, I wanted an item that would come together without adhesive or fasteners, by interference fit.  In CAD, I designed a model that had handles, but also spots for the batteries and battery charger to be affixed to, that I planned to machine with the CNC Router.  I planned on cutting out four pieces that fit together using interference tabs from MDF, (medium density fibreboard, same material as the wasteboard) with the CNC router, and then constructing the final item from fitting these four individual pieces together.

The Final CAD Model
A few cuts that produced a faulty piece because of errors in the programming

3.) What issues were resolved?

To say that this project was problematic would be an understatement.  The CAD model had to be reworked a few times to provide a more refined final product, but to actually machine it was difficult for myself.  This design necessitated full profiles (cutting a piece out entirely from the stock), through-pockets(creating holes all the way through the material, and swapping of bits while working on the same piece.  The first error I made was accidentally resetting the machine while swapping bits, messing up the location of the second cut with the different bit, or accidentally programming the cut with a different bit than the one that should actually be used.  I resolved this issue by taking more time to double-check everything between steps.  The second error I made was the size of the holes that the tabs would go into.  Essentially, I was attempting to fit a square peg in a round hole.  This issue was solved by slightly expanding the round hole, and filling it down to be a square hole. These two issues combined led to a frustrating week or two on this project, and pile of messed up cuts.  Again, more thorough double checking prevailed, creating the final model successfully.


4.) What was gained? 

Overall, this was another lesson in doing due-diligence; measuring twice and cutting once.  Additionally, I learned how to fit a round peg in a square hole, perfecting the interference fit between a peg and hole for all future interference fit projects.  The project as a whole was another lesson in patience as well, to not rush things.  In addition to lessons learned, anyone who uses the shop at Guilderland now has an easy way to transport a set of Milwaukee batteries and a charger.

The Final Physical Model