Last week I found a Leatherman Signal on clearance, so figured I had to pick it up. I don't really need the survival elements since I don't venture outside the city often, so I figure I should swap out the removable parts for extra bit storage. I'm definitely not the first to do this, but I put my own twist on it.
I noticed that the volume of the whistle was enough to hold two bits. I verified this by popping out the whistle, closing the Signal, and sliding a pair of bits into the cavity. They fit in two different orientations, so I was feeling pretty confident I could make it happen.
I used my flatbed scanner to get reference images for the whistle and file, then made some "blanks" in CAD to ensure my basic measurements would fit. A quick 3D printed test looked promising. Here are the reference scans for those interested.
Next was modelling the bit holders. It took a few iterations. I tried inserting the bits from the end, from the inside, from the outside. All of these left only a very thin wall on the sides of the bits that usually broke when cleaning up the prints. But then it dawned on me to snap the bits in from the sides.
The bits are actually held in more securely than I was expecting. They snap in very easily, yet even smacking the holder into your hand doesn't always pop them out. I made a little hole so I could use the awl to pry them out if needed. Also note that one end of the bit cavity tapers just a tad. Originally I had curved the top of this holder to accommodate a full cavity, but it made the grip while using the knife surprisingly uncomfortable. By shaving down the corners of the cavity I was able to make the holder much lower profile at the expense of not being able to hold bits internally that are very
wide at both ends. I think there are only two or three like that, so it was a decent compromise for me.
I also made a bit holder to replace the file. It is inspired by Metro's bit holder, which I think is similar to the one on the MUT.
Now I can carry around 4 flat bits, all within my multitool.
Philips bit lives in the bit driver, then the flat head lives on the outside holder (it is the most sleek there, too wide for that narrowed cavity in the whistle holder, plus Leatherman sells them separately just in case by holder gets loose over time 😅). Since I'm in Canada, a Robertson bit is a must. I'm also a bike commuter, so the 4 and 5mm Allen hex bit rounds out the selection nicely.
The Signal still opens just fine. No collisions.