Long time lurker, first time poster. Decided I would share this mini-hack that will take you all of 5 minutes.
I got a nice jacket for Christmas and wanted to mod it right away for good EDC use. I knew about the Gerber GDC Zip blade but I couldn't justify the cost for something so small. Quick look around the office/workshop and I found a candidate for my own version. A "flippy" USB drive... Pretty straightforward so here we go.
Step 1: Find Your Candidate
After I set my idea of re-creating the Gerber blade I needed a candidate that would be small enough to clip easily on my zipper while not being too cumbersome. I found a little flippy USB drive that seemed like a nice option. I considered one of those retractable USB drives as well and I think could be done just as well. I just liked the flip.
Step 2: Gut the Sucker
My USB was only 1GB from a tradeshow so I knew I wouldn't miss the storage (funny how 1GB effectively throwaway at this point). Carefully pry apart the housing. Usually these things are cheaply made and mine was no exception. You still want to be careful so you don't crack the housing. There was a decent glob of hot glue holding the memory card in place that came out with some scraping. I then cut down the body so that more of the blade could be available for cutting and that the blade would still have clearance for the flipping action. As for the blade itself I first considered putting in an X-acto blade but then realized with a little Dremel work any regular sized utility knife razor could be made to fit. Plus the blade is so cheap I can easily put in another as it loses its edge, breaks, etc. I opted not to secure the blade with epoxy or glue for that exact reason. I didn't take real dimensions but you can see in the picture that I cut the blade down with a slight incline that way the back of the blade had some girth to act as a natural detent to keep it in place.
I then reassembled the housing, compressed the metal to hold it tight and voila!
Step 3: Finishing Touches.
With final assembly a few things became immediately aware. Big one was how to keep it from opening when I didn't want it to. A quick visit to the workshop and nice thick O-ring became my retainer. I also hooked up a small carabiner which gives me quick deployment as well as extending the handle of the blade making it nice in the hand.
Clipped to my jacket and we are all done. Pretty happy with it and definitely handy to have just on my jacket and total cost was effectively zero since I had the parts laying around.