i made my own for a while, still have a ton of stuff to do it. They are pretty dang reliable, but you will screw up a few, and when you look at the cost involved, its almost the same as the mid level illuminated knocks.
I was thinking about the same thing when I watched the video. I guess if you have the time it's a fun little project!
Double Take's Nocturnal nocks are the way to go. They are the cheapest I have found and work better than any of the other ones IMO. I have used a few different ones but these are the simplest and most dependable that I have used.
I had the same concerns about adding weight to the rear of my shaft, I had the FOC just where I wanted it on my arrows. To bring the FOC back to where I wanted it while using the Firenocks , without having to buy all new heavier broadheads ... I added 25 grain Boosters to the front end of my arrows, they screw into the arrow insert and then your broadhead screws into the Booster and now my FOC is very close to where it was before adding the Firenocks to the arrows. As for the lighted nocks I have tried the Lumenocks, G5, CX, Tracer, Nockturnal and the homemade ones and found the Firenocks to be the best choice for me.
After using the Nocturnal's I went back to the Lumenocks.The Lumenocks are much brighter i can see them in the target at 60+ yards.I lose sight of the Nocturnal's at 30 yards. This is on a bright day, but it's nice to see my arrow hit on a Sunny day.
I actually decided to go with the nockturnal nocks, fluorescent green. I shot my 164 class using them. They are sweet, it looked like a laser beam going into the buck. My buddy who runs the local archery proshop suggested I try them over the tracer's.