I have made snappers out of wiper stiffener and once out of the coat hanger like dinero uses in the movie midnightrun
Stainless bike spoke is the best. they are quite small and very good, they also will not weaken unless you want to weaken it by rebending the coil
I don't have a ruler here in the netcafe Im at, so Im going to use a dollar bill to try to describe the measurements.
I have two of them here
The smaller of them is just as long at the phrase "the united states of america" above Georges head. the coil is as wide as the word "the" and was wrapped around the shaft of a nut driver tool, that takes socket wrenchs. this would be approximately 3eighths inch inside diameter, or just about enough to put a ball point pen through.
the trap box that holds the striker is between the o an f of the word "of"
The striker is as long as from the f in "of" to the end of the word "america"
Those who know my work will recognize that I usually make tools that are compact and stripped of all unnecessary length. and these are smaller and more convenient than any other snapper picks I have seen on youtube which has a lot of snapper videos, and different from any of the snapper picks in the thread on making them.
the coil is much smaller than anyone else has posted
the length is shorter
the trap box for the striker is only about an inch or even a bit less, of the two I have on the table, one trap internal length is as long as the word "america" and the other has a trap internal dimension as long as the word "states" on the dollar bill. This dimension could be reduced by half in the next ones because the bike spokes are very strong and do not need much press down to work very well.
I believe that the smaller trap will make it easier to use.
Do not try to make this thing too strong, the effective strike is often quite light compared to what the spoke is capable of.
I bend the thing until it is all shaped before I file the probe to thin it. do not hammer this flat like the coathanger tutorials say, this is completely unnessary because the wire is already wide enough and only has to be filed on both sides to thin it out.
The probe does not go straight from the coil to the tip of the striker but it has a bend just in front of the point where the trap strikes the wire. this improves the ergonomics of how you hold this
and there is a lenth of plastic pen barrel cut to sheath the part of the striker that is inside area from the coil to the trap, this is not seen on other snappers, but it does two things, it holds the wire loosely so nothing/fingers obstruct/dampen the strike and it also protects the fingers from the annoying snap that may be repeated a number of times. this must be put on before the ergonomic bend I mentioned
and the last step is to file the wire on both sides and if you need to reduce the width of the resulting striker, be very careful as you do this, and quit filing before your reach the desired dimension (thin enought to move freely in keyways, mine vary in width here a bit because some have gotten quite thin in the process of final sanding.)
Remember this, a really forceful snap may not work as well is a somewhat lighter one. so do not emphasize super force as you set the tension
Setting the tension is done by looking at the angle of the two arms out of the coil before being trapped and the angle after it is in the trap, the greater the difference in those two angles is the tension setting.
Do not go crazy tweaking the tension, just set it and then experiment using the pick and moderating tension by controlling how far down you press the trap arm.
Wake up and smell the Kafka!!!