Here is what I made.  It didn't take very long to throw together.  It was simple and easy to make.  Made the whole thing out of scrap minus the 3 dollar guitar string.  
I tried the train transformer but I didn't have any luck.  So I used an older style battery charger.  I don't think the new ones will work because of a safety they have in them. 




It takes a few minutes to get set up, but once you do, you can do a dozen arrows in no time. As long as you make sure your cutting wire is red hot.  First set of kids arrows! 

A buddy and I have been using this for about 3 years.  I bought 2 pack of guitar strings and have only used one! 
Patrick