nichanderson ,
Did you solve you wire tension problem?
PM me your email, and I'll send you pix of mine.
No springs in the way, no bow(hehe)...
You basically have two vertical springs on each arm at the top, hot wire end goes to spring, down, around the meeting point of two bearings, out a little hole, across and the reverse on the other end.
The beauty of it is, no springs in the cutting area, no loss of wire end position when arms go opposite directions, and NO alligator clips of the wire.
The electricity passes through the bearing and supplies the wire with juice, even when the springs stretch and the wire travels.
It's all very SIMPLE, and took me forever to figure out.
Like I said, I'll send you pix, those are worth more words than what I typed.
Regards,
Justin in AZ