I made an arrow saw that is as good as any that you can buy for about $30 TOTAL.
It takes some rigging but here it goes.
I bought one of those cheap 4" 90 degree high speed grinder that you can buy at any flea market for about $15. I removed the handle that is threaded into the frame with a 1/4 bolt. The grinder will now have 2 1/4 threaded holes opposite each other on the frame. I bent a piece on 1/4" by 1 1/2" stock in a u shape, drilled holes in each end and bolted them to the grinder, making a solid mount. I mounted the grinder to the end of a 36" piece of 2x6 so that the blade is 90 degrees to the length of the board. next I took a piece of 2" angle iron about 2 ft in length and mounted it parrallel to the board with the up right in the back and even with the center of the cutting wheel. I made the arrow holding bracket by benting a thin piece of flat 1" stock so that it had a flat side about 3" long then a 90 degree bend with a 2" upright follwed by a slightly greater than 90 bend back at you and then an upward lip to hold the arrow. This looks like a u with a lip on one side. The side with the lip got slotted to fit inbetween the blade. I cut 2 slotted holes on the bottom side and mounted it with bolts coming up through the 2x6 with wing nuts on the top, so that could adjust the holder in as the blade wears out. The other end of the jig that hold the nock end of the arrow was made by taking a piece of meatl, I used alum, about 2"x1"x" ,machining a slot in one end to ride on the angle iron. I drilled and tapped the back to accept a bolt to lock it on the jig. The front right side has an indentation in it to hold the nock made by usind a 5/16 drill bit and making about a 1/4' hole. I mounted a piece of tappe measurer on the jig, offset the depth of the hole to give an accurate measurment on the front side of the sliding block.

It sounds like a lot, but all I did is copied a comercial jig, and replaced that $100 cut off motor with an inexpensive grinder. I use 3" fiberglass waferboard blades.