This is an essential tool if you are going to attempt to sharpen a saw. You can sometimes find old cast iron ones or shop made wooden versions on eBay or at flea markets, but they can be expensive.
I thought I would like to use an offcut of oak to make one.
Resawing the oak to make the Jaws with a Japanese style rip saw. Surprisingly easy with a sharp saw. These saws track well so are excellent for Resawing.
Installing the clamping screw. This is made from a beech dowel and threaded using 1 1/2 inch thread box. (Link to one here http://www.highlandwoodworking.com/manualwoodthreader1-126tpi.aspx)
The clamping pressure is provided by this oak nut. It is tightened by hand, despite the nut shape.
The inside of the vice jaws are shaped to provide clamping pressure as close to the saws teeth as I can get. This reduces chatter and noise when filing.
The vice is designed to hold a 26inch panel saw, you can put smaller or larger saws in.
Final view showing the clamping of the saw plate close to the teeth.