Horizontal control is achieved with an easily fabricated fence that allows precise control of the position of the tool end in relation to the work piece. Below is a quick and dirty jpeg drawing that I made up until I can get over to the shop and take a photo of the fence. It only takes a slight bump of the handle that hangs down from the fly wheel to get the tool to do it's work. No jumping around, chasing pieces of bouncing steel. Just a an easy bump and your tool sinks into the hot or cold steel. I'm amazed by the power of this set up on cold steel. A chisel I made out of S7 steel easily sinks into cold steel with just a bump on the handle and then it rebounds back to you.
Photo of the fabricated fence I use to control the horizontal indexing of my workpiece. You can use the fence that moves in or out to control the position of you tooling relative to your workpiece as seen in the photo below or you can flip it so that the fence is facing 180 degrees to it's current position. This allows a better view of the workpiece, because the fence is not in the way. The base plate of the fence is a piece of 1" thick x 6" wide and 22" long. I used two pieces of 1" square stock that are tapped for a set screw and welded to the side of the base plate and drilled two 3/8" holes that allows the round rod to move in or out for precise positioning of the piece you are working on.
Any questions, please call or email and I'll be happy to go over any of this with you.