Since 2012, the HD model has featured twin 90-lb flywheels (previously 75-lb), a two-and-a-quarter-inch wide rack gear, and a
pivoting pusher design with four bearings traveling under the top flange of the I-beam. The pivot point for the rack gear
is a hardened 5/8-inch shoulder bolt located above the I-beam, just behind the pusher plate. The advantage to this design is
the consistent space between the I-beam and the pusher plate, resulting in less chance of debris getting between the two and
causing resistance on the return stroke. Again, keeping the surface of the I-beam relatively clean is still important with any
SuperSplit model (this will be demonstrated in the forthcoming video section).
The HD model has more impact force and is ideal for the tougher woods, or for those who consistently tend to split their wood
closer to the 24-inch maximum length the machine will accept. With the HD model, the flywheels will stall less often on difficult
wood than with the J model. Note that stalling the flywheels is not a bad thing! Instead of busting a gut trying to split a piece
of wood that is giving a lot a resistance, the SuperSplit will give the wood “Round One” and will then follow up with another shot using the full momentum of the flywheels, until it pushes it through the wedge.