The axe mechanism.

Wanted a simple, light, compact and efficient mechanism for the double-headed axe. 

E-mailed the AutoCAD drawing of the brackets to DJT Engineering (Oxford) to be CNC milled - more good use of the Tracked Rapier door material. They did a really nice job of them.

Had a new rod for the pneumatic cylinder (100 mm bore, 250 mm stroke - over 50% longer than that on KHz) made up out of EN24 steel, with a rack cut into it. Couldn't get it hardened due to the risk of warping. Sweeps through about 220 degrees.

The 2.5 mod teeth go all the way along the length of the rod, right into the cylinder. The tips of the teeth come to within 0.25 mm of the diameter of the cylinder and the existing seals seem to do a pretty good job of swallowing the teeth and maintaining the seal. We still use the cylinder at full pressure (170 psi) in both directions and it works surprisingly well.
These shots show the rod fully extended. Note the support bearing for the rod.

The rod almost fully retracted, with the axe arm extended.

The custom made rod with piston attached.

The complete axe arm and head with safety covers fitted. Got the head case hardened to a depth of 40 thou' (1mm) by Quantum Heat Treatment, with only slight warping.