older: 2002

28 August

Terrorhurtz almost complete.
Front armour is 1/4" stainless steel, backed by 1/2" 7075 ally.
Side skirts of 2014 ally are attached by 1mm titanium sheet hinges.
Rest of armour is 12mm Lexan.

Flatpack robot.

The chassis goes together. Edges of 12mm panels are tapped M6. You can see here the main ram mounting lugs.

The finished polyurethane tyres. Learning from Team Delta, I machined the bearing pockets in the wheels around 0.02mm oversize and then used Loctite to retain the bearings - much easier than trying to get the pockets exactly 0.01 undersize and then pressing in the bearings.

The assembled chassis from the side, without the skirt fitted.

18 August

Rebuild of Terrorhurtz for Series 7. Significant redesign, with the main change being a major upgrade to the axe. See below. Other changes:

· Chassis and armour are now all 12mm Lexan, apart from the floor (6mm).

· Extinguishers mounted longitudinally, for easier access and to make room for the new buffer tank.

· Large rear ground clearance and deeper skirts to avoid the wheels getting lifted off the ground if someone gets under the front of us.

· Pneumatic rear strut/wheelie bar to reduce jumping when firing the axe.

To improve on the rather convoluted gas path of the old system, we've gone for a single large (5 litre) buffer tank mounted centrally. Off the shelf stainless steel air reservoir by Festo. Buffer tank is connected directly to the valve and the valve feeds into the ram via a short pair of pipes.
The old system was fed by a long section of 12mm id pipe, with several 90 degree elbows.
In the new system, the ram is fed by two very short sections of 13.6mm id pipe.
Hopefully this will result in much improved speed from the axe, or we should be able to turn the pressure down and get the same power but for more strikes.
It will be mounted the other way up in the chassis, with the buffer tank below the ram.

Got the side bulkheads watercut out of 8mm 20124A T6 ally. Machined up a pair of stub axle out of the same material. With the new layout of the extinguishers taking up more width, the cantilevered axles save space, allowing us to stay within the max overall width of 1200mm.

Machined up some new wheels out of 4" 2014 bar. Will get polyurethane tyres moulded onto them.

Got a new axe head watercut out of 8mm mild steel. Ground a nice edge on it and the front ramming blade, also in 8mm steel, ready to take them tomorrow to get case hardened to 1mm depth.
Once I get them back, I will weld some 2mm sheet steel into the cut-outs in the axe head.

Modified the pneumatic ram that we used as the nose lifter in Killerhurtz, to act as the actuator for the rear stay/wheelie bar.

Got a nice little Bosch 5-3 port valve to drive the tail bar ram. A 5-3 valve means that you can hold it in any position, with the ports closed, rather than it being either fully up or down.

Cutting out the chassis panels from 12mm Lexan. Using Dominic's A2 printer makes cutting out panels so easy - print out the design, complete with guide lines for the saw, stick it to the panel, clamp a fence onto the panel, aligned with the guide line, and run a circular saw along the fence.

older: 2002