Update:

Shred
Been testing Shred lately and have upgraded the weapon http://i1280.photobucket.com/albums/...psfaf23599.jpg
http://i1280.photobucket.com/albums/...ps5f282fa9.jpg
http://i1280.photobucket.com/albums/...pscdc6f48b.jpg
http://i1280.photobucket.com/albums/...ps2d2c549d.jpg
http://i1280.photobucket.com/albums/...psd56d647a.jpg
The wheels seem to stay on longer now I have cut a flat across the grub screw, so can tighten it more. Switch has been added - a 10amp @ 250v 2-way toggle switch - seems a bit overkill, but 'better safe than sorry'. http://i1280.photobucket.com/albums/...ps9c1538ee.jpg
http://i1280.photobucket.com/albums/...psbd278e76.jpg

Cookie Cutter
Did a brief test run off some AA's and seems to run pretty well

Pizza Cutter
Bought 2 100mm diameter castor wheels from Clas Ohlson. http://i1280.photobucket.com/albums/...ps326f8f58.jpg
Will use 4inch Colson Performa wheels for competition, but these should do for now. Drawn up a 1/2 scale diagram of Pizza Cutter, and all looks like it will fit. Will upload more pics soon.

Sorry for the long post, but that's what I've been up to.