Right, lets have a go, with some modifications to last time, some just tweaked, others replaced. I may change my mind slightly later.

Lightweight
ttp://http://www.geocities.com/alex_j_holt/BALDUR3.jpgwww.geocities.com/alex_j_holt/BALDUR3.jpg
Little Baldur
A little invertible box with a scoop at the front designed to survive everything. The scoop works both ways up. The weapon pivots on the side also prevent it getting stuck on its side. the armour is most heavily layed on at the front so it can charge into spinners.
Speciality: Armour and wheels

Middleweight
http://www.geocities.com/alex_j_holt/t7.jpghttp://www.geocities.com/alex_j_holt/t7.jpg
Tengu
Doesnt need too much introduction I feel, a top spinner disc with two blades weighing 3.5kg in this instance at about 2cm from the ground. (Ignore the upper blades in the pic, those are a different weapon set up not used here, just add the upper blades to the lower blades) My infamous spinner ring sits just above the blade and is used to dissipate the attacks of horizontal spinners by transfering the enrgy into it so it goes whizzing round and tengu is unharmed. Its made of thick, plasticised rubber and basically just mounted on casters. There are four small internal wheels on a skid steer system, protected from being under cut by a metal foam skirt which gets squashed slightly if tengu is rocked at all. The bar on top pivots on some side and is powered by actuators to self right.
Speciality: Weapon and wheels

Heavyweight
http://www.geocities.com/alex_j_holt/BPQhttp://www.geocities.com/alex_j_holt/BPQ
Black Panther Queen
A pyramid with the tip cut off low down, skirts, and a double headed pnuematic axe and flipper. The flipper is in two halves but attached at the back, so that it doesnt interfere with the axe. There is a slight bias in armour towards the front.
Speciality: Weapon and wheels

Superhevyweighthttp://www.geocities.com/alex_j_holt/redknight.jpghttp://www.geocities.com/alex_j_holt/redknight.jpg
Red Knight
OK - the complex one. The main body is quite titchy, its all about the weapon. The weapon pivots off the centre, and follows an opponents direction using motion sensors - and is essentially a huge hardox plate on castors with a 10kg flywheel set into it for damage. Anyway, it basically means that whenever someoen attacks unless they are very fast theyll hit the plate, and the disc.
Speciality: Attack and Defense