PAnts originally came about following discussions on the (now defunct) Tinweb forum during UK Robot Wars Series 2. The discussion lead to the creation of antweights as a weightclass and myself and a few others built robots to see if it was possible. The picture above was taken from the ironically named Antweight World Series fight that was organised in Oliver Steeples house.
PAnts (Pandamonium’s Antweight Sister) was built using Hitec HS80 servos for drive, a 4.8v 110mAh NiMh battery and a metal geared HS81 servo for the weapon which produce about 2.6kg-cm of torque at 6.0v.
Modification is simply a case of removing the case, gently lifting out the top gear. This is then drilled through and the notches in the top of the case are ground out to allow 360 degree rotation. The only remaining trick is to glue the feedback pot so that you get a neutral point in the centre of your control stick. Once this is done, you’re in business!
You will note that the weapon was actually a self-righting device originally, having been inspired by Rex Garrod.
The Pants above (2002) uses Dycem covered wheels, carbon fibre axe shaft, 300mAh batteries (2/3 N cells I think) and now uses the high-speed modified HS81 servos. The new Pants was much faster and could outrun most competition at the time. It had a little less pushing power, but can still push a full can of coke easily. Speed modifcation was done by re-using the gears from the servo but putting them in a different order to get more speed but less torque.
The Pants above (also 2002) is the familiar one used in Robot Wars: Extreme series on TV. It used sticky tyres (using a lint roller cartridge) and the copper strip at the front. The side panels where made of plasticard and covered in extra thick insulating tape. The drive came from 2 SD200 servos.
This was the experimental scoop used in a couple of World Series. The scoop is actually very impressive and I did consider not going back to the axe. This variant of Pants runs both ways up. The scope is made of 1.5mm aluminium and can be used as a third wheel. The practical downside is that if you pick up something too heavy, it can lift PAnts wheels instead of the payload.
Over the years, Pants has become a firm favorite with competitors, fans and casual observers. I have been selling Pants plans and construction kits through the shop for some years and it continues to be the most popular choice. I have built various versions of Pants. This is a white Pants I built for one customer. Pants has come in all colours over time. The black Pants here is the original.