Ant-Weight Robots

This is our second ant-weight robot:

Build Diary

September 2002
James decided to build an Ant of his own and started saving his pocket money. The new Ant is to be a bi-wedge design called RampAnt. To save on cost it will share R.O.N.N.Y's transmitter and will initially use some AAA NiMH batteries which are currently spare. That still leaves a receiver and two servos to save up for. Meanwhile the design can start...

30 October 2002
Ordered a Hitec Feather receiver today, but need to continue saving for the servos! RampAnt will be built after Christmas, as hopefully the funds will be boosted then!

31 October 2002
James designed the RampAnt logo (above) today.

31 December 2002
Birthday and Christmas boosted the funds considerably, but still no sign of the receiver. Will try ordering via another shop when Hitec's distributors re-open after their year-end stocktake. Decided on SD-200 servos for drive since they are a reasonable price, performance looks OK on paper, and no-one has anything bad to say about them!

January 2003
Got the SD-200's and some bits & pieces (from SMC), some batteries (from Overlander), and a Hitec Feather Rx (from Action Kits). Modified the servos, stuck on some of R.O.N.N.Y's wheels and built up a quick rolling chassis for a demonstration at school.
Figured out the biggest size that will fit in a 4" cube, how to fit all the bits in and how big to make the wheels so it will run upside-down if necessary. Drew scale drawings of how all the bits will fit in. Now need to find time to build it all...

February/March 2003
RampAnt was built up over several weekends, on a base of 4mm balsa laminated with thin plastic from margarine tubs. The wheels were made from the bottoms of baking soda tubs with mouse mat rubber tyres and Dycem treads. The armour is 1mm polycarbonate panels fixed together with 0.5mm strips.
The original idea was to have bulging sides which would cause RampAnt to self-right or invert, but not get trapped on its side. However, in the end there was not enough width for this to work and it seemed too difficult to build so an alternative solution was developed. Flat sides were used, with a lump attached to the outside face of each wheel, to act as a cam which would lever RampAnt back onto its wheels if it got turned onto its side.
This required some redesign of the sides (to almost nothing!) but the armour still seemed fairly strong and the self-righting worked well. RampAnt is also designed to be invertible and indeed works as a reasonable wedge/pusher either way up!

There are some pictures here.

29 March 2003
The Southern Antweight Challenge. RampAnt's first event, and a fairly successful one despite being drawn against MilitAnt in the first round! The armour stood up to the impact, but the insides all got knocked loose. A quick strip-down and everything was stuck back in place. RampAnt got through to the third round and was knocked out by War Ant.

April 2003
James had decided before SAC that RampAnt needed to have a flipper added. With 10g to spare, it seemed feasible. A Naro HP was chosen as it gives good speed and torque and weighs 9g!

May 2003
RampAnt was stripped down and a flipper cut out of the bodyshell. The base and wheels were drilled full of holes to (hopefully) allow for the extra weight of the flipper linkage.

28 June 2003
AWS XI, Leeds University. RampAnt's first AWS and our best result so far! RampAnt reached the quarter finals, being knocked out by Resurrector, the eventual runner-up.

5 July 2003
Mile Oak School summer fair. A 3-hour pay-to-drive marathon. RampAnt survived completely unscathed, requiring only a recharge and wheel clean in time for the next event...

12 July 2003
Grand Antweight Tournament, Brighton University. Although R.O.N.N.Y. won the tournament, RampAnt scored a creditable 12 out of 16 points, being beaten only once in the football and once in the assault course - due to running right-way-up with no ground clearance instead of upside-down.

Last updated 12 July 2003
Email us at

Return to the Robots Page

Return to Gary's Home Page