Servo - September 2011

Practical Matters

the public were allowed in). These issues are simple, but almost always overlooked.

The spiderbot stood watch as the people began arriving.

Batteries will last longer as the friction is lower, heat soak inside the robots is reduced, and high speed camera footage becomes simply spectacular, so I would highly recommend taking some simple insulation precautions to keep out the majority of the water. So, enjoy outdoor events, even if the heavens open and the rain comes down.

General Hazards

The outdoor event has many advantages, but also many common problems. If you are fighting robots outdoors, you may be doing so as part of another event — maybe a summer fair. There are likely to be other attractions, and as a result things like radio microphones, remote transmitters, special effects, and security radios flood the airwaves with their own frequencies. If you are using older radio gear, this can be a problem, since electromagnetic interference is not a nice thing to be suffering with in the middle of a field full of people and several combat robots.

Assuming you do not have radio interference, the next problem you may face is crowd control. Be sure to keep things out of reach or tethered down. Be aware also that the nice wet arena floor that is making the fights so much fun will turn you into the half-time clown if you jump in to un-stick the robots, and skate over the wall onto your face.

Indoor events have everything we need, but outdoors we have certain logistical issues that are often forgotten about.

Having spent megabucks on the latest battery charging equipment, it can be rather embarrassing to realize after the first fight that most fields do not have power outlets every few feet. If the outdoor event organizers have provided power outlets, it can be assumed that you will have only one or two at the most, and they will inevitably be fused to 3A and then blow when you plug six chargers in at once. Generators are a handy thing to have because they make you self-sufficient — assuming, of course, that the organizers have covered them in their risk assessments and allow you to run them.

Fire extinguishers are usually prevalent indoors, but not so common outside. Make sure you have suitable and sufficient fire fighting capability, especially on hot days when the grass is dry. Safely positioned trays and boxes are also useful for putting down screws and components, as small things getting knocked off the tables do not land on a nice flat floor, but disappear into the grassy carpet.

Another unexpected problem can be that of image rights. Indoor events usually state in the terms and conditions of attendance that the visitor agrees to their image appearing in photographs and video images of the event. The general public walking around their local fair have not accepted any such contract, and so any pictures or footage of the event may need their signature before it appears on the Internet or in magazines (which is why the photos in this article were taken very early in the day before

After the Event

How many of you get home from an event and dump the contents of your vehicle into the shed/garage/workshop, slamming the doors in the knowledge that the contents will not see the light of day again, until the day before the next event? If you do this after an outdoor event, you are in for a real treat when you dig out your robots for their next fight.

Robots rust even the titanium ones — in one form or another. Surface corrosion, oxidation, discoloration ... call it what you want. The humidity from the event will find every single corrodible component and rot it.

Cosmetically, this makes your robot look like rubbish, but it also has hidden implications, as electrical contacts become unreliable, bearings seize up, and motors degrade internally. It is important to look after your robot after an outdoor event.

Place it somewhere dry, re-touch any damaged or sun-bleached paint, wipe it down with water deterrent or light oil, and brush out the grass/mud/dust before they become a permanent feature. Cycle charge the batteries, check them for damage or foreign objects (grass gets everywhere!), and check and clean the motors, speed controllers, and especially the pneumatic systems. Write down any of the things that made your day difficult, or made it work well, as you will forget.

Outdoor events are fantastic when they go well. They are low cost, great fun, and low on stress. So, follow this guide, find a local fair (and a friendly small arena owner if you don’t have one), and sign yourself and your robots up. If you’d like more helpful tips, go to