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| How (not) to build a robot - P.Collier
/ C.Loader |
| Most people watch Robot Wars on TV
and think one of two things to themselves. Either they think about the
content of the sport (usually, 'Go on, cut 'im!') or they think about the
technical aspects of the robots. These latter group are then just a breath
away from the dangerous phrase - I COULD DO THAT!! Well, if you are in
that group, this short build guide is for you. |
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| There are a number of these type of
guides on the web, just check out the Cunning Plan or Dangerous Machines
websites for such examples. This one is different in that we focus on the
things NOT to do. We learnt a lot from building Panda, and I figure that
anything you can give to help people start is worth doing. |
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| 1) Design and Name: Spend some time on
this, but not too much. A good name can help bring a design to life, but
a working name is just as good. Draw lots of crappy sketches and don't
waste days trying to model you designs on 3D graphics programs - you're
just losing time! Get the best three or four designs together and don't
be afraid to get other people to look at them. If it can be picked apart
on paper, it's got no chance in the ring!! |
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| 2) Think seriously: Really, you must now
think hard. Robots cost a lot of time and money! Let's just repeat that:
A LOT OF TIME AND MONEY!! Panda cost us over 1000 UKP and we spent probably
at least 3 evenings a week and half the weekends over a 3 month period.
7:30pm to 1 or 2 in the morning quite often. If you are not prepared /
able to put in at least that commitment, don't bother. Really! |
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| 3) Drives and stuff: Get the drive sorted
out first. DO RESEARCH - read every web page there is both for UK and US
contestants. Learn what speed controllers are, what type of radio control
gear you need, how to connect them, where to get motors, what type or batteries
to use. Most people use Bosch, Sinclair or wheelchair motors, geared down
around 10 or 20 to 1, running at 12 or 24V DC, using 4QD, Vantec or homemade
speedcontrollers through joystick or digital interfaces from the 40Mhz
FM radio control systems (made by Futaba or HiTec (same spec, but HiTec
is cheaper!!)). Consider boring practical things such as wheel bearings,
axles, wheels and motor mounts. Don't skimp on the motor mounts or bearings
- we did and we nearly didn't get into the contest because of it. Don't
bother to make your own gearing unless you have lots of time - messing
gears well is not easy! Motors at this level kick out a lot of torque and
will have to be well mounted - we ended up using 2mm steel plate after
bending about 6 sets of mounts! |
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| 4) Get building: Start with either the
chassis or drive chain. The sooner you get the drive chain going, the sooner
you can practise driving - it's not easy guys!! If you are waiting for
parts, start on the chassis. You need space to work and be prepared to
make some noise as well. Don't start anglegrinding at midnight - the neighbours
may find a new use for the grinder! Don't leave orders until the last minute
- they always take longer than you think. Our C5 motors took 3 weeks and
the speed controllers 10 days. The RC gear had to be ordered through the
shop and these took 1 week. |
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| 5) Power: Get the largest batteries you
can accommodate and afford. We used lead acid gel 7AH cells, but needed
6 for the drive - at 2.5 Kg each, thats 15Kg gone from 79!! The best I've
seen are either the huge car battery sized 24AH+ cells - use 1 or 2, or
the 12AH cells which are slightly bigger than the 7AH cells. Also remember
they take a long time to charge - at least 4 hours, often overnight! Keep
all cells charged (including the RC ones) at all times. Our RC battery
failed at rehersals and we lost control of the robot. Remember also to
fit failsafes as soon as you have something which moves. Then if you lost
control or the batteries fail, it just stops. Failsafes are more important
than the on-off switch mentioned in the rules. You MUST have them. |
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| 6) Weight: The rules are ALL there to be
followed. Keep an eye on your weight and make sure you don't end up making
something far too heavy. Any body can make a powerful robot that's 300Kg
- try doing it in the featherweight category though! ALL materials are
heavy; we have wood, plastic and metals on Panda and they are all heavy. |
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| 7) TV: Remember that the robot is for TV.
Make it have exciting weapons, paint it to be eye catching and practise
driving. Panda didn't get the paint job we intended, but More Panda will
have. It does make a difference. If you don't practise driving, you will
lose VERY quickly indeed. Remember also that Robot Wars is a COMBAT sport
- a blood sport for the new millenium. You're robot WILL GET DAMAGED, possibly
even completely destroyed. It goes with the territory. Expect it and accept
it and you won't end up as a sore loser. |
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| Finally, if you want advice, help, sources,
tips, then ASK! Either me or any of the other roboteers. It's a friendly
rivalry and everyone I've met and spoken to has always been friendly, helpful
and often very generous - until you get in the ring.
If you are entered for '99, good luck -
if you come up against us, watch out, Panda was a teddy bear compared to
R2!! :-))
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