If you are a novice builder then you have just taken the
first step to recovery. This page is for you. We are here to help! On this page
you will find links and files to help first time builders get their feet wet and
their first combat robot into the arena. This page is a recent addition to
the site. Check back often as new files and links are being added frequently.
Although effort is made to ensure the information is correct and accurate on
these pages, WBX is not responsible for errors or omissions. If you find an
error please tell us about it
The following books have been recommended by other builders
as being great resources for novice builders.
Kickin' Bot, by Grant Imahara. ISBN 0-7465-4113-7
Combat Robots Complete by Chris Hannold, ISBN 0-0714-08886
Build Your Own Combat Robot by Pete Miles and Tom Carroll, ISBN 0-0721-94642
All are available at Amazon.Com, BN.Com, and many other fine booksellers. Don't
forget to check at your local public library.
Top
The following links provide information on the basics of
building a combat robot. If you would like to push deeper into the technical
aspects of building check out the links on the Technical
Links page. You will also find more information and ideas by
following the links Builder Links page.
Once you have a basic grasp of building a combat robot, visit the Parts
Links page, a great way to do some shopping for parts. Remember, you don't
have to build it expensive, just build it right.
Roeper Robotics -
If you don't believe you can build a combat robot, check out this web site!
Logan Bot - A
site by high school kids with basics of bot building
Robot Combat
Market Place - Information and advice for novice builders and if you're
feeling particularly technically challenged they offer combat robot
starter packages.
Globotic
- You have some money stashed away and really want someone else to do 90% of the
work? This site offers a large line of complete combat robots (kits and
assembled) and parts.
Team Cool Robots - Check
out the builders page with information for new builders.
Team
Secret Weapon - A how to page to help you on your way.
Team Saber - Check out
the Tips/Hints page, great stuff to help you on your road to recovery.
Converting
Starter Motors - Converting car starter motors for use in your combat robot.
Flying
Pig - Shows how a number of simple mechanisms work. Watching these
mechanisms work will give you some ideas on how to uses simple mechanisms to
build your weapon system.
The
Brazing Book - For those who have forgotten just how useful brazing can be,
such as attaching un-like metals, and a solid base of information for those
wishing to learn how to braze.
How
to Solder - A good review of soldering, so you can make sure you've done the
job right.
How
to Weld - For those who want to learn how to weld, or for those who need a
good refresher.
There are more reasons for building a combat robot than most
people realize. There are as many reasons as there are builders and competitors.
Here are just a few.
"The
sport challenges everyone's design and engineering abilities no mater what level
they are at." - HL
"Building
a bot and competing is great way to do something fun and exciting with my kids,
and my wife enjoys it too." - TM
"It
encourages engineering skills in young people." - PV
"I
like to wreck things." - DI
"It's
a great sport, where else can you see a 14 year old kid with a $1500 battlebot lay
waste to some engineers $20,000 dream machine. No matter how much they spend on
their bots
doesn't guarantee that they will win." - LN
"Its
exciting to see the wild and innovative designs that people come up with."
- DP
"Win
or lose, everyone is just such a great sport about it all." - SB
"You
see everyone, young and old, men and women, anyone can build and compete."
- RK
"Half
the fun is building, the other half is watching it get torn apart in the box,
and the third half is building it all over again." - SK
"I
got tired of getting dental work because of hockey." - OT
"I
can't afford the speeding tickets anymore." - AB
"It's
cheaper than beer." - JJ
"My
heart just races when my robot is in the arena, I think I might explode." -
DF
"My
son and I have such a great time building the robot, the competitions are just
the gravy." - WR
"Girls
just wanna have fun, and beating the bolts out of some guy's robot in the
arena....well, what can be more fun
than that?" - TT
"My
school marks are up cause I have to do math and stuff, my mom thinks its
great." - RL
"Everything
I look at I want to turn into a combat robot, my wife's wok looks like it would
make a pretty good spinner bot. I just can't help it. I think I'm hooked."
- RT
These diagrams should give you basic set-up for some of the
different systems that may be contained within your combat robot. Remember to
read your owner and installation manuals. Follow the manufacturers directions as
exact requirements may very.
Controller
Wiring Diagram - Wiring a controller to run drive motors and a weapon. In
this diagram radio control channels 1 & 2 are used for the drive motors and
channel 3 runs the electronic switch to activate a weapon system. This diagram
should give you a pretty good idea how it goes together. If your buying a
controller package for your combat robot, with speed controllers, servos,
receiver and transmitter, most components are plug-in. Remember
to read and follow the manufacturers instructions.
Servo
Switch - Wiring a servo and switch to control a reversible motor. There are
great other methods of controlling an electric motor using solenoids or speed
controllers, that you may want to consider but if your doing things on the
cheap, this a workable option.
CO2
Pneumatics - A diagram of a typical single CO2 powered piston actuator for a
combat robot. Remember that not all lifting mechanisms are CO2 powered. Many
very good designs have been built using electric motors with well designed
levers and screw drive mechanisms.
Foreword
So your living on a
tight budget but you would still like to build a combat robot. Well there are
many competitors who admire you for your commitment, hours of searching, and
willingness to search for a few new tricks to make things work. Sometimes it is
amazing the great combat robots that people will build for a minimum amount of
cash. If you’re building on a budget then resourcefulness and creativity must
be your greatest allies. Be aware that you’ll find yourself spending a lot
more in time searching salvage yards, liquidation dealers and garage sales for
your parts, not to mention more time fabricating brackets and parts. If you have
to build with economy in mind, here are a few suggestions that may save you a
few bucks, and a few suggestions that won’t.
Motors
Check out surplus
stores and salvage yards and EBay for suitable electric motors. Power chair and wheel
chair motors can be a real bargain if you’re lucky. Visit a liquidation store
where they sell merchandise from businesses that closed up shop. I have found
new 18V variable speed reversible cordless drills with batteries and chargers
for $24 each, a couple of these motors will work for a light weight robot, and at that
price you may even be able to pick up a spare or two. Take a look at buying
someone’s junk car for $50. It should come with windshield wiper or power
window motors for your drive system, and a starter motor for a weapon system. Be
aware that starter motors are not reversible and may need modification.
As a bonus your will get sheet metal for armor, enough wire for a few
combat robots and a solenoid to activate the weapon. There are also all sorts of
other materials that can be put to use in a combat robot if you’re inventive
and resourceful.
Form
a Team.
Family members are
not the only people who find themselves on teams. If you have a few friends who
are willing and able to pitch in, you may want to think about forming a team.
You’ll be increasing the resources of skills, labor and cash.
Seek
Sponsorships
Is your boss a fan
of combat robotics? How about your co-workers? Many companies have found combat
robotics to be a great way to gain visibility. Try building a combat robot as
part of your companies program to improve moral.
Radio
Transmitter and Receiver
Don’t get cheap
here. A good quality radio is well worth it. Nobody is saying that you should
run out and buy top of the line. Remember that you can build a number of combat
robots and use the same transmitter for all of them by buying additional
receivers for each of your bots.
Electronic
Speed Controllers
If you are
going to use high amperage motors you may not have much choice but to spend the
money on an expensive speed controller. You can get package deals from vendors
if you buy your radio system at the same time.
If you absolutely must, you can set up a switching system with your servo
motors. However, be sure to carefully design your switching so it works reliably
and won’t fall apart the first time your robot gets rammed by your
opponent. By using a $10 solenoid and a $5 leaf switch, you can activate a
weapon system or self-righting mechanism, but a spike relay module for $50 bucks
or a solid state relay for about $35 is a far more reliable option that can be
purchased to work with your radio system.
Build
Invertible
If you design your
combat robot so it can be driven when it’s up side down you can save yourself
the cost of a self-righting mechanism. If you spent a little extra for a good
radio system, you will be able to set your system up so that you can flip a
switch and your transmitter will allow you to drive normally without having your
controls reversed.
Avoid
Complex
A complex robot
with all sorts of bells and whistles is more difficult to build, more expensive,
and more likely to break down. Keep your design simple. Keep your mechanisms
simple. It will make things easier to troubleshoot and repair if things do go
wrong.
Search
the Internet
Electronics,
electrical, armor materials and just about anything else just might show up on
the internet at a price you can afford. Try a search for motor or other parts
you may need on EBay. You will be surprised what you can find, up to complete
combat robots.
Search
Your Home
You just might be
surprised at the things that will show up that can be used in a combat robot.
Spinning
Weapons
Spinning weapons
(AKA: KE or Kinetic energy weapons) can be seriously destructive. If you design
your robot to use a spinning weapon, you will find it tougher to drive because
of “gyroscopic effect”. The real solution is to wire a gyroscope into your
radio receiver to correct the problem. So if you’re looking to save a few
bucks, you may want to consider an axe, hammer or lifting device.
Pneumatic
and Hydraulic Systems
Avoid the CO2, HPA
(high pressure air), and hydraulic systems, if you trying to save a cash. The
components can be expensive.
Lawnmower
Wheels
Don’t use
lawnmower wheels or any hard plastic wheel for that matter. You’ll just slide
around like you were on wet ice. Use sticky rubber tires.
Track
Systems
Unless you have
access to a snow blower, stick to a wheel system. Track systems require more
power to drive and they are more expensive.
Multi-wheel
Drive Systems
You may have to
crunch the numbers to save cash on this one, before you build a multi-wheel
drive system. You can use less expensive drive motors, but you will need more of
them and more tires. A competitive advantage can be gained by having more
pushing power, and if a motor dies you’re less likely to find yourself doing
circles in the middle of the arena. Remember to hook your motors up in parallel
(black to black and red to red).
Mounting
Motors
Custom machined
motor mounts can be expensive. Look for motors with the mounts. Make your own
mounting brackets or try using U-clamps (make sure the motor housing can take
the stress).
Sprockets
Locate a couple of
10 speed bikes. Used bicycles can be a source for steel tubing, chain sprockets
and idlers for a chain drive system. Sections of tire can be used as a shock
mounts for electronics.
Local
Library
The library is a
great resource for information on mechanisms, how to books, radio control
systems and even books on how to build a combat robot. Why buy when you can
borrow?
Build
Light Weight
Building a bigger
heavy weight or super heavy weight combat robot means spending more money, it
really is just that simple.
Final
Words
Be resourceful! The
variety of materials that builders have used in construction of a combat robot
is incredibly diverse. Armor has been made from titanium, steel, poly carbonate,
even plastic drums and computer cases. Each material has its own advantages and
disadvantages. Capitalize on the advantages of the materials you use and build
your combat robot to minimize the weaknesses. Many very competitive robots have
been built on a budget with salvaged and recycled materials. We can all learn
from and appreciate builders who prove themselves through their resourcefulness and innovation,
and not through their bank account.
In
no particular order, the following are the most common technical and equipment
problems encountered by combat robots in the arena. As you design and build your
combat robot be aware of these problems.
Drive
chains jumping off of sprockets.
Roller
chain should be clean from debris and well lubricated. If the chain is climbing
the sprocket, this may indicate that the chain is stretched or not tensioned
correctly. Make use of an idler sprocket to maintain tension on the chain. Make
sure that your idler and sprockets are lined up correctly.
Gas
engines that stall and/or do not start.
Keep
your gas engine well tuned up. If the event will allow it, warm up your engine
for a few minutes prior to the bout. Avoid 4-cycle gas engines such as lawn
mower engines, as they can become damaged if inverted. If you really want to use
a gas engine use 2-cycle engines from chain saws and lawn trimmers. Avoid
gravity feed fuel systems, if your combat robot is on its side or up side down,
even for a few seconds it could mean the end. A sudden jolt can stall a gas
engine. Have an electric starter that can be activated by your radio system.
Note that some venues will require that the engine is cold for the technical
inspection, others disallow gas engines altogether.
Floor
debris or bent frame and body materials result in wheel interference.
There
should be sufficient clearance between your wheels and your frame to allow small
pieces of debris to pass by without interference. Small screws, nuts, shrapnel
and debris should not be a problem. Don’t leave so much space that your
opponents can easily exploit the opening as a weakness.
Speed
controllers that can’t handle the amperage of drive or weapon motors.
Check
the amperage rating on your controllers, make sure they can handle the maximum
amperage draw from motors etc. Use high amperage solenoids for activating weapon
motors etc. Speed controllers and solenoids should be rated well above the
maximum current that it will be required to handle.
Motors,
batteries, and other components vibrating loose or poorly mounted.
Nylon
tie wraps, duct tape, spit and gum just won’t cut it. Fabricate metal straps
and brackets that fasten securely to hold batteries and other components in
place. Make sure to use lock washers on nuts and bolts. You can drill through
the nut/bolt and use cotter pins or machine wire to prevent nuts from vibrating
loose.
Wire
terminals and connections becoming loose.
Use
solder on type wire connectors instead of the crimp on type. Use a terminal
block and ring type connectors. If you use disconnect terminals, compress the
female connector with pliers to make it fit tighter onto the male connector. Use
lock washers with screw connectors.
Improper
mounting or foreign debris results in wires and electrical components shorting
out.
Use
a barricade type terminal block for wire connections. Cover electrical
connections with shrink-wrap or paint on electrical insulation. Look for spots
where insulation may wear/burn away from wires due to vibrations or heat. Use
wire wrap to help prevent wires from chafing against the chassis or shell. Keep
wires off of electric motors and other components that become hot during a bout.
Punctured
tires
Use
solid rubber or foam filled tires. Use an inner tube to reduce the likelihood of
a puncture. Protect tires with armor or shields.
Breakage
of substandard fasteners (bolts, nuts, rivets, etc.)
Weld
chassis parts together where you can. Aluminum rivets will not hold your armor
in place; use high tensile bolts to hold things together.
Insufficient
ground clearance.
Damaged
floor panels, floor panels that have been repaired with screws and debris from
previous bouts or even debris from you or your opponents are the culprits here.
Make sure that your combat robot has enough clearance to climb over most small
chunks, bits and pieces. Use flexible or hinged skirting to prevent other bots
from getting underneath and flipping you.
Drive
and weapon mounts that don’t have sufficient strength for the robot weapon
design/type.
Make
sure the chassis and weapon system mounts of your combat robot are strong enough
to withstand the forces encountered from striking your opponents. A spinning
weapon’s mounts and brackets encounter nearly as much force as your opponents
will during impact.
Underrated
fuses that blow.
Use
slow blow fuses where appropriate to protect electric motors etc. Your fuse
should not blow if you stall your electric motors at full power for a few
seconds. Be careful not to use fuses that have to high of a rating or you may
not be protecting more expensive components. It’s bad enough to lose a bout
because of a fuse, its worse if it’s due to burning out an expensive electric
motor.
Motors
that overheat.
Use
motors that are appropriate for the size/weight of combat robot you are
building. Use heat sinks, electric fans and cooling fins to help dissipate the
heat generated during combat.
Stripped
gears
Avoid
gear head motors with plastic gears. Use good quality metal gears for your drive
system. Check for gear alignment closely when building your robot. Make sure
your gears mesh correctly without excess backlash.
Undersized
shafts and axles break.
Not
much you can do here but make sure that you use strong shafts and axles. Avoid
mounting wheels on long unsupported shafts. Use flex and spider couplings to
absorb shock.
Lack
of protection from arena hazards.
Use
armor on the top, sides, front, back and bottom of your robot. A soft underbelly
can be a very nasty way to die in the arena.
Home
built components (speed controllers, electronics, etc.) failing under combat
conditions.
Unless
you’re an electronics wiz, use manufactured electrical components. Sometimes
there is no real advantage to re-inventing the wheel. There are numerous
electronics available at competitive prices specifically designed for combat
robots. Electronics and components susceptible to damage from being jarred and
shaken should be mounted with shock absorbing mounts.
Stripped
or loose shaft couplings and set screws.
Avoid
round shafts with set screws, if you must use set screws try filing/cutting a
flat spot on the shaft for the set screw. If you can, use keyed shafts or better
yet use square or spline shafts. Weld hubs and sprockets directly to shafts if
possible.
Radio
interference or insufficient range.
Use
resistor plugs in gas engines. Connect capacitors leading from each motor
terminal to the metal case of the motor. These capacitors help quench spikes
right at the motor. Make
sure your receiver antenna is the right length and not enclosed by radio signal
blocking materials such as metal armor or chassis. Mount the receiver antenna
well away from wires (especially the wires that power your electric motors) and
electric motors. Use a separate power source for motors.
The
combat robot is slow or sluggish towards the end of the bout because of
batteries that are not properly charged or have insufficient capacity.
Keep
a spare set of batteries handy and fully charged. Make sure to cycle your
rechargeable batteries to full discharge every month or two, even when not in
use for a few months. Your robot’s batteries should be able to handle a full
load for at least 5 minutes.
Sheet steel is very abundant at most salvage and scrap yards. It is also one of
the less expensive metals to purchase and is available in thickness from 0.3mm
to several centimeters. When compared with aluminum, steel is approximately
three times heavier and not much stronger. Titanium also has better properties
than steel, as it is lighter and stronger.
The big advantage of mild steel over other materials is that it's rather easy to
work with. Steel can be welded with inexpensive tools and reasonably easy to cut
and form. Angle grinders, hacksaws and hand drills can all be used for most
tasks. However, the same cannot be said for some advanced plastics or high tech
metals that can be very difficult to work with.
Steel has an advantage in that, battle damage can be easily repaired. When
dented, steel can be hammered back into shape. Rips and tears can be hammered
and welded. In extreme cases, completely destroyed sections can be removed with
an angle grinder and replaced using a portable welder. This kind of work is well
within the capabilities of most people. Mild steel offers a number of advantages
to the DIY combat robot builder. But it requires care to use well if one intends
to stay within tournament weight limits.
Stainless steel is stronger than mild steel, but a little harder to work with.
Stainless steel is also readily found at salvage and scrap yards. But it is also
a little more expensive. Welding stainless steel is no more difficult than mild
steel, however it does require that you use welding rods for stainless steel
materials. As for the rest, stainless steel has many of the same advantages and
disadvantages as mild steel.
Aluminum given its light weight, seems like suitable armor material. But in its
pure form (type 1100) it is soft and unable to resist serious punishment. The
type of aluminum available in DIY stores (usually type 1100, 3003 or 5005) is
very soft and to weak for use in a combat robot. More suitable aluminum alloys
are types 2024-T3/T4, 6061-T6 or 7075 but are difficult to find and expensive.
To find these types of aluminum at a scrap or salvage yard in a suitable size is
very unlikely.
Aluminum can be difficult to work with. Its softness tends to clog up saws,
files and grinding discs. It can even dangerous to grind aluminum, as cutting
disks tend to dig in, causing them to shatter. Welding aluminum requires more
specialized skills and is not done with cheap tools. Also the welds tend to form
weak spots if not properly heat treated afterwards.
Threading holes in aluminum is not a good idea. Bolts will tend to pull the
threads out if the thread depth isn’t at least 3 times the thread diameter.
For example, for a 3/8” bolt you need at least 1” deep tread. Aluminum seems
best suited for internal mounts and large pieces like flanges and mounting
brackets. To attach it, use bolts and nuts with big washers.
Titanium is supposedly indestructible, lightweight, much stronger than steel,
very hard. However it is not workable with normal tools. Titanium weight is
halfway between steel and aluminum. As far as being lot stronger than steel,
well that depends. Titanium's weight/strength ratio is superior when comparing
mild steel to one of the titanium alloys. Comparatively high strength steels
such as “Dokol” or “Hardox” are much stronger than non-alloyed titanium.
Keep in mind that there are many types of steel and titanium, each with
different properties. Like most metals titanium is not indestructible. Titanium
can also be a fire hazard. Under the right conditions it is combustible. As for
the hardness of titanium, that depends on which alloy you have and what kind of
heat treatment it received. Grade 1 and grade 2 titanium can be worked with good
quality steel cutting tools. Titanium is a poor conductor of heat. The heat
buildup requires that titanium be cooled during machining processes.
Welding titanium is a real problem and requires more skill than welding steel.
It has to be welded in a completely inert environment. Above 800 degrees
titanium will bind with oxygen and carbon resulting in very poor welds that are
easily broken. Not every titanium alloy can be welded with good results even
with good technique and the proper equipment. Finding titanium at the scrap yard
is also a miracle.
Magnesium
can be used for framing and supports. However, magnesium is difficult to find at
salvage and scrap yards. It is similar to aluminum for workability, but welding
is more difficult. It’s lighter and weaker than aluminum. Magnesium is brittle
and is often used as an alloy with aluminum and zinc. These alloys have a dull
gray in appearance and slight greasy feel. Many cast aluminum items are actually
a magnesium/aluminum alloy. Most magnesium alloys can not be welded. The only
means of repairing these materials is by using a product called
"Techno-Weld", which is a type of low temperature brazing compound.
