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Old Nov 15, 2012, 03:28 AM
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Evil Twin's Avatar
Joined Feb 2004
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Build Log
Fast, cheap Battlebots!

Fast, cheap Battlebots! (1 min 37 sec)


They go 20+ mph and can be built for as little as ~$75. Detailed build instructions and more details will be added. The cars are 1/18 scale AWD Megatech Megapro's which is the same car as the Maverick Atom XT, HPI Mini Recon or Propulse. Some of them go for as little as $40 new on ebay. The ramps are made of flexible lexan and mounted with surgical tubing so usually nothing breaks. Protective bumpers are made with vinyl tubing.
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Last edited by Evil Twin; Nov 15, 2012 at 03:47 AM.
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Old Nov 17, 2012, 09:18 AM
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builder bob's Avatar
United States, MA
Joined Oct 2011
601 Posts
that is so awsome! i want one to just drive around!
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Old Nov 20, 2012, 04:16 AM
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Joined Feb 2004
101 Posts
Parts list
Most of the parts are bought in bulk to save on shipping and make it easy for new people to join. I make multiples of each part using a template, then assemble the battlebot as people join our lunchtime battlebots group. Below are the materials needed to make a basic battlebot, followed by a list of upgrades in the next post.

Basic Build

Vehicle
We use the 1/18 propulse or megapro because they are cheap ($40 to $60 new without battery from ebay or rchobbyexplosion) and they have full ball bearings and ball differentials. Also the plastic it's made of is flexible so it takes a lot of punishment. If someone adapts the design to a different vehicle, especially different scales (micro?!?!) please post.

Vinyl Hose
Vinyl hose is used for bumpers and scuff guards, buy a few feet of each size at Home Depot or Lowes. Most hardware stores should carry tubing.
Front bumper ~1.75" length of 3/8" ID braided pvc hose
Front shock tower top bumper is made of two pieces of vinyl hose, one stuck inside the other to make it firmer: 1.25" length of 1/4" OD x .170" ID stuck inside 1.25" length of 3/8" OD x 1/4" ID
Rear bumper ~2" length of 7/16" OD x 5/16" ID vinyl hose
Rear shock tower scuff guard 2.5" length 1/2" OD x 3/8" ID vinyl hose slit along the length

Fiberglass Rod
The rod is used to support the front shock tower during impacts, a 6.25" length is needed for each vehicle. Buy 6' lengths of 3/16" diameter rod from Tap Plastics.
http://www.tapplastics.com/product/p...rglass_rod/159

Ramp
7" x 10" x 1/16" thick clear Lexan/Polycarbonate Sheet (Lexan is a brand name of polycarbonate, any brand will do). Don't go any thicker, or you will have problems steering. http://www.tapplastics.com/product/p...ate_sheets/516

PVC Pipe
10' 1/2" schedule 40 pvc pipe. Purchase from Home Depot, Lowes or any hardware store. A 1-13/16" length is needed for each vehicle.

Battery
We now use Lipo's, the one below is less expensive than a nimh pack and will run for >30 minutes with a stock or equivalent speed brushless motor. This is one of the few 1800mah packs that will fit the car. NOTE THAT THE POLARITY IS PROBABLY WRONG ON THIS PACK, IF SO YOU WILL HAVE TO SWAP THE WIRES IN THE CONNECTOR OR REPLACE WITH ANOTHER CONNECTOR TO AVOID DAMAGE!!!
GENS ACE 1800mAh 7.4V 20C LiPo Battery for AirSoft Gun
http://www.hobbypartz.com/98p-20c-1800-2s1p-2222.html

Surgical tubing
I think this is what we use, my friend gave me a bunch so I'm not sure. 1/8" I.D., " O.D., 1/16" WALL. Purchase from Home Depot or Lowes. Most hardware stores should carry tubing.

Charger
2s lipo charger. To save money you can have one person charge all the batteries with one charger.

Misc.
LOTS OF ZIP TIES OF VARIOUS LENGTHS AND THICKNESS
Connectors: All power connectors are swapped out with deans male and female connectors.
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Old Nov 20, 2012, 04:29 AM
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Upgrades

Motor/speed control
The extra drag of the ramp is hard on the stock motor so it will likely burn out after 2 to 10 hours. We allow brushless motors and speed controls for reliability as long as the speed is kept about the same as stock. This keeps the game fair and helps prevent parts breakage. Below is our current favorite brushless motor and speed controls.

Brushless Motor: Tacon 2030-21T Brushless Motor 4300KV, it's ~$15 at hobbypartz. The stock pinion will fit this motor and it's one of the easier brushless motors to mount in this vehicle.

Brushless speed control: Turnigy TrackStar 18A 1/18th Scale Brushless Car ESC ~$15 at hobbyking or Turnigy Brushless ESC 18A ~$17 at hobbyking or EzRun-18A-SL Brushless ESC ~$29 at hobbypartz

Wheels/tires: Better tires will allow the vehicle to turn sharper. Use Mini-t front ribbed tires front and back with Mini-t rear rims all around. Do not use mini-t front rims, they won't fit. Associated 18b rims will work too.
tires: integy MT-037 http://www.integy.com/st_prod.html?p...938&p_catid=72
rims: 4x mini-t rears or 4x associated 18b
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