Servo - July 2009

Wave Of Mutilation —

Thomas Kenney’s

Ultimate Beetle — lives up to its name.

Axi is the undisputed champ of high end brushless motors.

The B16 from Robot

MarketPlace was the unanimous choice.

0.040” titanium plate.

Table 1 shows the specs from that machine.

Drive Motors

The B16 from Robot Marketplace seems to be the one ($32 each). One top builder recommends swapping the stock motors with BaneBots HS180s ($3 each), a fairly minor modification. The up side is much more torque; the down side is that the BaneBots motors are only rated to eight volts, so running them with a 3S LiPoly pack ( 11.1 volts) might cause some failures. Of course, at $3 a pop, the HS180s could be changed every couple matches ( www.robotmarket place.com; www.banebots.com).

are several other choices including my favorite Lynxmotions and different types from the Robot Marketplace, but I’m coming around to the builder’s choice, after three articles. Why? Because both Dave’s and BaneBots fit inside the wheel, while others scab on the ouside, adding width. And, width = weight.

TABLE 1 ITEM

• Drive Motor

• Wheels

• Hubs

• Drive ESC

• Drive Batteries

• Weapon

• Armor

• Radio System

• Power Switch

• Fittings/Parts

DESCRIPTION
Four Escap 33:1 gearmotors
2” Lite Flites, doubled
4 mm Lynxmotion
Sozbots Classic
NiMH 2/3A 1100 mAh, 10 cells
0.040” Ti 6AL-4V wedge
Top and bottom: 3/32”
hardened Kevlar honeycomb;
Front and Back: 0.030” Ti
6AL-4V; sides 0.125” 6061-T6 Al
JR Quattro 75 MHz PPM with
GWS four channel receiver
RadioShack
Zip ties, Velcro, aluminum, UHMW

Drive ESC

Drive and Weapon Batteries

Wheels

Lite Flites from Robot Marketplace or BaneBots. Around $4-5 a pair. Size is totally dependent on the desired speed/torque and geometry of the bot, but around 1.75” to 2. 5” is the range most seen.

Hubs

Three different ESCs were submitted: the BaneBots 3-9 ($58 a pair); Sabertooth 5 ($60); and the Scorpion XL ($120). All three will do the job using two B-16s, which stall at 2.1 amps. Not having any personal experience with any of these, but based on specs, the BaneBots are a bit closer to the limit than I’d like (although they do offer a five amp version for $93 a pair). The Scorpion is oversized for this app, at 12. 5 amps continuous. So, I’d probably opt for the Sabertooth as the “best value” option. (Prices are from the BaneBots and Robot Marketplace sites.)

Every vote cast was for a LiPoly, of around 1,300 mAh, 3S size. This will range in price from a Rhino brand at Hobby City ($20) www. hobbycity.com; to a Thunderpower at Robot Marketplace ($45).

Weapon Motors

Our builders suggested a generic, Chinese, 28 mm or 36 mm brushless, inrunner or outrunner. For more money — and some would say higher quality — an Axi 2808 to 2820 is suggested. The Turnigy brand will run $18 to $25, where