Absolute Chaos Robotics
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Beetle Weight Drive Parts

$1.49 - $14.99 - On sale

These components were chosen to provide a powerful and reliable drive system for a 3lb robot, as demonstrated by their performance in the Jolt! Kits.

Combine these parts together with your choice of sizes for Fingertech foam wheels and HTD-3m or S3M belts and you have a belt driven 4wd setup all ready to go!


Double Geared 25mm Motors

These high powered motors can provide one of the highest power-to-weight ratios for a brushed beetleweight drivetrain, and the double gear train decreases the likelihood of sustaining damage during large impacts.

General Motor Specifications:
Rated voltage: 12V
Stall current: 4.47 A
No load current: 580 mA
Diameter: 25 mm
Shaft diameter: 4 mm
Shaft Length: 25 mm
Mounting holes: 2x M3, 17mm apart at centers

940rpm Motors
No load speed: 940 rpm
Stall torque: 5.8 kg-cm
Gear ratio: 21.3:1
Length (gearbox and motor): 57.2 mm
Weight: 90 g



STEP model available here.

Dual Channel Brushed Drive ESCs


These Electronic Speed Controllers (ESCs) are a great budget-friendly option to power a robot's drive train. They have a more powerful BEC than most other options, and are one of the least expensive options for an ESC that has braking when the throttle is at center stick (for better driving control), plus they come with wires and connectors attached, so no soldering required! These are the same ESCs used in the Jolt! kits.

Input voltage: 6-14V (2S-3S)
Rating: 5A continuous, 7A peak (enough to run most 22mm/25mm geared motors)
BEC: 5V 1.5A
Size: 24mm x 23mm board
Weight: 12g
Features: overcurrent protection, overheat protection, center stick braking (must be turned on), safe startup, safety shutoff on signal loss

The single yellow wire is intended to control steering, and the 3-wire plug is intended to control forward/reverse.

This ESC has some different options that can be used to tailor its performance to your needs. To adjust one of the settings, plug the single yellow wire into ch1 of your receiver and the 3-wire plug into ch2 of the receiver, then move the stick to one of the corners mentioned below and power on the ESC/receiver. When the power up beeps finish, return the stick to the center to save the new setting. Only one setting/increment can be adjusted per power-up of the ESC.

ESC options:
Center Braking (On/Off, default: Off) - Top Left (ch1 low, ch2 high)
Mixing (Mixed/Independant, default: Mixed) - Top Right (ch1 high, ch2 high)
Initial Velocity/Exponential Curve (Low, Medium, High, default: Medium) - Bottom Left (ch1 low, ch2 low)
Acceleration/Delay (Low, Medium, High, default: Medium) - Bottom Right (ch1 high, ch2 low)

ESC Mixing Modes:
Mixing (default) - The two motors can be mixed to respond to inputs from either channel for tank style driving without requiring mixing on the transmitter. Set this mode as described above.
Independent - The two motor channels can be independently controlled by two receiver channels. Set this mode as described above.
Synchronized - Both motor channels can be controlled by a single receiver channel. Place the ESC in Mixed mode and either disconnect the single yellow wire or connect it to ground on the receiver.

Single Channel Brushed Drive ESCs


These ESCs are similar in performance to the dual channel ESCs, but are only used to drive one motor channel.

Input voltage: 6-14V (2S-3S)
Rating: 5A continuous, 7A peak (enough to run most 22mm/25mm geared motors)
BEC: 5V 1.5A
Size: 28mm x 21mm board
Weight: 9g
Features: overheat protection, center stick braking, safe startup, safety shutoff on signal loss

The ESC also contains a switch to use a forward/brake/reverse control scheme used in some model cars, but this is not typically useful in combat robots. Set the switch away from the receiver wires to turn on center braking mode.

When using more than one ESC connected to the same receiver, it is recommended to remove the middle pin on all but one receiver connector so that the Battery Eliminator Circuits (BECs) in the ESCs do not fight each other and decrease the lifespan of the circuits.

Chaos Hubs - Belt Driven Hubs for Foam Wheels


These hubs are great for providing a way to indirectly drive up to two wheels off of a single motor with a HTD-3M or S3M timing belt. The hubs can be pressed by hand into the center of 3/4in thick foam wheels with an ID of 3/8in, such as FingerTech's foam wheels. A tool to aid in inserting the hubs into the wheel and a "wrench" to turn the locking washer to hold the wheel on are available, and are included FREE with any order of 4+ hubs.

Length: 1.25in
For foam wheel bore: 3/8"
For shaft size: #8 screw or 4mm
Tooth Count: 14-20 (additional tooth counts available on request)
For wheel width: 3/4in (19mm)
Weight: ~5.5g

STEP model available here.

For determining your needed belts and spacing for your Chaos Hubs, we recommend the BBMan calculator. Enter the settings for Metric, HTD 3mm teeth, and 6mm belt width, as well as your desired pulley tooth counts and distance between the motor and the wheel hub. Use the resulting Center Distance in your deisgn for the hub spacing.

The belt sizes used in our kits are available here. For other compatible belts, you can search on V-Belt Guys with "XXX-3M-04 Synchronous Timing Belt" by replacing the three Xs with the Belt Pitch Length you need. For example, if needing a 150mm/50T belt you would search for "150-3M-04 Synchronous Timing Belt".

Aluminum HTD Timing Pulley
These pulleys mount onto a motor shaft to transfer power to the wheel hubs. Both 15T and 20T pulleys are available.

Shaft Hardware for S3M Hub
Contains the parts needed to mount the S3M wheel hubs, including a #8 screw and a threaded insert to mount it into the frame. It is recommended to support the far end of the axle screw as well for best durability.

Screw head width: 0.27in
Screw length: 1-7/8in
Threaded insert hole size (drilled): 15/64in
Threaded insert hole size (Printed TPU): 5.5mm
Threaded insert body length: 0.361in
Shaft Hardware weight: 7.5g

Timing Belts
A limited range of timing belts will be stocked here to match the timing belts used in our kits.

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