2 Epoch 2: New Brain Day
Epoch 2 Total: ~$190
Full electronics upgrade: FOC sensored brushless motor and ESC, 6-channel radio system, underdrive transmission, and stainless steel hardware. We went with the premium Roverin M30 G2 system for the best possible low-speed control—critical for a 3-year-old driver.
After this epoch: FOC sensored brushless power with the smoothest possible slow crawl, 40.3:1 underdrive gearing (59% slower than stock), IP67 waterproof electronics, 200% drag brake for controlled descents, Bluetooth app tuning, 6 channels for accessories, speed limiting for safe toddler driving.
The kids’ job: Unboxing the transmitter, learning the controls, testing speed limiting, watching Bluetooth connect, rescue missions with the tow rope.
2.1 Bill of Materials
| Item | Part Number | Source | Price | Notes |
|---|---|---|---|---|
| Roverin M30 G2 FOC Sensored Brushless ESC & Motor | Roverin M30 G2 | Injora | $98.95 | FOC sensored; 200% drag brake; IP67; Bluetooth tuning |
| CNC Aluminum Complete Transmission (40.3:1 Underdrive) | 4M-55 | Injora | $27.99 | 59% slower than stock; required for 180-size motor |
| INT-T6M 6CH Digital Radio Transmitter + Receiver | INT-T6M | Injora | $41.14 | Speed limiting function; 4 aux channels for winch/lights |
| Stainless Steel Hardware Kit (M1.6/M2/M2.5 screws, nuts, pins) | 4M-15 | Injora | $22.23 | Grade 12.9 stainless; organized box; includes tow rope |
| Metal Tow Rope with Hook (2pcs) | — | Injora | (included above) | Scale accessory for rescue missions |
2.2 Why These Parts
Roverin M30 G2 FOC over MBL32 G2: The Roverin is the premium brushless option for micro crawlers. Key advantages:
Why FOC Sensored? FOC (Field Oriented Control) is the gold standard algorithm for precise low-speed motor control. Sensored motors eliminate startup jitter completely.
- FOC (Field Oriented Control): The gold standard algorithm for precise low-speed motor control—delivers strong torque even at extremely low speeds
- Sensored motor: Eliminates startup jitter and cogging, providing the smoothest possible slow crawl
- 200% adjustable drag brake: Twice the braking power of standard brushless systems—critical for controlled descents when a toddler drives off the couch
- IP67 waterproof: Can be submerged 1 meter for 30 minutes—superior to splash-resistant alternatives
- Bluetooth app tuning: Real-time parameter adjustment via INJORA Link app (iOS/Android)—no programming card needed
4M-55 Aluminum Transmission with 40.3:1 underdrive gears: The Roverin uses a 180-size motor (not 370), so it requires a compatible transmission. The 40.3:1 underdrive gears reduce speed by 59% compared to stock—combined with the FOC control and 200% drag brake, this gives Alasdair the slowest, most controlled crawl possible. Perfect for a 3-year-old learning throttle control.
INT-T6M transmitter: 6 channels (steering, throttle, plus 4 aux channels for winch/lights later). Has speed limiting function—critical for a 3-year-old driver. Can limit throttle endpoint to 50% so the truck moves at walking pace. Affordable at ~$41, and receivers are inexpensive if we add more vehicles later.
Stainless steel hardware kit: Stock screws are soft and strip easily. Grade 12.9 stainless steel won’t rust from snow/water exposure, won’t bend or strip, and provides spares for inevitable dropped screws. Organized box makes it a good sorting activity for kids.
Metal tow rope: Scale accessory for later rescue missions when the winch is added in Epoch 4. Fun visual detail that Alasdair can attach to “rescue” stuck toys.
2.3 Why Roverin Over MBL32?
For a 3-year-old driver doing slow crawling, the Roverin’s advantages directly address the use case:
| Feature | MBL32 G2 + Fat Viper | Roverin M30 G2 |
|---|---|---|
| Motor control | Sensorless (good) | FOC Sensored (best) |
| Startup smoothness | Minor cogging possible | Zero jitter |
| Drag brake | Standard | 200% adjustable |
| Waterproof rating | Splash resistant | IP67 submersible |
| Tuning | Programming card | Bluetooth app |
| Price | ~$82 | ~$127 (with trans) |
The ~$45 premium buys meaningfully better toddler-appropriate behavior: smoother starts, more controlled stops, and bulletproof waterproofing for unpredictable conditions.
2.4 Important Setup Notes
The Roverin’s BEC is adjustable 0-10V. The INJS2065 servo (from Epoch 1) requires 6V-7.4V. You must configure this in the INJORA Link app before first run—do not leave at 10V or it could damage the servo.
ESC Heat: The Roverin runs hot under sustained load due to its high-performance computing core. Monitor temps in the app. For slow toddler crawling, heat shouldn’t be a concern.
Transmission Assembly: Grease the gears well during installation. The 4M-55 is pre-assembled; the Roverin motor mounts directly to it with the pre-installed 0.4mod 11T pinion.
2.5 Alasdair’s Tasks (Age 3)
- Sorting screws by size into the parts tray (the stainless steel hardware kit comes in an organized box)
- Unboxing the new transmitter and putting batteries in (with help)
- Learning which trigger is go and which wheel is steering
- Testing the speed limiting feature—seeing how the truck goes slower when dad adjusts the settings
- Pressing the bind button to pair the receiver (satisfying beep!)
- Helping dad open the INJORA Link app and watching the Bluetooth connect
- First drive with the new controller at reduced speed
- “Rescue missions” with the tow rope—attaching it to toys and pulling them
2.6 Q&A
How do I set up speed limiting on the T6M?
Hold wheel backward + trigger backward to maximum, power on transmitter, release controls, press 3rd channel button (indicator flashes for programming mode). Adjust throttle endpoint to limit max speed—50% is a good starting point for young kids.
What about the underdrive gears I was planning in Epoch 5?
The 4M-55 transmission includes 40.3:1 underdrive gears—that’s 59% slower than stock, already built in. You likely won’t need the additional low-range crawler gears from Epoch 5. Evaluate after testing.
Why not the MBL32 G2 + Fat Viper combo?
The MBL32 G2 is a good system, but for a 3-year-old driver the Roverin’s FOC sensored control, 200% drag brake, and IP67 waterproofing are worth the ~$45 premium. The startup smoothness alone makes a difference when learning throttle control.
Video Guides:
- Injora T6M Setup Tutorial — Programming and binding
- Roverin M30 G2 Overview — ESC features and setup
- INJORA Link App Tutorial — Bluetooth configuration
Community Discussions: