Monty

• Minimum 4 channels, mapped as in the table above.
• Receiver: must output at least 4 independent channels.
• Transmitter: must support curve-based channel mixing (e.g. EdgeTX or equivalent) so a single pot or switch can blend front/rear throttle across the full Dig → 4WD → Burn range. The Sanwa/Airtronics MT-4 is a good option with MOA mixing built in, or an EdgeTX stick radio like the Radiomaster Pocket.
• 4WS can run independently on CH4 or be mixed with steering, depending on your preference and your transmitter's mixing options.

All pinions are 48 DP (diametral pitch) — confirm your pinion and gear mesh use matching 48DP hardware. A few known-good combos (not an exhaustive list):

Rule of thumb Confirm the pinion you buy is 48DP and falls inside the range listed for your motor before ordering — pinions outside these ranges either won't fit the gear mesh correctly or won't clear the axle housing.

Important After mounting each pinion, check that the in-axle transmission still spins freely by hand. A mismatched or misaligned pinion can bind the gear mesh and damage the transmission.

Motor guards Most of these motors are open-can outrunners (exposed bells and magnets), so a motor guard is a good idea against rock strikes and debris. 9C RC also provides a free, 3D-printable front skid plate STL that can be used instead of a classic motor guard.

Recommended minimum torque: at least ~40 kg·cm. These examples are all at or above that baseline:

• JX B40
• Reefs 800LP
• AGFRC A66FHLW
• NSDRC RS650 High Torque Low Profile (46–80 kg·cm depending on voltage)

Servo horn A 25 mm servo horn is recommended for correct steering throw.

Powering the servos (BEC = Battery Eliminator Circuit, which regulates power to the servo) — choose one of:

• Split BEC — use the front ESC's BEC for the front servo and the rear ESC's BEC for the rear servo.
• A single external BEC rated at least 10A.
• Direct power — servo wired straight to the battery/ESC power rail, bypassing a BEC. For example the NSDRC RS700 V2 High Torque Low Profile Brushless Servo (46–80 kg·cm, 8.4–16.8V direct-power range, not routed through a BEC).

Safety note Never plug both ESCs' BEC positive (red) wire into the receiver at the same time — two BECs feeding the same rail can fight each other and damage the ESCs or receiver.

Connecting one battery to two ESCs: Monty's front and rear drive units each have their own ESC, but there is only one battery — so both ESC power leads need to be joined into a single battery connector. We recommend standardising on XT30 plugs throughout (battery, ESCs and harness) to keep this simple. You have two options:

1. Buy a ready-made Y-harness (parallel connector) matching your connector type (XT30 recommended). Plug each ESC into one side; the single end goes to the battery. The easiest option for first-time builders — no soldering required.
2. Solder your own Y-harness — if you can't find a pre-made one for your connector type, splice both ESC power leads together into a single battery connector. Make sure + goes to + and – goes to – on both sides, and insulate the joints with heat-shrink or electrical tape.

Either way, the result is the same: one battery plug feeding both ESCs in parallel.

• Best choice: high-clearance, comp-style wheels.
• Best choice: narrow-offset rims make the most sense on Monty's width.
• Example: Dlux 1.9" and 2.2" rims fit well — many other generic 1.9"/2.2" VP-pattern wheels also work.
• Tuning tip: heavier wheels up front and lighter ones in the rear is a useful weight-distribution trick for better front traction when climbing.

Tire size range: 4.19" to 4.75" diameter, in both 1.9" and 2.2" fitments. A few examples known to work well — not an exhaustive list; any tire in this range should fit:

• Radio system — 4 channels minimum, EdgeTX or equivalent mixing support
• Drive units ×2 (1 per axle) — motor + ESC, or 2-in-1
• Pinions ×2 — 48DP, within the correct range for your motor
• Steering servos ×2 (1 per axle) — low-profile, at least ~40 kg·cm
• 25 mm servo horns ×2
• BEC — split, external 10A, or a direct-power setup
• Battery — GNB 380mAh 3S (or equivalent)
• Power harness (Y-splitter) to feed both drive units from one battery
• Wheels ×4 — 1.9" or 2.2", VP 6-screw pattern
• Tires ×4 — 4.19"–4.75", matched to wheel size