Embedded Files
1. Omni‑Claw Robot Car
1. Omni‑Claw Robot Car
Platform: Meccano‑compatible chassis on four 86 mm single‑row omni wheels for holonomic skid‑steer motion.
Drive Motors: 2 × TT all‑metal 6 V gearmotors, 1 : 90 (≈120 RPM at 6 V).
Manipulator Motor: 1 × N20 micro gearmotor (6 V, 150 RPM, metal gears) driving the front claw.
Power: 3 × AA NiMH/alkaline battery pack (≈3.6–4.5 V under load) – adequate for the geared motors, but a 2‑cell Li‑ion pack is recommended for longer runtimes.
Control: 6‑channel 2.4 GHz radio (PWM) + dual H‑bridge driver board (L9110S) for the TT motors; single MOSFET driver for the claw.
This compact robot combines skid‑steer mobility with a powered two‑finger claw. Swapping the original 3″ Meccano pulleys for 86 mm omni wheels reduces scrub friction and lets the chassis pivot effortlessly, even on carpet. The chassis remains built from classic Meccano®/Märklin strips and custom 3‑D‑printed adapters, with the two TT gearmotors chained to the front and rear wheels on each side. A micro N20 gearmotor now powers the worm‑and‑sector claw, giving slow, high‑torque gripping under radio control.
2 Mechanical Design
2 Mechanical Design
2.1 Chassis
2.1 Chassis
Side rails: blue 11‑hole plastic girders.
Cross‑braces: red Märklin 3 × 5 girder (torsion), green Märklin 11‑hole strip (upper deck).
2.2 Drive Train
Motors: 2 × TT 6 V, metal gears, ratio 1 : 90.
Transmission: Fischertechnik® blue chain loops (~80 links/side) mesh with printed 20‑tooth sprockets to couple front & rear axles.
Wheels: 4 × 86 mm single‑row omni wheels (polymer hub, rubber rollers). Printed 6 mm hubs adapt the Meccano 4.76 mm rod.
2.3 Claw Module
2.3 Claw Module
Backbone: C888 fluorescent‑green spacer strip.
Swing sector: printed 30‑tooth quadrant; driven by a brass worm on the N20 output shaft (worm:spur = 1 : 30).
Range: ±45° (≈55 mm finger spread).
3 Assembly Highlights
Motor cradles bolt to side rails; sprockets press‑fit to 4 mm D‑shafts.
Loop the chain, tension via printed idler.
Press omni wheels on hubs, align rollers perpendicular to chassis.
Mount claw backbone on 3‑hole hinge; mesh worm & quadrant; adjust limit screws.
Wire motors to driver board; route receiver leads; strap batteries low.
4 Electronics & Power
4 Electronics & Power
Motors – 2 × TT 6 V metal-gear, 1 : 90, seated in printed cradles.
Radio – 6-channel 2.4 GHz TX/RX (PWM outputs; no separate H-bridge required).
Battery – 4 × AA holder (NiMH or alkaline) centred low between the rails.
7 Downloads
7 Downloads
All STL files (sprockets, cradles, hubs, chain guides) plus a wiring diagram and drilling jig are available at:
https://<your-site>/3d
Page updated
Google Sites
Report abuse