Product Selection · Application Guide
How the ZXG3 integrated slew drive, with a TMS03 motor inside, slews the drill boom of a large gantry-mounted underground drilling rig under heavy off-centre load.

On a gantry drilling rig, the boom joint carries the whole load. A large drill boom has to slew accurately into each hole position and hold that angle while the feed pushes against rock — repeatedly, under heavy off-centre load, in a confined heading. That joint is where the ZXG3 integrated slew drive works.
Why a housing-rotating slew drive
- ZXG3 — boom slew. The ZXG3 turns its own housing and outputs through a flange, mounting directly at the boom joint with no separate slew bearing — 360° rotation and up to 35,000 N·m at the joint.
- TMS03 — the motor inside. A TMS-series radial-piston motor drives it at low speed without torque ripple, so the boom indexes precisely and holds position under feed load.
- Encoder-ready. The ZXG3’s encoder interface feeds boom angle back to the controller — the basis for intelligent, semi-autonomous drilling.
Speccing a boom slew drive? THOTH matches ZXG3 slew-drive size and motor type to your boom load and duty. Talk to our engineers →
![Gantry Tunnel Drilling System: [ZXG3] & [TMS03]](https://thoth-hydraulics.com/wp-content/uploads/2026/09/case-57-zxg3-tms03-1100x450.jpg)