Dual-Pallet Power: Custom 4th-Axis Workholding for Brother VMCs

At Martin Trunnion Tables, our custom fixtures are designed with one goal in mind: making your machine tool more productive. This week’s featured solution showcases a dual-pallet Brother vertical machining center, each side outfitted with a dedicated Brother T-200Ad rotary table and a fixture custom-engineered to the customer's specific part and process.

This isn’t just a pair of fixtures—it’s a coordinated system that unlocks continuous, high-density 4th-axis machining across both pallets with minimal operator intervention.

Purpose-Built for a Dual-Pallet Brother System

Our customer runs a Brother pallet-changing vertical machining center, with a T-200Ad rotary table mounted on each pallet. This allows them to maintain continuous production—while one fixture is being machined, the other is being loaded or unloaded. Each pallet features a completely different fixture setup, designed around two distinct clamping strategies:

Pallet A features an internally clamping fixture using Mitee-Bite ID Expansion Clamps

Pallet B runs a robust external clamping solution using Mitee-Bite Dyna-Force® clamps, Carr Lane spring-loaded locators, and Fairlane GripSerts®

This dual-fixture configuration allows the customer to run a family of parts with different geometries, without changing setups between cycles.

Pallet A: Precision ID Clamping for Full 5-Sided Access

​The fixture on Pallet A is built from precision-ground cast iron and outfitted with custom-machined Mitee-Bite ID Expansion Clamps. This setup is designed for internal clamping, allowing:

- Unobstructed machining of five faces

- High-density part layouts

- Minimal distortion, even on thin-walled parts

Every clamp is matched to the internal geometry of the customer’s part, allowing quick loading and ultra-reliable repeatability—even in lights-out environments.

Pallet B: Robust External Clamping with Positive Location

On the other pallet, a second custom fixture is designed around external clamping and precise positioning:

- Mitee-Bite Dyna-Force® Clamps deliver strong holding force in a compact footprint, ideal for dense fixture layouts

- Carr Lane Spring-Loaded Locators ensure the part is consistently seated during each load cycle, with minimal manual adjustment

- Fairlane GripSerts® bite into the material securely without marring or distorting it—critical for raw stock and castings

This fixture is all about speed, consistency, and durability—built to withstand aggressive 4th-axis machining strategies without compromising part quality.

High-Density Machining, Zero Setup Between Cycles

What makes this setup truly efficient is the way it’s integrated into the Brother pallet system. As soon as one pallet finishes its cycle, the second rotary table spins into position, and machining resumes--no downtime, no fixture swaps, and no program changes needed.

By designing each fixture around specific parts and using the full range of the rotary table’s motion, our team helped the customer:​

- Run two unique jobs back-to-back

- Maximize spindle utilization

- Eliminate unnecessary handling

- Simplify operator workflow

Designed and Built In-House

Like all Martin Trunnion Tables fixtures, both systems were designed from scratch in Fusion 360, machined in-house, and assembled by hand. The precision-ground cast iron base, exact-fit clamps, and strategically machined reliefs reflect the level of detail that goes into every custom solution we build.

Final Thoughts

This dual-pallet Brother setup is a powerful example of how smart workholding can transform a machine tool into a high-efficiency production system. Whether it’s internal or external clamping, we build fixturing around your parts—not the other way around.