Adding a 4th or 5th axis rotary table to your CNC mill unlocks incredible multi-sided machining capabilities. But when you decide to automate that setup by adding a pneumatic vise to the rotary platter, you immediately encounter a frustrating physics problem: how do you get air to the vise without the hose tangling?
If you simply run a pneumatic hose from the machine wall directly to the vise, your rotary table is no longer capable of continuous rotation. The moment the table spins past 360 degrees, the hose wraps around the trunnion, pulls tight, and eventually snaps. To achieve true infinite rotation while supplying air to your workholding, you need a rotary union CNC solution
feeding the vise must pass through the center bore to allow infinite rotation.
The Mechanics of a Pneumatic Rotary Joint
A pneumatic rotary joint CNC (or rotary union) is a mechanical device that transfers fluid or gas from a stationary source into a rotating component. In the context of CNC machining, it mounts to the back of the rotary table and passes compressed air through the hollow center bore of the unit, exiting at the front platter where the vise is mounted.
Because the air passes through the center axis of rotation, the table can spin continuously in either direction without any hoses tangling. This is mandatory for complex 5-axis simultaneous toolpaths or when running automated pallet-changing systems on a 4th axis rotary union.
The Challenge of Retrofitting
Historically, adding a 5th axis rotary union or 4th axis union was a massive headache. Machine tool builders often charge exorbitant fees for factory-installed rotary unions, and retrofitting an aftermarket unit usually required custom-machined adapter plates, complex plumbing, and a deep understanding of the specific rotary table’s internal geometry.
For example, a Haas HRT160 rotary union requires a completely different mounting interface than a Brother T200A or a Haas HRT210. This lack of standardization meant that shops either paid the OEM premium or abandoned the idea of automated rotary workholding altogether.
The Universal Solution: AxisAir™ by Gimbel Automation
Gimbel Automation recently solved this retrofitting nightmare with the release of their 4-Port AxisAir™ Universal Rotary Union Kit. Priced at $1,589, it is currently the most accessible way to establish a CNC rotary table air supply.
sleeve from the inside
What makes the AxisAir unique is its universal mounting system. Rather than requiring custom machined bolt patterns for every brand of rotary table, the AxisAir utilizes an expanding puck system. This puck slides into the rear bore of the rotary table and expands outward to grip the rotating sleeve from the inside.
Because the pucks are printed on demand to match the exact bore diameter of the customer’s machine (fitting bores as small as 36mm), the AxisAir can be installed on almost any rotary table on the market in minutes.
Available configurations include:
Haas HRT160 or TRT160
Haas HRT210 or TRT210
Brother T200A
Haas HRT310
Custom bore sizes (specify when ordering)
Four Independent Ports for Complex Automation
While a simple open/close pneumatic vise only requires two air lines, the AxisAir is a 4-port union. This allows it to pass up to four fully independent air lines through the center bore simultaneously.
This multi-port capability is critical for advanced automation setups. For instance, you might use two ports to control the open/close function of a self-centering rotary vise, while using the third port for a part-seat confirmation air blast, and the fourth port to actuate a secondary clamping mechanism or pallet receiver.
Pairing with Pneumatic Workholding
The AxisAir is designed to work seamlessly with Gimbel Automation’s Rotary AutoVise™ line —self-centering pneumatic vises specifically built for 4th and 5th axis rotary tables. These vises feature bottom-feed air ports that align directly with the AxisAir’s output, creating a clean, integrated system with no external hoses crossing the rotary platter.
To control the vise open/close functions via your CNC program’s M-codes, pair the AxisAir with
the MCodeAir™ Solenoid Kit ($929). This plug-and-play kit connects your machine’s spare
relays to pneumatic solenoid valves, allowing G-code commands like M51/M61 to actuate the
vise automatically.
For clean cable management between the solenoid box and the rotary union, the OmniTube™-7
($32.79) bundles seven 6mm air lines into a single sheathed tube.
Specifications at a Glance
Conclusion
If you are building an automated cell that relies on multi-axis positioning, you cannot afford to be
limited by tangled air hoses. A continuous rotation air joint CNC is a mandatory piece of
infrastructure.
By utilizing a universal solution like the AxisAir, shops can easily retrofit their existing rotary tables for pneumatic automation, unlocking infinite rotation and true lights-out manufacturing capabilities without paying OEM markup prices. Explore the full rotary union collection to find the right configuration for your machine.
