Adding an external rotary table to an existing 3-axis CNC machine can be a practical way to handle indexed drilling, milling, side machining and multi-face work. A useful recommendation, however, needs more than a table diameter. The machine, CNC control, workpiece and intended process all affect the table size, clamping method, controller approach and installation work.
This checklist explains what to send before requesting a CNC 4th axis retrofit quote.
1. CNC Machine Make and Model
Start with the machine builder, exact machine model and approximate year. A clear photo of the machine nameplate is helpful.
This information helps confirm the available table area, travel, enclosure space and spindle clearance. It also helps identify whether the project is better suited to a compact rotary table, a larger hydraulic-clamp table or a different fixture approach.
2. CNC Control Model
Send the complete CNC control name and version when available, such as FANUC, Mitsubishi or Brother. Please include photos of the control screen and electrical cabinet if possible.
For an external controller retrofit, the required communication or trigger method depends on the individual machine. Ethernet, serial communication and I/O signals can all be relevant, but compatibility must be checked for the exact control, machine wiring and intended program flow.
An external controller is commonly used for indexed rotary positioning. Continuous simultaneous X/Y/Z/A interpolation requires a separate review of the original CNC architecture and should not be assumed from the machine brand alone.
3. Machine Table Size, Travel and Available Space
Please provide:
- machine table dimensions;
- usable X, Y and Z travel;
- maximum table load if known;
- photos of the table and machine enclosure;
- spindle-to-table clearance and any fixture restrictions.
These details help determine whether the rotary table and workpiece will fit without limiting the normal machining envelope.
4. Workpiece Drawing, Size and Weight
The workpiece is often more important than the machine alone. Send a drawing, photos or a simple sketch showing:
- maximum diameter and length;
- weight and approximate center of gravity;
- material;
- required clamping method;
- features to be machined from different sides.
This allows the rotary-table size, center height, bore and brake or clamp requirement to be matched to the real job.
5. Intended Machining Process
Describe the actual operation. For example:
- side-hole drilling;
- multi-face milling;
- bolt-circle drilling;
- angled positioning;
- repeated indexed operations in batch production.
Please also state whether the rotary table only needs to index to programmed angles or whether the process requires simultaneous machining. This distinction directly affects the recommended control approach.
6. Electrical Cabinet Photos and Available Power
External controller hardware is normally installed in the CNC electrical cabinet or a suitable separate enclosure, while the rotary table operates inside the machine. A photo of the cabinet interior helps review installation space, wiring routes and available power.
Please do not modify machine wiring before the control method and safety requirements have been confirmed.
7. What Happens After You Send the Information?
YidaiCNCParts can use the information above to make an initial recommendation covering rotary-table size, controller option, brake or clamp consideration and likely communication approach. Final suitability should always be confirmed for the individual machine and application.
For related guidance, see our external 4th axis retrofit solution, CNC rotary table selection guide and FANUC, Mitsubishi and Brother compatibility guide.
Request a CNC Retrofit Assessment with your machine information and intended process.
