In order to be able to drive a spindle (an induction motor ), you forcibly need a VFD . Regarding the VFD, I would take care to choose one that supports sensorless vector control (SVC) and not only stupid V/f control. Good VFDs are the Omron MX2 aka Hitachi WJ200 , the Hitachi S1 , and the Invertek Optidrive E-3 (made in UK).
omits the VFD input current rating .
Note that a VFD is a heavy source of EMI and is intended to be mounted into a control cabinet .
The spindle is in no case powered over a Onefinity Power Supply, but through its VFD which can be a VFD with single-phase 200 V class input (for domestic North America 240 V on split-phase electricity , or if you use only one phase in 230/400 V Europe), or a VFD with three-phase 400 V class input (if you have the usual 400 V three-phase in Europe), or a VFD with three-phase 200 V class input for North American 120/207 V three-phase (only in industrial/commercial areas, usually not available in domestic areas). The VFD’s voltage and supply circuit is independent of the voltage and supply circuit of the Onefinity machine. You can (and should) run a 220 V VFD/spindle on a 110 V North American Onefinity machine, as the spindle is never supplied by the Onefinity but by its own supply.
The spindle is exclusively switched on and off by the FWD/REV/RUN commands of the VFD. There are two ways for the CNC controller to control RUN and SPEED of the spindle: The buildbotics-derived Onefinity Controller on Original/X-50/PRO Series uses the Modbus over RS-485 serial communication inferface (two wires), while on the Elite Series, unfortunately the MASSO G3 Touch CNC Controller does not support Modbus, so it controls the VFD RUN/STOP by switching a programmable input terminal of the VFD on and off and spindle SPEED by regulating the voltage of a 0–10 V analog voltage input found on the VFD. See VFD wiring in Masso Documentation. PwnCNC offers a spindle control cable for the Elite/Masso with which you can connect the VFD to the CNC controller.
Many people here buy the ready-to-use solution from @PwnCNC available here but there are also ready-to-use solutions from the many spindle manufacturers, e.g.
Particular attention should be paid to the spindle cable, as it is a strong source of EMI and can damage the spindle if it is incorrectly mounted and earthed. It is highly recommended to buy the spindle cable ready-to-use directly from the spindle manufacturer. Reputable spindle manufacturers always offer this. Manufacturing a spindle cable is not for beginners.
Installing and using a spindle requires that the CNC machine and all its moving parts are correctly grounded and bonded. This is often omitted as the Onefinity manufacturer does not even mention it.
A spindle is neither a hand tool like the Makita hand trim router, nor a machine, but a machine component intended to be part of a machine. Therefore when you put the Onefinity CNC and a spindle and VFD together, you are the builder of a machine and have to comply to the safety regulations valid in your region. One of the most important is IEC 60204-1 .
The Makita hand trim router is a double-insulated Class II (IEC 61140) device that is not grounded. However, the Onefinity CNC is a grounded Class I device. All of its components that are able to carry current must be grounded . Important: The electrical connection of the individual components of the machine via the linear bearings or the ball screws is not a valid protective ground connection. Each moving part must be connected to ground with its own protective earth conductor . As mentioned in the thread linked above, grounding the entire CNC machine in accordance with safety regulations is not only mandatory as of the safety standards, but also noticeable in terms of preventing EMI and eliminating electric shocks due to potential differences.
Note that the use of a TN−C earthing system with PEN conductor (combined PE and N conductor) breaks the protection concept of protection class I.
The additional importance of proper grounding when using a spindle is that it is earthed and that it is driven by a VFD that uses high carrier frequencies internally. Proper grounding, shielding and filtering is necessary to prevent motor bearing currents which can damage the bearings of the spindle.
Here you can get a rich choice of spindles:
Be aware that on chinese spindles, the power rating is often wrong. See here for an example .