Written by Oscar Westergaard
I needed a desktop size CNC milling machine at an affordable price to handle multiple operations in metal, primarily aluminum, but maybe occasional softer steels as well. From tons of research of desktop CNCs, the Genmitsu 3030 PROVer MAX ended up checking most boxes.
First, the rigidity of the 3030 PROVer MAX is good enough to handle the needed operations. This is one of the first vital parameters when wanting to mill metal. The larger the operations and the harder the metals, the more rigidity is needed to get proper dimensioned parts. With the Genmitsu 3030 PROVer MAX’s thick aluminum parts, solid connections and just as importantly – its HG15 linear guides and ball screws it is fit for the job.
Second, the ability to replace the spindle on the machine was proven in many videos. This was a critical point as the 300W stock spindle on the machine was definitely not powerful enough to continuously run metal operations at fairly short process times. However, most videos showed separately controlled routers being attached, a video series on YouTube by James Dean Designs about upgrading the spindle on a CNC gave enough confidence that this was possible to fully integrate. (Huge credits to James Dean Designs)
This tutorial will go through the required steps to fully integrate the Genmitsu 2.2 kW water-cooled spindle with the Genmitsu 3030 PROVer MAX. With this setup you will be able to run your CNC machine and spindle all in one without having to separately control the spindle and the CNC.
The setup will probably work just as well for other spindles using a VFD, but this tutorial is made using all equipment purchased from SainSmart so some steps might vary if you use other spindles and VFDs.
I am no expert or professional in any field related to the guidelines in this setup. All steps performed are 100% based on my own testing and anyone who choose to follow this guide does it at their own risk and responsibility.
Step 1 – Assembly
The assembly of the spindle on the CNC machine is easy. The spindle comes equipped with multiple fittings, one of them matching the spindle mount of the Genmitsu 3030 PROVer MAX (blue part shown below). The green highlighted clamp is for holding the spindle itself. The spindle is heavy but the rigid mounts and built of the machine handle it with ease. All equipment and tools required for mounting the spindle is included in the spindle box.
For the wiring you should follow the instructions that follow with your spindle and VFD to complete the proper wiring. For the Genmitsu 2.2kW spindle, all cables are fully completed and ready to connect to the spindle and VFD. The setup guide provides easy to copy images of the wiring. The cap to protect the electrical connections on the VFD pops easily off when pulling. The water-cooling hoses are also easily attached with a screw compression fit.
It is important you use the cooling when running the spindle as the high power of the spindle produces a lot of heat. It is no issue at all when the coolant is flowing, but if you run long duration tasks, check the water temperature from time to time and if you think the water is getting too hot, you can always pause the job, replace the water and proceed. The spindle cools fast with fresh cold water. You can also control the temperature by feeling the outer surface of the spindle. It is clear when the spindle is proper cooled or starting to heat up.
When you have completed the assembly, you can power on the VFD. The default setting will usually let you set the frequency (0-400Hz = 0-24000 RPM) using the buttons on the VFD and if you click “Run” the spindle will start up. Click “Stop” to stop the spindle. Before doing this, make sure the collet nut is not loose as it can come off when the spindle starts rotating if it is loose.
Step 2 – Connecting the VFD and CNC controller
When you have completed the assembly of the spindle and VFD and performed a test run to check all is correctly powered, then you can begin the wiring connection between the VFD and CNC controller on the back of your Genmitsu 3030 PROVer MAX. Before starting the wiring, make sure all power is shut down to prevent any risk of electrical shock or accidental spindle incidents.
For the wiring you will need to connect the VFD and the “Laser” port on the CNC controller. I did this using simple jumper wires and dupont connections.
The CNC controller side: Connect one wire to the “PWM” pin and another wire to the GND pin.
The VFD side: Connect the wire from the PWM on the CNC controller to the AI1 slot on the VFD. Connect the wire from the GND on the CNC controller to the GND slot on the VFD.
Now you will have to connect a few slots on the VFD with each other. Connect COM to GND. Connect X1 to GND.
The short explanation of the wiring is that PWM on the CNC controller sends a variable voltage signal that ultimately decides the RPM of the spindle. This is received by the analog input on the VFD that will them send the appropriate power to the spindle. The X1 and GND and COM and GND are responsible for spindle rotation direction and starting/stopping the spindle. This knowledge is 100% based on trial and error and has no more theoretical backing to it.
You have now completed the wiring. A good tip is to make sure your cable connections are fixed and the cables are out of the way of the CNC base plate as the Y-axis of the plate can extend quite far back and accidentally pull out our break cables in the way.
Step 3 – Changing settings on the VFD
When you have finished the wiring of the CNC controller and VFD, you need to change some settings on the VFD to properly read the signals sent by the CNC controller and to adjust the spindle control to work well with your entire setup. The following settings will have to be set on the VFD. Do this using PRG/ESC, Data/Enter, Up and Down buttons on the VFD.
Many VFDs have the same settings, but they can be located differently. A good tip is to check the model of your VFD and find the manual online. If the model of your VFD is not the MK100-2S2.2G-DK that I have, you can check your own model’s manual and find out where it hides the same settings.
- P0-02 set to 1: This tells the VFD to receive its command signals from the terminal (wired input).
- P0-03 set to 2: Sets the source of the speed reference to the AI1 port (analog input 1) that you have connected with the PWM pin from the CNC controller.
- P0-17 set to 5 seconds: This controls the acceleration speed of the spindle. This value should be fairly low to ensure your spindle has reached the desired RPM before the tool has reached the stock.
- P0-18: This is the deceleration time of the spindle. Set as you like.
- P4-13 set to 0.00V: Minimum expected received voltage from the PWM.
- P4-14 set to 0%: Input received from the PWM of 0V is equal to 0% spindle RPM.
- P4-15 set to 5.00V: Maximum expected received voltage from the PWM. The CNC controller sends 0-5V, so you need the VFD set to the same range.
- P4-16 set to 100%: Input received from the PWM of 5V is equal to 100% spindle RPM.
Step 4 – Adjust maximum RPM on the CNC controller
The last step to finish the setup is to tell the CNC controller that it can now run up to 24000 RPM. This is the maximum RPM of the 2.2kW water-cooled Genmitsu spindle. The default value of the CNC controller is 12000 RPM.
To change the maximum RPM, connect the CNC controller to a PC running UGS (Universal G-code Sender).
Select the correct COM port and use baud rate 115200.
When connected, go to the command line and type in: $30=24000 and click Enter. To check if the setting is set correctly, type: $$ and click Enter. One of the lines will be the $30 setting which should now say 24000.
The full setup is now completed, and you can start sending jobs to your Genmitsu 3030 PROVer MAX and leverage the full capability and power of the rigid setup combined with the powerful spindle. When starting a job, you will see the VFD display showing the frequency 0-400Hz. 0Hz is 0% speed and 400Hz is 100% speed (24000 RPM).
I hope this guide helps you build an affordable, powerful and capable CNC milling machine.
