I ordered the NM-200 Series 2 AC spindle motor replacement kit and paid the shipping charges. When I called to place my order, Novakon said they would be able to ship a kit to me immediately. I ordered the kit with the understanding that I would be one of the first customers to install it and that there were no written instructions available at this time. They assured me that technical assistance would be readily available to assist me in the installation of the kit, programing of the Sunfar C300 VFD, and reprograming of Mach3. Their technical assistance was timely and excellent.
I had the kit installed and running within two days. I believe the kit can be installed in one day by following the written instructions and pictures that I will post herein.
I was able to run the AC spindle between 60 and 6000 RPM. The 60-6000 RPM variable speed range is accomplished without changing motor pulley belts. The torque at 60 RPM is strong and I cannot stop the spindle by hand. The spindle ran very smoothly at 6000 RPM. I am now able to cut, drill and surface plane steel at low RPMs. In other words, more aggressive cuts can be taken without bogging the spindle down. With the old BLDC setup, I was afraid to run the spindle below 4000 RPM for fear I would blow the BLDC controller board. Now, with the AC motor, I run the spindle as low as 150 RPM without fear of damaging the system.
The BLDC motor had virtually no torque at 400 RPM and had a maximum torque rating of 3.5Nm at 6000 RPM. The AC motor has a constant torque rating of 7.95Nm between the 150-6000 RPM range. What a difference (See the motor ID plates in the pictures below)!
I had been disappointed with the performance of the BLDC motor/VFD system. I had previously blown the BLDC controller board. Novakon sent me a replacement board under their warrantee policy. For over one year, I had been running my BLDC motor at 4000 RPM and above while waiting on Novakon to resolve the low torque problem.
Thank you Novakon, the low torque issue has been solved, and my upgraded NM-200 Series 2 Mill is one smooth running beast of a machine.
I believe the kit is a mandatory upgrade for NM-200 Series 2 CNC owners and that it is a good value if purchased by May 25, 2012 at the price of $695 plus shipping.
The AC spindle motor drive kit arrived via FedEx. The contents were well packaged as shown in the pictures below. My package also included some backordered tooling.
The AC spindle motor drive kit included the AC motor, steel mounting plate, DC-DC converter, motor pulley, Sunfar C300 VFD, cable connector, and miscellaneous wiring.
I will be posting detailed instructions on the Novakon AC spindle motor drive system installation as time allows.