[Novakon]

We are proud to introduce the newest capabilities of the Torus, Novakon's latest entry level CNC Bedmill.

One of the fundamental features added to this updated line of BedMills is a new Spindle AC Servo motor with a commercial driver, providing rigid tapping capability. This heavy duty combination is designed for industrial use and can be viewed in the video embedded below.

[ame=http://www.youtube.com/watch?v=1VeZ77BZBWQ&list=UUImd1SiE4oitZ-AMn_RITLQ&index=1&feature=plcp]RIGID TAPPING - YouTube[/ame]

Specifications for the AC synchronous motor are:

• 1200W power (1.6 HP)
• 0 - 3000 RPM (0 - 4500 with step up pulley)
• 10000 steps per revolution encoder resolution
• Accuracy to within +/- 1 Hz

HISTORY
We designed and built a new external motor mount casting in order to enable NM-145 (the previous line) owners to take advantage of this new technology via a retrofit kit, offered during the winter of 2011. By minimizing the number of parts to the ones illustrated in the attachments below, we created a great package that can be mounted with a limited number of drilled/tapped holes needed.

The electronic package was reviewed as well in order to address the new servo driver. A new electronic chassis has been built to mount the driver and host some of the components from the previous controller. The heart of the tapping capability is the product of a new break out board (BOB), designed and used exclusively by Novakon, providing function switching. The two functions are continuous rotation of the spindle motor and discrete control of the rotation similar to a rotary table. This BOB switching capability is facilitated to eliminate the software changes that are required by Mach3.

The function switching is automatic within the BOB. The only decision that has to be made by the user is if a 4th axis rotary table will be used or not. There is a single mechanical switch on the BOB to select the priority function. When selecting the tapping function, the rotary table has to be disabled since the control of the servo is now under output “A” control from MACH3. This trade off seemed to be a reasonable compromise. Of course, the rotary table is still available for use if tapping is not desired.

The G-code for tapping is very easy and straightforward. This is due to the BOB controlling the switch between the continuous rotation and discreet control. The sophistication between the commercial servo driver and in conjunction with our BOB has facilitated ease of programming via G-code. The programming of the driver/MACH3 steps per revolution is set to easily program the number of spindle revolutions from G-code. As an example, if an operator was to use a ¼-10 tap and thread the tool one inch into the material, it is simply done by writing:

G 91
A 10, Z-1
A-10, Z 1

This will do a helical cut one inch into the work piece and then reverse helical travel out.



“Pecking” can be done as well by a variation of this program. An example of the “pecking” is shown in the video . Shown in this video clip above, we are tapping ¼” Aluminum plate with a 5/16-18 tap. We chose a pecking operation to illustrate the precision of the rotation of the spindle. The soft Aluminum can be tapped without pecking, especially if a 2-flute tap is used instead of the 4-flute tap as shown in the video. More video projects are in progress showing tapping of harder metals such as steel and also softer materials like machinable wax demonstrating the precision and preservation of the threads.

The spindle motor upgrade KIT is a direct result of the research and work done creating the Torus line of milling machines currently available on our website. This KIT is available on a pre-order basis by contacting [email protected].

We hope this article has helped our community better understand the work we are doing to improve the performance and reliability of our equipment.

Best regards,

The Novakon Team

[Novakon]

http://www.youtube.com/watch?v=DXokg...ature=youtu.be