[Blakea1790]

I have recently purchased a preowned NM200 Pro-series 2010 model and could use some help on one of the issues I'm having. The machine is in good condition despite a good portion of the paint being gone, bad spindle bearing , and the need for a new x axis ballscrew assembly. I have dismantled a good portion of the machine but did run some dry cutting programs and the machine, seems for the most part in decent shape. One issues is that the spindle only rotates CW , even if I give it a M04 command, it still turns CW. I have used Mach3 only on the tormach I have which is for the most part preconfigured and there is not much you can do to the settings. I've followed this forum for a while and looking forward to bringing the machine back to a good operating condition. Also, I've noticed the original spindle and VFD seem really low on torque, I had the spindle running at 400rpm and was actually able to stop it with my hand. I'm looking to do the upgrade to the C300 VFD and new motor , but is it normal for this particular model to have such low torque? Thanks .
Blake

[UniqueMachining]

Blakea1700

With bad spindle bearings, it sounds like an excellent excuse to update to the 6000 RPM AC motor. The DC version was known to have low torque at under 1000 RPM.
My series 2 had the DC motor but as I never ran it under 1000 RPM, I never experienced a problem.

All the Novakon machines equipped with non servo motors are wired for CW rotation only. The only purpose I can see for CCW rotation would be rigid tapping. As this requires either a servo or encoded stepper it was probably presumed to be unnecessary.

Good luck with your newly found gem. Rebuilding it will give you valuable insights as to its operation. Careful attention to detail will ensure accuracy for years to come.

John

[Hirudin]

My old NM-200 and my Torus Pro both had/have CCW rotation ability built in.

Another use for CCW: OD boring.

[SCzEngrgGroup]

I would expect the NM200 uses the same spindle control logic as the Torus Pro, in which case there are only two control signals going from the BOB to the VFD. One is the analog voltage controlling the RPM, which must be working, or you would not have CW rotation. The other is simple a direction signal, which connects, IIRC, to the "FWD" terminal on the VFD. You must be missing that connection or for some reason the BOB is not properly driving that signal. If you command M3, then M4, that signal should either be high (~5V), then go low (~0V) (or it might be the other way around...). Check that with a voltmeter, and I suspect you'll find it's stuck high. You'll have the check out the wiring, and possibly debug the BOB itself, to figure out what's wrong. Also make sure Mach3 is properly configured to use that signal as the spindle DIR control. It should be on PP pin 14.

Regards,
Ray L.

[Novakon]

This functional description is totally true for this series mill using the C11G BOB. The controls are limited from this C11G BOB board as well as the implementation method. There is, however, a programming method that can be used on the C300 VFD that allows different modes of interpreting the two signals from the C11G BOB. You can reference the description in the C300 manual in section 6.1.

The factory default method- 2 wire mode 1: This simply allows a single switching input to turn on either the FWD or the REV controls. Leaving either input open will disable the C-300 VFD. The voltage input will control the speed only during activation of either direction. This is a very safe method to prevent erroneous turning of the spindle.

2 wire mode 2: In this mode the FWD and REV functions can be changed to mean "use the FWD for the enable/disable, and the REV will control the forward/reverse direction". Since there is only one control command from the C11G BOB, the FWD control would have to be hard wired closed and the relay input would control the FWD/REV directions. This also means that the variable DC control would have to shut it off (0 volts) and this is not always a true zero volts. small voltages can cause the spindle to turn slowly. A definite safety problem...not recommended.

Another option: If you don't need the 4th axis rotary table, then you may be able to use this output control to perform the needed FWD and REV controls. This is a custom application from the standard configuration.

The need for reverse on the NM-200 mill depends on your application. I am sure there may be special needs for reversing the spindle, other than left hand cutters.

In the new Torus PRO, we have more capability for reverse than the C11G BOB by using our custom BOB. This is another discussion unrelated to this mill and thread though.

I hope this helps.

Regards,
Novakon Team

P.S. The Novakon BOB's ability to control the "VFD enable with direction control" is a fairly recent addition to the Novakon BOB capability. Some earlier BOBs may only control the FWD and speed inputs to the C300 VFD.