Re: MaxNC Servo Upgrade

Thanks to Alan and Mike,

First, Alan. Yes the spindle motor mount is junk. Two long posts hold the
motor way up
and the pulley is hanging off the end of the shaft. That was the first mod I
did along with a
counter balance. I also mounted a PII 2 fan heat sink to the side of the
spindle head. It
got too hot to touch. Also milled the spindle pulley to act as a turbine to
help cool the spindle.
Also made some nice way covers a way lube system and coolant delivery/return
system.

The steppers are rated @ 203 oz/in as per PacSci Data sheet.
Don't know about the driver setup, it is the MaxNC phase drive, and the
software
is also MaxNC.
As for the rotary table, I believe it is the Sherline. Nice, heavy all steel
model.

Mike,
This is exactly what I was afraid of, so I asked.
Guess I'll just leave it be and convert my Grizzly Mini Mill(was going to
anyway).

>I'd be careful here. I suspect the drive electronics don't have a lot of
>extra current capacity so if you go to bigger motors, you might not get any
>more torque. Pacific Science makes good motors and the only way to PERHAPS
>get more torque would probably be a higher inductance (i.e triple stack)
>motor that would have a slower maximum speed (for the same current). You'd
>lose feedrate. If you replace the drive electronics to get more current,
>you lose the feedback servo system (unless you want to spend big bucks on a
>new servo system).

You are correct, it is 1/5 hp.

>If you have a MaxNC 15, it should have the 1/5 hp motor?

What I don't like is that it has sleeve bearings and brushes.

>The MaxNC 15 also runs 8500 rpm spindle speed.

10,000 RPM
But for what I do I need more cutting torque not speed.

>Finally, I'd think you have to be careful about weight. If you put

something too

>heavy on the non-counterbalanced Z axis, you're likely going to have
>problems overloading the servo system.

As noted above I did add a counter balance to the head.

>The Sherline motor is designed to be used only with the Sherline speed
>controller. As I understand it, it runs on DC and is torque
>compensated. This would not be compatible with the MaxNC speed controller
>at all. If you go to the Sherline, use their speed controller and it will
>not be under software control.

Not what I really wanted to hear (although it is what I figured), but I
guess that's the way it is.

Thank again,
Don