Introduction

I placed an order with Precision Matthews for a lathe and a mill a week ago, originally the order was:

  • PM-1030V Lathe
  • PM-30M Mill


The lathe was backordered, so a week later I reconsidered my choice of the mill and decided to go bigger and heavier for just a bit more money.

So, I changed the mill order to be the PM-932m with the Power Down Feed and cast iron stand.

Both the lathe and the mill will be here in December, and that is when I will start planning to convert the PM-932m to CNC.


Wishlist

Here's what I'd like to do to the mill:

  • Convert the leadscrews to ballscrews.
  • Start the CNC electronics with simple steppers, upgrade to full AC servos later.
  • Change the R8 Spindle to an NT30 spindle such as the one from Charter Oaks Automation.
  • Epoxy Granite All the Things
  • Convert the motion from dovetail ways to linear rails.
  • Replace the spindle head with a Chinese belt-driven BT30 spindle, rated for 10,000 RPM / 12,000 RPM Max.
  • Replace the 1.1kw/1.5hp AC motor with a 1.5/2.2kw AC Spindle Servo, rated for 6000 RPM, 8000 RPM Max.
  • Belt drive the spindle with the servo with a 2:1 overdrive.
  • Add a BT30 carousel ATC


Initial Designs

Thanks to KCJ for sharing his excellent CAD models, it's helped me get a much better idea and a quicker head start on designing the upgrade.

KCJ's models:
https://github.com/KurtJacobson/RF45...r/CAD%20Models


So the initial design for the BT30 spindle and 1.5kw AC spindle servo was based on taking a giant block of cast iron and making an entire head out of it.

Assuming I get the mill converted to CNC first, it should be able to mill its own replacement head.

Attachment 430566

Attachment 430568


Initial Parts List

Ball Screw Kit:
TBD, have to find a matching kit for an RF-45/PM-45/ZX45/etc.

Steppers / Servos:
TBD, prefer to start with less expensive plain steppers just to get things moving.

BT30 Spindle:
Plenty of inexpensive 6000 RPM BT30 spindles listed on AliExpress, but here's one example rated for 10,000 RPM with a 12,000 RPM maximum:
high speed ATC BT30 automaitc spindle for cnc machine / cutting machine 12000rpm

AC Spindle Servo
Found a AC Spindle Servo that comes in 1.5kW or 2.2kW sizes that fit within a 150x150mm square frame, complete with servo, driver, and brake resistor - and single-phase 220V compatible.

How do these torque ratings compare to the stock AC motor? I don't know yet..




ATC




All comments and suggestions are welcome, this will most likely be a multi-year build.


I am located in Atlanta, GA, if anybody else has a large mill and is willing to help, let me know!