G-Wizard Calculator:
Fast, Easy, Reliable Feeds and Speeds


Join 50,000+ CNC'ers!  Get our latest blog posts delivered straight to your email inbox once a week for free. Plus, we’ll give you access to some great CNC reference materials including:

  • Our Big List of over 200 CNC Tips and Techniques
  • Our Free GCode Programming Basics Course
  • And more!


GCode is Complicated
G-Wizard Makes it Easy

How can I use G-Wizard Calculator to find spindle speeds for a machine with a limited number of fixed speeds due to belt or gear drive?

Best Answer

When limited to speeds, let G-Wizard calculate its results with just a limit on the highest speed. Then see what speeds bracket that result.

You will have a choice to make in choosing which of the two that bracket the recommendation to take. If the faster one isn’t too much faster, it’s the preferred choice. By “too much”, I would exceed the limits by more than 10-20% unless you have checked the manufacturer’s surface speed recommendations and know you can get away with it.

If the faster one is too far away, you’ll have to take the lower one.

Once you have decided which of the two to use, just key that value into G-Wizard’s rpm figure and it will adjust the feedrate accordingly.

  • You must to post comments
Showing 1 result


Do you want to be a better CNC'er?

Get Better Tool Life, Surface Finish, and Material Removal Rates.


Start Now, It's Free!



  GW Calculator

  GW Editor



  Deals and Steals

CNC Blog








     Feeds and Speeds

     G-Code Tutorial

     CNC Machining & Manufacturing

     DIY CNC Cookbook

     CNC Dictionary

CNC Projects


     Machinist's Search


     Online Groups


     Reference Data


     CNC Dictionary


     Tool Brands


     Hall of Fame

     Organization: Soon!





     Our History

     Privacy Policy

All material © 2016, CNCCookbook, Inc.