WM16 Mill Spindle Hold

R. Finch describes a simple method of holding the spindle still on the Warco WM16 milling machine (and similar machines) when using a dial indicator

- R. Finch

Introduction

I was starting to make a drill sharpening jig which required a slot to be milled at a precise angle, so I set up a pair of toolmaker’s buttons on the mill table to use a sine-bar to set the angle. When I came to use the dial indicator to set the buttons parallel to the table, I realised that holding the dial indicator in the spindle required that the spindle had to be prevented from rotating in order to be able to obtain a satisfactory reading. This required a lot of head scratching and thinking as to how I could build a spindle hold without altering the machine itself.

I hesitated to call this a spindle lock, as that would suggest that the spindle was well and truly locked and should allow quite a bit of torque to be used. This is not the case – it merely serves to hold the spindle from rotating whilst the DTI is used. Similarly, I did not call it a spindle brake, as this might imply a method of bringing the spindle to a stop whilst it is rotating, so I decided to call it a spindle hold.

My first and primary objective was to make it such that no alterations were made to the milling machine at all. I found that I could not achieve this objective fully, as I did end up having to drill an access hole for the screw to operate the spindle hold. I considered that a single 7mm diameter hole in the plastic cover over the motor and spindle was acceptable. Otherwise, there are no irreversible alterations to the milling machine.