The Home Machinist!

Just noticed this:

<The variation increases the further down the bit I measure. At that location, it's .005"; about 7mm further down, it's .007">

Have you trammed the head of your machine? Sounds like it's not perpendicular to the table.

Richie

How is the accuracy of your cuts? Presuming that inaccuracy of the machined feature led you to make this measurement, I would agree that a test indicator should be used. I'd also measure over something larger, say a .500 plug gage held in a 1/2-inch collet.

Richie

Greetings gentlemen, I have an old Taiwanese "Jet" JVM-728 mill (which is actually a pretty decent little machine!), but the bearings in its vertical spindle are going to need replacement soon. To minimize downtime, I'd like to have the necessary bearings on hand before I tear down the hea...