stella_lane•19d agoProlific Poster

Shoutout to the old timer who watched me spend 20 minutes hand-scraping a vise jaw

He walked over, tapped the side of my mill, and said 'son, you know you can just indicate it in and take a light spring pass with a face mill, right', which saved me a ton of time on the next job.

3 comments

3 Comments

wendy39119d ago

Read an article once that said the spring pass trick only works if your spindle tram is dead nuts. The writer argued you should always sweep the face mill itself with an indicator first, like sethhernandez said, to get a true surface. Otherwise you're just making a really flat copy of a crooked starting point.

jamesm3819d agoTop Commenter

Wait, wouldn't a spring pass with a face mill just follow the existing surface? I thought you had to indicate it true to the machine's axis first, then take the cut.

sethhernandez19d ago

But what if your machine spindle isn't perfectly square to the table? A spring pass just copies the error. I always indicate the face mill itself, not just the part, and take a fresh light cut. That way you're cutting true to the spindle's axis, not tracing a maybe-crooked surface. It's extra work but the finish is way better.