TIL a dial indicator is useless if you don't zero it to the right spot

I was roughing a large aluminum plate on my mill at the shop last Tuesday and kept getting inconsistent depths. Checked the tool holder, cleaned the collet, even swapped inserts. After wasting 45 minutes and scrapping a $60 piece of stock, I realized my dial indicator was zeroed to a low spot on the table instead of the surface I was cutting. Lesson learned. Has anyone else chased a setup error for way too long before catching something simple like that?

3 comments

3 Comments

annaw7329d agoMost Upvoted

A $60 piece of stock... that's rough. Makes my stomach drop just thinking about it.

young.nora28d ago

Blew up a cheap Chinese indicator once because I zeroed it on a greasy spot and then cranked the quill down too fast. The needle snapped clean off and I had to fish little pieces out of my ways with a magnet. Learned two lessons that day.

uma_ellis29d ago

Oh man, "makes my stomach drop" is exactly right, @annaw73. That hurt to read. I did something similar back when I was trying to dial in a custom bracket for a race car, spent a whole Sunday chasing a quarter-inch offset. Turned out I'd zeroed my indicator to a patch of dried coolant on the vise jaw instead of the clean steel. Felt like a real dummy.