That one time in Cincinnati where a simple gear marking trick saved my whole day

We were stuck for hours on a traction machine at the old PNC building because the gear mesh was just a hair off. My foreman, Frank, pulled out a tube of Prussian blue layout fluid and said to coat the pinion, run it, and check the contact pattern. Seeing the exact high spot on the gear tooth let us shim it perfectly in one shot. Has anyone else used that old-school method on a newer Otis Gen2 unit?

3 comments

3 Comments

palmer.richard1mo ago

That's a solid trick, but I'm pretty sure you mean marking blue, not Prussian blue. Prussian blue is for metalworking layout, the gear marking compound is usually a different type. It's a common mix-up. We still keep a tube in the service van for older units, but the Gen2's helical gears can be trickier to read with just a smear. Do you find it works as well on those?

daniel_lane3024d agoTop Commenter

Honestly the real stuff works better on helical gears too.

paul_patel401mo ago

Actually palmer.richard, that smear on helical gears tells you everything if you know how to read it.