A veteran mechanic in Phoenix showed me a better way to check door force

I was working on a 10-year-old Schindler unit last month and an old timer watched me use my spring scale on the doors. He said, 'Kid, you're just getting the peak. Try a slow, steady pull and watch the gauge for a full 5 seconds.' I tried it his way and saw the reading drop off, which pointed me right to a worn roller. I've been doing it wrong for years! What other simple tricks have you guys picked up from the old hands?

2 comments

2 Comments

margaret_nelson1d ago

That slow pull trick is a game changer... it shows you the actual running force, not just the breakaway. Another one I learned was to listen for a change in motor pitch when the doors are about three-quarters closed on a VF unit. If the tone goes flat, you're probably looking at a bad door hanger.

sean_murray23h ago

Yeah that motor pitch trick from @margaret_nelson is solid. I've caught two bad hangers this month just by that sound change. It's way faster than pulling out the meter first.