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Swapped a 2:1 roping for a 1:1 on a traction job last spring | Elevator Mechanics - nhfree.com

Swapped a 2:1 roping for a 1:1 on a traction job last spring

I kept hearing from guys in the shop that 2:1 roping was the way to go for smoother rides, especially on medium rise jobs. But after three callbacks on a six stop install in Cleveland where the car kept hunting levels, I tore it all out and switched to 1:1. Took me an extra day and a half to redo the sheave setup and tension everything. Now it runs dead quiet and lands within an eighth of an inch every time. The old timers still give me grief about it, but I'd rather spend time upfront than chase ghosts later. Anyone else had better luck going against the grain on roping?

3 comments

3 Comments

oscarb714mo ago

Quiet and lands within an eighth of an inch every time" - that's the dream right there. I did the same thing on a hospital job in Akron. The prints called for 2:1 and I just knew it was going to be a headache with the leveling. Swapped it out, took the heat from the foreman, but the car never drifted once. Some of those old timers never had to chase a hunting car for three weeks straight. If 1:1 works on that specific load and rise, I say run it. No reason to stick with something just because it's "the way.

benk264mo ago

@oscarb71 I see it a bit different actually. That hospital job you mentioned with the 2:1 prints, swapping it to 1:1 might have worked there but you're also giving up a lot of torque and safety margin. I've been on jobs where a 1:1 setup on a heavier car or a taller rise just beats the motor to death and cooks the drive. The old timers might not have chased a hunting car for three weeks, but they also built stuff that ran for forty years without a problem. Sometimes the hunting isn't about the roping at all, it's the encoder, the rails, or the governor tension. I'm not saying you're wrong for your specific job, just that I wouldn't make it a blanket rule. If the prints call for 2:1 and you swap it without checking the load calculations, you could end up with a car that stops fine but burns up a 50 dollar brake coil every six months.

karen_hart4mo ago

You said "never drifted once" and that really nails it for me. I think a lot of guys get locked into the 2:1 setup because that's what they learned and they're scared to change it up. But if the car is hunting or drifting, all that extra roping does is amplify the problem. Once you strip it down to 1:1, you lose that mechanical advantage but you also lose all the backlash and slop that makes the controller fight itself. I've seen more than a few jobs where a simple roping swap fixed a problem that guys wanted to throw a new drive at.