Warning: swapping from steel to poly ropes on an MRL machine

I used to run steel cables on every MRL job because that's how my old boss taught me 8 years ago in Cleveland. But after a 6-month stretch where three separate jobs had cable fray issues near the drum, I finally tried poly ropes on a 24-stop install last spring. The difference in flexibility and noise reduction was huge, but I also had to learn new grooving patterns way faster than I expected. Has anyone else here had trouble getting the tension right on poly compared to steel?

2 comments

2 Comments

davis.linda1mo ago

Poly ropes are a whole different animal" is right, and not just for grooving. I switched over two years ago and the tension thing was the biggest headache for me too. Steel wants to be tight, tight, tight or it'll birdcage and fray, but poly is way more forgiving on the hard tension but touchy on consistency across the wrap. I found I had to ditch my old torque wrench method and go by feel and a digital tension meter every single wrap, not just the first one. And if you're used to steel's stiffness, poly's stretch can trick you into thinking it's loose when it's actually good. Once you get that rhythm down, though, you'll never go back to steel on MRL machines.

mark_smith5929d agoTop Commenter

I mean, I hear what you're saying @davis.linda, but is it really that serious? Like, I've been running poly for a few years now on a couple different machines and I never had to change my whole tension method. Steel, poly, whatever, I just set it and forget it basically. Maybe it's just me but I think people overthink this stuff. A digital meter every single wrap? That sounds like more work than the actual job. I just eyeball it, give it a tug test, and send it. Haven't had a birdcage or a bad wrap yet. Idk, maybe I'm lucky or my machine is just easy, but I think folks get too hung up on the details.