6 replies to this topic

[jeffee]

What is better? Does it matter if it's right of left?

[liftmech]

This is probably somewhere else on the forum. That said:
Ropes are built primarily right lay in our applications. This means that the strands spiral to the right as you look down on the rope. I recall seeing one left lay rope at Monarch, but that's it. I don't know of any benefit to either right or left.
Now, the direction the wires in each strand lay in does vary, mainly by lift manufacturer. Regular means the wires twist opposite the strands, so that they line up along the axis of the rope. This type of rope is quite common on Riblet lifts, because the wires are across the axis of the rope on the inside where the clip goes and provides sliding resistance. This type of rope is also used extensively in crane applications because of the smoothness of the rope as it passes over the steel sheaves.
Lang means the wires are twisted in the same direction as the strand, so that they lie almost across the axis of the rope. This provides sliding resistance to external grips (and makes the rope easier to handle during a splice, but that's another story altogether).
Splicer- got anything to add or correct?

[KMS]

It seems like a Lang lay rope, with longer exposed crown wires and, therefore more surface area, would have better resistance to bending fatigue as well as better abrasion resistance. The increased surface area may also increase the coefficient of friction and lead to a more efficient power transfer from the drive sheave. A regular lay rope would provide a smoother, more quiet ride. Of course, I may be wrong about all of this.... I've also wondered what the selection criteria is for right vs. left. Anyone?

[skiersage]

I have been told that back in the day, the lay of the rope was decided by the rotation of the lift (on external grip lifts). It was desired that rope twist favor inward so that carriers would swing to the inside if they were to swing. As to why it would be advantageous to have the carriers swing inward I do not know. I think this is the rule with deciding rope lay today, however with most of the newer lifts built today, I don't think it is as important as it used to be since modern lifts run a bit smoother. With Riblet lifts (lifts that use internal clips), The chair grips are fitted such that only a right regular lay rope can be used no matter what.

[liftmech]

You could use right lang, but as I mentioned earlier there is more sliding resistance on an internal clip if the rope is right regular.

[liftmech]

lift mistress, on May 24 2007, 12:14 PM, said:

It seems like a Lang lay rope, with longer exposed crown wires and, therefore more surface area, would have better resistance to bending fatigue as well as better abrasion resistance. The increased surface area may also increase the coefficient of friction and lead to a more efficient power transfer from the drive sheave. A regular lay rope would provide a smoother, more quiet ride. Of course, I may be wrong about all of this.... I've also wondered what the selection criteria is for right vs. left. Anyone?

Still don't know about right versus left, but your rationale for lang versus regular sounds dead on. I've usually heard about it in relation to clips or grips.

[hoodoo]

I think LM is correct on this one.... the configuration of the wires of the strand have more grip on the bullwheel with the Lang lay, it gets more bite, more wearing surface on wires..it lays at more of a 45* angle. The regular lay was used by riblet for the internal clips, just an old philosophy thing I think.