3 start rope with a 15' radi.

Do you mean 15” diameter? 15” radius would be 30” diameter. My lathe maxes out at 16” diameter so I couldn’t even turn the blank.

Legacy makes a CNC version of the ornamental mill called Artisan II. It could handle the rope. I’d look for someone in your area that has one and pay them to route the rope.

The rope cutter is made by Magnate and sold on Amazon if you wanted to jig it up on your lathe. You’d have to make an index pulley system and a sled for your router. It’d be some work, but doable if you are handy enough.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

No, Picture a 3” diameter 3 start rope turning. Then bend that turning to a 15” radi. so you end up with a 1/4 circle. Like taking a pipe bender to a piece of conduit to make a 90.

-- Have a great day.

Maybe I am not completely understanding what you’re trying to do.

Here’s what I got so far; You want a turning 30” in diameter, but only 90 degrees of it. This turning has 3 ropes that are 3” wide spiraling around this turning.

Here is an appropriate router bit to make a 3” diameter rope cut.

After you make your 90 degree blank (at 30”dia) you can figure the pitch of the rope to get 3 starts. I would make a plexiglass pattern template with a single slot. Once it is cut, I would form it around my wood blank with a heat gun. I would make a base plate for my router with a collar for the slot in the jig (More plexi). This slot would be repositioned on your workpiece for each cut of the rope until you’ve reached the top of the piece.

Don’t have time at the moment to do a quick sketch, but, then again, that would’ve been your job.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251