Mike,
The insert doesn’t need to be solid. Just machine a narrow slot in one side of the insert from the surface down to the central bore. Then, you can wedge the slot open with a flat bladed screwdriver while you slide the forestay in. When you remove the screwdriver blade, the slot will close. Once the insert is in place, the ID of the furling extrusion will hold the slot closed.
With modern CNC machine tools, pretty much any shape can be created. The machinist will have the old broken insert to use as a template.
Delrin 150 has tensile, flexural, and compressive moduli of 450,000 psi. It will stretch ~30% before failure. It is both more rigid vs HDPE and sufficiently flexible for this application. It has excellent fatigue strength and is unaffected by water. It has excellent machinability.
Roger Pihlaja
S/V Dynamic Equilibrium
Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows
From: Mike Riter<mailto:mike at traildesign.com>
Sent: Tuesday, June 7, 2022 9:53 PM
To: The Rhodes 22 Email List<mailto:rhodes22-list at rhodes22.org>
Subject: Re: [Rhodes22-list] Furling foil
I had the same piece break on my furler and thought it would be easy to get a new one machined at a shop. Because of its odd shape along with the groove, it proved to be very difficult for the machinist to replicate. Ultimately he had to come by my shop and take a bunch of
detailed measurements on the inside of the tube to get the piece to fit correctly. It was a pain and took a couple weeks to complete. I had asked him to make it out of more rigid material and he said that wasn't a good idea as the part needed to flex a bit. He did make it 1" longer on both ends than the original. It's been a year now with no problems.
Getting the cable routed back through it was pretty straightforward. I unscrewed the two part block at the top and was able to fit the cable end through the hole in the center of the new part.
I'm guessing that as hard as it was to machine, that the maker of the original furler tube had the part injection molded.
Mike Riter
SV Emma B
