monitor windvane chafe

[markxengineerin]

Anyone else find chafe here? There's no sharp edge, and not a lot of movement either- some movement because the lines were a bit too loose- evidenced by them hopping off the wheel adapter, so I've since tightened. Photo is after maybe 1 week of accumulated use on brand new line, so I must be doing something wrong

[wholybee]

Yes, it can chafe there, and other places as well. Tighter lines are not better, the monitor likes to have some slack. If they came off the wheel adapter, the alignment isn't right.

Start with lines that are about a meter too long. When it starts to chafe, pull the line out a few cm, tie another knot, and keep sailing. This helps not only that spot, but everywhere the line can chafe.

Also, how well balanced is the boat? If you have too much weather helm and the monitor is correcting for it, lines will wear out very quickly.

[markxengineerin]

I think i found the edge, it's internal. That plate holding the stopper knot is for some reason made of 2 pieces welded together, leaving an internal discontinuity. It looks like maybe they tried to stamp sheet metal to round off the outer edges, but if the alignment isn't perfect, this is the consequence.

Weather helm is a thing, yes, as I have a compromised rig and am trying to keep pressure off of certain areas w my sail plan. I hadn't thought of that as a cause, thanks. There's no chafe anywhere else in the lines, so I do think the main problem is this edge. There are a number of ways to fix it, just wondering if anyone else had seen similar.

[wholybee]

Originally Posted by markxengineerin

I think i found the edge, it's internal. That plate holding the stopper knot is for some reason made of 2 pieces welded together, leaving an internal discontinuity. It looks like maybe they tried to stamp sheet metal to round off the outer edges, but if the alignment isn't perfect, this is the consequence.

Weather helm is a thing, yes, as I have a compromised rig and am trying to keep pressure off of certain areas w my sail plan. I hadn't thought of that as a cause, thanks. There's no chafe anywhere else in the lines, so I do think the main problem is this edge. There are a number of ways to fix it, just wondering if anyone else had seen similar.

Can you smooth it with a small round file? Maybe take it to a fabricator, have them weld and add some material/fill the gap, then file and smooth. Do you have the manual and/or the cruising parts kit? The swinging arm comes off, and I have done it with the boat in the water. But, there is a wooden dowel in the parts kit you need to do it, and also extra bearings, as you will likely drop a few, especially the first time you take it apart.

I have (over 30,000 miles) had chafe and lines break in several places when I didn't move them every so often as I described. My first season out, it happened a lot as I was sailing over canvased and with a lot of weather helm. The monitor performed fine, but lines broke several times. Once in the spot you are having issues with, but I wouldn't consider it a trouble spot.

The trouble spot for me was at the horizonal sheaves that guide the lines into the monitor. They need to be aligned perfectly, and then tighten them so they don't move. If they move or wiggle as the line goes slack/tight, then you will get chafe there. And the sheaves that turn the lines to the wheel adapter. I was both getting chafe and sometimes having a line come off the adapter. I moved them by a few mm and turned them to a slightly different angle and that solved both issues.

I and most sailors I met changed to regular dynemma/amsteel instead of the special lines scanmar provides and recommends. It will creep and need constant adjustment for the first day of a multiday passage, but after that it is fine. It seems to hold up better and have less friction. The scanmar line doesn't creep, and that is why they use it, but seemed to have a shorter life. It is also unavailable except from them, and dyneema is cheap and everywhere.

[markxengineerin]

The trouble spot for me was at the horizonal sheaves that guide the lines into the monitor. They need to be aligned perfectly, and then tighten them so they don't move. If they move or wiggle as the line goes slack/tight, then you will get chafe there.

Yes I've seen some of that too, it's tough to tighten those brackets (on mine anyway) due to the orientation of the bolts and proximity of fastener to walls. My hardware might not be what was originally provided, but I am planning to switch to socket cap screws to make it easier.

Thanks for all the tips- I will try out some dyneema once this stuff wears out. I left all the extra length in the lines, so I have many opportunities for re-adjustment ahead.