Rope clutch modification

[reystos]

The other day I was trying to close the starboard clutch lever on my Bav31. It snapped right in my hand, leaving no way to open or close it without using tools.
It is equipped with Rudgerson clutches that have probably been directly under the greek sun for almost 19years now. Without second thought I removed both starboard clutches for further inspection. And then the port ones too.



The plastic levers developed tiny little cracks at the top, that were more visible under lablight. More like the material itself started to lose its integrity and became more brittle, so when I insisted it broke clean.



Being a know-it-all guy, I thought I should redesign the part to have more material inside. I feel safer knowing there is a stronger mechanical bridge between the cam and the lever. The original lever has some hollow parts underneath it. Perhaps to save material. Perhaps because under normal circumstances it would have been replaced already and not stayed there for so many years.



3D printing is our friend. I was lucky to have had grey material to match the colour of the clutch assembly. In terms of material strength, on paper, it looks like it could work.



You can see the new part in place, next to the old one. Good thing is it fits and is as well behaved as the original one.



This is what it looks like onboard, with the new parts installed.



I did get a bit carried away and started experimenting with other colours. The original levers were going to give up very soon, which I found out after I had removed them.



Hopefully there will be time to test the new parts in club races this season and be back with more information on this mod.

[PEA-JAY]

Hi it looks like an excellent job and very well documented. Thank you for sharing. With hindsight I have been very stupid not to have covered mine from the similarly vicious Malta sun. One never stops learning!

[joakey]

Being less patient, I've just been replacing mine with another brand of clutches/jammers the last couple of years but it will sure be nice as the prices of titanium powder come down to just be able to 3D print all sorts of replacement parts in Titanium.

[Jeff Jones]

Nice Job

[sy_Anniina]

Nice 

Would you be willing to share the 3D file used?

Actually we maybe should have a separate spares-3D-files download section, my guestimate is that this kind of activity will expand soon.

I am planning to 3D-print Raymarine ST60 sun covers with boat name embossed, once complete I'll report here as well. (they are next to impossible to source locally)

BR,

Tommi
s/y Anniina

[Mirror45184]

Nice.
Have experienced the same issue of breaking the handles. We found that if the line is pulled through the clutch as the lever is lowered it reduces the load on the handle. This was found with a new clutch, not subjected to the rigour of an Australian sun! My humble conclusion is that it is a clever, inherent design feature to sell more Rutgerson clutch handles. When I get around to it I will be replacing the clutches with a more robust design.

Although the printed handles do look very nice. Could possibly also print the function name into the handle for night sailing or braille!

Cheers

[MarkTheBike]

Very nice, Reystos. Good photos, really like the blue...!

...
Actually we maybe should have a separate spares-3D-files download section, my guestimate is that this kind of activity will expand soon.
...

Great idea, Tommi. I haven't got a printer yet but it's certainly getting closer the more bored I get stuck at home. And my clutch handles would be the first output. I'd probably choose white to reduce the degradation and improve night vis. Also like the idea of embedding the name. Having never used one of these, could the name be done in a different colour?

[reystos]

Printing in different colours would probably be overkill for any reasonably priced 3dprinter,as it requires a separate head with a different filament. But it is definitely possible to emded letters or names in the design, of the same colour.

By all means, this is work in progress. I am more concerned about testing. How well they can last in real conditions, before anybody else tries to use them and finds himself with a boom falling on his head or losing tension on a halyard while underway.

[Yngmar]

What did you print them in, ABS? I'm not sure, but I think the original ones might be glass reinforced Nylon and thus (originally) stronger than ABS.

[Mirror45184]

Not familiar with 3D printing, but would it be possible to embed a rod or flat bar in the handle? That would certainly make the handle stronger.

[Markus]

I have also broken two of these and payed ~30 eur/piece for replacement handles! I was thinking also 3D-printing but am not sure about the strength. Maybe a glass-fiber reinforced filament would work well:
https://www.3dxtech.com/glass-fiber-reinforced/

I would also be very keen to get the 3D-model if you are willing to share? 

[Lazy Pelican]

We had a similar problem, but fortunately carried some spare handles, however on examination we found that the underlying problem was a lack of maintenance. I dismantled all the clutches, cleaned and lubricated the relevant parts and they now operate very smoothly!
I suggest dismantling and cleaning every other season.

[reystos]

What did you print them in, ABS? I'm not sure, but I think the original ones might be glass reinforced Nylon and thus (originally) stronger than ABS.

Printed in PLA. My ABS and PETG test samples were not as strong, whether you believe it or not. ABS was brittle, not nice to print or test, so that option went out the window. PETG seemed brittle too, with much poorer layer adhesion, but my spare set is PETG in case I end up with planB.
The million dollar question is whether under the summer sun all will melt away. I will run some in-car testing to make sure.

So far, temperatures have gone up to 26C with full sunshine where the boat is and no deformations noted whatsoever.

[reystos]

40C, full sunshine during the weekend. First heat wave of the summer and all held well. No deformations, clutches hold.

[Goboatingnow]

It’s not the sun , pla is biodegradable and hydrophilic , water will ruin it

[reystos]

Unfortunately it was the heat that eventually deformed the handles following consecutive exposure to heat and sun over 30C.
I made new ones from PETG, they held properly throughout the summer and the -smallish- club race season.

[Craig]

I had a student push one down without winching on first and break it. On a Bav 38 from 2009. The replacement handles are actually slightly larger and meatier than the originals so I think Rudgerson handles are relatively weak. Rudgerson have recognised this and modified their replacements accordingly..

They are expensive to replace.

You might like to post some replacement parts on the Buy and Sell section on this site, I'm sure you will have a ready market. Also, covers for the Raymarine E80 chartplotters and the hard plastic covers over the wind, depth and autopilot panels.

Craig
"Shirley Valentine"
Gold Coast
Australia

[Lazy Pelican]

I would also be interested in replacement handles.

[reystos]

This is what the white PETG handles look like. From the few club races that were done this year in between lockdowns and covid mayhem.
I would very much like for more testing to be done on them, as I have only had them on for about 6 months now. Done 4 races and a few weekend island hops.