Date   

Re: [Amel Yacht Owners] melted muffler

robin hutter
 

put a new impeller pump in today as well as an alarm on the exhaust muffler and keep my finger crossed that the problem has gine away - everything else was checked thouroughly and found to be okay ...

If you don‘t hear from me again in this regard, that was the solution...

fair winds

Robin
Amel 54 #54 - Carré d‘As



Re: [Amel Yacht Owners] Slowing down in increasing winds

SV Perigee
 

Christian, Ian, Bill (K), Kent, Danny,

Firstly, belated thanks to you for all your input.  The delay in my reply is due, in part, to the fact that I was putting it all into practice.  Two legs, St Maarten to Antigua, and then Antigua to Martinique.

We are currently spending time in AMEL CENTRAL, MQ, for programmed repairs and maintenance.

We encountered boisterous conditions for both legs, no sustained down-wind sailing, mostly beam reaches and on-the-nose.  Winds to 28 sustained (apparent), with gusts to 35 in squalls.

The summary for the sail-trim: no need to slow down using anything but reefing up to 45 knots AWS.  I have not yet experienced anything above 45 knots, so trailing warps, chains, tyres, or the JSD will wait for another time or rather, hopefully, not!

Did do a little going downwind, and the wing-on-wing-on-wing works great out to 155º apparent, winds up to 25 knots, moderate seas.  The genoa fully out on the ‘correct’ side, dragging us downwind; the main being set on the windward side to balance, and strongly prevented; the mizzen following the genoa (and still prevented, of course).

For beam reaches and upwind, the amount of sail was set to obtain an average angle of heel of 15º - on the basis of my understanding that this amount of heel delivers the longest LWL (and hence STW).  Sails were trimmed for maximum boat-speed. This worked well, easily exceeding 8 knots STW in anything above 20 knots apparent wind speed.  When the wind picked up and there was a need to reef, sail was reduced as required to achieve a 15º angle of heel.  This kept the ride comfortable and fast, and the first mate happy.

We were at times pointing into the seas.  As Danny wrote, and I can confirm, that our SMs will quite willingly go “wave hopping” at 8 knots.  All that awful crashing and banging, quite unsettling.

So, from these short inter-island hops across and into brisk winds and confused seas, another rule-of-thumb:  slow down when the seas are “short and sharp”, especially when the wind is forward of the beam.

What is “short and sharp”?  My observation is that, when we are sailing upwind in winds of greater than 20 knots, and carrying best sail for that magical (mythical) 15º angle-of-heel, PERIGEE considers the seas to be ‘short and sharp’ whenever the period (in seconds) is less than the height (in feet).

How much to slow down? Can’t really say, but whatever it takes to avoid PERIGEE trying to launch herself heaven-wards through or over the waves.  I guess it depends somewhat on the direction of the seas. I also tried bearing off, but when the wind and wave-trains are not aligned, this might not work.  And in any case it then becomes the usual trade-off between VMG to WPT/Destination.  I didn’t get esoteric enough to look into the detail of the leeway trade-off when pointing up, but did get the feel that when heading anything closer than ~45º (apparent) to the wind, the boat slowed down whilst leeway increased, so we drifted sideways; so, the better option was to go faster at 50º off the apparent wind.  Danny mentioned that the wide keel (or, maybe it’s low aspect ratio, depth/fore-aft chord ), makes the keel stall quite readily.  I’m not sure how this all works, so I would definitely be interested to hear what others know, or think, is the case here.  What is that magic figure for ‘on the wind’?

BTW, we have happily and comfortably endured squalls (beam-reaching with all three sails up and heavily, but not deeply, reefed and trimmed as per above, 15º heel) with gusts to 45 knots (apparent), with only a moderate increase in heel.  Biggest sustained conditions experienced thus far: 6-7m seas in 35-42kt sustained winds, beam-reaching - only moderately reefed, as I hadn’t yet learnt about 15º heel and the SM design LWL etc at that stage, so looking back I was really quite over-powered, but it was still a very comfortable (and controllable) ride.

On a closing note, one interesting event was a ‘crash-gybe’ one night, whilst reaching in a squall.  This was to avoid crossing traffic (sail boat, but with no sails, or normal nav lights) which was sighted almost too late due to reduced visibility in the squall, combined with heads-down on the radar due to squall avoidance.  No damage done, as we were in standard offshore mode which is, even when on-the-wind, to have the main set with double preventers (one each port & starboard), and the sheet+preventer combination on the mizzen trimmed to minimise movement of the boom.  The genoa was reefed to the forward shrouds; this is now our SoP for upwind work in squally conditions at night. Never thought I’d NEED to use this arrangement, which was intended to minimise the consequences of an unintentional gybe (perhaps an A/P disconnect whilst below - I guess it happens).  But when I needed to put the helm down, powered up at going at 8 knots, with less than 3 boat-lengths to loud crunching noises, it worked a treat.  I must admit it did feel a little strange, and a bit disorienting, as I’d not tried a power gybe and then heave-to at night before.

The other vessel was not showing normal nav lights, only an anchor light - there was no response to horn or spot-light, even coming close on the second pass.  So, it seems possible that the other vessel was un-manned.  There was one vessel reported missing we later heard, having drifted off the shelf of an upwind island a day or so previously.  This was even with two anchors set.  The vessel signature on radar was obscured in heavy rain, and the anchor light blended rather nicely into the background island lights until almost too late.  No moon.  We could see the ghostly shape of the hull (no sails) only once we got close enough for the reflection of our nav lights - now, that really is too close, I can assure you.  It is my opinion that, in the absence of avoiding action, we would have T-boned this guy at 8 knots.  Gotta keep those eyes up and out of the cockpit.

And why is it that these things seem to happen between 2 and 4am, when the skipper is off-watch and asleep below.  Anyway . . .

... fair winds,

David
SV Perigee
On Dock #4, le Marin,
Martinique


Dome light in aft lazarette needs replacing

Derick Gates SM2K #400 Brava
 

Hi all,


After five years of ownership, I just discovered that the aft lazarette has a dome light. How did I find it? I was cleaning out the lazarette at night and noticed a light was on.  Having discovered the dome light, I went to switch it off.  Instead, it just dimmed to about 1/3 the intensity.  I tapped on the dome a little too hard, and found that the glass of the dome was now in 3 pieces, but the light still would not turn off.  Switching off the aft lights on the 24 volt panel did cut the power to the dome light, but otherwise it looks like the switch in the dome light is faulty and needs replacing.


Does anyone know where to get these dome light fixtures?  


Derick Gates

SM2K#400

Brava

Currently on the hard in Antigua for hurricane season


Re: Bow Thruster Rusted Shut

sbmesasailor
 

I'm a little surprised that Bill R. hasn't checked in on this one yet.  PB Blaster is good but Corrosion X is the new leader in releasing rusted parts.  Bill turned me on to it about two years ago and I don't use anything else now for releasing rusted parts.  You do need to let it work, apply and then wait a few hours or even overnight.

Dennis Johns
Libertad
Maramu #121


Re: [Amel Yacht Owners] melted muffler

Craig Briggs
 

Bill - I think this is his propulsion engine, not genset.
Robin - any updates on what you've found?


Re: A54 Sleipner bowthruster uneven brush wear

Craig Briggs
 

Scott,
Understand the oil issue - thanks for explaining. 
I don't know why you're getting uneven wear - the picture looks like the top two (or is it one wide one with two wires?) are really worn and the bottom two not.  Perhaps just put all new in and check the commutator for a rough spot (which would be odd) - it does look really carbon-ed up so you want to clean it up anyway. Then monitor going forward.  Sorry not much help.
Good luck with it,
Craig


Re: [Amel Yacht Owners] melted muffler

greatketch@...
 

If this is an intermittent problem, an air leak is a good guess.

Just remember that air leak can occur ANYWHERE on the suction side between the pump and the sea chest. Including places like the check valves on the A/C pump.

I am surprised at two things. First, why the genset did not shut down on high exhaust temperature. If this model genset is equipped with an high exhaust temperature switch it’s function should be tested. And to a lesser degree why the impeller did not fail running dry, or nearly so.

Bill Kinney
SM 160, Harmonie
Norfolk, VA, USA


Re: A54 Sleipner bowthruster uneven brush wear

cpp_berkeley <no_reply@...>
 

Craig,

Answers to your questions below:

1) After we let it cool down (~30 minutes) it ran fine. Perhaps a bit weaker but that's probably to be expected considering that some of the brushes have worn down considerably and actually even cracked, exposing just bare conductors. My fear is that going forward, it will continue to overheat prematurely and leave us without a bow thruster when we most need it.

2) The sidepower bowthruster has a drain plug underwater between the two props and a fill reservoir in the bow locker. Obviously oil is changed on the hard. My understanding is that the way to change the oil is to open the plug and continue filling the reservoir until the oil coming out of the plug looks clean. That way, you don't get air into the system.

The mechanic drained all of the oil and he put the plug back and filled the reservoir. The next day, the oil level had dropped, indicating that the air migrated upwards (and/or the thick oil slowly migrated downwards). This drop in oil level continued for a few days. It seems reasonably stable now, but I'm unsure whether some air was still stuck in the gearleg and never made its way out.

Also, we now have a strong "Mass -" leak. Thomas of S/V Garulfo posted that he had a bow thruster leak, possibly from carbon dust. I'll go check that now and report back.

But in general, any idea why the carbon brushes would be wearing so unevenly?

Scott

A54 #69 

S/V Tengah 




---In amelyachtowners@..., <sangaris@...> wrote :


Hi Scott,

Your post raises a couple of questions. 
1. You say the unit had a thermal shutdown - did it work after it cooled  down?  Any problems?
2. In what way did the mechanic have trouble getting air out of the system? On the SN and SM one simply turns the bottom section upside down to drain and then pours in new oil. No issue with air. Perhaps the 54 is a different design that I'm not familiar with.

Craig


---In amelyachtowners@..., <no_reply@...> wrote :

Hi all,


I was coming into the quay at Zante yesterday in our A54 with about 10-15 knots on the beam and used the sidepower bow thruster in 10-15 second bursts and all of the sudden, thermal shutdown!


After executing an exciting no thruster stern-to med mooring into a tight spot (with expectant spectators!) I opened up the bow thruster compartment to see a lot of carbon dust. I took the motor cover off and inspected the brushes and found that for each of the pairs (4 pairs, 8 total brushes), one was worn MUCH more than the other one. On some pairs, it's the top one that was worn more, on some, it was the bottom one. Some brushes were down to loose wire.


On the attached photo, you can see the extent of the uneven wear for one pair.


We recently had the boatyard change the bowthruster oil and they drained it all before adding new oil, which resulted in challenges getting all the air out of the system. We then completed a 1350 mile passage. These probably have nothing to do with it, but maybe I'm wrong.


Before I go out and spend money to replace the brushes and possibly experience similar uneven wear, anyone have any ideas as to why this happened and how to rectify it?


Thanks!


Scott

A54 #69 

S/V Tengah 



 


Re: Bow Thruster Rusted Shut

Steven Bode - SV Intention 1994-SM#117
 

Are there any Amelians anywhere near Barcelona who have one of these tools?!
(I know, it's a long shot).


Regards,
Steve Bode


Re: Prop Shaft Brake Pads

Alan Leslie
 

Hi Derick,
That's what happened to us. 
The issue seems to be that the pin is hard stainless steel and the caliper is rather soft alloy.
Two years ago I temporarily fixed it by epoxying a thick washer the moving caliper where the pin was going into the divot. 
As the pads wore my temporary fix failed again, that's why I resorted to drilling a hole and putting in an adjustment bolt. So now I can back off on the spring pressure bolt so the pin doesn't bottom out in the cylinder and adjust my new bolt so the pads grip the disk and the spring is doing its job.
There seems to be quite a bit of material on my pads left to go and Maud can't identify the pads I have. The ones she has look nothing like mine.
Cheers
Alan
Elyse SM437
Ono Island, Great Astrolabe Reef


Re: Prop Shaft Brake Pads

Derick Gates SM2K #400 Brava
 

Hi all,

I struggled with tightening the shaft brake for several years.  I tried new brake pads, and a new internal spring, and even moving the shaft brake orientation by placing a stainless steel hose clamp between the brake and the engine rails.  No fix seemed to help for very long.  I kept hearing the prop turning while sailing. So when in Martinique last January, I threw the problem at Albon.  He was able to establish two reason for the continued failure of the brake to grip the drum:

1. The calipers holding the brake pads were excessively worn and thus too loose to squeeze the rotor.
2. There was a divot in the end of the caliper where the pin from the brake would normally push on the caliper, closing it.

The fix was to get two new calipers from Maud by express mail, and to weld a disc onto the caliper to decrease the distance the pin had to travel to close the caliper and brake pads down on the rotor.

I will post pictures of the failed calipers and the divot in the old caliper so that others can know what to look for.
I am convinced that the failure of the shaft brake has led in the past several years to many more revolutions of the shaft than are reflected in the engine hours logged, and the premature need to change the wearing out bearing due to water in the C-drive oil (I.e. much less than the normal 400 hours or two years).

Derick Gates
SM2K#400
Brava


Re: A54 Sleipner bowthruster uneven brush wear

Craig Briggs
 


Hi Scott,

Your post raises a couple of questions. 
1. You say the unit had a thermal shutdown - did it work after it cooled  down?  Any problems?
2. In what way did the mechanic have trouble getting air out of the system? On the SN and SM one simply turns the bottom section upside down to drain and then pours in new oil. No issue with air. Perhaps the 54 is a different design that I'm not familiar with.

Craig


---In amelyachtowners@..., <no_reply@...> wrote :

Hi all,


I was coming into the quay at Zante yesterday in our A54 with about 10-15 knots on the beam and used the sidepower bow thruster in 10-15 second bursts and all of the sudden, thermal shutdown!


After executing an exciting no thruster stern-to med mooring into a tight spot (with expectant spectators!) I opened up the bow thruster compartment to see a lot of carbon dust. I took the motor cover off and inspected the brushes and found that for each of the pairs (4 pairs, 8 total brushes), one was worn MUCH more than the other one. On some pairs, it's the top one that was worn more, on some, it was the bottom one. Some brushes were down to loose wire.


On the attached photo, you can see the extent of the uneven wear for one pair.


We recently had the boatyard change the bowthruster oil and they drained it all before adding new oil, which resulted in challenges getting all the air out of the system. We then completed a 1350 mile passage. These probably have nothing to do with it, but maybe I'm wrong.


Before I go out and spend money to replace the brushes and possibly experience similar uneven wear, anyone have any ideas as to why this happened and how to rectify it?


Thanks!


Scott

A54 #69 

S/V Tengah 




Re: [Amel Yacht Owners] Re: rig tuning

Ryan Meador
 

Hi Eric,

Thank you for the advice. That's my plan whenever I unstep the masts. I'm sure there is a dead spot in the radar, but every other Amel seems to get by with it. I'd rather not have the weight on the backstay.

I don't think that is the cause of my present problem, though. Now that I've tightened the backstay, the radar doesn't move at all. I don't think it is contributing to the pumping. Certainly, Frank had it tuned such that it wasn't a problem, so it's possible.

Thanks,

Ryan and Kelly
SM 233 Iteration
Boston, MA, USA

On May 27, 2018 3:36 PM, "eric kimberlite@... [amelyachtowners]" <amelyachtowners@...> wrote:
 


Hi Ryan,
I would ask Questus if they can sell you the Questus mast mounting kit for the Questus. Mine has been working fine on the Mizzen mast for 16 years.

Frank mounted the dome on the backstay as he said he gets a dead spot behind the mast on the radar. I thought his mount as odd.

Amel rigging is ridiculously tight the cap stay is like a piece of rebar.
Good luck with your rig tuning.
Fair winds,
Eric


On Sun, May 27, 2018 at 10:15 AM, Ryan Meador ryan.d.meador@... [amelyachtowners] wrote:

 

I tackled this problem yesterday, and it did not go as planned.  My main mast is now pumping fore-and-aft in a wide range of wind speeds with the wind on the beam (I haven't been able to test any other wind directions yet).  The top of the mast seems to stay still, and there is little to no motion at the lower spreaders; the pumping is centered near the upper spreaders.

Before starting, I reviewed advice from this list, the Selden guide, Brion Toss's Rigger's Apprentice, Ivar Dedekam's Illustrated Sail and Rig Tuning, and other online sources.  I thought I had a vague idea of what I was doing..  Unfortunately, every one of those guides assumes you're starting from a freshly-stepped mast, so I had to improvise to apply the procedure to tune mine in-place (I couldn't use the folding-rule method because the stays were already under an unknown load).  Here's what I did:

  1. removed a slight forward tilt of the uppermost part of the main by tightening the backstay, which, as I suspected going in, was the loosest of all the stays -- the previous owner installed the radar on a Questus backstay mount.  I will probably put the radar back in its traditional place when I next unstep the mast.  I did not adjust the forestay.
  2. removed a slight lateral S curve
    1. tightened the starboard cap shroud
    2. the port intermediate shroud
    3. the starboard lowers
  3. I tightened all four lowers one turn just because they all seemed a bit looser than what was described on this list (they now make a sort of tone when hit with a wooden hammer handle, but they don't quite resonate)
  4. tightened mizzen starboard cap shroud one turn to correct slight bend to port
  5. tightened all four mizzen lowers one turn because they seemed loose
  6. loosened port mizzen backstay half a turn.  I know the backstays are supposed to be fairly loose and the port was a bit tighter than the starboard one
The masts were now in column and looked just about perfect.  When the pumping first became apparent (when the weather turned, of course), I added a turn to the main's forward lowers in an attempt to induce a minuscule pre-bend.  There was no perceptible difference in the mast shape, but there may have been a minor difference in the amount of pumping.

Does anyone have experience with this problem?  I'd greatly appreciate some advice on how to fix it!  I'm almost desperate enough to try a non-Amel-familiar professional rigger.

Thanks,
Ryan and Kelly
SM 233 Iteration
Boston, MA, USA


On Wed, May 16, 2018 at 6:25 PM, sangaris@... [amelyachtowners] <amelyachtowners@yahoogroups..com> wrote:
 

Hi Steve,

Yep, that's the booklet. Check out the "Folding Rule Method" of tensioning.
Sounds reasonable that the existing rig is loose due to stretch. That makes it pretty easy to tension back up - just count the turns you take on starboard and do the same number on port, assuming the mast is in column to begin with.
Craig SN68 Sangaris, Ft Pierce FL


---In amelyachtowners@..., wrote :

Steve, thanks for the data, that's very helpful.

Craig, thank you also for your advice.  That's a great rule of thumb.  I have The Complete Rigger's Apprentice, which discusses rig tuning a bit, but not as much as I'd hoped before I bought it.  I will definitely read the booklet you mentioned (which is perhaps this free PDF?).

I suspect the slight looseness in my rig is because the wire has stretched over time..  It was quite tight when I bought the boat, and I think the boat hadn't been sailed much by the previous owner after he replaced the standing rigging.

Thanks,
Ryan
SM 233 Iteration
Boston, MA, USA


On Wed, May 16, 2018 at 12:40 PM, sangaris@... [amelyachtowners] <amelyachtowners@...> wrote:
 

Hi Ryan,

I'd recommend Selden Mast's booklet Hints and Advice on Rig Tuning - you can download the pdf. They give a neat "folding rule" method (pg 32) of determining tension based on the fact that 2 meters of any diameter of 1X19 wire stretches 1mm for each 5% of breaking strength applied.

So, for example, if you want to tension your 12mm cap stays to 20% (Amel tight, maybe!) just tighten them until 2 meters stretches by 4 mm. That stretch will give you about 5600 pounds of tension, as the breaking strength is about 28000.

The Loos gauge doesn't handle wire over 10mm (actually 9.5 mm as it's rated for 3/8) and only goes up to 4500 pounds. That's why the results Nance and Underwood gave Steve Morrison in his post just show "very tight" for his 12mm stays.

After you get a sense for "very tight" you'll get to trust just feeling the stays and being able to judge if they're right. And use Joel's suggestion to go out, sail upwind in a good breeze and see if your lee shrouds are at all slack. If yes, they're way too loose. Oh yeah, and recheck after a while as the wire will stretch over time.

On the headstay there is a turnbuckle screw under the furler. ACMO just calls it "special" , as it's shorter than standard ones so the furler can be closer to the deck.

Have fun tuning!
Craig Briggs SN68 Sangaris


---In amelyachtowners@yahoogroups. com, wrote :


Hi all,

I'm about to embark upon tuning up my rig, which I feel is a little loose, but I'd love some guidance on how to do that.  I've scoured the archives of this list and found many mentions of guides from both Joel Potter and Olivier Beaute, but I haven't been able to find them.  The best guide I've found thus far is this one.   Can anyone link me to the gold standard(s)?

Also, has anyone done the tuning in a more scientific way, with a Loos Gauge?  I'm struggling to understand via qualitative descriptions just how tight is tight.  I think a quantitative measurement would be very helpful.

And finally, how does one adjust the forestay tension?  I admittedly have not studied it in depth, but I didn't see a turnbuckle or any other obvious mechanism.

Thanks,
Ryan
SM 233 Iteration
Boston, MA, USA





Re: [Amel Yacht Owners] Re: rig tuning

Derick Gates SM2K #400 Brava
 

I had my rig replaced by Caraibe Greement in Le Marin, Martinique, in January, 2017, using ACMO rigging that I had purchased and had sent to the Amel office in Le Marin. Gaetan Rivet runs the rigging shop there. Gaetan’s riggers measured the tension of each stay with an instrument that clamped onto the wires and tried to bend them. In that way they achieved the correct tension for each stay and the tension was properly balanced all around. Don’t ask me for the tension measurements - I don’t know what they were. I will not however that the new rigging was extremely tight, and that includes the mizzen back stays which were much tighter than I had ever had them before.

I returned to Le Marin in January 2018 and received the free “tuneup” that Gaetan had promised I could have when the rig was initially installed. In the intervening year the rig had stretched a few millimeters and was “too loose” according to Caraib Greement. They said this is normal, and they retightened the whole rig. They also said I should not expect any further stretching of the stays.

Perhaps Gaetan Rivet could be prevailed upon to reveal what tension he puts each stay under. I think that Amel might have this information at hand too.

Note that the length of each set of stays needs to be kept constant port vs starboard, not just the tension. Thus the set of turnbuckles on each side for a particular stay should look like they have the same number of turns on them as the tension is adjusted.

Derick Gates
SM2K #400
Brava
Currently on the hard in Antigua


A54 Sleipner bowthruster uneven brush wear

cpp_berkeley <no_reply@...>
 

Hi all,


I was coming into the quay at Zante yesterday in our A54 with about 10-15 knots on the beam and used the sidepower bow thruster in 10-15 second bursts and all of the sudden, thermal shutdown!


After executing an exciting no thruster stern-to med mooring into a tight spot (with expectant spectators!) I opened up the bow thruster compartment to see a lot of carbon dust. I took the motor cover off and inspected the brushes and found that for each of the pairs (4 pairs, 8 total brushes), one was worn MUCH more than the other one. On some pairs, it's the top one that was worn more, on some, it was the bottom one. Some brushes were down to loose wire.


On the attached photo, you can see the extent of the uneven wear for one pair.


We recently had the boatyard change the bowthruster oil and they drained it all before adding new oil, which resulted in challenges getting all the air out of the system. We then completed a 1350 mile passage. These probably have nothing to do with it, but maybe I'm wrong.


Before I go out and spend money to replace the brushes and possibly experience similar uneven wear, anyone have any ideas as to why this happened and how to rectify it?


Thanks!


Scott

A54 #69 

S/V Tengah 




Re: [Amel Yacht Owners] Re: rig tuning

eric freedman
 


Re: [Amel Yacht Owners] Re: Bow Thruster Rusted Shut

Ryan Meador
 

PB Blaster is what you want for freeing stuck parts.  It is much more effective than WD-40.  Judicious application of heat (which I don't think I would risk using on the bow thruster) makes it work even better.

Ryan and Kelly
SM 233 Iteration
Boston, MA, USA


On Sun, May 27, 2018 at 10:13 AM, Patrick Mcaneny sailw32@... [amelyachtowners] <amelyachtowners@...> wrote:
 

Steve, If your boat is out of the water, you can try lifting it up and then sharply pull it downward. When I first bought my boat it was stuck , it took many drops , but eventually broke free. Its sounds bad , but does no harm. When you reassemble it apply some no seize or at least some grease on where the shaft goes into the motor and you should have no problems in the future.

Good Luck,
Pat
SM#123


-----Original Message-----
From: steve@... [amelyachtowners] <amelyachtowners@yahoogroups.com>
To: amelyachtowners <amelyachtowners@yahoogroups.com>
Sent: Sat, May 26, 2018 7:31 pm
Subject: RE: [Amel Yacht Owners] Re: Bow Thruster Rusted Shut

 
That bow thruster tool looks like the ticket. Maybe i can make one like it here. I'll call Amel Monday morning and see what it takes to get one here.
-Bode



Re: [Amel Yacht Owners] Re: rig tuning

Ryan Meador
 

I tackled this problem yesterday, and it did not go as planned.  My main mast is now pumping fore-and-aft in a wide range of wind speeds with the wind on the beam (I haven't been able to test any other wind directions yet).  The top of the mast seems to stay still, and there is little to no motion at the lower spreaders; the pumping is centered near the upper spreaders.

Before starting, I reviewed advice from this list, the Selden guide, Brion Toss's Rigger's Apprentice, Ivar Dedekam's Illustrated Sail and Rig Tuning, and other online sources.  I thought I had a vague idea of what I was doing.  Unfortunately, every one of those guides assumes you're starting from a freshly-stepped mast, so I had to improvise to apply the procedure to tune mine in-place (I couldn't use the folding-rule method because the stays were already under an unknown load).  Here's what I did:

  1. removed a slight forward tilt of the uppermost part of the main by tightening the backstay, which, as I suspected going in, was the loosest of all the stays -- the previous owner installed the radar on a Questus backstay mount.  I will probably put the radar back in its traditional place when I next unstep the mast.  I did not adjust the forestay.
  2. removed a slight lateral S curve
    1. tightened the starboard cap shroud
    2. the port intermediate shroud
    3. the starboard lowers
  3. I tightened all four lowers one turn just because they all seemed a bit looser than what was described on this list (they now make a sort of tone when hit with a wooden hammer handle, but they don't quite resonate)
  4. tightened mizzen starboard cap shroud one turn to correct slight bend to port
  5. tightened all four mizzen lowers one turn because they seemed loose
  6. loosened port mizzen backstay half a turn.  I know the backstays are supposed to be fairly loose and the port was a bit tighter than the starboard one
The masts were now in column and looked just about perfect.  When the pumping first became apparent (when the weather turned, of course), I added a turn to the main's forward lowers in an attempt to induce a minuscule pre-bend.  There was no perceptible difference in the mast shape, but there may have been a minor difference in the amount of pumping.

Does anyone have experience with this problem?  I'd greatly appreciate some advice on how to fix it!  I'm almost desperate enough to try a non-Amel-familiar professional rigger.

Thanks,
Ryan and Kelly
SM 233 Iteration
Boston, MA, USA


On Wed, May 16, 2018 at 6:25 PM, sangaris@... [amelyachtowners] <amelyachtowners@...> wrote:
 

Hi Steve,

Yep, that's the booklet. Check out the "Folding Rule Method" of tensioning.
Sounds reasonable that the existing rig is loose due to stretch. That makes it pretty easy to tension back up - just count the turns you take on starboard and do the same number on port, assuming the mast is in column to begin with.
Craig SN68 Sangaris, Ft Pierce FL


---In amelyachtowners@yahoogroups.com, wrote :

Steve, thanks for the data, that's very helpful.

Craig, thank you also for your advice.  That's a great rule of thumb.  I have The Complete Rigger's Apprentice, which discusses rig tuning a bit, but not as much as I'd hoped before I bought it.  I will definitely read the booklet you mentioned (which is perhaps this free PDF?).

I suspect the slight looseness in my rig is because the wire has stretched over time.  It was quite tight when I bought the boat, and I think the boat hadn't been sailed much by the previous owner after he replaced the standing rigging.

Thanks,
Ryan
SM 233 Iteration
Boston, MA, USA


On Wed, May 16, 2018 at 12:40 PM, sangaris@... [amelyachtowners] <amelyachtowners@yahoogroups.com> wrote:
 

Hi Ryan,

I'd recommend Selden Mast's booklet Hints and Advice on Rig Tuning - you can download the pdf. They give a neat "folding rule" method (pg 32) of determining tension based on the fact that 2 meters of any diameter of 1X19 wire stretches 1mm for each 5% of breaking strength applied.

So, for example, if you want to tension your 12mm cap stays to 20% (Amel tight, maybe!) just tighten them until 2 meters stretches by 4 mm. That stretch will give you about 5600 pounds of tension, as the breaking strength is about 28000.

The Loos gauge doesn't handle wire over 10mm (actually 9.5 mm as it's rated for 3/8) and only goes up to 4500 pounds. That's why the results Nance and Underwood gave Steve Morrison in his post just show "very tight" for his 12mm stays.

After you get a sense for "very tight" you'll get to trust just feeling the stays and being able to judge if they're right. And use Joel's suggestion to go out, sail upwind in a good breeze and see if your lee shrouds are at all slack. If yes, they're way too loose. Oh yeah, and recheck after a while as the wire will stretch over time.

On the headstay there is a turnbuckle screw under the furler. ACMO just calls it "special" , as it's shorter than standard ones so the furler can be closer to the deck.

Have fun tuning!
Craig Briggs SN68 Sangaris


---In amelyachtowners@yahoogroups. com, wrote :


Hi all,

I'm about to embark upon tuning up my rig, which I feel is a little loose, but I'd love some guidance on how to do that.  I've scoured the archives of this list and found many mentions of guides from both Joel Potter and Olivier Beaute, but I haven't been able to find them.  The best guide I've found thus far is this one.   Can anyone link me to the gold standard(s)?

Also, has anyone done the tuning in a more scientific way, with a Loos Gauge?  I'm struggling to understand via qualitative descriptions just how tight is tight.  I think a quantitative measurement would be very helpful.

And finally, how does one adjust the forestay tension?  I admittedly have not studied it in depth, but I didn't see a turnbuckle or any other obvious mechanism.

Thanks,
Ryan
SM 233 Iteration
Boston, MA, USA




Re: [Amel Yacht Owners] Re: Bow Thruster Rusted Shut

Patrick McAneny
 

Steve, If your boat is out of the water, you can try lifting it up and then sharply pull it downward. When I first bought my boat it was stuck , it took many drops , but eventually broke free. Its sounds bad , but does no harm. When you reassemble it apply some no seize or at least some grease on where the shaft goes into the motor and you should have no problems in the future.
Good Luck,
Pat
SM#123


-----Original Message-----
From: steve@... [amelyachtowners]
To: amelyachtowners
Sent: Sat, May 26, 2018 7:31 pm
Subject: RE: [Amel Yacht Owners] Re: Bow Thruster Rusted Shut

 
That bow thruster tool looks like the ticket. Maybe i can make one like it here. I'll call Amel Monday morning and see what it takes to get one here.
-Bode


Re: [Amel Yacht Owners] Re: Bow Thruster Rusted Shut

Steven Bode - SV Intention 1994-SM#117
 

That bow thruster tool looks like the ticket. Maybe i can make one like it here. I'll call Amel Monday morning and see what it takes to get one here.
-Bode

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