Flipping a Macgregor

[BOAT]

I have tried! I can't do it! A guy in San Francisco got movies of his boat in 40 MPH winds (VERY common up there) with all sails flying and the Auto Pilot on thus he would not let the boat round up (When your on Auto Pilot the boat can't round up) and he was pegged at 45 degrees sailing near hull speed. I think he could have got to 50 degrees but he had a couple other guys on the high side with him. If he had reefed and furled I'm sure he could have gone faster but who is gonna try to reef in 30 knot winds!! Not me! If the boat is still sailing and steerable and not knocking down I'm just gonna keep sailing till I get back to the harbor just like he did!

Right in the manual that Roger wrote for the M boat you can read that the boat will not recover from anything over 60 degrees without ballast. I bet they tested the boat without ballast and probably knocked it down closer to 70 degrees or more - but to be safe Roger is saying IN WRITING that 60 degrees is the vanishing point, and that is WITHOUT BALLAST.

Do 60 degrees on a Catalina 27 and your swimming.

In all my attempts I had the similar results as the guy in the Bay area - I hit a wall at 45 degrees. That is when I start losing the wind over the top of the sail. I would need a spinnaker to get more wind back into the top of the mast at that angle, but I don't have a kite yet. (I'm looking). The wind RARELY ever gets above 25 knots here so it's not the best place to test this.

Beene would probably have the best info.

[BOAT]

I've tried in stable winds to see how far over I could get her and have walked on the rubrail and lower several times as mentioned above and almost once washed the sails (mostly wave action on a broad reach) but never a knockdown. I would wager a guess at 60 degrees is as far over as we've gotten (clinometer only goes to 50). At the same time however in a good gust a few years back bare pole we went over to 20 and were held there for a few seconds and waves were not the culprit.

You got this post in just as I was sending mine - yeah I saw a video of an M boat at anchor in 60 mph winds and the boat is getting pushed over on a bare mast close to 15 or 20 degrees - that's that high freeboard getting caught in the wind.

I think the blue hull does not do that as bad because the wind can't see the blue hull as well (it blends in with the water).

[sailboatmike]

If to want to see knockdowns under spinnaker just go to youtube there are a million videos of keelers pitchpoling from carrying huge amounts of sail in too much wind, its all good until the helmsman just gets it slightly wrong or the wind shifts a few degrees and then its just carnage.

I dont count spinnaker crashes as knockdowns, its sort of an accident just waiting to happen if they a flown in too much wind, it will happen the question is just when it will happen

[Ixneigh]

I haven't walked on my rub rail or exposed hull sides with the boat heeled way over and I dont ever intend to

Ix

[DaveC426913]

[grady]

If to want to see knockdowns under spinnaker just go to youtube there are a million videos of keelers pitchpoling from carrying huge amounts of sail in too much wind, its all good until the helmsman just gets it slightly wrong or the wind shifts a few degrees and then its just carnage.

I dont count spinnaker crashes as knockdowns, its sort of an accident just waiting to happen if they a flown in too much wind, it will happen the question is just when it will happen

Been there done that! Will do it again!!!!!!!!

[Signaleer]

(When your on Auto Pilot the boat can't round up)

Uhhh...what?

You should market that feature.

Sorry, Its late, I'm probably being a tool. But the physics that cause a round up do not have anything to do with an auto-pilot.

And honestly why the differentiating between the M and X in terms of knock down vs. hold down.

X is a self right with ballast in, as is the M. There's a what 300 lb difference (350?) I suspect (and could be wrong here) that there is less cloth (and less weight) aloft on an X, although other elements may add more weight. My point is the point of diminishing stability between both boats in incredibly similar.

Not that any of this matters, but I just thought why not mix it up... its Tuesday.

And I sailed that same area as that 26M in the video and that was not 45mph (although I give mad respect to that video).

We used a wind-speed indicator on that sail and that was 20 to 25 knots. https://www.youtube.com/watch?v=MXCKT17ktVo

Ed

[sailboatmike]

I really want an explanation why you cant be knocked down or round up under auto pilot, the forces acting on the sails are much higher than 2 little rudders could ever compensate for.

The only thing that would stop round up is perfectly balanced sails with the center of effort directly over the middle of the keel which as we ll know is the pivot point around which the boat turns.

Too much head sail and she turns down wind, too much main and she rounds up. Of course you can always play the main to keep the balance but that is not the AP stopping the round up thats adjustment to sail balance

'A bit of round up is a feature that we want in our boats as it builds in safety by turning the bow into the wind if we get hit by a gust and thus stops the boat being over powered and knocked flat

[Ixneigh]

Not sure but I think the autopilot does a better job them most people with these boats since it's very precise and does not get distracted. I can hold onto sail longer if I really pay attention but if I let the boat wander off course even a little then she'll often round up and then can be a pain to get her back onto course.
Since I'm easily distracted it's just easier all the way around to reef the sail and solve the problem that way.
It's obvious to me from these posts I am not sailing my boat to her true potential
Ix

[Signaleer]

I really want an explanation why you cant be knocked down or round up under auto pilot...

I'll give you one but before I answer I need to know which color Hull you have? I've heard some owners have painted their hulls blue...

[Retcoastie]

My autopilot experience, and I'm probably the worst sailor on this board, is that when I try to go, or get caught, where I shouldn't be, is the auto drops off line. It starts beeping and goes to standby. Then I have to quickly re-engage or hand steer. If I'm still in those conditions it will drop again and again. It just can't hold course when she goes over too far.

Ken

[BOAT]

That;s not what happens on my boat - I have the M boat. The autopilot just keeps adding downwind rudder - and it only takes a little bit.

The M boat will just stay on course and keep heeling right over way past 45 degrees - I do it all the time. The boat goes from 25 to 35 degrees which causes the boat to try to drift a little bit into the wind because the shape of the hull is asymmetrical at that angle (curve of the boat hull is larger on the down side so it makes the boat want to turn towards the up side) but the AP just keeps it on the same bearing no matter what the heel angle goes to - as long as the rudders are in the water the boat just keeps sailing.

It's that slight turning towards the wind that happens when the boat heels over that I am talking about. When the wind gusts stronger the boat heels over like 30 degrees and if you don't touch the helm the boat will start to turn slightly upwind - in my case about 10 or 20 degrees. Then if the wind backs off the boat heel angle goes back to 18 degrees the boat starts to turn back downwind. My boat will make this slight S turn all day long with very little helm input. The AP does not allow it to do that - if the wind gusts up and heels the boat the AP holds the bearing solid by adding rudder.

When a PERSON is on the helm and the gusts come up they tend to scare the helmsman who unconsciously allows the boat to turn into the wind because it reduces the heel angle. The AP does just the opposite: if the boat tries to turn upwind the AP will add downwind rudder to hold the boat on that exact GPS heading it's set to follow. No reducing of the heel angle because the AP does not get scared.

The kind of Rounding Up you guys are talking about in some of your posts (spinning on the keel, etc , , , ) is what a lot of keel boat owners call a knockdown - it's when the boat heels over so far it spins on it's keel and turns sharply towards the high side thus stopping dead in it's tracks. Often this involves rudders out of the water. Usually then the boat pops back up into the wind and in irons with all sails luffing like crazy. That is the maneuver I am trying to get a video or some stories of on an M boat but so far I can't find one, I keep getting stories about X boats or other boats. There has so be SOMETHING out there - I just can't seem to find it.

[FishyFabs]

BOAT,

Which autopilot do you have? Mine cannot control the boat in strong winds.

[BOAT]

BOAT,

Which autopilot do you have? Mine cannot control the boat in strong winds.

I have the RayMarine EV100 Tiller Pilot. it works REALLY GOOD.

http://www.macgregorsailors.com/forum/v ... AUTO+PILOT

The pilot never falls out of mode - not even once yet.

The secret to ALL tiller pilots according to the RayMarine factory is the tiller arm length. Our tiller arms on the M boat are only 13 inches but RayMarine says to get the full swing arc and power of the control ram you need an arm at least 14 to 18 inches long, so I extended mine to 14.5 - the longer fulcrum gives the control ram it's proper power stroke leverage on the rudder and prevents the "falling out mode" issues you mentioned. A short tiller arm puts too much pressure on the ram and also makes the movements required to control the boat so tiny the feedback loop is too fast for the unit to comprehend. It need more swing than 13 inches to effectively anticipate and make small changes in course in regards to it's software.

The way these things think in simple terms is "Gee, I made a slight correction at this gyro angle and this happened", so it updates it's rudder movements to compensate for the feedback it gets from the GPS. After 30 minutes of learning the boat the thing is bullet proof, but being DIGITAL it needs to divide up it's rudder swing into little digital slices (I assume there are probably two or three digital positions for one degree on the compass dial - maybe more? seahouse might know) If you try to compress these digital positions into too small a space by shortening the swing of the arm they lose their effectiveness and the pilot thinks it's getting forced about faster and harder than it really is and it will fall out. The software has limitations.

The AP on 'boat' will steer at any angle - if the rudders are in the water and that AP can get any kind of course change from the rudders it will just keep on hunting until it gets the boat on bearing - it's an excellent pilot and seems to know what way the boat is going to heel or pitch before the boat even knows. The multi axis control on the thing is bigger than the gyro on a Cessna and works like a piece of fine art. I run it in performance mode because i have enough batteries and in that setting it will barely deviate even one degree. The corrections it makes under performance mode are tiny, but effective.

It also has two less aggressive settings that will use less electricity and allow deviations back and forth of about 2 to 6 degrees - on the lowest setting it pilots like as if I were on the helm so it allow the boat to do that slight S turn heading I described the boat does by itself with no helm input.

If you have a wheel pilot then I can't really suggest any solution - I only use the ram pilot. I do have a very fast hard over time set on my pilot - you might be able to improve you wheel pilot by speeding up your hard over time on the AP.

[Signaleer]

Rounding up...