Shroud tension for a MAC26M with rotating mast

[charlesvanmidd]

I have noticed the mast on my Mac26M does not rotate when I tack. The boat sails well but have noticed the mast mast rotate where the main sail guide (in the mast) is to starboard. It will not rotate to port - stays in one position only. The upper shrouds are tight - lower shrouds are snug with some slop. I have adjusted the mast rake as indicated in the owners manual.

Any suggestions?

[NiceAft]

I had the same problem, as did/do many others. I sprayed WD-40 on the washers for the rotation assemble at the base of the mast. It worked well for awhile. Yesterday, while on the river, I noticed the mast again did not rotate. I no longer care.

I sail the boat and enjoy my time on the water. When I take the boat out for a trip in August, I will spray it again. It will work for awhile.

I have come to the conclusion that having a mast which does not rotate should be the worst thing to ever happen to me

Don't worry about it, and just enjoy your boat.

Ray

[kziadie]

If you can rotate the mast with your hand then lubrication and/or replacing the washer at the mast base with a bearing will probably help. If you cant rotate the mast the tension between the port and starboard shrouds are probably uneven or you have a bent spreader. I bent my spreader shortly after I got my boat through improper trailering (letting the spreader lie on top of the lifelines and it took me months to figure out the problem. Ideally you would want to check the tension with a Loos gauge, but in the absence of one I would try backing off some tension on the starboard shrouds.

Kelly

[delevi]

I would take the time to remove the washers from the mast base and lube with teflon. This is much better than spraying and should last an entire season. Makes a huge idfference. I have very high upper shroud tension and it rotates fine. I concur that you may also have uneven shroud tension and/or bent spreader. Check that first.

Without a Loos gauge, you sight up the mast track and see if it's straight or bows to one side. Do this with the mast locked in center position since it will bend when rotated w/o the sail up. This is corrected with a raised mainsail under load. Also, your lowers shouldn't be slack. Certainly looser than the uppers but not slack. Contrary to Roger's manual, even the leeward shrouds should not go slack when sailing, at least from several articles I read on rigging.

A tight rig will generally perform better than a loose rig, provided that both sides are even and you don't exceed reasonable limits. Mine are 600 lbs uppers and 280 lbs lowers. Sails very well and the mast rotates just fine. Sometimes needs a bit of manual help in light winds by simply grabbing the main sheet and giving a pull aft (the part feeding through the blocks, not the line you adjust.)

Hope this helps.

Leon

[John Christian]

I had the same problem with my 07 M. Seems especialy problematic in light winds. I used some white lithium grease I had on hand for my garage door tracks. It seems to help.

I wouldn't recomend WD-40 as it's really more of cleaner and doesnt leave much residual lubrication.

The rotating mast really needs some type of bearing to ensure good rotation in light winds.

[kziadie]

John, BWY sells a bearing that will solve the light air problem. Dont remember the price... maybe $25 or so. Works fantastic.

Kelly

[Divecoz]

JB 80 $3.95 a can, it will last all season. You can add/spray more if needed or even every week. Or you can add the nylon washer a few bucks or the bearing $20 or so bucks . For me, for now. it's JB 80. Later , at the end of the season, I thinking the bearing.

[charlesvanmidd]

Thank you for all the advice.

[Inquisitor]

Archeology time... had to dig this one up as all the others about shroud tension were for those boats with back stays and not rotating mast.

I'm was about to get one of the Loos gauges mentioned... but even if I had one...

How does one crank down shrouds to 600 pounds? I've just been pulling down with my weight < 200 pounds and sticking in the pin. I'm trailering and setting up on a regular basis... not staying in a slip.

[Tomfoolery]

How does one crank down shrouds to 600 pounds? I've just been pulling down with my weight < 200 pounds and sticking in the pin.

You don’t. With the MRS rigged and cranked down hard, you cut the forestay loose, adjust the side stays, then pull the mast forward and pin it, slacken the MRS, then check the stay tension.

Alternatively, you can ‘walk’ the vernier adjusters one pitch at a time, as they’re 1/8” increments, using two awls or similar pointy pokers. But I would only do that to make the adjustments to find the correct pin locations, and leave them there after that. Use the bottom pins to unpin, or just leave them pinned, which is way easier.

A Johnson lever for the forestay will make it waaay easier to pin the forestay, by the way. You’ll cut rigging time by a LOT if leaving the side stays attached, and cinching down the forestay with a Johnson lever. Just watch those stays as you raise the mast, and stop every so often to check the side stays, as they tend to get hooked on stuff as the mast goes up.

But you shouldn’t be re-adjusting side stay tension every time you raise the mast. If you don’t want to leave them connected, at least unpin them from the chain plates, which doesn’t change any adjustments, and remember which stay goes to which hole.

[Inquisitor]

How does one crank down shrouds to 600 pounds? I've just been pulling down with my weight < 200 pounds and sticking in the pin.

You don’t. With the MRS rigged and cranked down hard, you cut the forestay loose, adjust the side stays, then pull the mast forward and pin it, slacken the MRS, then check the stay tension.

Alternatively, you can ‘walk’ the vernier adjusters one pitch at a time, as they’re 1/8” increments, using two awls or similar pointy pokers. But I would only do that to make the adjustments to find the correct pin locations, and leave them there after that. Use the bottom pins to unpin, or just leave them pinned, which is way easier.

A Johnson lever for the forestay will make it waaay easier to pin the forestay, by the way. You’ll cut rigging time by a LOT if leaving the side stays attached, and cinching down the forestay with a Johnson lever. Just watch those stays as you raise the mast, and stop every so often to check the side stays, as they tend to get hooked on stuff as the mast goes up.

But you shouldn’t be re-adjusting side stay tension every time you raise the mast. If you don’t want to leave them connected, at least unpin them from the chain plates, which doesn’t change any adjustments, and remember which stay goes to which hole.

Thank you Tom,

Since I keep at home, and rig for even day sails, I used to keep everything rigged, but it always scratched up the top. When the M came back out of the field this time I'd had it totally de-rigged. I'm re-rigged for the first time in three years (in the yard) yesterday to make sure I had everything and mainly... do I remember how everything goes. I didn't have any extra pieces, so I'm thinking I'm in the ballpark. Even unfurled the Genoa and raised the main. Mother Nature blessed me with a couple of hours of no wind. Since I'm self, manual or Internet taught... maybe I should ask...

1. I found the Johnson Stay Adjuster on Defender. Can a furled rigged M tolerate the extra length of this thing in the forestay without compromising rake and/or mast rotation too much? And even so, it would mess up the geometry for using the front cleat for the furling line.
2. Are there any tricks to keeping it rigged, mast lowered for trailering that doesn't scratch up the top so bad?
3. Any tricks to raising that doesn't catch a wire or line every two seconds?
4. I always thought the rigging was supposed to be relatively loose so the mast rotation would work... reading this thread, are the 600 lbs uppers and 280 lbs lowers still good numbers?

[Tomfoolery]

How does one crank down shrouds to 600 pounds? I've just been pulling down with my weight < 200 pounds and sticking in the pin.

You don’t. With the MRS rigged and cranked down hard, you cut the forestay loose, adjust the side stays, then pull the mast forward and pin it, slacken the MRS, then check the stay tension.

Alternatively, you can ‘walk’ the vernier adjusters one pitch at a time, as they’re 1/8” increments, using two awls or similar pointy pokers. But I would only do that to make the adjustments to find the correct pin locations, and leave them there after that. Use the bottom pins to unpin, or just leave them pinned, which is way easier.

A Johnson lever for the forestay will make it waaay easier to pin the forestay, by the way. You’ll cut rigging time by a LOT if leaving the side stays attached, and cinching down the forestay with a Johnson lever. Just watch those stays as you raise the mast, and stop every so often to check the side stays, as they tend to get hooked on stuff as the mast goes up.

But you shouldn’t be re-adjusting side stay tension every time you raise the mast. If you don’t want to leave them connected, at least unpin them from the chain plates, which doesn’t change any adjustments, and remember which stay goes to which hole.

Thank you Tom,

Since I keep at home, and rig for even day sails, I used to keep everything rigged, but it always scratched up the top. When the M came back out of the field this time I'd had it totally de-rigged. I'm re-rigged for the first time in three years (in the yard) yesterday to make sure I had everything and mainly... do I remember how everything goes. I didn't have any extra pieces, so I'm thinking I'm in the ballpark. Even unfurled the Genoa and raised the main. Mother Nature blessed me with a couple of hours of no wind. Since I'm self, manual or Internet taught... maybe I should ask...

1. I found the Johnson Stay Adjuster on Defender. Can a furled rigged M tolerate the extra length of this thing in the forestay without compromising rake and/or mast rotation too much? And even so, it would mess up the geometry for using the front cleat for the furling line.
   I don't have an , so I can't give specifics, but I believe folks move the mast hound up to compensate for the extra length of the Johnson lever. I just crank down on my MRS to pin the forestay, but mine attaches using the spinnaker halyard which makes it easier.And yes, you will have to move the fairlead for the furling line to the drum - the furling line off the fairlead under tension should be at 90°to the middle of the drum so the fleet angle between the line and the drum is the same at both drum flanges. The fairlead will have to be moved back when the drum is moved up.
2. Are there any tricks to keeping it rigged, mast lowered for trailering that doesn't scratch up the top so bad?
   I hang the furler drum from the MRS pole and it all goes up together with no dragging. Nothing else tends to scratch the top that I'm aware of.
3. Any tricks to raising that doesn't catch a wire or line every two seconds?
   About all I can do is eyeball the routing of the wire and synthetic ropes to foresee any snags. But if anything does try to snag, I can stop anywhere to free it up. It admittedly is difficult sometimes to see a snag with all those wires and lines dangling about, though, and a hard snag will put a permanent bend in a shroud, so I have to be careful. This is where having some 'help' is actually helpful.
4. I always thought the rigging was supposed to be relatively loose so the mast rotation would work... reading this thread, are the 600 lbs uppers and 280 lbs lowers still good numbers?
   That I couldn't say. I don't recall reading here that anyone keeps the shrouds loose due to the rotating mast. Perhaps your issue is a sticky disk or bearing, if it has one. BWY has a retrofit kit to replace the synthetic disk with some sort of bearing, but again, I don't have an and don't know much about that rotating feature.

[Ixneigh]

Loose shrouds on this boat are bad. In extreme cases it will bring down the mast. (Repetitive shock loading) a good rule of thumb in my opinion is when sailing hard, the lee shrouds should still be snug and not flopping around. I have a turnbuckle on my headstand. I can tension the rigging with that. In certain cases you can (or I have) experienced the mast bouncing when blasting the boat through four footers to weather. I’m not sure if tightening the rigging even more would help with that. Most will motor in those conditions anyway. I added backstays which seemed to solve the issue.
The mast bearing from BWY is great. I use corrosionX on it.

Ix

[Tomfoolery]

Missed the question about furling line fleet angle, which I answered above in green.

[Inquisitor]

For now, I'm trying to do this without changing the forestay geometry with the Johnson Stay Adjuster (JSA). I did get the Loos Meter...

Has anyone else measured their shroud tensions? Is 600 upper / 280 lower really good numbers?

I've got the MRS cranked tight, and the Spinnaker halyard tied to the bow and as hard as I pull the halyard, I can barely get to 300 on the uppers. I can get to 280 on the lowers. The mast is bent more than the manual suggests and the mast doesn't rotate worth a flip. Doing it by myself up and down the ladder, move the pins crank on the halyard/MRS then try to put the pin in the forestay is wearing me out. I spent maybe three hours up/down the ladder. I'm not sure I see a way to get this WITHOUT the JSA. I know most people don't have this JSA, so what kind of tension do you have on your shrouds AND how do you get the forestay pin in when on the ramp?