Hello all,
Picked up #129 last month and have been loving the boat so far. Ive made a few modifications, updated the GNAV to 16:1, I used 16mm because I had them laying around, working loads are similar to what was on it. I re-spliced the mainsheet with 1/8'' dyneema to a split tail and moved it to configuration B to clean up the stern.
I do have a few questions. The boat came with a spare carbon mast, however it looks like the upper stay connection points are 3" higher than the current mast on the boat. Class wise, would it be illegal to order different length uppers to account for this? Or do I need to move the mounts down? The boat also came with an upright rudder mount, however it looks to be a little crooked on the stern, I haven't checked it with the keel on a lift or anything yet but was just curious if they usually appear to be this crooked?
Looking forward to making it to a few of the Great Lakes events next year!
Carson,
Nice splicing on the mainsheet. You may decide you want something less stretchy on the vang over time but as long as it doesn't break, it'll work. The 16:1 vang is otherwise legal as pictured (though if someone from the Tech Committee has another opinion, always defer to them). Not sure what to tell you about the backup mast. That sounds strange though. If the rudder bracket is crooked, you can remount it to straighten it up - if you're a handy guy, using a laser sight and any similar means is ok, as long as the remounted bracket is on straight and isn't moving around. It was an aftermarket upgrade so the potential for mounting it crooked is there.
The mainsheet splice was definitely one of the more difficult splices i've ever done, would probably be easier if it was done on new line. The vang is dyneema core all the way back to the cleat, so it should be good on strength and stretch, hopefully. Can someone verify the UPPER mount length for me? I have about 51-3/8" from the top of the mast to the very top of the slot. Picture included. The mast is the standard SuperSpars mast, so not sure how it would be different? The measurement on the backup mast is 48-5/8".
Thanks for the info Peter!
Carson - Nice work. Couple things.
Mast measurements I have are from the base of the mast "Bottom of heel casting, w/o rectangular alignment block" to the bearing surface for the J-hook. From a bunch of masts the TC measured in 2011, that number should be about 7683mm. Please email me directly with what your actual measurements are.
Afraid your gnav purchase is too high. You have a 5:1 on the moving part (the car) on the boom times a 4:1 below the boom = 20:1. If you back the car purchase down to 4:1 and you'll be fine...
Good luck with your new boat!
Dave
TC chair
Sent you a message with the mast measurement. I copied the top part of the Vang based on the setup on Harkens website which is 8:1. Double block to a double block with becket, 4:1 right? Or does the through block on the front of the boom count as a 5th purchase?
https://www.harken.com/DeckLayout.aspx?id=13769
Thanks.
Can't vouch for Harken. For purchases you count the parts of line attached to the moving part. Bet you a beer that if you pull 5" on your upper purchase that the car will move 1"... block thru the boom is just redirecting- adds no purchase. Then multiply by the lower purchase- in your case 4:1
Dang, you're right! Thanks Dave.
Carson
Hey Carson, we had that vertical rudder bracket installed at a boat shop (Jim Betts). He laser aligned it with the keel so should be good to go.
Glad you are enjoying the boat!
Cool, thanks Garrett!
Has anyone made a chart of target boat speeds and angles for given wind ranges? We had the boat out for a Wednesday night race in 10-20 yesterday, felt great, but hard to tell what the boat is capable of when there are no other Vipers to compare to there.
I reached out to Paul Young about the mast, he suggested leaving the current mounts in and adding new mounts at the proper measurement. That way I wouldn't have to do any carbon fiber reinforcing where the old mounts are. Even gave me a part number 👍🏼
Quote from: Carson Downing on July 11, 2019, 10:34:51 PM
Cool, thanks Garrett!
Has anyone made a chart of target boat speeds and angles for given wind ranges? We had the boat out for a Wednesday night race in 10-20 yesterday, felt great, but hard to tell what the boat is capable of when there are no other Vipers to compare to there.
There has been a bunch of conversation on this topic over the years in old forum posts, but I can't find anything right now about it in the archives, nor do I have any polar diagrams for a Viper. Assuming you're on a windward-leeward course (which is really the only thing that matters from a VMG standpoint), our general rule sailing downwind (which can be violated of course) is "don't try to plane unless you can plane 100% of the time." Otherwise in puffy conditions, if you go high to plane and the puff runs out, you've lost a lot of gauge on the boats to leeward. Generally this transitions happens at around 12-13 kts sustained, but the word "sustained" is key. If you're not planing but you're doing more than 9.5 kts consistently, you should probably be planing 100% of the time and going 11+ kts.
Otherwise, set the boat up to the tuning guide to make sure you're maximizing your speed potential upwind. Hike hard and don't let the boat heel too much - if your leeward rail is in the water upwind, you're way too heeled (and likely very slow too).
10-20 knots of wind is a huge range for wind speeds - makes sense for a lake, but if you're in those conditions, you're changing gears a lot and if the wind isn't going below 10 knots, you can set the boat up for the puffs instead of setting up for the lulls - you'll still be fully powered in 10 knots of wind (as opposed to the much tougher condition of 5-15 kts where you want to set up for the lulls). Usually we are at full power and are starting to depower aggressively at 10 knots (i.e., 3.25" of mast blocks, upper shrouds at 34-35), and if that is our setup, we want to be going 5.7-6.0 knots upwind all of the time (which is possible if you're sailing with at least 540 lbs of crew weight - pretty hard to do if you're sailing lighter than that in those conditions - heavier teams will be able to do 6.1-6.4 upwind depending on sea state - pretty hard to go more than 6.4 kts upwind in a Viper on a true close hauled course in flat water and no current unless you're overstood, which doesn't count, and if you are able to do that, try taking a bit more height and make that weather jib telltale lift a bit more). At a certain point (usually around 13-14 knots, more pressure upwind doesn't make the boat go any faster - you just heel more, so you can take some more height and pinch/feather to compensate and still try to go the same speed (again, assuming flat water). Downwind...10 knots of wind you can go 7.5-8 kts and in 20 knots of wind you can go 14.5-16 kts...so find those puffs and keep the boat under the mast.
Hi Peter--following up something you said in FB thread--wondering about how much chock you use. It seems you vary from 2.5" in the light to 3.25" over 10 knots (that's more than we've ever dared/been able to wedge in there). Any thoughts welcome--thanks for all all your contributions.
The number of mast chocks you're able to wedge in will be directly related to your mast butt position and your headstay length. We have our boat set up to the North tuning guide (which is probably not all that different from Brad's Doyle tuning numbers, though I haven't seen Brad's latest numbers), which involves having the headstay at max length and the mast butt in the aft most position. If you do that, suddenly you'll see that you have room for A LOT of blocks. We can get 2.75" of blocks in fairly easily (i.e., singlehanded). From there, it's often a two person job, where we have one person pull aft on the mast (with feet braced on the coaming, all weight on the mast), and the other person ready to add mast blocks. Depending on the position of your "mast block hardware" (i.e., block and cleat), you may need to file away the sides of the aft most block. Our boat did not come supplied with a Harken block on the deck since it serves no purpose (i.e., our mast line goes from the eyestrap, around the mast a couple of times and through the eyestrap a couple of times, to the cleat - pics attached) and we told Rondar they could save themselves $20 and 5 minutes of labor, and our clam cleat as supplied on the newest boat was mounted a couple of centimeters outboard to eliminate play between the mast blocks and the cleat, so that helps a bit. Getting the last bit of blocks in takes some effort. We have the retaining line over the top of the blocks, NOT through the blocks - the orange line in the pics is just to keep the blocks from getting lost. We also put a trapeze handle on the end of the retaining line so that in light air when we're trying to pull the mast forward to induce headstay sag / in general just to keep that line tight and keep the blocks from popping up, we're able to do so. There are some other people who have taken a different approach given the relatively small range of adjustment of mast blocks and permanently mounted the forward mast blocks to the front of the coaming with a bolt, have drilled a tiny hole in the bottom of the aft most mast block (i.e., the curved block) and tied it down to the front of the mast step so that it doesn't ride up, and only adjust a few of the middle blocks. That's pretty slick too if you want to do it - we've meant to try it but honestly it's one of those projects that is lower priority for us. Final note is that the attached photos actually show us with 3.125" of mast blocks in - we have one additional 1/8" block that we use in 16+ kts that we call the "turn it to 11" block (and a quarter incher is out in these photos as you can see). I cannot endorse this approach unless you are 100% confident in your Viper tuning ability - if you have too little upper shroud tension (i.e., less than 35), you WILL invert your mast with this setting (I once tried 3.5" of mast blocks and inverted my mast in the parking lot - not a good look). That said, I think headstay sag control is the most important control to get right in a Viper if you want to be fast upwind in hiking conditions. Teams that get it wrong have jibs that are too full, are overpowered, and have to ease a lot more to compensate, and they just go slower and sideways while hiking more and more with little improvement in performance. I'll post an example of that in a second.
There's a lot going on in the photos. Ignore the green/white line - that is a tow line / bow line. Ignore the white line - that is a spin halyard. Retaining line is dark blue. We also don't deal with tiny mast blocks mostly - we use big adjustments in quarter-inch increments except for the Turn It to 11 block.
Huge thanks Peter! lots to digest here--Matt (also--last I heard from Brad, Doyle also recommends max headstay and step max aft. They recommend shortening the headstay in big breeze, which seems to me less effective than adding chocks.)
Brad and I have talked about the shortening headstay route - I plan to try it in 15+ kts at some point but haven't had a good opportunity yet. I don't know that Brad is doing it in lieu of blocks - I think he is doing it to change the helm, but I'll let Brad chime in on his rationale at some point. I will say that when he did it on a day in Sarasota when he was overpowered (18-20 kts and not enough crew weight) he was able to hang upwind and we (even more overpowered at 490 lbs) were not even close. So I'm curious.
Photo attached of what good and bad headstay sags look like. Granted, this photo is slightly unfair in that teams are rounding a weather mark, vangs are eased, etc., but a few things are obvious.
1. 269 has very little headstay sag - very straight, flat entry on the jib luff. This was in around 13 knots of wind. We had 3.25" of blocks in and the uppers were around 35.
2. 159 has a moderate amount of sag. Not as fast, but hey, they're rounding the windward mark in front of us, so I shouldn't be a hater. I'm not sure this is why they were ahead though.
3. 222 has an in between amount of sag, but you can see they're a little overpowered. Also, this was a short beat (0.6 nm - YRALIS Saturday racing - we got in 4 races in 2 hours and the teams are all pretty close to each other). The bigger point is that it is clear visually when there is too much headstay sag. For people who aren't as good at sighting the rig, our baseline is that if all crew are hiking reasonably hard, we should have all blocks in. You're allowed to change blocks mid-race, so if you're wrong, it's easy to deal with (relatively - we do it downwind typically - that's it's own post about good technique for making this happen when you realize on the first beat that you're set up incorrectly, and what philosophy you should have pre-start when you're not 100% sure about where the rig should be with upper shroud tension and mast blocks).
Quote from: Peter Beardsley on July 12, 2019, 10:40:19 AM
Quote from: Carson Downing on July 11, 2019, 10:34:51 PM
Cool, thanks Garrett!
Has anyone made a chart of target boat speeds and angles for given wind ranges? We had the boat out for a Wednesday night race in 10-20 yesterday, felt great, but hard to tell what the boat is capable of when there are no other Vipers to compare to there.
There has been a bunch of conversation on this topic over the years in old forum posts, but I can't find anything right now about it in the archives, nor do I have any polar diagrams for a Viper. Assuming you're on a windward-leeward course (which is really the only thing that matters from a VMG standpoint), our general rule sailing downwind (which can be violated of course) is "don't try to plane unless you can plane 100% of the time." Otherwise in puffy conditions, if you go high to plane and the puff runs out, you've lost a lot of gauge on the boats to leeward. Generally this transitions happens at around 12-13 kts sustained, but the word "sustained" is key. If you're not planing but you're doing more than 9.5 kts consistently, you should probably be planing 100% of the time and going 11+ kts.
Otherwise, set the boat up to the tuning guide to make sure you're maximizing your speed potential upwind. Hike hard and don't let the boat heel too much - if your leeward rail is in the water upwind, you're way too heeled (and likely very slow too).
10-20 knots of wind is a huge range for wind speeds - makes sense for a lake, but if you're in those conditions, you're changing gears a lot and if the wind isn't going below 10 knots, you can set the boat up for the puffs instead of setting up for the lulls - you'll still be fully powered in 10 knots of wind (as opposed to the much tougher condition of 5-15 kts where you want to set up for the lulls). Usually we are at full power and are starting to depower aggressively at 10 knots (i.e., 3.25" of mast blocks, upper shrouds at 34-35), and if that is our setup, we want to be going 5.7-6.0 knots upwind all of the time (which is possible if you're sailing with at least 540 lbs of crew weight - pretty hard to do if you're sailing lighter than that in those conditions - heavier teams will be able to do 6.1-6.4 upwind depending on sea state - pretty hard to go more than 6.4 kts upwind in a Viper on a true close hauled course in flat water and no current unless you're overstood, which doesn't count, and if you are able to do that, try taking a bit more height and make that weather jib telltale lift a bit more). At a certain point (usually around 13-14 knots, more pressure upwind doesn't make the boat go any faster - you just heel more, so you can take some more height and pinch/feather to compensate and still try to go the same speed (again, assuming flat water). Downwind...10 knots of wind you can go 7.5-8 kts and in 20 knots of wind you can go 14.5-16 kts...so find those puffs and keep the boat under the mast.
Awesome info, We weren't too far off then. 550lbs on the rail, we were able to be around 5.8-6.3 upwind. Downwind our top speed was 13.7, consistently over 10 knots though.
I'm also liking the Configuration B mainsheet setup, with the split tail at the center of the boat. Mostly because I can swing the tiller extension back and not worry about the sheet at the stern. Was nice to be able to twist the main more, and I was able to get sufficient leech tension with the Gnav, which allowed me to ease the sheet when the breeze picked up. I need to get numbers on the Gnav for consistent trim. How far are you guys able to get that car to move forward? I got the car to about where the block runs into the forward stop and felt like I shouldn't wail on it anymore, had the boom bending pretty good. Of course this was 16:1 so I didn't want to break anything 😜
I'm definitely interested in how you change blocks on the course, I had a hell of a time fitting all the blocks in on the trailer.
Mainsheet setup is definitely all about personal preference. Good arguments can be made for aft sheeting or center sheeting. Some of those arguments can be found at http://forum.viper640.org/sailing-handling-tips-and-techniques/technical-committee-announces-new-test-of-stern-bridle/msg19868/#msg19868
That is otherwise a lot of vang tension - tracks and stoppers are not always in the same spot, but if you're able to hit the front stopper, you're probably using too much vang and are at risk of breaking some hardware (gooseneck and boom mostly - boom would be more rare, but we've definitely seen people break goosenecks and I think I've seen at least one broken boom before, exact cause I am not sure).
Changing mast blocks while racing:
1. Don't do this upwind unless you're removing blocks. If you're adding blocks, it means you're overpowered, and to change blocks, you need to take people off the rail, which you don't want to do if you're overpowered, so...
1a. It would need to be a pretty big change from too windy to too light to want to remove blocks while sailing upwind and you'd want to be confident that the breeze wasn't coming back on that leg of the course. This is not something we do glibly on 269.
2. The main reason we do this is because our rig is out of whack and mast block changes mid race are only a temporary fix. We're not allowed to change upper or lower shroud tensions mid race so this is the best we can do.
2a. Example: Race 2 of 2019 Viper New Englands two weeks ago: started in 7 knots of wind and we had 2.75" of blocks in or so and we were around 27 or so on our upper shrouds. Within 2 minutes after the start we were fully hiking in 12-13 knots of wind with our upper leeward shroud flopping around and lots of headstay sag. Woops. That is suboptimal since as mentioned above, the headstay sag made our jib too full and we were overpowered. To deal with being overpowered, one thing you can do is ease your main...which causes you to sag your headstay even more and continue to power up your jib (to a point). Double whammy. So then you need to ease your main EVEN MORE to keep the boat under control...and by then you need to ease your jib since now you've closed the slot from easing the main out a few feet, and then with your sails cracked too hard, you're barely going upwind anymore (at least compared to the leaders).
Since we couldn't tighten the rig, we used every other depower option upwind first - outhaul, cunningham, jib halyard fine tune, jib leads aft a couple of holes, vang on, sails cracked a tiny bit (more jib than main so that we could keep the headstay tension on), feather a bit more than we might otherwise like to keep heel angle under control, hike hard and suck it up for a bit.
When we turn downwind:
1. Kite up
2. Figure out where you want to go. If you want to gybe, do that first. If you want to roll someone, do that. Don't lose sight of the bigger picture. But if you want to go straight and are able to do so for 60 seconds without getting rolled...
3. Have the forward crew loosen up the mast block line and get everything queued up - blocks above deck if they were hanging low, etc.
4. Pass the spin sheet to the driver
5. Middle crew pulls mast aft as described in prior post, forward crew jams in blocks (or removes blocks quickly)
6. Driver passes spin sheet back to middle crew while forward crew cleans up and tightens up the mast block line
We've found that every quarter inch of mast blocks that we add after 2.5" of blocks adds about 1.5 numbers of Loos gauge tension-ish. So adding blocks doesn't usually get us to where we need to be, but it'll make things less painful for the second beat - we'll still usually need to get the shrouds aligned once we finish so that we're fully set for the following race.
If we're not sure about where we want to be with shroud tension / mast blocks going into a race, we tend to leave some mast blocks out (whether it is 0.25" or 0.50"), and we set the shrouds appropriately for the wind conditions that we have at the time, MAYBE a touch loose on the shrouds by half a turn. Thought being that since we can't touch the shrouds but can add / subtract blocks, if it gets windy we can add blocks during the sequence or on the first run and be pretty close to where we want to be, or subtract blocks and also be pretty close.
Most teams aren't messing around with blocks during a race so we know that if we have this in our back pocket, we're going to be able to extend on the second beat and that is a nice confidence boost for when we're hiking to overcompensate on the first beat.
A note of caution for newcomers to the class.
You are sailing a carbon mast with no backstay. These masts will break in big breeze if you dont observe a few basic and commonsense best practice guidelines.
The following factors increase the risk of breaking your mast sailing downwind. None of them individually will cause the mast to fail but until you perfect your technique they are items to be aware of
1. You increase the stress on the mast the further aft you place the mast (ie max headstay length and max aft in the mast step) because you reduce the angle that the uppers are holding the mast in column.
The best position for tune is max length headstay. If you have to make any tradeoff, having the mast butt one hole forward is better than shortening the headstay.
Shortening the headstay in big breeze improves the angle that the uppers are pulling back on the rig (and can allow the uppers to apply more tension to the headstay) but the disadvantage is that it reduces mast rake in big breeze which is not fast. I dont know what Brad does if he shortens the headstay but I would contemplate also moving the mast step one hole forward to preserve rake. We have not tried this.....but if you move the top of the mast forward, I would move the base of the mast forward as well.
2. Not enough tension on uppers in big breeze, puts the mast at risk downwind.
3. Too much tension on lowers in big breeze, puts the mast at risk downwind (holding the lower half of the mast "back" means that the top half of the mast is taking all the stress.....visualize how easy it is to break off the tip of a carbon fishing rod if the hold the top in both hands versus allowing the whole rod to bend)
4. Too much chocking down low puts a mast with too little upper tension at severe risk. Same as #3 above, but too much chocking can create reverse prebend and sets up mast inversion.
5. Easing out the mainsheet too far, losing the leech tension that is holding the mast in column.
6. Easing the Gnav too much, losing leech tension.
The best protection for the mast is max tension on the uppers and keeping the mainsheet and boom end close to the boat.
I mention this because if an owner has : Mast max aft, only 27 Loos on the uppers and a big breeze comes up.......then going to max chocks aft at the partners downwind sets up a high degree of risk for the mast. It means one of two things:
1. The owner also owns stock in Superspar
2. The team is very skilled and adept at keeping the rig in the boat. They need to be watching the headstay like hawks downwind and putting the gnav on hard if they see it going overslack. They will have the main sheeted in downwind with the boom end close to the transom corner and doing jibes with a fair amount more vang than normal ....blow through gybing smoothly to prevent broaches and avoiding a snap tension on the mast coming out of the gybe.
Unless the race result is worth $4,000+ , a newcomer needs to exercise a considerable amount of caution if they are caught out in big breeze with low tension uppers......to finish first, first you have to finish!
Enjoy.
undoubtedly me but how do I get to see the pictures?
yep - it was me.
ignore
Peter et al this was a very helpful post for us since we were sailing our boat for the first time in Noroton.
We have tried easing the Max headstay length 1-2 cm beyond the North sails guide but didn't notice much a difference...this was only in practice though in puffy conditions fully hiked. It seems extending the headstay a few cm might be helpful (it is in some boats) but perhaps the very flexy top section of the Viper and no backstay negates this affect. We will try it more though and possibly have to move the mast step forward though....screwing up all the mast block measurements and shroud tension numbers.
We were sailing slightly heavy in Noroton and had difficulty upwind and holding lanes off the line....but remembered this post and started taking out blocks and by race 2/3 we were a bit faster upwind allowing us then to start playing the shifts. Since we were heavy, we needed alot of headstay sag. We certainly lost some pointing ability by doing that and were down to 2.25 " blocks for a period time on Day 1 with 25 Loos on the Outer shrouds, and especially Day 2 when the wind was lulling at around 8 mph.... until our prayers for more wind came true. Since we were having to foot everywhere with alot of headstay sag, we tried winning the pin end a number of times or searching for big holes using a port approach.
We tried changing blocks on the upwind but just wasn't possible with the load from mainsheet.
Wasn't too hard to do on the downwind though but the 1 person struggled with it. We are a beginners to the Viper but epoxying in the front block (or perhaps just velcro) and only changing out the middle blocks makes alot of sense...so we may consider that. It's pretty tough getting in the new block under tension even with 2 people. Was thinking a short 2:1 block system around the mast at deck level to the keel lifting eye might make it easier for 1 person to do. Wondering if anyone has tried this.
Viper is really a wonderful boat to sail...even compared to the foiling craft I've been frequenting of lately.
Those experienced with racing in Noroton, it was difficult to ascertain benefit of sailing more inshore on the incoming tide. Fleet by in large played the middle. We were wondering why more weren't favoring a side....perhaps we were far enough offshore and the upwind too short that it didn't matter ?
Quote from: BVickers on October 24, 2019, 11:12:50 AM
We have tried easing the Max headstay length 1-2 cm beyond the North sails guide but didn't notice much a difference...this was only in practice though in puffy conditions fully hiked.
Guys, odds are good this wasn't legal - the North guide recommends the headstay length be 7588mm - which is also the max length allowed under the class rules. There are times when all of us may want longer headstays but class rules prohibit anything longer than 7588mm presently - definitely doublecheck that length before going to the next event with your boat. See Class Rule 5.1.
Quote from: BVickers on October 24, 2019, 11:12:50 AM
We were sailing slightly heavy in Noroton and had difficulty upwind and holding lanes off the line....but remembered this post and started taking out blocks and by race 2/3 we were a bit faster upwind allowing us then to start playing the shifts. Since we were heavy, we needed alot of headstay sag. We certainly lost some pointing ability by doing that and were down to 2.25 " blocks for a period time on Day 1 with 25 Loos on the Outer shrouds, and especially Day 2 when the wind was lulling at around 8 mph.... until our prayers for more wind came true.
That's a pretty light setting, but there was enough chop last weekend to make it work at times. Still, we never go below 2.5" of mast blocks.
Quote from: BVickers on October 24, 2019, 11:12:50 AM
We tried changing blocks on the upwind but just wasn't possible with the load from mainsheet.
That, and unless you were able to keep the boat flat while doing it, you're taking people off the rail at the wrong time usually. Unless we are at something less than max blocks, moving blocks for us is usually a 2-person job.
Quote from: BVickers on October 24, 2019, 11:12:50 AMIt's pretty tough getting in the new block under tension even with 2 people. Was thinking a short 2:1 block system around the mast at deck level to the keel lifting eye might make it easier for 1 person to do. Wondering if anyone has tried this.
Paging Dave Nickerson, but probably not legal unless you wanted to use the actual keel lifting purchase - remember the fundamental Viper class rules in 1.4 and 1.7 - can't alter equipment unless specifically authorized by the rules.
Quote from: BVickers on October 24, 2019, 11:12:50 AM
Those experienced with racing in Noroton, it was difficult to ascertain benefit of sailing more inshore on the incoming tide. Fleet by in large played the middle. We were wondering why more weren't favoring a side....perhaps we were far enough offshore and the upwind too short that it didn't matter ?
WLIS doesn't have a lot of tide relief for Viper racecourses - if you sail closer to shore in smaller boats there can be more of a difference. That said, I thought that on Sunday the left was favored upwind - whether that was relief from the flood tide, a geographic shift with the parallel shore, a bit more pressure, a bit of relief from the chop from the easterly, or all of the above, there were definitely a few times when teams sailed around us who hit that corner hard. Still a pretty good effort by Rachel in her first Viper regatta as a skipper (and first non-Sunfish regatta!)
Thanks for the input. Thus far we have been practicing with the headstay at 7580 and have tried up to 7600 getting to understand the boat. Mostly regarding we sail the boat heavy thus far while we are doing Keto diet and diet coke with our rum to lose weight, and we were curious how it would feel with the mast butt more forward and going up to 7588 and even further. Our boat certainly tends toward lee helm lock with being shorter than 7580. Since the rules prohibit moving the mast butt during a "regatta" it's likely a mute point anyway.
Mast block removal:
Dave, was wondering about taking the mast chock line back around the mast to the keel lifting eye or whatever that lines is called....as it's released anyway when changing blocks and creates an easy 2:1. Seems ok per the rules since it's part of the boat. Stepping on the cabin console to put in the blocks with 2 people like we were told flexes the deck quite a bit, but my guys should be Starboat crew :)
Carson, don't mean to be extending this thread into another direction....
But....Dave and someone tell me what this exactly means in terms of Forestay Length measurement point to help me figure out "The questions that bother me so" Jimmy Buffet
Getting differing opinions of this and what it means
"The length of the headstay shall not exceed 7588 mm and shall not be less than 7512mm measured from the bearing point of the upper tang to the bearing point of the lower attachment point."
Is this undersurface of the T tang to the top of the clevis pin ?
And it's way too cold outside for November
Bill
According to Defender.com... So that would mean the center of the forestay pin on bottom? I'm sure a member of the TC could verify this.
Picked up a CNC over the holidays. Fresh mast chocks anyone??
Nice work. Does the mast chock that meets the mast have a 7 degree angle or so, or is it straight? http://forum.viper640.org/repairs-maintenance-and-upgrades/mast-chock/
Yep, 7 degree bevel for the mast. Theres a half inch of material in front of the mast, .75'' total thickness. I could also make these in any shape and thickness up to 2" thick.
oooh--sweet! Can I ask how much for a set, or even just for the one by the mast?
How soon are you needing one? I haven't made any other pieces yet, but was thinking:
1- 1" piece
3-.5" piece
1-.25" piece
That would bring the total up to 3.25" with the curved front chock.
I'm interested as well.
Thanks,
John
Quote from: Carson Downing on January 07, 2020, 01:56:36 PM
How soon are you needing one? I haven't made any other pieces yet, but was thinking:
1- 1" piece
3-.5" piece
1-.25" piece
That would bring the total up to 3.25" with the curved front chock.
Carson,
If you're doing these from scratch, I would suggest the following:
1 2.5" block (no one ever goes less than 2.5" of blocks - maybe you can go 2.25" if you think that the thinking on that could change in the future if some new tuning philosophy ever takes hold)
- The rest in 0.25" increments unless you wanted to put the final two in 0.125" increments for people who are tweakers. I am a pretty big tweaker though and I keep my gears pretty simple (2.5", 2.75", 3", 3.25", and a crazy setting that I do not recommend unless you really feel confident in your tuning and sailing abilities and don't mind buying a new mast if you're wrong about that of 3.375").
Quote from: Matt Rowlinson on January 07, 2020, 01:02:20 PM
oooh--sweet! Can I ask how much for a set, or even just for the one by the mast?
I sent you and John a message regarding this.
Quote from: Peter Beardsley on January 07, 2020, 04:26:54 PM
Quote from: Carson Downing on January 07, 2020, 01:56:36 PM
How soon are you needing one? I haven't made any other pieces yet, but was thinking:
1- 1" piece
3-.5" piece
1-.25" piece
That would bring the total up to 3.25" with the curved front chock.
Carson,
If you're doing these from scratch, I would suggest the following:
1 2.5" block (no one ever goes less than 2.5" of blocks - maybe you can go 2.25" if you think that the thinking on that could change in the future if some new tuning philosophy ever takes hold)
- The rest in 0.25" increments unless you wanted to put the final two in 0.125" increments for people who are tweakers. I am a pretty big tweaker though and I keep my gears pretty simple (2.5", 2.75", 3", 3.25", and a crazy setting that I do not recommend unless you really feel confident in your tuning and sailing abilities and don't mind buying a new mast if you're wrong about that of 3.375").
I can only do 2" thickness max on the CNC, it's a little guy. Otherwise I would have to bolt a few together. I like the idea of the rest of them all being 1/4" though.
Finished set. Went with a 2.5" chock up front and three 1/4" chocks as Peter suggested. 1/4" chocks sit higher than the beveled chock, and they have a small bevel at the bottom so it's easier to push them in. There's also a small recess in the main chock for the line, so it doesn't get caught in between the chocks when you are inserting them. Fun project! I have extra material, so shoot me a message if you are interested.
Spring projects have officially started.
Got the boat hung up in the garage to check if the rudder and keel were aligned. They were perfect, however the keel is canted to starboard by quite a long ways, which is why the rudder looked crooked. So I got the top cassette pulled out and it is probably going to stay out permanently. I have a plan to add a wedge attached to the lower cassette inside the keel box and then another wedge on the back of the keel that pushes the keel forward onto shims (Talked to a member of the Tech Committee about this vaguely.) Does anyone know how the threaded inserts are held in? it looked like they were literally just sandwiched between the deck and the top cassette with 5200, so I may just glass them onto the deck.
Started fairing the keel, wasn't anywhere close to the class shape! Pretty all over the place as far as being straight as well, but looking better.
Got the mast prepped for new clear coat, new main halyard and cleating system, 2:1 jib halyard installed, switching back to rear boom sheeting after some interesting testing, and new instrument bracket to test out.
Ready to get back out on the water!
More photos from previous post.
Quote from: Carson Downing on March 05, 2020, 02:21:21 PM
So I got the top cassette pulled out and it is probably going to stay out permanently. I have a plan to add a wedge attached to the lower cassette inside the keel box and then another wedge on the back of the keel that pushes the keel forward onto shims (Talked to a member of the Tech Committee about this vaguely.)
Definitely confirm that with Dave Nickerson first before committing to that approach. A lot of owners of Mark III Vipers may want to do the same but I'm not sure it'll still be a one design Viper 640 if you go down that road (though I've always wanted there to be a legit retrofit of that system - needs to be blessed first).
If your first keel fairing job goes well and you realize there is no need for a backup keel, you know where to find me - offer still stands for me to come out to Iowa and do a regatta with you.
Hi Peter,
I'm in complete agreement that we need a legit retrofit for pre-wedge boats. It is not exactly one design now and I believe there is discontent over this issue and it may (if it hasn't already) hurt participation in the future as well as devalues those boats. I for one can't just go out and buy a newer boat but would put money into a retrofit.
Cheers,
John
I've exchanged emails with Dave about a wedge concept a few months ago. My first idea was to add wedges like the current boats towards the center of the keel. This would include a connected top and bottom cassette with aluminum rods and delrin pieces in between to support the wedges. So all the load would be on the top and bottom cassette. But, after I got the top plate off, I don't think there's room, and it would be heavy and not as easy. So, wedge on the trailing edge of the keel and wedge in the lower cassette to shove the keel up against a forward shim is simple and effective, and easy to raise and lower. I'll draw up some final plans and get a "for sure" approval from the tech committee before testing.
I'll also post them here and get class opinions. Because if they work well, it would be a great upgrade for MKIII boats as a performance and maintenance option.
Peter, not ready to let the 2nd keel go. However, if you ever find yourself stuck at the in-laws and want to go for a sail, give me a call! We have a good time on Wednesday nights killing the tri-maran's and old lead mines. And free beer helps too 😉
Be interesting to see if some of the Australians pipe in on this thread as some of those boats at the Worlds a couple of years ago in Oz had already developed a "solution" to the non-wedge boats. It was an interesting approach. I took some pics, however am unable to find them.
Craig
Installed a new Main halyard cleating system today, testing it out Wednesday night. Swivel mount didn't work as planned (same as spin halyard cleat), still slipped a little.
hi carson, I recently replaced the main cleats on my mast but I went with CL218 mk2 from clam cleat, 2 of them. and I get zero slippage. it might be the small tang that holds rope down in front doing the trick.
cheers