Laser One

Laser One header

Noodles and Dutch getting wet

This week “Dutch” Kain Xenobuilder launched the Laser One, his latest addition to The Mesh Shop fleet. Laser One is a two-person racing dinghy that emulates the popular Laser, and it incorporates many of the innovative features found in Dutch’s earlier boats.

Laser Class

laserThe ‘real’ Laser was first introduced over forty years ago at the 1971 New York Boat Show. The cat-rigged dinghy was inexpensive, easily transported on a car roof, and very fast. It quickly caught the attention of the RL sailing community, and within three years the first World Championship was held. In 1996 the Laser was added to the Olympic sailing competition roster too.

The boat remains extremely popular now. An estimated 200,000 Lasers have been built so far.

The One Design specs are set by the  International Laser Class Association, and three versions of the boat are commonly recognized for racing. Although the Laser can hold two sailors, the great majority of competition is single-handed.

olympic lasers

Here’s a vid to get you going:

If you have the time, now check out the London 2012 Olympic Laser medal race!

Mesh Shop Laser

Dutch Xenobuilder is well-known for the detail and accuracy he puts into his Mesh boats, and the new Laser One continues that tradition.

two lasers

The boat faithfully recreates the physical dimensions of the Laser design spec, and it goes a good deal further. The image above compares the new, 100% Mesh build with Kephra Nurmi’s prim version of the Laser from 2009. Kephra’s a great boatbuilder who strove to make his Laser as realistic as possible. However,  three years ago the tools were simply not available to provide the wealth of detail that abounds in the new Xenobuilder boat.

details laser rig

click to enlarge

Let me show you what I’m talking about. If you check out Kephra’s green and white 2009 Laser above, you quickly notice that the sheets, rigging, and hardware needed to manage the sails are all missing. They simply wouldn’t fit within the SL prim limit.

Now look at the new Mesh Shop build. All that important stuff is now present, and the detailing is remarkably true to the real Laser. To illustrate my point, in the figure to the right I’ve included three close-up views of the hardware and lines for the mainsheet, the vang, the Cunningham,  and the outhaul.

The images show a lot of fancy details, but how accurate are they? Well, judge for yourself. Here is a diagram of the Laser sail shape adjustment system from one of the online Laser parts suppliers.

laser boom rig

click me

Compare my pictures above to the rigging details for the real boat. I’m impressed the SL Laser One is a very close match to what you could buy in RL. In fact, the match and the detail are so close, I’m willing to bet that’s a Harken vang system on Dutch’s boat. :-)

Actually, that’s probably a safe bet for me to make, since if you get really close to the blocks, you’ll be able to read the Harken name-logo that’s printed on them. :-)

Here’s the take-home message: Dutch’s build for this virtual boat is a very close match for the Standard Laser in RL.

Working Centerboard

This is the first Mesh Shop boat that comes with a centerboard, and I’m happy to report that feature is quite nicely implemented, using the PageUp/PageDwn keys. The CB is also physical and adds over a meter to the boat’s draw when fully deployed, so watch those rocks!

However, in contrast to the centerboard the Laser One‘s mast, boom, sails and rigging are all phantom. Although this detracts in some ways from the boat’s realism, Dutch points out that a sailor wouldn’t be able to stand on the boat otherwise. This was a trade-off decision by the builder.

Personal Textures

Dutch has a new, very easy system that allows texture modification for the sails, hull and rigging. A sailor just needs to take one of the included templates, modify it to their liking, then upload it and copy the texture’s UUID code. To install it, the sailor just needs to say “texture [boat part] [UUID code]” and voilà, the boat has a new paint job. You don’t need to edit or unlink anything, or drop files anywhere in the boat!

Laser One performance.

If you’ve sailed other Mesh Shop boats, you’ll be quite comfortable taking the helm of this boat. The new Laser is powered by a BWind 2.5 sail engine, and it shares a number of control features with the VO-70, OD-65, and the Nacra.

ipad2There’s a “cruising” mode that acts like a standard BWind boat, and there’s a “racing” mode that’s adjustable through a tablet interface. (You can get a free iPad tablet here, and you can also get a copy of the wind setter manual here. If you want a copy of the Laser One manual, click here).

Laser One uses an iPad2 wind setter tablet. As far as I know the only difference between iPad2 and the original iPad used by the other Mesh Shop boats is the avatar position. If you forget and use the old tablet in this boat it will still work fine, but it might be hard to find a viewing angle where you can tap on the screen.  :-)

I’ve already discussed features of the BWind 2.5 engine in Mesh Shop boats here, here, here and here. I won’t go into details in this post except to comment once again that this is a unique system and the boats are not compatible with the WWC setters found at racelines. The boats also lack wind shadow and the “usual” wind variances common to other SL boats. Dutch believes the new system has advantages, and that it will grow.

Hud and control features

xenograft hudsLaser One uses a simple, numerical info HUD that’s similar to the Nacra. It displays data about boat heading, the wind speed and apparent angle, and the degree of heel.

The tiller is controlled by the left and right arrow keys, and the sail angle is adjusted with the up and down keys.

Unfortunately, the basic BWind system of sail sheeting is notoriously inaccurate, and (in my opinion) fairly useless for racing. If you want more precision adjusting your sails, here are two undocumented override options for the Laser:

1) If you own a Nacra, you can use that boat’s control HUD with the Laser. It will give you 1° sheet adjustment accuracy.
2) if you don’t have a Nacra and are unwilling to buy that boat just to get the HUD,  you can try making chat gestures similar to the ones that come with the Volvo Open 70. Here’s a command gesture example that should let you edit your own: “/29000 sheet-1” .
(If for some reason you’re anxious about making homemade gestures, some time ago I boxed-up Fearless Freenote’s gesture set. If you want a copy, drop a note to Fearless, Hannelore Ballinger, or me in Second Life.)

Speaking of gestures and such, I was impressed during beta testing that the Laser often responded sluggishly to control commands. That issue cleared up when I changed the chat channel. The command is “channel xx” where xx is any two digits. Once you switch channels, the boat will remember the settings when returned to inventory.

Life in Balance

OK, back to practical sailing.
Real Lasers
are light weight boats with a sizable single sail and a narrow beam. That makes them quick to respond, but also relatively unstable and highly sensitive to weight distribution (hiking). The Standard Laser (aka Laser One) is usually sailed solo, and it’s recommended that a sailor weigh at least 185 pounds to provide effective ballast to counterweight the rig.

That emphasizes the importance of hiking for optimum performance, and the SL Laser One is no different. It has four hike stations for the skipper on each side.

laser hiking positions

click for biggerness

The figure above shows the approximate heel angle for each hiking position. The most extreme hike spot puts the boat on a 39° heel. Within a matter of seconds that invariably ends up hitting the 40° threshold.. and the boat capsizes. :-)

It takes around ten seconds for the boat to spontaneously right itself. You then get a chance to raise sail and try again. :-)

laser heelI haven’t yet plotted out the influence of different heel angles on boat speed in any detail, but as the figure to the right shows, hiking to windward on a beam reach can easily buy you a ten percent speed boost while preventing you from flipping over.)

The Laser One can hold one crewperson in addition to the skipper. I haven’t yet looked at crew effects, since most laser racing is done solo. However, I’m guessing the crew effects will be similar to the Nacra.

Polar Performance

Laser polar

The chart to the right shows a plot of boat speed versus wind angle for a Laser One with a solo skipper using a real wind speed of 15 kn with the centerboard down.

The red curve documents boat speed as a function of real wind angle, while the blue curve shows similar data plotted against apparent wind angle.

As you can see from the RWA results, the maximum boat speed is roughly 60-70% RWS and occurs on a beam reach. This is consistent with Handicap data showing the Laser One is approximately 27% slower than the Melges-24 (The Handicap Index boat). That’s realistic and appropriate; the Laser is smaller, has a single sail, and no keel.

The irregular shape of the Laser One performance curve above may be due to the inherent ‘jitter’ in the BWind 2.5  wind engine, with fairly sharp drop-offs as the headings turn windward or leeward. On the other hand, the RL Laser polar is an irregular curve as well. :-)

LaserPolar via btinternet and Laser One

click to enlarge

Most charts of real sailboat performance are displayed using a radial (polar) format, and the chart to the right shows an example for the Standard Laser. It includes five curves that show boat speed for different RWS intensities that range from 8.5kn to 30kn.

On that same chart I’ve superimposed data for the Mesh Shop Laser One using the BWind default RWS=15kn (the dark blue curve indicated by a green arrow).

The shape of that Laser One performance curve is  similar to the RL boat polar, and the range of Laser One boat speeds for RWS=15kn falls between the RL Laser curves for RWS=13.5kn and RWS=19kn. In other words, the Second Life Laser One’s performance closely matches the “First Life” Standard Laser.

Centerboard Ups and Downs

On sailing dinghies, a retractable centerboard (CB) takes the place of a keel. The CB enhances lift and allows a boat to hold course on an upwind heading without side-slipping due to wind pressure. However, on downwind points of sail, the CB  becomes unnecessary and just slows the boat due to drag.

The Laser One has a CB that nicely demonstrates these effects. In the image below-left, my boat’s on a close reach with the CB down, and it has little trouble holding a constant heading. However, if you raise the CB the boat starts to slip leeward and the nose rotates downwind. As shown below-right, within half a minute my boat fell off the wind by 40 degrees!

laser cb upwind

On far downwind points of sail the CB just slows you down. You may notice on the previous polar chart that the Laser One‘s performance on a broad reach dropped off more quickly than the RL Standard Laser. That’s probably because the measurements on the virtual boat were all made with the centerboard down.

If you lift up the CB with the wind to your back, you’ll get a significant kick in performance, as shown in the sequence below.

laser centerboard downwind

Actually, with the CB raised and the boat in level balance on a dead run, you can even get Laser One to plane once the boat speed reaches 8kn or thereabouts. I can’t comment on that point yet though, since nearly all my testing of this boat used the 15kn default wind. You’ll need a much stiffer breeze to hit a boat speed of 8kn when sailing the Laser One. :-)

By the Lee

Let me comment on just one more novel feature in this boat. When sailing a run, Lasers can get an added boost when sailing By the Lee.” Let me explain that in two minutes: :-)

The forces driving a sailboat are a combination of dynamic lift and drag effects.

downwind airflowOn most points of sail, the boom is pushed to the lee side of the boat and the laminar flow across the airfoil travels from “luff to leach” (from the mast to the free sail edge) (first pic on the right).

On a dead run (middle pic), drag forces push from directly astern and hold the sail in place. That allows a boat to cross the wind to the opposite tack without actually flipping the sail (termed ‘sailing by the lee‘). This reverses the direction of airflow across the sail (third pic above), and in boats like the Laser a skilled skipper can use that to get a performance boost.

by the lee

The Laser One models this RL effect. The image to the right shows my boat on a Starboard tack with RWA 170 and a boat speed of 5.4kn. The next image show the boat a few seconds later. It’s crossed the wind and is now on a Port tack with RWA 166, but the boom hasn’t flipped sides. The boat’s sailing “by the lee” and it’s moving at 5.9kn, a 10% speed boost. :-)

This is a nice effect, and the performance gain is large enough that I’ll probably end up plotting out all the angles and combinations at some point, trying to see what works best. :-)

Summary

The Mesh Shop Laser One by Kain Xenobuilder is a cat-rigged dinghy racer inspired by the RL Laser Standard. The build is 100% mesh and the SL dimensions closely conform to the ILCA design specs. The boat’s level of detail and RL accuracy are impressive.

The  boat uses the BWind 2.5 engine, and the control and info display features are similar to (and overlap with) other boats in the Mesh Shop fleet. The boat includes a number of realistic race performance features, including a functioning centerboard and 8 skipper hiking positions to balance the boat (with a capsize animation when hiking fails). The Laser One has a polar performance curve that nicely matches the real Laser Standard, and in the hands of a good skipper the boat will plane and sail by the lee.

Like other Mesh Shop boats, Laser One is not WWC-compatible, it does not have wind shadow, and it uses a unique wind variance system. These are intentional features that distinguish the boats from most others sailing in SL. However, I doubt these issues will discourage any sailors from racing Laser One as soon as they can get it out of the box. :-)

Bottom-line, I think the combination of a remarkably authentic build plus sailing features that emulate a real racer will make Laser One a hit with SL Sailors grid-wide. But hey, go visit Dutch over in Tschotcke, drive the boat around the block yourself, and see what you think! :-)

laser breadnut

6 responses to “Laser One

  1. Go read Noodle’s and Orca’s comments about Laser One too!

  2. Over the past few days, a number of nice people sailed hotlaps in the new Laser One, including Kain Xenobuilder, Kris Hollysharp, LucyInTheSky Afrenesis, Jane Fossett, and Yala74 Resident. The laps were scattered over five of the six Hotlaps courses: Plum Gut, Breadnut, Linkous, Knaptrackicon, and Hepurn.
    Remarkably, the handicap factor for each course turned out to be nearly identical, ranging from 0.71 to 0.74.

  3. Beautiful Lasery post with all the details and more; Thanx Jane. It’s great. That comment you made about the handicap factor made me wonder: How can the ratio between the Laser and the M24 be so right, when the Melges24 seems so overly fast?

    • Hiya!
      I don’t have a real-life Melges 24 polar to compare it to, but in SL the Quest M-24 can do better than 80% RWS on a beam reach and it hits 90% RWS with the spin up.
      The Hotlaps data shows the average handicap for all boats is 0.87 (the median is 0.85), and the third quartile is 1.04. That means that over 25% of SL handicaps are faster than the Melges-24. That includes all the Wildwind boats, the different ACAs, and the three other Mesh Shop boats.I was also impressed that Slanty showed M-24 was a bit slower than the Tako 3.3 (Handicap 1.03). So, the Melges-24 is fast, but not overly fast for SL boats.
      Here’s a quick-and-dirty chart where I superimposed the Laser One curves on top of the Melges-24 graph.
      It’s no surprise the M-24 is much faster.
      Oh, and

      *** Does anyone have the VSK5 polar for the Melges-24?

      I’d love to see it. :-)

  4. Fascinating. Looks so much like a real Laser.

    If there’s one thing I would improve it’s those hiking positions. Real Laser sailors hike with legs (almost) straight.

  5. To Noodle and Jane both, in building the M-24 I modeled the polar curve on a RL polar chart I got from you Noodle.
    The only real problem with the chart was that is was for an 8 knot wind speed, so I had to intreperate for the much higher wind speeds of SL.
    Of course I didn’t just scale it up as no boat could do that in RL but I got it as close as I could to what I would expect a real boat to do.

    Q :)

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