Monday, December 21, 2015

This from the Moth Home Builders facebook page:

3 june 2015
Time to add some spice to the home build conversation. I was once a keen home builder but sucummed to the purchase of a Mach2 three years ago. I have enjoyed my Mach2, but the experimental bug does not go away. I talke to a few people at regattas over the past year about this boat but I had nothing to say it had promise until this week.
This photos are almost a year old. Yes its a wing sail and yes it did make it to the water last year, and no it was not a success and yes it as a complete pain in the arse to transport, rig, launch and to sail with. Some good ideas, but mostly a bad idea for moth sailing. The back bit is in a big box and the front bit has been recycled into a new soft rig which seems much more practical and much more functional. The concept was for a deck sweeping unstayed rig with minimal windage and end plate effect. To do this the mast is 200mm forward than standard and the foot length is shorter to allow tacking behind the rig.
The hull is flat topped and the rig/sail come all the way to the deck, the CoE is consequently 500mm lower than a std moth. The hull is wider and shallower than normal to increase the end plate effect and reduce windage.
The hull and these features have been retained under the new rig which I tested for the first time last saturday. It has the same large dia main spar, and some of the same leading edge fairing, but these are no longer rigid and are suported only by special camber inducers so the fairing twists with the sail and battens.
The rig has minimal windage as there are no stays, spreaders or compression struts, and the boom, vang and cunningham are all inside the double skin lower part of the sail.
Its all home built with a lot of cost saving shortcuts hoping to prove the concept before spending up big.
But after only one sail which was abrieviated by breaking one of the main wing bars (made from broken sail board masts, I am sufficiently pleased to have confidence in spending more time and money on the project. It was less than 10kts and although I could not really get enough lift on the rudder, it did fly and it seemed to glide through the tacks withut slowing, But my body movements were limited somewhat by the wing tramps separating from the hull.
One brief sail only, but lots of promise. Wing tramps are fixed, rudder aoa fixed, wing tubes next, another sail in a few weeks. More photos of various bits if anyone is interested.
I have built 12 moths and owned 4 others. Thats as well as 26 other boats I have owned or built for my friends, myself or my family since 1962. That make this boat #42. For Douglas Adams fans that could mean that this is my ULTIMATE boat or the ANSWER to the design question for moth sailing. We willl see. Good name though.

 3 dec 2015
After 6 months off doing other stuff I am back onto this project again. The new wing tube sockets are in and the deck repaired. Bowsprit next, new telescopic wand needed. Some interesting things to do with the rig too. Might sail it before Christmas after the M2 gets loaded onto the truck for the Perth Nationals.
19 dec 2015
 Ready to sail today, wing angle incresed, the double deck is gone so I can see what all the controls are doing. I have changed the boom and vang arangement to make less impact on sail shape. Photos later today. Expect the unexpected. Its forecast to be a bit windy for a test sail, so hope it all hangs together.
 Rigged and ready to go, no windage from spreaders, compression struts, stays, boom, vang. Its all inside the sail.
 Sail needs some work, it was a bit of a rush this week after some delays getting the boxes loaded onto the truck for Perth. But I went sailing, completed the race, had a few issues which made tacking difficult, so quite a few swims. But nothing broke.
Phil Stevenson's photo.
 The camber inducers fit around the mast and extend forward to form a neat aerofoil shape. then the gaps between them and forward of the mast are covered with shells of K/C hybrid laminate
The shells
The whole rig is down to the deck, the mast band is at deck level, minimising lower tip losses, and reducing both capsize moment and total aero drag.
There are two booms inside the sail which is doubke skin below the bottom batten. Both have conventional type goosnecks just below the batten. They have pin joints at either end so can rotate. The idea is that they are half wishbone shape, hange vertically in neutral and rotate to leeward to match the sail camber on either tack. This first attempt had a bent boom for the longer upper one and worked Ok until one of the endplugs sliped in and jammed the pivot. The smaller lower boom just goes down to the back end of the mast strut, spreads the vang loads and gives teh mainsheet somewheer to attach. I used a straight tube this time but it will get a bent one next time.
 The whole rig is 200mm forward of standard, the centreboad is 300 forward of M2 position, so it really needs the bowsprit. When I sailed last winter without the bowsprit control seemed marginal, yesterday it was on rails. Foils used were M2 verticals, old large M2 rudder foil and a Makita main foil. My others are all in the box for Perth. The forward rig is to allow tacking behind the sail. Yesterday I had both booms a bit long and the vang line between them was below the sail, so I managed to catch it nearly every tack and fall over. this will be fixed next time, I just ran out of time after loosing a couple of days with teh truckies.
 The boat is amazingly quiet, even compared to other moths. I think it will foil tack easilly once i sort out the gap and my technoque, A couple of times It came about so fast I fell overboard as it accellerated, I just have to work out where to aim my bum or what to grab.
Hope you all enjoy the story. Not sure when the enxt sail will be, probably after Perth. Hope there is something here to inspire the mad home experimentors.

Wednesday, January 23, 2013

2013 Aust Moth Nationals at Wangi

I posted this on but due to web link stuff I do not understand it did not appear on I hope by posting it here the links might get picked up and be seen by anyone who missed them.

We have had 15 races, 4 on each  two days, there are a lot of tired sailors.
The regatta has been dominated an won with a day to spare by NZ Peter Burling. He becomes the first international to win an AUS nationals regatta and the first Aust Open Champion. Scott Babbage has been second yet again but this time at least he becomes the Australian Champion as first Austalian.

The big crowd of volunteers from Wangi ASC have done a great job, the weather has been very good and the winds generous.
Next year we venture to Yepoon, with an AUS worlds in 2015 at a venue yet to be determined, Perth, Sorrento and Woollahra are bidding.
Thanks to ZHIK for the three big boxes of prizes, and to CST Composites who funded the excellent video coverage from Beau Outterdidge. There are other families involved at Wangi, you just do not know all their names.
The final results and the AGM are posted under National Documents:
There are lots of Photos courtesy of Kingsley Forbes Smith here:
See all of the videos here:
Congratulations to Peter Burling (Aust Open Champion) and Scott Babbage (Aust National Champion)

Wednesday, February 8, 2012

Yawn, out of blog hibernation

Its been a while but just in case anyone really cares here is my moth activity update for the last 12 months.
. Last two posts were about rules changes? Still nothing finalised but I was on a committee of review and our decisions are being drafted into a rule proposal by Adam May for a vote sometime. Seems almost everyone else has forgotten and does not care any more.
. Just before my last post Sawdust and Soot died. The ultra light ply hull broke in two while sailing. I must have been too embarrassed to tell anyone.
. Dave Lister kindly leant me his original Manic for the Belmont worlds which I used with my foils and rig.
. Belmont regatta was a great success for IMCA Aus but not for me. I broke a lot of my stuff and none of Dave's for many alphabet results.
. After the regatta I got Karma back form Chris Dey, who almost got into the A fleet with it after minimal sailing beforehand.
. Only sailed it a few times before getting some angina pains, resulting in a heart stent and no more sailing that season. Resultant rehab has me now fitter than I have been for years.
. Over the winter I put a new working deck on Karma and lowered the wings and tramp down to normal levels. Built a new main foil from Bruce McLeod's new mold, simplified and stengthenned a lot of stuff and repainted the hull white.
. This season the boat proved much more reliable but the new foil seems to have a 20kt speed limit, as well as launching late. I'll fit a different foil before trying to sell it.
. Went to Nationals briefly with slow boat and poor settings for rough location.
. Bit the bullet and bought a Mach2 last week after deciding that I have had enough of making carbon dust. I figuring I have only a few more years of moth sailing left so might as well enjoy the sailing part of it even more. And looking at all the other Sydney fleet options I could not find anything else worth sailing.
. Aust will be bidding for a 2015 worlds at Geelong which is worth hanging in for even if I will be nearly 65 by then.
. So sorry for the few readers who like hearing about my latest experiments. Thats over, so you will probably not need to check with me again. I'll be just one of the multidue on one of those black boats going much faster than I used to be with any luck.

Sunday, December 26, 2010

What needs to be fixed.

We are almost there in the tedious process of deciding if Bora can use his wing.

How did we get in such a mess?
This week ISAF decided our current rules did not cover mesurement of wings so they could not be measured. Why?
Its only our current rules which do not cover wings because before that the rule read:



The boat shall carry only one sail. No extra sail shall be on board when racing.


The sails and spars shall be measured in accordance with ISAF "Measurement and Calculation of Sail Area". The ISAF Sail Measurement Instructions shall not apply. The measured and calculated area shall not exceed 8.00 m2, except that:


Clause 3.2.5(b) of the ISAF Measurement and Calculation of Sail Area shall not apply.


Only the area of that part of the spars that will not pass through a ring 90 mm internal diameter shall be included.


For a sail which encloses the mast, an area equivalent to the length of the luff multiplied by 50 mm shall be excluded.


For a sail which encloses the boom, an area equivalent to the length of the foot multiplied by 90 mm shall be excluded.

When we ammended our rules in 2005 to measure true area rather than the 3 offset simpsons rule method (Clause 3.2.5(a)), we deleted the above reference to the "ISAF Measurement and Calculation of sail area.. MCSA" which is what the CCats use to measure their wings and which Bora found still contains a reference to its applicability to the Moth class.

If we had retained that reference ISAF this year could not have made that decision. There are other matters of ambiguity, like how we apply luff length limits, mast length limits and the one sail rule, but we could have measured the area.

So in 2005 we inadvertantly banned something which the rules had specifically previously allowed. Its important that in 2011 we do not inadvertantly write new rules which prevent development in any new direction.

I am advocating strongly to reinstate the ISAF MCSA as our standard for area measurement. But we also need to decide a few more very basic things.
1. Do we want to ban all solid sails? Not just complex ones like Bora's.
2. Do we need the one sail rule or how do we apply it to multi panel wings.
3. How do we measure luff length of wings, or can we replace luff limits with a rig height limit.

My personal choice is to accept wing development as the class did pre 2005. They will get better, cheaper, simpler, more packable and faster.
I do not really care about the one sail rule, but if we delete it we have one less thing to argue about.
The simplest method of controlling aspect ratio is to limit total rig height to a distance above the keel of the hull. This is at present about 6.3m, which would be a good number to choose.

If we adopt the ISAF MCSA then we might as well get rid of the two other inconsistancies and measure total area of all exposed sails, wings and spars, ie delete the luff pocket allowance and the 90mm free mast area . We would have to increase the total to 8.3sqm to match existing rigs.

Please consider carefully we must not make mistakes this time which will cause dramas in the future.

Friday, December 24, 2010

The WING Issue

I am posting this probably too late to influence any vote currently underway within IMCA. But I feel a lot has to be stated which has not been clearly put in one place elsewhere.

The present vote is to decide if two specific wings will sail in the Belmont regatta. The default is they don't and 2/3 vote is needed to get them in. Its a tall order and the reasons behind it are obscure.

Apparently ISAF were asked some questions and they repied that under the current rules the wings are illegal.

What we do not know is what questions and documents IMCA gave to ISAF and on what basis ISAF made this decision. We do not know if the illegality is for all wings or for some particular design aspect of the two wings now at Belmont and waiting to race. We do not know if such aspects were modified these wings might be deemed legal. Its a bit of a mystery.

Back in July the IMCA executive had a debate and made an interpretation of the existing rules which seemed to cover most aspects of wing design. Unfortunately they then failed to offer this document to ISAF for endorsement and hence it became illegitimate. We do not know if ISAF were given the oportunity to endorse this document when asked other questions in December. It would seem to me that this would have been the simplest solution, ISAF endorsing the IMCA interpretation. But it became apparent that at leat one contentious rule was not addressed and also that some of the executive had been influenced by some anti wing lobyists. Its another mystery.

Whether the class should allow wings philosophically seems a no brainer. The class has spent over 75 years leading the sailing world in small boat development and as a consequence its always lead the small boat world in performance, in the foil era, in the narrow boat era, in the scow era, always ahead of everything else. Its not time to put on the brakes now.

The various arguements against wings are mostly self interest. Some of the fast Mach 2 sailors who think they might have a show of winning a worlds see Bora's wing as a serious threat. The manuafacturers of sails and spars see a business threat, the builders see changes in design which might make their boats obsolete or their tooling redundant.

The cost, durability and transport issues are things which will be overcome. Just because one well off American has spent more than most can afford on building and transporting wings does not mean everyone else needs to go the same way. There are other build methods other designs and its not compulsary anyway. There will certainly be times when a mast and sail are faster anyway.

The earlier questionaire also incluses some spurious questions, the concept of a tavel box restriction is nothing the vast majority of moth owners will ever need to wory about. This year about 30 people moved moths overseas to the Worlds regatta, similar numbers went to the USA, less to Dubai and to Europe. Its a minority activity by a dedicated few, not a universal class perogitive.

None of these things are in the class objectives or rules and should not influence any rules decisions.

We are sailing a development class and development should continue which improves performance.

We need to reinstate the IMCA rules reference to the ISAF sail area measurement manual which existed from the 1960s until omitted as part of some amendments in 2004. With some other agreed tidying up we will avoid another 6 months of angst and aprehension such as we have just experienced. Lets get it right in 2011.

Please all have a happy and peaceful Christmas, and I will see many of you at Belmont in 10 days time.

Friday, October 8, 2010

It sails

Sawdust & Soot has now sailed twice. It seems to fly easilly and goes faster than Karma at least downwind. Found a leak needing a repair, fixed but have had a week away in the country before sailing gets started properly. Now all ready for tomorrow's first StGeorge club race, under the management of Manly skiff club, do not ask, its a long story and its not really over yet.

Next project is to modify the fin case on Karma to suit a Mach2 foil set for Chris Dey. He has borrowed my boat and purchased some M2 foils in preparation for a Belmont return to moth racing.

Time to build a wing?, probably not this year. Maybe next winter. Some discussion on a few blogs and M2 forum currently, seems to show weak support for a restriction on wings?

Have a look and post an opinion, not here.

Sunday, July 25, 2010

Slow progress.

Due to some diversions, I have done very little on the moth for about a month, but as its only another month until some clubs start racing again, I now have to make a big effort to complete the project.
The photo does show some progress since my last post and there are a set of foils and two rigs in the shed as well, so I do have some hope of making the new season's openning races.
FWIW the hull and wing assembly as shown weighs in at 14kg, which I am very happy about.