Dragon Force Standard Sail Measurement.

[David Foster]

OK. I know that if I am using the standard sails in a Dragon Force event, I don't need to have the standard sails measured, as the rules clearly state the builders sails comply.

The question is - If I entered the standard DF in an RG65 event, presumably I have to measure the sails, fill in the form and mark the sails accordingly? Presumably, the same would apply if I was using third party DF sails?

David

[buzz coleman]

Hi,

There is no requirement for sail measurement sign off. Measurement may take place at a restricted class event. If you wish to remain within the class rules make certain the measurement are correct and all will be ok.

Remember purposley braking the rules gives winning no meaning.

[David Foster]

Hi Buzz. Thanks for the reply.

I noticed that the RG65 site says that currently the UK doesn't require formal measurement, sign off etc., but the 2014 RG65 rules clearly state in rule 6.3 that the area of each sail must be indelibly marked on the sails. Are you saying that this is not necessary in the UK for any RG65 boat, whether a DF or other design?

David.

[Chuck LeMahieu]

You practically need  an engineering degree to properly measure RG65 sails... ;)  No one actually wants to do this , and trust that competitors will do it on their own,  

[David Foster]

Thanks for the responses, Chuck & Buzz.

I had studied the RG65 measurement spreadsheet & example and decided that the complications of measurement were enough to put me off experimenting with different rigs and hulls, but I shall now continue experimenting!

Thanks.

David

[Barrie Norman]

The RG 65 class has always needed the boat and sails to be measured, The Dragon force even if sailed as a restricted class has to conform with the RG65 class rules which override the one class rules.

[Joanne Sharpe]

Just as a matter of interest, I used the spreadsheet for sail area calculation on this site and entered the dimensions given in the DragonForce Restricted class rules for the 'A' rig.

I didn't save the result, so this is from memory, but the 'A' suit specified for the DF came out at around 2,100 sq. cms. area (6% below the RG class maximum of 2,250 sq. cms.) and the mast specified is around 900 mm., which is well below the RG class maximum of 1,100 mm.

This means that a DF rig and sails that is within the Restricted Class rules (with one bizarre exception) must be within the RG rules by definition. The bizarre (hypothetical) exception is that Joysway make some of the painted sails that are outrageously over sized (manufacturer's sails are deemed legal), but this seems most unlikely.

After witnessing the recent Nationals and seeing top skippers with Restricted Class DFs staying in reasonably close touch with development class boats, one wonders how well a Dragon might go with a full area suit of paneled, high aspect ratio sails (to the RG max. of 2,250 sq. cms.) on a metre plus mast - under the right conditions of course.

It seems that one strength of the DragonForce which is yet to fully emerge is that it can be set up as an outright Development Class boat (say tall swing rig ... carbon fin etc.) and  it can still be changed back to Restricted rules in a few minutes. Maybe this is a source of significant growth for the RG 65 class?

Take care

Joanne

[David Foster]

Buzz says that measurements don't need to be signed off, but that you need to make sure your measurements are correct as they may be checked in a Restricted Class event.

Chuck says they are a nightmare to measure and no-one wants to measure them, so it is up to the owner to measure them.

OK, I think I understand both the above - Self certification with the possibility of checks that they are correct at Restricted (RG65) events and presumably we have to mark the sails with their area, as required by the RG65 Rules.

Barrie says the RG65 class has always needed the boat and sails to be measured. He then goes on to say that if you are sailing your Dragon Force in a restricted class event, the Dragon Force has to comply with the RG65 Rules. If that is the case, are you saying, Barrie, that each Dragon Force entered in an RG65 event must be measured and have the sails measured and correctly marked with the area, as specified in the RG65 rules, even if they were the original Dragon Force sails? I assume so, and rightly so, in my opinion.

If the above points are all correct, then can I assume that all the Dragon Force boats sailing at the recent RG65 Nationals had their sails marked with their area and were measured by their owners according to the RG65 requirements?

David.

[David Foster]

Joanne.

Funny that you should mention about rigging a Dragon Force hull with a high aspect rig to see how it compared, as I am doing just that at the moment. I intend to experiment with a number of different types of rig on my Dragon Force to see how the rigs compare with the standard DF rig used by other members of our club. That should provide a very simple yardstick as to the relative performance of the different rigs. Depending on the results, I shall decide on what RG65 hull and rig I might want to go for.

I assume you had to measure your A, B and C DF rigs and mark the sails before entering the Nationals?

You refer to the Manufacturer's sails sometimes being outrageously oversized. Surely they couldn't be sufficiently oversized that they would exceed the 6% undersize that you mention they are actually supposed to be.

David.

[Joanne Sharpe]

Hi David,

At the Nationals, I had drawings of all of the rigs I was using (Arne Semken templates) showing all of the dimensions, areas and calculations. As far as I am aware, scrutineering of DFs at the Nationals was focused on keel bulbs and covering the screw hole (not allowed in restricted class rules) . Some boats were recategorised as RG65s.

We may be getting into tricky territory here because I am not aware of anyone who is qualified to measure RGs, but that may just be down to my ignorance.

Changing the subject, I've attached two photos, one of my boat at the Nationals with compliant Dragon sails (Semken template), the other of a boat with an Andreas Hoffmann swing rig.

I built a swing rig as per Andy Hoff's measurements with paneled sails and stuck it on my Dragon yesterday. Mast 104 cms from deck to top of crane, area 2235 sq cms as near as makes no odds (I had to trim 1cm from the top of the main to fit my rig).

Try it, it's a different boat. In light airs it flew.

Joanne

[David Foster]

Thanks for the info and the pictures, Joanne.

What did you use for the gooseneck/cross junction on the swing rig, out of curiosity? They seem to be either high tech moulded CF or aluminium in many cases. I haven't quite worked that bit out yet!

I hope to have a McRig up and running soon. There seem to be a number of them racing competitively in the States. Time will tell. After that, a high-aspect rig, then a swing rig. All for light weather initially.

I will post a pic or two, once done.

David.

[Joanne Sharpe]

Let's call it a hybrid LOL.

I did a very simple pintle as a swivel on advice from one of our older members who sails swing rigs all the time (did you meet 'Old Norman' when you visited us?). Brilliant guy, but has his little ways.

It's simply a carbon tube (7mm OD) that's packed out with tape on the outside to a snug fit in the forward deck step hole with a piece of 4mm piano wire secured in the middle so that it sticks up about 10mm above deck height. The wire slides inside the mast which is 6mm OD x 4mm ID pultruded tube. No bearings and works just fine !!

The main booms are also 6mm carbon tube and the flying jib boom is 4mm CF tube. I used 'one or two' cable ties instead of the neat bindings that Eric illustrates, placating my conscience with the 'proof of concept' get out clause hee hee.

I then made up the cross as in this article by Eric Rosenbaum, with one modification:

http://iomdesign.wordpress.com/rigs/

I didn't have any fibre glass plate made up as in Eric's photo for the side 'cheeks' so I used 1.5mm ply instead. Perhaps a little over engineered, but the whole rig and sails weighed in at 76 gm which I though was acceptable for a proof of concept.

I used a 'washer' between the pintle set up in the hull and the mast base / bottom of the tree cross which is 'Teflon' ish - just a slice sculpted from an old cutting board from the kitchen (available for peanuts at Morrisons hee hee).

Also, if you're experimenting with McRigs for RGs, it might be worth making contact with Matt Riley AKA GBR 20 (he's on this forum). He showed me one at the Nationals (it didn't get used as the weather wasn't right).

I hope this is helpful, but if there's anything else, I'll help if I can.

I may go testing again later today at my local canal basin and will see if I can get a photo of Dragon and rig.

You can find the sail template at:

rg-andy.blogspot.de  ...  under 'downloads'.

Take care

Joanne

[David Foster]

Joanne.

Brilliant! Have you ever been a Blue Peter Presenter?

Oddly enough, I stumbled on the article by Eric Rosenbaum last night and I had already downloaded the templates from rg-andy-blogspot. I guess I haven't really got any excuse not to get on with it now!

I have already cobbled up a mast stub for the McRig, so can probably use that as a basis for the Swing Rig too.

Mind you, if it doesn't put down some serious rain soon we are going to be in trouble. At one of my sailing lakes where we normally sail 1 metres, we are using the DF with short fins and beginning to touch bottom with those as the level is about 2 feet down on normal. To make matters worse, the rather large fish are now taking an interest in the fins and it isn't unusual to see the DF either dip down or pop out of the water every now and again! On another pond, the level is down and the weed is beginning to take hold.

Thanks for all the info.

David

[Joanne Sharpe]

Hi David.

I only use sticky backed plastic for sail corners and deck patches hee hee.

Our water levels at Weecher are dropping too - we're down to about 25ft in the middle (gloat gloat). I'm not sure that I'm wishing for a return of the bad weather just yet - we were still discussing the difference between hypothermia and mild hypothermia in the middle of May !! (The 'folk lore' is that it can only be mild hypothermia in May). You've sailed at ours, so you know that you always have a transmitter mitt in the car, just in case :o).

I had an exchange of emails with Bill Hagerup a couple of weeks ago  (BIG exponent of McRigs) and I got the impression that he may be coming to the view that swing rigs can generate more performance under the right circumstances.

It has to be said however, that a McRig is so simple and easy to make that it would be rude to ignore that option. Please feel free to use 'Auntie Joanne's Proof of Concept' methodology so that if it's a total failure, you can claim to have learned something !!

Just to get back to my overall feelings about the DF. The restricted class rules 'A' rig is nice, easy to handle and sails well and of course is great for 'one design' racing. However, if you're prepared to step outside of the Restricted Class rules and work to the maximum rig & sail dimensions/ specifications allowed with the RG rules, it can be made to go surprisingly well.

Wing sail anyone?

Take care

Joanne

[Joanne Sharpe]

Typo alert !!

In a post earlier this morning (at 9.24am BST), I described a piece of 4mm piano wire protruding 10 millimeters above deck level.

Please do not follow this measurement and try 10 centimetres instead !!

Doh !!

Joanne

[David Foster]

Weecher is a great place to sail. The lack of trees around it and being fairly high up makes for good winds, though I will concede that the temperatures are a bit lower than elsewhere! Most of the places where I sail have somewhat flukey winds which make things interesting. The fish were biting well today. I would guess that between the 5 of us racing, we must have had at least 20 strikes! It really gives a meaning to the saying "Taking the wind out of your sails". Good afternoon's sailing though.

The Footy I am currently building is a Bill Hagerup design, with a McRig. It was whilst researching that that I came across a McRig for RG65s. As you say, it is such a simple rig that I really can't afford not to give it a try, if only because, on face value, you would expect it to be too simple to work well, but apparently not. Time will tell.

Whilst I love experimenting, I have to admit that I really enjoy sailing where the results are largely down to how you set up and sail the boat, rather than down to the boat.

Re. Your other post about the 10mm typo, I think anyone who tried it might have discovered the error pretty quickly!

David.

[Chuck LeMahieu]

Since it bears on this discussion here is Eric Rosenbaums Dragon Force swing Rig:

[Joanne Sharpe]

Thanks Chuck,

Makes mine look a little agricultural hee hee.

Proof of concept, yes that's it. I think Eric and I are within 10 sq cms of each other on main sail area :o)

Will get some pics ASAP

Take care

Joanne

[ChewbeeDoo]

@Joanne 

My dragon now has a full (2250) RG Swing rig, So I can experience the "gain"

The gain in surface does not do  much, I also crafted "true" I.e Sails with draft.

what I can say is that in very low winds the Dragon move earlier an faster than with DF Class rig BUT

The dragon is a boat that loves wind, and here in paris we have not much wind in this case the dragon suffers

As soon as the wind build sup then it is really u p o the skipper ;)