GRF's rig school

Doug it's difficult for me to present an alternative to the points I'm
making. This whole thing blew up because I criticised their rig on their
thread, Phil took their view and started this 'tongue in cheek' thread
initially, but along the line all the D1 crew as well as Mike Lyons , defence
was simply to question a)My ability, which is fair enough, but not really
fair since they've never seen me sail and b)My Judgement call based on
presumably lack of scientific background, despite the fact I've read
everything there is to read on fluid dynamics. (Air and water are both
fluids) and have had thirty odd years experience in the field.

Then the convict weighed in mid thread saying I've got it totally wrong
without actually spotting what the right and wrongs were.

Simply put imo a rig that big needs stays, or at the very least a stiff mast,
stiffer than the one they are using. Or it needs to have more pre-bend cut
into the sail to stiffen it up for the kite use. Even the original of this
genre, the MXRay had luff curve and pre bend cut into the rig and that
was a smaller more pin headed sail.

Edited by G.R.F.

A 'rude' out burst?

Why rude?

Cos I don't like your new toy?

Or the way you are contriving to use the forum for whatever reason, a
better deal, some form of self agrandising self publicity, I've no idea..

But you've been hear five minutes and you're now dictating to me how I
should use them and the tone I should and shouldn't use..

You are doing the selling pal.. I'm posting the sales objections..

Rudely? Moaning?

That's just a matter of perception of syntax.

Here it is the original quip.

Originally posted by G.R.F. OMG look at the distortion.. Tell me What's the point of having an extra front sail if the main one distorts like that? Look at it. Top all twisted off mast tip bent out of shape, damn our windsurf rigs are more dimensionally stable than that, what's that mast made of? Bendy bending stuff from the Planet Bender?

Which then precipitated just the usual patronization I've come to expect
from dinghy industry types.

Edited by G.R.F.

Originally posted by ex laser G.R.F.their is only one person being patronising on this forum.<font size="7">YOU

Hey laser face..

Read the title.. It's my thread..

It's a no brainer, don't like my style - why visit the thread?

Essay no two... (My English teachers would be proud apart from the spelling)

Greame, firstly let me put the record straight.  I am not trying to sell anything here or anywhere on the forum (apart from possibly the B14 fleet).  I have know interest in the D1 at all, I have never knowingly met anyone from the project, and the only time I have seen one in the flesh was at the last dinghy show, where, if I am honest I though it was quite an ugly boat.  I am way too small (at 70kg) to ever be competitive in that boat, and frankly I personally find single handed sailing boring - just my opinion, but I can also understand why people enjoy it.  My only interest is in the discussion and its accuracy (and I enjoy a good debate).  For what it is worth I don't think you overstepped the mark. 

Perhaps it is the sterility and lack of personal context inherent in writing on forums like this, but I tend to get from a reasonable number of your posts a rather aggressive tone.  I have no issue with you picking fault wit designs, and I do agree with you on a number of things, its just at that point I keep quiet, as 'me too' does not really advance the discussion.  If you remember my initial comment on the mast bend was that perhaps thee was a touch too much as well, but my theory was that it was more to do with an error of the user than an error in design. 

If I have jumped to a false conclusion as to your level of knowledge on the D1 project I apologise, I had not read back through the whole thread, and that is my mistake - sorry.  The one thing I would like to bring up though is that you talk about it having a flexible tip when the photos show it does not.  The first thing I did was to hold up the edge of a bit of paper to the photo, the top third of the mast is straight, all the bend is in the middle 25%.  This follows in the same vein as many of the new carbon masts that have been designed of late, stayed or not. 

From my knowledge to build a mast for that rig which does what you suggest it would result in a very heavy spar, the resulting design spiral from a heavier rig we both know.  I suggestion is that it is better to, yes design it to minimise fall-off to leeward, but within reason in terms of mast mass or sectional area, then after that it is up to design the sail to work with the bend that remains rather than fight it.  You end up with a lighter boat which should give you back some of what you may have lost. 
If I am being really honest, given its a sealed mast, and its unstayed why they do not have a tube luff like the moths I don't know, if that is in the depth of the other thread let me know and I'll trawl back through and read it.  I think they have missed a great trick there.  One of my past projects looked into the feasibility of putting something equating to a tube luff on stayed rigs, but I never quite got round to finishing it, as it mutated into looking at putting wing sails on IACC yachts (I wasn't too far off the mark in the end). 

What made me question you level of knowledge of fluid mechanics is you mention of laminar flow foils, this is my pet hate, below the waterline this phenomenon is practically useless, rigs yes, air's viscosity is low enough for it to be a factor, but in water, its irrelevant unless you have the smoothest surface in history and you are travelling very slowly.  The maths and anecdotal evidence both back this up.  The confusion is that at very high speeds similar foil sections to 'laminar flow sections' become the most efficient but for subtlely different reasons. 

As I have suggested before I am genuinely interested in meeting up with you at some point and discussing all of this, believe it or not I do have a healthy level of respect for you, there are just certain things I disagree with, probably as a result of the different backgrounds we have.  I would love to take you for a sail in the B14, and to try the Alto for us to see what each others weapon of choice is like, I could come down for a weekend and we could argue fluids mechanics over a few pints on the saturday night.  The offer still stands. 

I hope thins clears things up, I am trying not to let this discussion get personal, badly-granted, but trying. 

Phil

Edited by Phil eltringham

I'm sorry to say i actually agree with Grumpf here, the whole D-one thread has been self publicised drivel, mainly started by the Italians.  I read his post and agreed with him the mast looked horribly bent, especially as it doesn't look that windy in the photo. 

The main problem is the sales pitch has all been a bit poor, when someone throws an objection or a negative question, you should surround the real objection with benefits and features which meet the potential buyers needs.  Thus overcoming the objection. (Some raw key basic selling tips for you) Check out the RS100 thread, that has had just as many negative comments, but they have been dealt with properly.  

As i see it, if GRF had been treated with intelligent educated answers to his quires and objections you may actually of sold him a boat.  But as you have mentioned before "He isn't the target audience"

 

 

Edited by Merlinboy