Get this!

[kayu]

1) a flat area through the middle of the chord, this produces bumps or corners in the curve fore and aft of the flat area.

2) an overly large leading edge radius, this causes drag.

3) a rather thin foil, again common to many singles, this reduces ability to turn through tighter arcs and encourages spin out at higher angles of attack.

4) It's just not a well worked out foil, it's a standard sort of result typical of fins ground out by disc sander particularly those which are on a box base since this makes proper foiling more difficult.

Sorry Roy , most of that can only be taken as your opinion. Granted all boards with a slide box are restricted to a 10mm thickness , and a hand foiler is only as good as his last fin....(lol).....it's why Geoff prefers glass-ons....your theory on leading edges with "overly large radius" , I completely disagree with.....forgotten the number of fins Ive softened the leading edge on - and they always perform better for it....... If a customer is prepared to spend the $$$'s and get high end , hand foiled glassed on fins , they are certainly available from most builders of quality boards.....but the mass market disposable stuff is another ball game......

[Roy_Stewart]

Sorry Roy , most of that can only be taken as your opinion. Granted all boards with a slide box are restricted to a 10mm thickness

They most certainly are not!

That's only the case for the old 'grind it out of a plate with a disc grinder' fins (like the McCoy's)... our fins have exactly the thickness which we design them to have regardless of the fin tab thickness.

your theory on leading edges with "overly large radius" , I completely disagree with.....forgotten the number of fins Ive softened the leading edge on - and they always perform better for it.......

I didn't say that all fins have a leading edge radius which is too large... and I agree that many have a radius which is too small, however the McCoy original which I have has a leading edge radius which is way larger than it should be and would not be seen on any well designed foil of even 50% greater thickness. The leading edge radius is so large that there's very little room for taper to the maximum chord. It exacerbates the flat section problem in the fin.

If a customer is prepared to spend the $$$'s and get high end , hand foiled glassed on fins , they are certainly available from most builders of quality boards.....but the mass market disposable stuff is another ball game......

Sorry but the hand foiled glass ons are not in the same league as computer designed and manufactured foils. I was shocked to see how much better the 3D printed foils are than any hand foiled fins including my own, and I spend up to 40 hours hand foiling a longboard fin...

Anyone who sees the McCoy Gull Wing alongside the Warp Drive Gull Wing can see the difference in the quality of the foiling immediately... and of course the Warp Drive fin is only 170 grams in weight compared with the McCoy which weighs 320 grams.

On the subject of weight the warp Drive has significant positive buoyancy, given that this is in the fin not the board it comes with no penalty in terms of board thickness. The McCoy fin on the other hand has negative buoyancy which has to be overcome by the hull of the surfboard.

Here's a McCoy Gull Wing which was finished with a gold spray. One can see where the gold spray has worn off in a line about 2/3rds of the way back starting near the fin base. It has worn off there because that's the back end of the flat zone and there's a big corner/bump there in the foiling. Behind that there's a trough followed by another corner, then the trailing edge hooks in with an accelerating curve like a hooked leech on a sail. It's no worse or better than most hand foiled single fins but it's not good. There's another bump/corner near the leading edge, that is the front of the flat zone.

[Roy_Stewart]

Fongs the fins are not 'popped out' (which implies moulded) and are certainly not mass produced.

A 9 inch fin takes 8 hours to make, and about a third of our orders so far have been custom fins, a process which takes much longer than making hand made glass fins.

I am stating that the method can produce better fins in terms of performance than is typical for those which are hand made, although hand made fins have their place.

The Gull Wing drawings took over 20 hours to make, that's not counting test prints and bench testing. Plus there's some hand finishing on the trailing edge required.

[kayu]

Not buying it......hand made fins from a pro , and glassed on are the best , end of. The market you're targeting does not include top-shelf fins ......the Chinaman has already had you for breakfast.

[ctd]

Not buying it......hand made fins from a pro , and glassed on are the best , end of. The market you're targeting does not include top-shelf fins ......the Chinaman has already had you for breakfast.

Good thing all top quality products nowdays are still hand made.

[Roy_Stewart]

Not buying it......hand made fins from a pro , and glassed on are the best , end of.

Disagree, water doesn't care who made a fin or what their work status is, it's just physics.

oh, and glassed in is more efficient than glassed on.

The market you're targeting does not include top-shelf fins

Is that so?

......the Chinaman has already had you for breakfast.

Lol !

[Roy_Stewart]

Good thing all top quality products nowdays are still hand made.

Mate all top quality comments are hand written so get to it.

[Roy_Stewart]

The fact is that 3D printing is revolutionising manufacturing in many areas.

Fin wise it can produce shapes which can't be done by hand, and it gets better results than hand shaping by far.

One small example is that you already stated that single fins for boxes are limited to 10mm in thickness... 3D printing has no such limitation... and good luck shaping micro grooves and small tubercles by hand.... or a defined Eppler or NACA foil... most 'pro' fins don't even get out of the starting blocks in terms of foil shape quality, they have flat spots and bumps, and the foil design is vague and undefined.

Then there's design... you are only thinking of the making of the design but the design itself is also an issue... and doing it by computer is so far ahead that it is ridiculous.... I make wooden boards by hand and am all for it, but the subtlety of computer generated curves is hard to beat.

It's expensive to 3D print high quality in PC though... home printers doing ABS don't cut it... definitely top shelf price wise and in terms of quality.

Don't worry though you'll still get food on the table making your excellent woodies for Geoff.

[Roy_Stewart]

Roy, a friend of mine surfs a modern adaptation of MP's famous cutty board. Its around 5'9" x 20" x 2 3/4" with modern bottom and foil. Looks very similar in planshape to the old MP board. Its one of Mark Pridmores MP3's.

What size and foil shape single fin in your range would you recommend him to try in that board? Its designed to be a 2+1, so the tail a tad wider than a pure single fin. If that changes your advice.

Thanks!

Sorry I missed your question.

Either the spitfire or the Gull Wing should do well.

Size wise I'd go for 8" to start with, if used as a single fin.

Foil shape wise I'd go for the Eppler 168 as it is ideal for radical direction changes.

[Roy_Stewart]

well I've been testing the spitfire version and I'm impressed with the weight, foil and flex, as well as the overall design. The fin performs very well.

I already have a McCoy with a gull wing so It would make a perfect blind test against a fin I know already works well.

Also, excited to test that gullwing in other single fin based designs to see how it goes.

Hi Steve I'm happy to send a bigger spitfire and a Gull Wing, we'll just have to work out what sizes you'd like.


I have a bunch of spitfires with various sizes and foils. the GW's are all 9" at present but we can dial up a smaller one if you like.

( Edit actually they are 9.5" whoops)

[spork]

Actually I'm with Roy on this, there is no way a hand shaped fin will be as accurate as a computer generated and printed shape. Even more so if you have to make two side fins, identical but mirrored, and then a centre fin to match foiled evenly both sides. Also, current designs can be scanned and copied to achieve identical plan shapes and foils. Internal construction is flexible and therefore twist and flex patters can be experimented with, as can hundreds of plastic compounds, even metals. 3D printing is the future of manufacturing for millions of products. I'm already using my own design fin boxes and plugs and have began work on fin design.
Roy, I'm not sure of your leading edge design, I assume its to try and break up the flow to ease cavitation? or is it to control the amount of water moving towards the tip? Do you angle the grooves to match the rocker at the back of the board so the angle of attack is optimal? Are you controlling twist with internal bracing given the amount of side pressure on the tip trailing edge? What filament are you using? Have you thought of adding flares to the bottom of the fin so it sits in the box like a glass on, also adding stability in the box?

[spork]

Well, they'd best get rid of the AKU machines then. Replication of proven shapes is what is making surfboards better, as is the ability to adjust any aspect of a blank before its made. Almost all shapers now use computerised design tools. The shape of the wave is irrelevant to this argument, its about consistency in the design and production process.

[Hollowed out]

Unless you can validate your fin knowledge and foiling experience to equal Roy's, then the knockers are simply pissin in he wind.
Stump up or shut up

[channels]

Not buying it......hand made fins from a pro , and glassed on are the best , end of. The market you're targeting does not include top-shelf fins ......the Chinaman has already had you for breakfast.

They used to say that about full handshaped boards as well.

[kayu]

Well, they'd best get rid of the AKU machines then. Replication of proven shapes is what is making surfboards better, as is the ability to adjust any aspect of a blank before its made. Almost all shapers now use computerised design tools. The shape of the wave is irrelevant to this argument, its about consistency in the design and production process.

If anything the machines have made surfboards worse. The machine is not nearly as accurate as you think. The only positive about the machine is the labour cost saving to the manufacturer......which is fine , but they don't make magic surfboards , and they don't replicate boards to the same standard as an experienced production shaper......and if they aren't hand finished by a shaper that's familiar with the design , they will be a dud.....I have no problem at all with the machine , but there's just too many people making use of the machine that rely totally on copying someone else's designs , because they can't design it themselves......like Roy , who not only knocks off someone elses fin design , but also blatantly uses the designers name to promote the thieved design.........classic.

[kayu]

Not buying it......hand made fins from a pro , and glassed on are the best , end of. The market you're targeting does not include top-shelf fins ......the Chinaman has already had you for breakfast.

They used to say that about full handshaped boards as well.

They still do....and there's more truth in it now than when they first started saying it.......machines are great things to supply the masses , no question about that.

[Roy_Stewart]

The machine is not nearly as accurate as you think.

Our shaping machine is.

The only positive about the machine is the labour cost saving to the manufacturer......which is fine , but they don't make magic surfboards , and they don't replicate boards to the same standard as an experienced production shaper

Bollocks.

By the way it always cracks me up to see shapers claiming 'hand shaping' and raging against 'the machine' when in reality they use a host of machines... and don't really shape by hand much at all. It's a pretty idiotic claim really, but they have to have a straw to clutch at when using a hand held machine is their only claim to fame.

there's just too many people making use of the machine that rely totally on copying someone else's designs , because they can't design it themselves

The same applies to hand shapers.

The tools used do not have any relationship to design originality.

......like Roy , who not only knocks off someone elses fin design , but also blatantly uses the designers name to promote the thieved design.........classic.

More rank BS from Mr bitter.

Here's how it is:

1) The surf industry is a classic case of most people 'copying' each other,

2) I've come up with more original designs than the vast majority of shapers.

3) The McCoy Gull Wing development shown here has been made as a custom order for a customer in Australia who rides McCoy Gull Wings and wanted to try one with the BLEF feature. I'm not going to turn him away just to please you... and it is nothing to do with you. Some people think that adapting and improving existing designs ( thruster for example) is necessary for design development. Stick in the muds like you however would have all thrusters made by Simon, and all Gull Wings by Geoff. If followed through, that philosophy would leave you with nothing since you design nothing original and make Geoff McCoy knock off boards yourself.

4) As for using McCoy's name to sell my product, it's called acknowledgement of the design...I'm giving credit where it is due... it's the only polite thing to do. I also contacted Geoff about it to let him know what I'm doing. I've even offered him a commission, as some people suggest should be done for Simon re. the thruster.. In my opinion the Gull Wing design is legit and it's popularity will only increase if others 'run with the ball' and develop it, rather than having it strictly quarantined. Overall having others pick up on Geoff's unique visions and genius is good for him, and surfing generally.

5) Only the planshape is McCoy's everything else is different including the flex and even the planshape has been changed in several ways. Planshape is the obvious feature which everyone sees first... and plods like yourself seem to think that it defines the fin, but it doesn't.

[Roy_Stewart]

Roy, I'm not sure of your leading edge design, I assume its to try and break up the flow to ease cavitation?

The bumps introduce beneficial spiral vortices, which manage flow to reduce drag, increase lift and provide a huge increase in angle of attack capability. The difference in the ride is very noticeable.

or is it to control the amount of water moving towards the tip?

Well spotted, yes that's one of the results of the BLEF feature, and it reduces induced drag.

Do you angle the grooves to match the rocker at the back of the board so the angle of attack is optimal?

The BLEF and associated channels are set up parallel to the bottom.

Are you controlling twist with internal bracing given the amount of side pressure on the tip trailing edge?

The flex characteristics are mostly determined by the skins and the shape of the fin plus materials used. Internal structure has less of an influence. We have a vertical cross hatched tube structure internally to stiffen and support the skin. Flex is moderate on the Gull Wings, and low on the Spitfires which are not really a flex fin design.

Re. tip pressure the pressure at the tip trailing edge is low, as it always is with fins, due to the pressure distribution which is always concentrated towards the leading edge. The trailing edge is solid, due to convergence of the skins as the foil becomes thinner.

What filament are you using?

Polycarboante.

Have you thought of adding flares to the bottom of the fin so it sits in the box like a glass on, also adding stability in the box?

You mean a fillet at the base?

I've considered it but decided against it. The fin base on the larger fins extends in width beyond the tab, making a base which sits flush with the bottom. This is entirely due to the size and shape of the foil at the base and isn't designed as a particular feature. Basically the fin base shape is independent of the tab. Strength tests ( in the water and bench tests) have been very good.