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Re: 2012 North LTD Raceboard with crooked fin box

Posted: Fri Jul 06, 2012 7:34 am
by Nico
I find it amazing that 2mm should be within tolerance.
This sort of thing can easily be bypassed by having a properly machined jig to set box in boards with 10th of mm and less tolerances.
If your fin is off, your board is off.
Dirk of all people should know this
N

Re: 2012 North LTD Raceboard with crooked fin box

Posted: Fri Jul 06, 2012 10:26 am
by tautologies
How much is 2mm by the fin bow at the nose of the board? Must be quite a bit. Initially I thought it was over the whole board which isn't much...

Re: 2012 North LTD Raceboard with crooked fin box

Posted: Fri Jul 06, 2012 12:01 pm
by wdric
damian wrote:
wdric wrote:
ktouhey wrote:give Ristafins.com a shout.
they might be able to pot a back fin special to account for the offset on your board.
Rista have done this for me, but it means paying for another set of fins that are only good for that board :o

Hi Rick
Just out of interest did you get a board like this one too? how much was yours out and was it really that noticeable on all points of sail or only on one tack heading downwind? (i thought you had the standard North fins)

How much better are the Rista fins?
Well since you ask, my rear fin appears to be very close to the center, but my front fins were evenly toed in by about 3mm (1.5mm each) but are central to the board, unfortunately this is also considered withing tolerance, so I made the decision to buy another set of fins to correct the north problem.
The rista fins are made to be parallel, the main reason for me to get them. And yes had them at the nationals and was disappointed at our missed opportunity to have some racing with everyone to see how we all went against each other, maybe they was my secret weapon to get me to the start line and finish twice :rollgrin:

Since I still stuggle a bit to consistanly go down wind at speed in over 15 knots in the chop and stay on the board for to long I honestly dont believe my skill is good enough to rate the difference between them and the north fins. the north fins have no cant, but the rista does. My first impression was they do seam to be a bit smoother to ride off the breeze which is my main area I need to work on but have only been using the 17 in lighter conditions in all sessions before yesterday where I had the chance to break out the 13 and had a little difficulty going down wind.
Once I get a bit more dialed on the board I plan to swap them and check out the difference.
Dave is still running the north fins. Hopefully we will get some wind on saturdays over the winter and we can get some serious racing happening with the local formula windsurfers at marmong, cant believe I have owned a 17m since end of may and we havent had enough wind on a saturdays to actually have a race yet :(

Re: 2012 North LTD Raceboard with crooked fin box

Posted: Thu Jul 12, 2012 8:47 am
by damian
Thanks for the reply Rick

Your fins definitely seemed to be working well for you in Townsville :thumb:
and dont worry there has probably been even less wind over this side of the paddock since we got back i have only had 3 sessions :cry:

Man i would love to be able to experiment with different fins but i am a poor man and can only afford the fins that i got with the board.

Cheers
dude and see you in Melbourne

Re: 2012 North LTD Raceboard with crooked fin box

Posted: Mon Jul 16, 2012 8:27 am
by wdric
mexiwind wrote: After closer examination i took the board to my local shaper friend who measured from center line of board to fin boxes and one box is more than 2mm out from the front to back of the box!! After marking up the board with precise measurement the shaper also noticed that the nose of the board was not symmetrical and one rail was sanded much sharper than the other. All being said i took some pictures and sent them to the USA distributor, who forwarded them on to North, and to my surprise they said that this was within tolerance for these board!! They forwarded me the email from Dirk Hanel who told them to deny the warranty claim as 2mm was within tolerance!!
I wonder if they are using the IKA board rules as the reason to say it is within tolerance?

I just found this on the IKA site and the tolerance is quite large if applied to something like fin boxes. EG: allowed 1%, so if fins are 500mm apart they could argue that they could be up to 5mm different between boards!

We agree to supply only equipment built in accordance with the above specifications and that the final weight shall be within tolerances of 5% of the values recorded; and the final measurements shall be within tolerances of +/- 1% with a minimum of +/- 2mm and a maximum of +/- 5mm of the values recorded. The minimum and maximum measurements of the class rules MUST NOT be exceeded by the measurements plus the allowed tolerance !
Copied from the IKA site
http://internationalkiteboarding.org/im ... %20v08.doc

Re: 2012 North LTD Raceboard with crooked fin box

Posted: Mon Jul 16, 2012 9:45 am
by ronnie
wdric wrote:
mexiwind wrote: After closer examination i took the board to my local shaper friend who measured from center line of board to fin boxes and one box is more than 2mm out from the front to back of the box!! After marking up the board with precise measurement the shaper also noticed that the nose of the board was not symmetrical and one rail was sanded much sharper than the other. All being said i took some pictures and sent them to the USA distributor, who forwarded them on to North, and to my surprise they said that this was within tolerance for these board!! They forwarded me the email from Dirk Hanel who told them to deny the warranty claim as 2mm was within tolerance!!
I wonder if they are using the IKA board rules as the reason to say it is within tolerance?

I just found this on the IKA site and the tolerance is quite large if applied to something like fin boxes. EG: allowed 1%, so if fins are 500mm apart they could argue that they could be up to 5mm different between boards!

We agree to supply only equipment built in accordance with the above specifications and that the final weight shall be within tolerances of 5% of the values recorded; and the final measurements shall be within tolerances of +/- 1% with a minimum of +/- 2mm and a maximum of +/- 5mm of the values recorded. The minimum and maximum measurements of the class rules MUST NOT be exceeded by the measurements plus the allowed tolerance !
Copied from the IKA site
http://internationalkiteboarding.org/im ... %20v08.doc
Unfortunately I think they probably will fall back on those tolerances as their standard.

It reads ambiguous to me.
"measurements shall be within tolerances of +/- 1% with a minimum of +/- 2mm"

That can be taken to mean that if the board is within 2mm of the correct dimension it fails.

It can also be taken to mean that all dimensions under 2 metres have a tolerance of +/-2mm.

If North were going to insist that they could turn out boards with the fins twisted by 2mm I would never buy a North board, so its a good thing that problems like the one highlighted on this thread are made known to potential buyers.

Re: 2012 North LTD Raceboard with crooked fin box

Posted: Mon Jul 16, 2012 10:00 am
by lobodomar
wdric wrote:
mexiwind wrote: After closer examination i took the board to my local shaper friend who measured from center line of board to fin boxes and one box is more than 2mm out from the front to back of the box!! After marking up the board with precise measurement the shaper also noticed that the nose of the board was not symmetrical and one rail was sanded much sharper than the other. All being said i took some pictures and sent them to the USA distributor, who forwarded them on to North, and to my surprise they said that this was within tolerance for these board!! They forwarded me the email from Dirk Hanel who told them to deny the warranty claim as 2mm was within tolerance!!
I wonder if they are using the IKA board rules as the reason to say it is within tolerance?

I just found this on the IKA site and the tolerance is quite large if applied to something like fin boxes. EG: allowed 1%, so if fins are 500mm apart they could argue that they could be up to 5mm different between boards!

We agree to supply only equipment built in accordance with the above specifications and that the final weight shall be within tolerances of 5% of the values recorded; and the final measurements shall be within tolerances of +/- 1% with a minimum of +/- 2mm and a maximum of +/- 5mm of the values recorded. The minimum and maximum measurements of the class rules MUST NOT be exceeded by the measurements plus the allowed tolerance !
Copied from the IKA site
http://internationalkiteboarding.org/im ... %20v08.doc

Wdric,

I also think North used the Registered Production Boards Tolerances to back their case regarding Mexiwind's board.

But not rightly so, IMO.

Those tolerances are to ensure builders do not change the design within a given registered model, NOT to ensure quality control!!!!

I wonder which results North's top rider would get with a toed center fin.................

Re: 2012 North LTD Raceboard with crooked fin box

Posted: Mon Jul 16, 2012 10:07 am
by lobodomar
ronnie,

actually it's not that ambiguous
tolerance is 1%, as long as it's not less than 2mm and not more than 5mm

So in your example, anything under 200mm (20cm, not 2m) could have a 2mm error.

Not saying I agree with it.

Re: 2012 North LTD Raceboard with crooked fin box

Posted: Mon Jul 16, 2012 10:11 am
by lobodomar
ronnie wrote:
If North were going to insist that they could turn out boards with the fins twisted by 2mm I would never buy a North board, so its a good thing that problems like the one highlighted on this thread are made known to potential buyers.
Agreed 100%

Re: 2012 North LTD Raceboard with crooked fin box

Posted: Mon Jul 16, 2012 11:30 am
by Tiago1973
It would be quite cynical from North if they reverted to IKA rule box to make such a claim (that that board is per spec).

I expect North to have outlined their intend design in a drawing and use it as a reference.

but sometimes looks like anything goes...