Kia-Ora,
I'm in my final year of a bachelor of engineering degree, doing work in composites/CAD/FEA. Below is a quick analysis on a kiteboard, pretty colours.
If anyone in Auckland has any use for my skills they are up for hire - work relating to kites or boards preferred but I can clean cars, mow lawns etc too.

Pay negotiable

Cheers

Reuben

0274 268 905

i'm assuming that you didn't get the job in WAAAAAAAAAAAAAAAAA then.

Engineering in NZ? Forget it. I have an NZCE and will never use it. Far rather clean toilets at Maccas and the pay is allmost as good too!

My mate has an NZCE in electronics engineering and 6 years work experience and he's still only on 40k. for that 40k gross (Clark takes about 30% of that) he had to spend 3 hours each day in travel and work for assholes.

If i really wanted to make something out of my life then i'd head over to Europe and work and kite there. Plenty of world class kitespots in Europe too.

Job in Perth starts in Feb Mark, and the engineering situation in NZ isn't that bad is it?

Just after some cash for this year, get me through til Feb. Your could be right about pay in NZ though, and John will only take 23% of mine so bring it on.

Come on people, I can clean cars inside and out, mow lawns, weed gardens.. not to mention analyse and model the stresses/strains/deflections in kiteboards, size pumps, maintain compressors, analyse, make and break stuff..

Anyone know if underground/dvnt/decay do finite element modelling on their board range? or is it all intuition and experience?

Reuben

have you got that job in Perth? If so then congrats... now i won't be all alone when/if i move over there.

As for engineering in NZ. Let's put it his way... I can earn more money in Australia being a burger bitch at Maccas than being an enginner in NZ. So in short... yes the engineering situation in NZ is awful. Yes there are probably ok jobs out there but do you really wanna have to deal with Auckland traffic everyday?, slave your ass off for not very much pay and then pay clark a large amount? (the average NET pay in OZ is higher than the GROSS pay over here). It's cheaper to live in Perth and no traffic issues either.

If you live in NZ and wanna kite like you said you do, best to get a job that finishes early like midday. It works sweet as for me. i could never handle working 9-5 in Auckland and still be keen on kiting. i'd have to change jobs or quit kiting. Auckland's traffic, tides, and unreliable wind just doesn't allow you to do that.

If you wanna still live in NZ, kite and have a decent job may i suggest Wellington. Not affected by tides and much more reliable wind... and MUCH less traffic.

Sheee-it thrasher, you sure down on the motherland, and injuneerin. Sounds like yo sho' been dissed in this life. What happened to ya? Your old fella too small or somethin?

w3rd

We never applied FEA to a board model, not to say that it is not a good idea, any more knowledge is useful and I am certainly considering this in the future. I would be interested in seeing how FEA compared to real data we collected from measuring rocker deflections at different points and under different loads (10 prototype boards - different flex characteristics). The results of these experiments are part of why a dvnt board is so comfortable/ controllable to ride and land now.

Of course for destuctive testing FEA has nothing on a well designed practical experiment (you know -change one variable at a time..), and although it cost a small fortune, we learnt so much from that in the begining. In the early days I remember sending prototype boards down to Mike Cann (100kg freefall kitelooper) and being quite upset when he broke the news that he had destroyed them, but it was learning from destructive testing like this that benefits us so much now as we have had no failures of our past 2 seasons boards that we know of, and Mike now complains of bruised heels from his dvnt board - commenting that it should have been in half many many times after bombdrop kiteloops.

Without the knowledge that we now have, it would have been guesswork, and we certainly would not feel comfortable with that. Being a BEng. (Hons) Mech Eng sure has been useful in developing dvnt boards. dvnt boards are now frequently getting respected over and above any other boards on the market by their riders, but that was not without great effort and expense over the past almost 5 years. If fact every rider that requested a demo with consideration of a purchase - showed the money for one this year. All commented on how smooth and comfortable they were to ride.


Hope that gives some insight Ruben

Jeez I need to go ride - tooo long

FEA is great for static load modeling where kiteboards are a cross section of quite a few load models. Then there are a couple of factors that are very hard to incoroporate in an FEA model like non-linear flex, torsional stiffness, pop and dampening under different riding modes. Take for example trucking up wind, loading up before jumping and the difference between landing flat and tombstoning the sucker after a kiteloop. You can predict where it would break but the reinforcement to prevent it might not blend with the other characteristics and that's where the art of it all comes in.

Now if you offered to do some CNC modeling with access to a multi-axis CNC mill then I think you'd be in business! Had I only the room to build one as I sure have the means. :O)

Out of interest your model shows the load point in the middle and you'd find it located mostly around the heels of the stance position ie. your back foot if you're going upwind and most boards break just ouside the heel when the core and laminate is crushed for that very reason.

BTW I never finished my engineering degree either and went computer sciences and programming instead.

Well done Reuben!
Flex in boards is a great topic and so many board companies talk about flex and control etc but ignore the obvious.

Flex is most often demonstrated as being in the spoon shape. And yes boards do spoon the more they are loaded. Some like that and call it comfy, but I do not. the more rigid a board the more i like it. faster more efficient more control etc. Lets face it everyone has their own personal favorites out there.

My observation: (I sell kites and boards and get lots of feedback)
Riders with an old hi torque kite with a chunky profile like flexy boards, they provide more control because they find it hard to get the kite to the edge by just sheeting out.

Riders with fast kites with thin leading edges or easy depowering like Flat kites. They get way more out of a board with less flex. More speed, more wind range and overall more performance.

So if your riding a hot new kite, make sure you get on a fast board to get the most out of your rig. A slow old flexy board might sill feel ok but combine a new kite with the right board and you can feel the difference and enjoy far more light wind performance and also precise control at the upper end. Well past what the flexy boards can hold.

Reuben has shown with simple graphics what a lot of board makers don't consider, and that is that when you really load up a board the flex reverses and thats why it snaps or simply gives up the edge and throws you sideways.It flexes in the opposite to the spoon shape.
Imagine your riding hard out, especially on a "C" kite that pulls like a truck. You have to rail like a bastard and your board starts bending like a spoon. It can suddenly bend in the opposite direction and throw you off.
heavier riders experience this far more than lighter riders due to the loads involved.
This is the main reason why I don't ride flexy boards.
Flexy is marketed as a feature but it's not.

Ever seen anyone in a shop flip a board over and show you its inverse flex. Because thats the real deal. The real direction it will flex whan you rail it up hard.

Well done Reuben, you have some skills there.
As for jobs, have a chat with Hamish and Gavin. Their popping out some funky boards designs. Or Corne (local Orewa kiter) works doing exactly this stuff in hull design. Bigger field than boards so more scope for paid employment.

Flexy boards or non flexy boards... it's a personal choice. What works well for one guy is not guaranteed to work for another. Lots or variables come into play. I've noticed more and more flex being removed from designs. That's great for me!



(((Different designers have different perspectives on flex, the above is mine.)))

I totally agree, saying a board is good because it has flex is nonsense.

A wobble board will lack predictable control, kill speed due to bending and causing too much drag, lack comfort/smoothness, and can kill of any potential boost power that you can load up. In fact I think the public has had the wool pulled over their eyes due to marketing lies for too long - which makes this a good thread.

Pop is also another overused marketing term that is nonsense without explanation. Pop is the ability for a small amount of flex to retain some potential energy to help your jump - like a spring. I know too much about pop, I have been skating for 20 years and this is where the term came from - the fact that skateboarding is cool is probaly why the companies use the term for marketing - but I can assure you many of them don't even know what it is!

Take your board and try and flex it at the tail - if you can flex it easily without all your weight against it - IT WILL HAVE NO POP. The flex has to be balanced to your weight and the force of the kite pulling the board edge at take off for pop - very important in a freestyle board.

I was very surprised to see more kiteboards snapped in half this last season than I ever saw before. I think part of the reason for this is because many kiteboard manufacture have transferred from asia to eastern europe and although the snowboard companies that build them may be very clued up/qualified? composite engineers - there is no substitute for experience. Also there is way more profit in kites than board and so proportionally less R & D money is put in.

In New Zealand we are lucky to have the greatest testing ground in the world just outside our back door. dvnt can test in probably the most varied conditions available within an hours drive - anywhere in the whole world. And the fact that they are manufactured in New Zealand means we can quickly tweak and change our designs without the pressure of having to market/sell a load of dead loss mass-produced kiteboards before the end of the season. We can also stay on top of quality which is VERY difficult if you move your factory/production far from your base.


I think the correct amount of flex in the right place (SMALL flex but POPLESS) can help out cruisers and freeriders by causing drag from the rocker line thus slowing the board from drag which would make it a positive thing and help their riding, also I can see the disadvantages of a flexy board may be outweighed when considering riding 'hucking style'. You know - Ruben Lenten, Mark Jacobs and Dave Edwards and the occasional 10 foot bomb drop with no kite uplift the kind of thing you can get frequently with a flat kite also if you are not careful to hold onto the bar!... Those kinds of riders are few and far between but I sure like watching them ride!

Recent kite design also effects suitable board design. Our team riders and customers also ride flat kites and they can get away with wider boards now that they can kill the kite power more easily - but they certainly would not want to ride a totally rigid board - no way in hell!


Lee wrote: "Reuben has shown with simple graphics what a lot of board makers don't consider, and that is that when you really load up a board the flex reverses and thats why it snaps or simply gives up the edge and throws you sideways.It flexes in the opposite to the spoon shape. "

My Response: YOU ARE WRONG you cannot make sweeping statements like this when it comes to engineering, we are qualified engineers. The FEA model by Ruben is interesting to look at however I am sure it was not meant to be an accurate model as there are a couple of very important omissions from it. When I studied studied FEA on my Engineering Degree I was also taught how inaccurate it can be and a kiteboard would be one of more likely items to be inaccurate by its very varied nature. But yes I agree with some of your sentiment - unlike ,dvnt kiteboards, most boards have too much flex and that the companies producing them did not conduct the necessary R&D.

HOWEVER a rigid board will punish you on hard landings and does not exactly do wonders for your knee joints in chop. Your legs will also tire more quickly. A rigid board of equal layup is also more likely to break fromjump impact because it cannot transfer energy so easily and spread the load along the beam. Very bad, very stiff boards on the market were part inspiration for dvnt producing a product that was suited as a KITEBOARD and not a WAKEBOARD or WINDSURFER.

I hope this is informative is useful. I had been meaning to write an article about this for some time.

dvnt has listened to and learnt from its riders and will continue to do so- they are the ones in the driving seat -any constructive feedback is always welcomed - we are always open to new ideas and technology..

Thanks for finally inspiring me to write my piece about some of the work we have completed. Ultimately we are just out to ensure kiteboarders on dvnt kiteboards have more fun on the water.

... or you could just make a few plyboards. The good ol plyboards get the most use out where i kite and are cheaper to fix when you grind the shit outa them or hit rocks.

As for being down on the motherland. I'm assuming that you mean NZ? Down on Wellington? Never. how could i diss a place that windy? Down on Auckland? Occasionally but i mean what i say when the traffic is bad and inconvienient to kite after a 9-5 job. And a friend of mine has stopped engineering alltogether because it's not worth it. The traffic, the low pay, the stuffed up bosses.

As for Hamish and Gavin. I'm sure they would love you to help them out Rueben but don't expect much money out of them... they're students. If you wanna still work and kite and just want some money to get you through till WAAAAAAAAAAA in Feb i'm sure there are some vacancies where i work at at maccas Pakuranga. Heck your could even start at 4am with me. Pay is 9.50 an hour. It ain't much but you'll be able to kite every day from midday onwards.

Smells like talking it up to me :wink: :shock: 8)

Thrasher:
I did 5 years at KFC to get me through high school, scraping 2mm of grease from my face after a 8 hour shift doesn't really appeal to me anymore, although all-you-can-eat popcorn chicken does... I'm after a bit of outdoor hard labour or specialised computer work. Also, I live in the city and the most I've ever had to wait in a car for a kite has been 50mins and that was muruwai. Kohi, Shoal, Shread are all within half an hour, fine by me!

Ian:
I totally agree about how simple and non-realistic my analysis is above. It was a quick 5min modelling job in ProEngineer and then half of that in ANSYS, it in no way represents real life loading cases, but aren't the colours pretty? We have had the point drilled into us in our classes that computer modelling is incredibly easy to do but incredibly difficult to get right. Loading cases, supports, quanitfying loading etc are all difficult especially in sporting equipment such as kiteboards. I'm looking into it and I'd be intertested in getting some data off you relating to deflections midspan etc, as I can compare these for different layups etc using a more detailed composite FEA program (ANSYS CLASSIC). Results will be interesting. I look forward to hearing from you.

Lee:
Cheers for the compliment, maybe I could print some pretty colour pictures for your store? Also when in Perth last week (job interview (got the job)), I called into a kite-store named Airborne Kiteboarding. I mentioned the kite scene in NZ and out of all things then knew about NZ (limited their knowledge of us was) they mentioned a guy 'Lee' with the BEST license.
Thats pretty awesome I reckon, I felt proud to say I knew you haha.

Keep the convo going...

Reuben


Lee: Cheers for the