Just remembered, have this pic of a french yacht that can adjust the seat forward or back also the steering ,worth thinking about.

Just adding ott class5 build so that we keep a reference to post

www.seabreeze.com.au/forums/Land-Yacht-Sailing/Construction/Plans-or-specs-for-OTT-class-5-build/

landyacht said...
[ been there. tried this style front we changed to C bars which was a big improvement , then to a layover, the difference in a flying class 5 is incredible. definitely wouldnt go back.
..............

what I was refering to blake was the forks overhead , like a bike. the C bar and layover are all improvement(IMHO)
in the layover front ends I have built and/sailed, I think the key is not to let the mounting point get to low relative to the centre of the wheel. from the photos Ive seen of the fed 5's, i do wonder if this is part of the problem. my first 2 layover set ups were shockers, the present one on my promo is the best ive built, and the mini set up is just too sweet for words(on a mini) , but would be not so good on a 5
.
IF I was building an OTT 5 I would be trying to keep the end of the front spar
level or even slightly higher than the centre height of the front wheel.

With regard the last post, the ORIGINAL drawing for the Fed 5 DID NOT have any lead nor trail. As with any good layover the axis of the steering pivot meets the tyre patch exactly. It may be that what was made has lead or trail, but as I still have a set of the original drawings which Mike Hampton did in my hand right now, I can assure you he is pedantic on this point.
If you had built as many yachts as Mike, you would know this better than you know your family!

the drawing youve shown is what we use on our minis as it is easy to attach close up solidly attachedfoot or hand steering. i would have to credit the idea to paul Becket of Blokart as his was the first i had seen , although Ive now seen similar set ups that occured at the same time.
My own thinking is its not that good a set up to attach class5 5 type steeering shafts or cables, but it is really great on the minis where the feet come closer than 300mm or so

landyacht said...

the drawing youve shown is what we use on our minis as it is easy to attach close up solidly attachedfoot or hand steering. i would have to credit the idea to paul Becket of Blokart as his was the first i had seen , although Ive now seen similar set ups that occured at the same time.
My own thinking is its not that good a set up to attach class5 5 type steeering shafts or cables, but it is really great on the minis where the feet come closer than 300mm or so

Maybe you should credit someone else on this forum for designing the Blokart steering. Paul, it may have been the "first you had seen" but the first I saw was in 86 on the Glen, and many were built in that period in Europe.
FWIW the Glen was delightful, the major issue was learning that it would hop the front end INTO the apex when bouncing rather than washing away. Most of us tapped a few turning markers learning this!
The idea of a handsteering for the Blokart was decided on here in Kerikeri after Paul saw the Coccinelle which JP Krischer designed for kids/families (actually his now 21 year old godson) and was parked in my shed at the time. Sean (who turned 21 yesterday) had it by the time he was 3. Hand steering as anybody knows how to steer with their hands, but I am sure that most of you have had questions from the public asking about steering with their feet.

My understanding of flexible axles is they store power in the peaks and release it
in the lulls The rules of class 5 metal tube axles was the reason axles became longer
and angled to get the flex
Some other classes have more matierial freedom
There are people on this forum who have been with landyachting long enough to be able to give the answers on this and other design evolvement with the class5
Some earlier posts have covered these topics as well

Gizmo said...

Hiko said...

My understanding of flexible axles is they store power in the peaks and release it

How? Based on Isac Newtons law of motion "LAW III: To every action there is always opposed an equal reaction:"
Storing power in the axle and giving forward motion is just not possible.
A flexible axle / chassis may provide a MUCH smoother ride for the yacht giving the sail a better chance of working nicely. But remember that the flexing of the axle, chassis and mast comes from some force... the wind, and if the wind is flexing things its NOT adding to forward motion.
Just my personal thoughts... but I'm happy to consider other ideas with proof.

think of your yacht like one of the jumping frog toys , you push down on the back and it pings out and jumps forward. I suspect that the same principles apply to an OTT class 5, plus you get the "smoother ride " as a bonus

Big can of worms...
Storing and releasing energy: yup, that happens for sure. The catch is what gets absorbed from potential lift or move you-forward-energy doesn't necessarily get released as the same kind of force, or in the right direction; it is not always like winding up a spring. If there is any dampening in any of the materials doing the flexing at least part of the energy goes to heat and noise and material degradation and???? Aluminum makes a lousy spring.
On the other hand, There are a lot of other benefits from suspension. Like not beating the pilot to a pulp. Not upsetting the sail shape, giving us some chance of keeping the boat going the way we are pointing it... And, Class 5 landsailers are often right on or over the edge of being overpowered so dumping some wind energy back into the world unused is a good thing if more power just means going sideways or blowing over. Sometimes it gets stored, like the acceleration as you come down from almost tipping over with the thing still sheeted in; sometimes it is just lost to the world like all the bouncing trying to ride a full suspension mountain bike on the street.

I find my self wishing I could go back to school and get an engineering degree then to my local trade school to really learn to weld, then someplace to learn composite molding, then apprentice with a sailmaker for a few years...Then I need to retire so I have time to clean out the garage and build something outside of my head.

This is why I love this Forum. We have a bunch of (Essentially) Blokes with a common interest that are prepared to look outside the box. People that are using their heads for other things besides bashing Nails in.Great Stuff! As you guys know I am only a New-by to LY Sailing and Building.

Axle Flex and Energy Storage et Release.

My build as those who have read my thread will know I have used a lot of Old Damaged Carbon Fiber Masts, some of which have failed in their particular use or lack of Engineering though, both in the Schrodinger's Cat and Occum's Razor.
However to date the Axles have survived nicely, both in the Razor and the Cat. In the "Y" Frame situation there is a lot of spring activity to the point the Razor just about lulls you to sleep "Rock-a-By-Baby in the Land Yacht"That's Cool!
There seems to be very little Layover against those Axles in 10-15Kts... Go to
www.seabreeze.com.au/forums/Land-Yacht-Sailing/Construction/Just-working-out-a-build/?page=11

The Pic's there show a great deal of energy usage I feel.

However if one takes the Axles (No Pic's available) on the Cat "T" Frame, she becomes a real Bone Shaker on Rippled Sand even on the Tarmac you could hear and feel the surface. The axle length between the 2 machines vary around 170mm in length and are approximately the same in other properties including rear wheel spread.

Both machines GO like the Clappers when quartering the wind and sail very high to the wing the Razor seems to accelerate or at least held as close as 5degrees from directly upwind, the Cat would be very close to that as well. I was shocked to think that these beasts could come up so close-------------------------, At least in my inexperienced hands. When sailing directly down wind the sails went slack very quickly as we gained wind speed.

From observation I did note the Mast laid over under Gusts but did not take the yacht with it. At no time Did the Razor Lift a Wheel under Gusting Wind, however in slightly lighter conditions the Cat did lift a wheel, several times under gusts. In the case of both machines the Steering appeared to improve vastly with speed and wind speed (Probably normal for all machines)

I just thought I'd add a little fuel to this Debate[}:)][}:)]Sh**t*!

Ron

Gizmo said...

landyacht said...
think of your yacht like one of the jumping frog toys , you push down on the back and it pings out and jumps forward. I suspect that the same principles apply to an OTT class 5, plus you get the "smoother ride " as a bonus

While the frog idea is an interesting one BUT it works on using friction pushing against something like a bench top or finger to make it move, but if that bench top had minimal friction [like a turning bearing in a wheel] it wouldn't work.
If it were true... you could put a landyacht on a flat surface load up the yacht to flex the axles and if that load was rapidly taken off the yacht would it go forward....mmmmmm [I doubt it!!!]

since my flat yframe 5 is still sitting in the shed from an Excellent weekend of sailing /racing at Walyungup, i went out,put a volunteer in the cockpit, pressed down on the back, and let go, stepped forward and did it again, although I cant say that the test was conclusive, as the yacht rolled off the slab onto the gravel, but i was happy given that no forward pressure was applied by me
edit- maybe i shouldnt be telling you lot this[}:)]

Gizmo said...

landyacht said...
think of your yacht like one of the jumping frog toys , you push down on the back and it pings out and jumps forward. I suspect that the same principles apply to an OTT class 5, plus you get the "smoother ride " as a bonus

While the frog idea is an interesting one BUT it works on using friction pushing against something like a bench top or finger to make it move, but if that bench top had minimal friction [like a turning bearing in a wheel] it wouldn't work.
If it were true... you could put a landyacht on a flat surface load up the yacht to flex the axles and if that load was rapidly taken off the yacht would it go forward....mmmmmm [I doubt it!!!]

The frog idea is correct in that the friction is not on the surface but the sail pushing back against the wind itself
Every one seems to be thinking in terms of wheels on axles, whereas, it is wheels on axles connected to the rest of the yacht so that what affects 1 part of the yacht affects all of the yacht.

Vic,
Thanks for the details! You have answered a lot of my questions. Not sure if you've encouraged me to to try building wheels or convinced me not to. Are the disks are just bonded to the edge of the rim, no glass wraps around into the bead? How wide does the rim end up being?
Thanks again, great info.
Blake

New wheel fitted to aus23o have to clean up around the bearing
Cheers
aus230

Vic, Trav uses scrap steel reinforced hydraulic hose. Cheap as!