I can see why he had a 90 second handicap. Are the other craft in the same class?? Why Is this vessel so fast?? I have watched this video several times and can't figure it out. the other rigs appear to be somewhat the same and I'm sure It's not the shock alone, maybe it's all the sailor!! Gotta hand it to that guy, he's getting it on!!!!

Bit Of a run down on the yacht. It has not always been as quick as it is now. It is a OTT with 26"wheels (Home Built) that have been widened to 75mm. (still a class5 but to current specs). The other yachts are club88 (designed in 1988) and are a great yacht that take some beating when the wind is up over 25kph.

I have cut and changed thing's many times to get this yacht to where it is today, Main improvements to performance is the mast position and the adjustability of mast rake.
The coil suspension (only on front) has virtually eliminated sail shake. Now for the crunch, I am going to detune the yacht for next season by going back to wheel barrow wheels on the back(for lake walyungup) and develop it again from there. For lake Lefroy I will still be using the 26"wheels
Cheers
aus230

Thanks for the reply AUS230. I sure am interested in building a Lefroy mini but also want to build a class 5. I'm sure the mini is a great learning prelude to the class 5 yachts so that's where I'll start.
Could you tell me, Out of all the plans and builds,which one you would build? If you have built one, can I get the build link? Or should I just go with Paul Day version? It looks pretty good! maybe someone can get me up to date on modifications on the original too.

Kaona

Kaonaona, if you are interested in racing in the future you may want to build the mini. The 5 sqm is class is very small here. the International Mini is growing. This is last Americas Landsailing Cup's score tally . You can see the class numbers.
www.nalsa.org/Sailwave%20results2014.htm

Proposed changes to plans???

Just finished scratching this out! Any opinions on this design?

The "KEY TO TRACTION" is to have your wheels on the ground whenever possible.

If that is disputable then everything from here on is hooey! Which it's not.

If you control your weight then the only other deciding factor is tire failure. More about that some other time.
If you have a constant positive force (Torsional, centrifugal and weight transfer) On the outside wheel and a constant negative
weight on the inside wheel then it is only going to help you to get your inside wheel on the ground......Get it? The best way to
do it is to add a weight controlling device, hence the spring! This type of set up gets its familiarities from the old Mods and Sprint cars.

If you notice in the drawing, the roll center is lowered effectively lowering the center of gravity......Get it? I've read quite a few of your post's and have a bit of respect for you so I'm sure you know exactly where I'm getting at with the suspension. I think this may be an innovation in the sport. You think Vic is fast now wait till he tries some "WEIGHT TRANSFER".

Here is a diagram for those that don't know.

KAONAONA said..

Gizmo said..

Just something to think about....basic physics.
Where is the energy coming from to 'flex' the suspension?
What are you wanting the suspension to do?
Let me break it down further if the sail / rig generates ALL the force to make a land yacht to move is any of the force wasted.
What AUS 230 has done is made a yacht with a rig that is very stable and doesn't shake around thus giving a VERY smooth airflow over the sail.
Rear suspension will allow the rig to lean over easier and de-power the yacht, where as front suspension will take a lot of the rig shake out.

I positively do believe there is wasted energy, after all a lot of air spills over them sails. and how much speed is lost when you do slide around the turns?

Yes your chassis will tilt a bit to the downwind side in the straightaways until it is loaded then those load forces start transferring back to the other side. have you ever seen the chassis tilt in a Sprint car? I tilts to the inside. Now what could you possibly do with that???????? It would cause forward motion because the energy is being utilized and not wasted.

What do you think about this boys?

Now this is the ultimate in sprung weight transfer! You can load the inside wheel and change your mast rake just by transferring your weight All the while maintaining a windward position on your mast. ALWAYS! I'm sure this will put the power to the ground.

Still working on the steering sketches. But to let you know, It's hand steered from the rear of the tramp similar to a H-16/14 It will have center sheeting with a traveler.

The center of gravity is lower than any rigid chassis even if my COM was higher. It may not appear to be so but my butt would be just as low as any mini around and shoulder height is as similar. Seat belts is what keeps you in any mini seat/tramp. I have yet to see a build that has the seat belts drawn in so I didn't bother. This would not be my racing rig but a fun fast well handling craft that would be hard to beat around any course.

BTW I will mostly be sailing in an off road park shared by dirt bikes and quads in heavy winds

Sailing a landyacht with rear suspension on the saltpan at Kingston in January was a bit of a dud. If the surface is a little moist, the sail rig loads up on the suspension and the leeward wheel digs in. Becomes a severe problem of overcoming inertia. Same setup on a hard rough surface, a fast comfortable ride. On the Birdsville track we did over five hundred k's on the suspension in the picture which consists of the stub axle and brake disk mounted on a pivot arm, which has eight wraps of half inch bungie cord to provide spring tension. Wheels were the narrow space saver wheels used as emergency spare tyres. For my two cents, suspension on the rear end works well for sorting out ruts and potholes, paddock bashing and long distance cruising, but definitely interferes with the performance on softer surfaces. At Kingston we also ran a landyacht with a pod that could be pulled up or down across the back axle. The system worked, the pod could be pulled up to windward and was stable. Not sure if it proved anything else. While the pilot was taking a comfort stop on the beach it took off and sailed into the ocean.

Test Pilot and others,

All of the above post's I made were strictly for process of elimination and most of the drawings were based on a "Fun yacht" not a serious LLM flat out racer!

Thank you all for helping me sort out the design. When I read salty lips post it woke me up to the reality of suspension performance on a land yacht. His results were less than favorable unless running in very rough terrain or off road.

When I do the "Fun yacht" I will take pictures throughout the build and post it.
But It will be all about the performance to win races From here on.

Please keep advising me as I go. I never have a problem with scrapping ideas, designs and drawings or a whole project and starting over, so please hold no punches. If it's lame tell me. If it's good tell me.

And away we go,

Thanks,
Kaona

Had the springyacht to Ivanpah last year. Pretty soft leaf spring suspension, soft enough to eliminate sail twist. Could point a tad higher and bit faster than the fed 5. might be advantages.

I keep coming back to watch these two videos. These buggies really scoot!