the board I built got sailed at Widgiemooltha (Lake Lefroy) this weekend and was absolute magic to sail. maybe we might christen it the WIDGIE BOARD.
It weighs in at 15 kg and I think you could easily get it down to 10. Test pilot No 2 was our local blokart dealer who is a sailboarder from way back. He got quite good by the end of the weekend , but turninng without getting off the board has yet to be achieved. You need a 4-5m surf sail . the slalom sail we used would end up under a wheel when you bailed. After 2 days of bad sailing ( Ive never windsurfed or skateboarded, today I just hopped on and ripped across a salt pond. (1km) without any problems . It is soooo great to get a buzz from something new. Here is test pilot 2 showing how it was done




Yes the boom was too high and we needed more luff tension. which we corrected next day. water was only a few mm deep and the which is why there are no ripples. . Anybody thinking skim board and kite?
wind was about 7knts. this is on the main lake after an overnight rain. we sailed on a Evaporation pond till the main lake drys out.
After todays sail I will have to think carefully about which toys to get out on the weekend, as this sailboarding thing is getting more interesting by the day .
I reckon weve got the bestest photos on the web now

we had 2 spills eachand found thatwe tended to roll. main injury was bruised ankles from donging the sides of the board when not moving.
The version 2 board has a lower CG. and is slightly shorter and 4kg less.. I did have a set of pads but had to hide the purchase by wrapping them as a birthday present , only to find I had the date wrong and the gift went unopened till next week. I must also admit to having done a lap of the pond in tshirt and high impact type beanie. Damn it was cold

Board got altered today. I tookthe rear gearfrom the original board and fitted it to the new board . thet gear has less turning motion and didnt wobble at speed before. I also removed the rubber mounts and replaced them with teflon ones. this stiffened the movement without it sticking. Now it looks like this

The front is basically like one shown in other photos and uses pressure on a block of polyurathane to give it stiffness. If this is too wobbly I will stiffen it up by altering some of the layers to rubber or teflon.

VERRRRY NEAT. Any chance of a full frontal view (of the board/steering) so we can get our little brains around the sheer simplicity of what youve built.

Hey Paul,
I don't know where you find time to do all this stuff.

Question on B6's wheels. Do the hubs carry precision bearings with a steel spacer sleeve between? If so who makes and/or sells them, are the tyres solid or pneumatic and what size are they?

Live long, have fun, be happy. Cheers Cisco.

Edit. I see a schreader valve in earlier photo and it looks like they have precision bearings so main question is re spacer sleeve.

landyacht said...

cisco said...

Hey Paul,
I don't know where you find time to do all this stuff.

Question on B6's wheels. Do the hubs carry precision bearings with a steel spacer sleeve between? If so who makes and/or sells them, are the tyres solid or pneumatic and what size are they?

Live long, have fun, be happy. Cheers Cisco.

Edit. I see a schreader valve in earlier photo and it looks like they have precision bearings so main question is re spacer sleeve.

.
they are Fallshaw golfbuggy wheels. 12" they have a precision bearing that takes a 12mm shaft. .commonly used in wheelchair application. (I have a stock pile of wheelchairs.............really). I paid about $ 40 each but that included the axle assembly which is quite brilliant because you can bolt it through a flat plate.
the supplied axles are really strong so you can side mount them on a blokart style front fork.
They also make a 16" and a 20" wheel ,but they would not take the side load on the rear of a landyacht.
there is no spacer as the axle assembly accounts for he bearings and cannot pinch the bearing too tight

Gizmo said...

Ok then Paul... here is something to inspire you !!!!
http://www.sevenravens.com/landsailing/hypertryke/index.html

fascinating. Somebody is trying to re-invent a Pat Finch design circa 1993 and giving us all the scientific reasons why it should work

There'll be a mathemagical way of working out the ideal location for the centre of effort from the sail/wing in relation to the centre of traction provided by the wheels in a horizontal plane, coupled with the goal of getting the widest wheelbase around the centre of effort to resist the tipping moment..

With the traditional raked sail rig, the centre of effort from the sail is nearer the back than in a vertical mounted wing rig (where it is much nearer the "mastbase").

If sideways traction was not a consideration, then the widest part of the footprint would go as close as possible to the centre of effort from the rig.

Because spinning out at 120km/hr and grating yourself on crusty dried salt would not be very fun, traction is a concern, and you get better traction from two wheels than one.

cisco said...

Apart from all that the steering set up gets more complicated. There is a reason (that I am at a loss for words to explain) why 99.99% of wheeled vehicles in the world have front steering wheels. I think it allows for a tighter turning circle for the same amount of steering wheel angle.

Yeah, the front goes around rather than the back swinging out.
The turning circle analogy is incorrect, look at forklifts, they wouldn't work if you tried steering with the front wheels.

in a three wheeled landyacht with the two front, one single config you could turn the back wheel the same as a rudder on a boat, would give you a more realistic sailing feel.

Here is a copy of a page from "Aero-Hydrodynamics" by C.A. Marchaj

and here it is. It doesnt look amazing,and didnt get a fancy paint job but it works the best yet. As soon as I find another wishbone /mast base set I will build another so that we can have a race


the timber is King Billy pine from a kitchen table circa 1920's so I varnished instead of painting . Grip is via strips of marine ply glued and stapled to the deck then a coat of varnish and sand,followed by a second coat of varnish .
Rear is a 16" plastic wheel and 2x12" wheels at the front. the set angle of the front steering is 45degrees and the rear is fixed