Looks good!

Correct me if I'm wrong, but isn't the steering a little bit off -- there's bucketloads of negative caster there? Don't you want zero or slightly positive caster?

Also what would the torque loading be on the main chassis tube, bearing in mind how much leverage the mast has, and how long the tube is before it splits into the rear axle?


I've never even ridden in a landyacht so my ideas might be way off the mark

You've forgotten the most important detail... what will it be called??

Is this what you mean Nebbian?

hills said...

Is this what you mean Nebbian?

Indeed yes, Hills I'm too lazy to draw it up...

There's so much technology in a good steering/suspension system -- roll angles, caster, camber, bump steer, king pin inclination, the list goes on. Amazing how much thought has gone into a couple of bits of steel that everyone takes for granted.

Anyway good to hear the design has changed slightly, hopefully this saved you some money and time on your project

The sandpiper steering was "light" mainly because the seat was leaning back a fair bit and this reduced the weight on the front axle but it steered quite nicely .. untill we added the jib...then in high winds and a soft surface it wouldn't turn at all. We even tried horizontal wings on the front forks to keep it down at speed (didn't work) the best way to turn in high winds was lean forward a bit, slacken off the jib then turn.

For more info on wheel caster ... en.wikipedia.org/wiki/Caster_angle

Bike bits sometimes are ok..you might be better just getting the upper and lower bearings and the cups they run in and sit them into a piece of tube ( this is what the sandpiper used)
Just another point in using bike wheels, have a read of the class 5 rules....

"WHEELS, There will be two non-steerable rear and one steerable front wheel. The overall diameter of the tyre shall not exceed 650 mm. Wire spoked wheels are allowed provided the spokes are protected by covers on both sides."

Mind you for a Class 6 bike wire spoke wheels work fine as a front wheel but they collapse as rear wheels , Plastic bike wheels are stronger BUT the tyres will roll off at high speed .. "been there done that!!!"

A thought in the design of "this" Class 5 was to use a clamp on the main spine tube for front end. This would enable changing to a roll over front end with just a few bolts if you wanted to ... even between races!!
This is also the reason that the rear wheels have zero camber (ie. straight up and down), this enables a change in the main spine angle to the ground, without re-aligning the rear wheels.

To the people that have asked....the CAD program used is avaliable FREE from

www.cadstd.com/

Its a simple FREE Cad program and works very well, still not as creative as a pencil on the back of a beer coaster but the results from the Cadstd are GREAT.

Howdy Nebbian,

Where do you shop?

Every shopping trolley I get hold of has all wheels with minds of their own, all wanting to go in every direction, but the one I want them to!

Back when the tyres used to peel off,and the plastic rims shattered we would carry spares. These days I carry spare yachts. Travis Bartlett is currently experimenting with thos very wheels. In the old days we were not absorbing the shocks and bumps very well, but I think we are learning.
If you dont like the look of the yacht ,dont get in it.
In Argentina the strong wind rule was"no-one will be forced to take thier yacht to the starting line". Ie If you dont feel safe ,dont sail

NO I WOULDN'T use push bike wheels/ tyres for a class 5 ( way to risky).....
I might ONLY use a 16" push bike wheel / tyre for a Class 6 and then ONLY for the front wheel.
(Just my personal opinion)

I've got a set of plastic rims being modified in adelaide at the moment,and the set of Carbon rims we tested at gillies failed due to the wrong type of epoxy resin being used. I'm trying them on te minis at the moment.
the experiment is very much early days as I want to fit them to a OTT mini that wont fade away from my fertile brain

gizmo1160 said...

NO I WOULDN'T use push bike wheels/ tyres for a class 5 ( way to risky).....
I might ONLY use a 16" push bike wheel / tyre for a Class 6 and then ONLY for the front wheel.
(Just my personal opinion)

16 and 20" work fine on cl 5 front end if used as a layover and on smoother surfaces on the back.

this set managed 98.1kmph back in 1993.
A 12" fallshaw golfbuggy rim managed a speed of 110kmph in early 2007. they make a 16" and a 20" rim that we havent as yet tested

Many thanks Gizmo message loud and clear,would have thought that landyacht could have given the same answer but didnot

But then I'm not GIZMO

Yeah I was thinking of doing that as the stubbs only have a couple of cm to attach to the bracket. That's also the reason I thought they might be better on a Lefroy Mini

Yes a few heaps = 1 sh#tload. A very old ISO standard

There seems to be a bit of a delay with my lefroy mini project, something about fingers and lawnmowers!

Telltales placed by sailmaker. the trailing edge ones eventually flog out the sail.
I put some in a line 1/3 back from the luff, and a few on the trailing edge.

Re: minis . chassis are finished, prefered pain to boredom.
If you look at some ofthe last postings you will see bandaged fingers for scale and dating purposes. I have 1 front fork and a pedal to weld than those bits can get painted and I can start doing some drawings for seats. that is where the art comes in

AERODYNAMICS... Can someone define aerodynamics and what would be allowed and what wouldn't in Class 5 rules.
As a lay down seat to some degree is aerodynamic or are the rules refering just to the chassis?
I have noticed many pics from overseas that the Class 5 yachts have very slick almost enclosed seats.

This is how the Class 5 rules state it....

9. AERODYNAMICS, Fairing or other devices of an aerodynamic nature on any part of the yacht chassis are forbidden.