I'm starting this post to do a step by step building lesson as I build a Lake Lefroy Mini. I intend to go through it from tools materials, wheels, steels, sails, masts, pulleys and ropes including building hints and "dont's".

PLEASE DO NOT POST TO THIS THREAD as it will get too long with repeated questions. Please post all questions, suggestion, or disagreements onto a separate thread and I will endeavour to keep the world in eternal happiness.


Lets start with the history of the design.

The project started 3 years ago as a challenge to equal or better some of the great design aspects of a BLOKART, without the pricetag. One lesson we learnt was that the blokart actually represents excellent value and is a lot harder to replicate than you would think.

The self imposed rules were to use the same wheelbase and sail area as a starting point. Materials were to be sourced as locally as possible and be materials that others could also source in their area.

Utililize recycled materials as much as possible.

The "final" product looks and sails great and managed to come up to many of the standards set by the BLOKART but certainly not all.

This yacht was designed by a team of up to 20 people in WA and SA over the three year period. I am indebted to the input that each person has put in.


PLEASE NOTE: THE FOLLOWING INFORMATION AND IMAGES ARE COPYRIGHT TO PAUL DAY. YOU ARE WELCOME TO USE AND DOWNLOAD THIS INFORMATION FOR PRIVATE USE FREE OF CHARGE AND WITH MY BLESSINGS. YOU MAY NOT REPRODUCE THIS INFORMATION OR IMAGES FOR COMMERCIAL GAIN.

regards Paul Day

Photo's and step by step instructions to follow.
PLEASE DO NOT POST TO THIS THREAD BUT START A NEW ONE FOR QUESTIONS.

Tools to build with.
MINIMUM LIST
Large square
Small square
Bevel marker
Good protractor
Round file
flat file
large centre punch
small centre Punch
Hacksaw &/OR 100MM GRINDER
Drill with 13mm chuck
Good metal vice
Welder capable of a good weld with 2.5mm rods
A good flat level surface that you can weld on

RECOMMENDED TOOLS
Drill stand, 6 0r 12 speed
325mm metal drop saw

CONSUMABLES
good quality 2.5mm welding rods, Clean new wire if MIG
100mm metal grinding disk
100mm regular cutting disks
mega line cutoff disks( very thin cutting disks)
(Hint -Dont buy cheap Disks)

photo of tools below. note fingernail trimming tools for copyright enforcement support. The round object is a mystery. If you know what it is there is a prize. it has the ID of M-8 and patent march 23,1915.2221. I think it may be a machine gun mount but I dont know

wheel 1 Fallshaw 4.00x8. steel. fitted with 20mm ID precision bearings. heaviest wheel in photo. Also available with2"/1" wheelbarrow bearings(2/1WBB)
Rated Excellent

Wheel 2 Fallshaw polypropylene 20mm ID precision bearing. also available with 2/1WBB
Rated Excellent

Wheel 3 Wheel ProductsS.A. steel with 2/1WBB. this wheel first used in 1985. and was fitted to cl 5 yacht in 1st place at 1986 Pacrim NZ. wheel still in use
rated Good

wheel 4 Polyplastics W.A. Polypropylene with 2/1WBB.
Rated Good

Wheel 5 Experimental polycarbonate/ABS wheels by Poly Plastics W.A. wheels tend to explode But I would like to thank the company for being willingto do the experiment at thier own cost .. modified and fitted with 20mm ID precision bearings

MAIN CHASSIS /MAST TUBE STEEL.
photo below is of some suitable steel types for your lefroy Mini

The top tube is 60mm,2.5mm wall hot dip galv steel pipe from Smorgan steel. it is available in shorter than 6m lengths as fenceposts. this is the tube we will use for the mast tube. It MAY be suitable as a main chassis tube and I will build a chassis with this as well as one with one of the other tubes.
Tube 2 is NQ CORE TUBE recycled from a Diamond drilling company. it is a seamless tube, 57mmOD and 3mm wall. Often refered to as seamlessERW.
this is great tube for a full size class 5 yacht ,probably a bit too big for a mini, but if you can find some as salvage get as much as you can.

Tube 3 BQ CORE TUBE Same deal but49.5OD 2.1 mm wall. the best tube Ive yet found ,but a bit rare. ideal for a Mini

Tube 4 Underground diamond Drilling Rod. Seamless ERW tube of 46.8mmOD with 3mm wall. . Found as 3m drill rods.

for hose who are going to research sources for the seamless tubes I would recommend trying to ring around drilling companies in capital cities first. many bigger companies are city based despite the work being in the Bush. . You will need 300mm of the Galv Fencepost material for the mast step so if you cant locate any of the other material,dont lose sleep over it

The simple steering system shown in the previous photos was originally devised by a BLOKART owner in Esperance who only has one hand. Name of Shane Mortimer.He was having difficulty with steering and sheeting with one hand. He devised a simple cross bar clamped to the lower end of of the hand steering gear.
. Whilst I stuggling with a short system on the new yacht it was described to me and a simple sketch completed the design.we Have come to call the system "ROLL STEERING" . withe the feet on the steering the movement is actually up and down rather than back and forwards. It only takes one or two turns in the yacht to get the feel of it.. You can actually steer easily with only one foot.
when the yacht lifts a wheel your feet just flow along with the surface you are sailing across.
here is that original sketch.

The rear axle is built from 35x35x2mm galv square tube, 500mm long. 2 dropsaw cuts which dont go all the way through will give the right wheel layover angle when welded back up


cut and drilled rear axle ready to weld.

clamp on a flat surface and weld up cuts. this should give a bend of up to 4degrees on each side.

The mast tube. I will be using 60x2mm Galv nominal bore pipe. this is commonly used for fenceposts. The next chassis will use the same tube for the chassis.
the top of the mast pipe should be flared out on an anvil or your vice . this helps to prevent the edge of the steel digging into the fibreglass mast you will be using later. All the sailboard masts I have come across so far will fit. the biggest I have seen is a Kilwell BL3 one piece with a heavily reinforced 100mm base
flaring the mast tube will only take a few seconds with the right tool
more tommorow.

Day 2 of chassis number 1 build. A bit late finishing work so not too much achieved. ( chassis is finished though)

Im concentrating on finishing the front of the chassis. here is the drawingof what Ive done . NOTE not to scale tonight

heres a better view of the welding jig I use. its raised up so I no longer need to bend and the frame rotates through 360 degrees, so I can flat weld all the joints

The mast step I flared and cut has now been welded on. I weld the tops of the joint first then use a ball peine to work the pipe against the main beam tube. this wont be necessary with the Galv chassis as they will be the same size pipe

The main beam tube had previously been cut on a 30 degree angle( see plans) and now a piece of 3mm plate is marked, cut with a thin cutting disk and welded to the front

or not

there might be a delay in th continuation of the 2 minis were building of a few weeks. sorry.
due to a slight mishap i qualified myself for the %^#@!$ stupid idiot award of the year by slicing and dicing a few fingers. due to the bulky bandages(refered to as a stump bandage) i wont be able to fit a welding glove on for a month or so .
i do apologise to all,but will get the rest of the photos and plans done ASAP.
fortunately long term it will only affect my ability to pick my nose ,which may disrupt my bulls**t detecting abilities slightly.

REAR AXLE TIME. This is the bit gizmo was asking about. The material is 30x30x2mm galv RHS . It doesnt really look strong enough but it hasnt bent on rough salt,rough sand,supergripping asphalt, or when slammed into a Toyota. 2 axles per yacht ,the right one if fitted with a mount for a simple handbrake. this is not designed for stopping at high speed ,but is designed for slowing when planning to stop. If you plan to sail on Lake Walyungup do fit this brake as it will chew up the lake. have a look at the wheel brake system they use there instead.[
the axle stubs are 20mm dia. to fit the 6204 bearings in my fallshaw wheels. the 20mm round is fitted into some 25x25x3mmRHS which then slides cleanly into the30x30x2mmGALV RHS of the axle
the finished item.

next drawing are some alternative axles i have tried in both 1" and 20mm axles
the wheel I'm setting it all up for is the Fallshaw wheels discussed at the start of the execise
this be them. other piece is the simple handbrake.

THE DREADED FRONT END.
this is probably the trickiest part of the whole construction process. because the steering is a "lay over " type steering it is very important to get all the components aligned. If you get it wrong ,the quickest fix is usually to throw the fork away and start again.

heres one built by the JOHN WAYNE team. NICE paint job and welds, but you can see where I had to cut and reweld it to align it.
Ive decide to go back to basics for these 2 minis and use square RHS.
I'll build 2 front ends from 2 different size steels. As youll see in the photos right angles are used as much as possible and the angles can be checked for movement throughout the build.

Here is one I built for a 16" bike wheel. some of the measurements are different ,but the process is what matters.

Top view showing the right angle components.
In the next post I'll explain how I established the angles seen in the side view. it is important to understand the process in case you want to try a different diameter wheel to the wheelbarrow wheel i'm using.

now copy the angle from the drawing(in this case 128degrees) to the side fork. the steering shaft half is then tacked into place and eyeballed to check the alignment of the axle shaft and the base of the fork.

the 2 components should have obvious parallel alignment . if not adjust with hammer. the wheel sould be fitted back on to check the tyre centreline alignment.

looking good so far!
Now finish off your welds, recheck and adjust your alignments and do a test fit to the chassis.

it fits!
This set of forks were built from 30x30x2mm galv RHS.
You could build the same forks out of 25x25x3mmRHS. we have used this size for some years now with no bent units

The chassis have been put aside to be painted and while that happens you can start thinking about your seat.
The 2 options Ive drawn are the basic measurements that we used to create the fibreglass seat . With the photos you will get the idea of what to create in Glass or ply or a combination of both.

Heres the shape on paper and some photos.

from the top you can see how the seat is a really simple shape.

and from the side you can see how well it comes out of the mould.
In the next post I will put up a drawing of the cheap, easy to build wooden alternative that fits the Galvanized Chassis

for those who want to know what a mold looks like here is our mold for the seat in the specs. note on the underside the valves to plug in water hose when removing the seat from the mold. the mold is quite open in form to allow ease of lay up and removal.

Everything is painted and Ive started assembling the yachts. rear axles simply slide in and a 8mm X40mm bolt and nyloc nut hold them in place. the seats are drilled and fitted with holes cut for the mast step.bolts should be 8x30mm. I use large plastic washers that I make myself with a hole saw. usually 40mm OD and whatever centre hole is required. between the seat and the chassis I place a rubber washer cut from an offcut of belting rubber or if available some SYNTHANE from an industrial scrap bin .

it is a soft polyeurathane rubber sheet used for lining chemical tanks, but I use offcut scraps from the bin of an industrial rubber company.
the plastic washers are cut from a scrapped 200l plastic drum and are a nylon type plastic.
next we need to fit the wheels to the axles. on these yachts I will be using a washer and pin. the pins in the photos are known as MINSUP clips ,used as safety clips on minsup type airline fittings. you can buy Rclips in hardware stores or salvage pins from old fire extinguishers.
try to get the thinnest,skinniest diameter 20mm washers you can find . place the wheel and washer in place and lightly punch the hole position. after removing the wheel give it agood punch and then drill a bit bigger than the pin thickness
the finished job should look like this.
these wheels are narrower than the Fallshaw I built the yacht for ,but Ive run out of them and I am using up the last of the polycarbonate experimental wheels .