Gday all. Hopefully this will tell a half interesting story following the construction of my first mini-yacht. Here are a couple of stats from the top of my head:
Wheelbase: as per a blokart (1.65 x 1.4)
Frame: 30x30x3.0 and 30x30x2.0 steel
Mass aimed for: about 30kgs (35kgs with largere rear wheels)
Anyway, Ill get more details as I keep building. First image here is what it looked like as an experimental testbed. I was a little unsure of the power availible from the windsurfer sail but tests proved it should provide enough horsepower to play with.
Testing was conducted in the small paddock pictured as everywhere else is too rough. I flipped it twice due to a limited turning circle. Manouverability is much improved in the current rebuild. Mainsheet was a piece of cord run through a single pulley.
Here is the frame prior to final modification. The mast step has been removed, rear axles are still present and the steering geometry hasn't been corrected.
And finally finshed, all up I spent a short evening working the kinks out.
Then comes a seat. This was one of those old school chairs minus the steel tube legs. Half hour with a heat gun and some time sitting on it upside down while it cools and I now have a comfy reclined model. The back will be reinforced against the new prong(??) out the back where pulleys will be mounted. Mounting it will be done using four bolts through a plywood base.
Here is the almost completed steering arrangement, only thing left is some paint. The design was taken from the windflyer yacht design, the one with the windsurfer sail mounted behind the pilot who sits upright in front. The forks pivot on a 3/4" bolt, steering ball joints were 3/8" in size (the threads) and foot pedal is 30x30x2.0 (if memmory serves correctly). Overall there is good turning and it always returns to centre when pressure is released from the controls.
Thanks for everyones time and this forum space. Catch you next time for more updates.
Looking good!!
I used those mini ball joints in my steering as well. Does it have enough up & down movement in the ball joint so that there is no risk of it popping off at full lock?
The ball joints have enough travel at present but i'll be adding a physical stop to limit the travel of the forks. At present time there seems to be no tendancy for pop offs 
Thanks for the comments. Hopefully I can get more done soon, I really want to put this thing through its paces and the wind around my area at present is some of the best we see.
A Quick pic showing the maximum travel of my steering setup. I haven't yet added stops to limit movement to a little less than that seen here. There appears to be much better travel than with my old Datsun120Y tie-rod ends I used before
A here is my mast base. Holes are to save mass and will be closed using a PVC sleeve inside the steel.
See you later, Lachlan
I think its going to be a ripper!!
If you find you need to limit the steering, I have posted a photo of what David put on my steering so I could adjust the end stop. The other direction is limited at the front. (I won't clog your excellent thread with the pic 
)
On behalf of all the amateur landyacht designers and builders in Aus I would like to officially welcome you to the ranks. excellent 2nd effort.
the only suggestion I can offer is that a strip of 12mm conveyor belt rubber with 2 holes drilled in it will do the same job as that expensive joint. I dont think that we have 1cent pieces anymore so that would cost 5 cents per joint
why not get a blade behind the tractor, or a length or steel and grade a track in the paddock. I would sail on that
The steering joints were a little pricey at $13 each but I wanted to test them out. I'll have to use them on a bigger yacht seeing as I stole all the tie rod ends from my Datsun for the first yacht. All I have to do is unbolt them, replace them with some cheaper rubber strip Thanks for the good idea, Ive never thought of using that.
The travel stop idea is a ripper! You maybe might see a similar setup in a few pics time. Thanks for that, I was going to just weld a lump of steel in the way.
Last night I welded some supports to my mast base. It was a horrible night actually, not a thing went right. As a result the left hand brace is 10mm further inboard than the other [}:)] Just aesthetics anyway, at least on this scale yacht. The braces are ~30m OD x 1.5-2.0 wall seamless steel. I picked up a couple of 4m lengths for $5 each at a junkyard. Guessing I should get some more at that price and its better steel than my frame tube.
Oh, and the paddock is powdery rubbish soil, very hydrophobic and just turns into bulldust. Its ok though; a couple of k's out the road we have a farmers permission to sail and the many roads that criss-cross the area.
Ok. All Ive done since the last post is welded a nut to the forks to lockup the steering slop better (pivot pin isn't overly tight, just a snug fit), driled holes for split pins in the front axle and pedal pivot, sanded the frame a little, wiped the frame down with a little petrol and painted it. 50% of it anyway, i still have to weld the rear axles in. Hopefully I'll get that done in a couple of hours.
P.S. Yes, I jumped the gun by painting and am asking for trouble!
.
I knew it. I told everyone, white = trouble! Not 4 hours after adding the devils colour I bleed on the frame. No matter, it was only a small slice and hardly hurt. Today though I rubbed some silver solder flux into it and now its got a sting to it, very harsh burning sensation when that happened 
Here she is, the completed buggy. All I need to do is replace a few of screws with bolts and add some rubber (or equivalent) to the foot pedal.
I did some adding up of mass and have figured what you see there to be 32Kg with the big wheels. If I had used plastic wheelbarrow wheels all around the mass would be closer to 25Kg. Oh well, I figure im a featherweight myself so it'll compensate
Howdy blokes,
Have in mind to counstruct a land yacht. Just some starting advise.
If the rear wheels are angled, what generally are the degrees?
How important is the position of the mast step? I sail, and on, on water yachts the step position is most critical for correct performance of the vessel.
Steering geometry, have been kicking around net, 49 to 50 degrees forward angle appears to be commonly used, does this seem about right?
Thanks for help
Howdy Sandflyer, I'm sure one of the designers will be along any minute to answer your questions. However if you're thinking of building a yacht you can pick up a set of plans really cheap (basically they just charge for postage and photocopying) where you'll get the best design that has been tested and modified to perfection over the years. Speak to "Landyacht" as he's designed many over the years and is creating a thread on how to build a Lake Lefroy mini, or you can get plans from "Test" for the fed 5 or Pacific Magic.
As for your questions my Pacific Magic has a variable step for the mast so it goes from almost vertical to about 20 degrees depending on weather conditions. What is critical is where the mast step is located along the chassis spine. Its best to get that off one of the plans.
My wheels are angled at about 10 degrees off vertical, but mine are the most angled by far at the ALYC so I guess anywhere up to 10 degress should be ok.
Steering geometry I'll leave up to the experts as I just adhered to the plans
Thanks Hills,
re mast step, yeah rake is not a problem. Intend to build adjustable rake system. The position of the step along the spine and how it is determined was the crux of the question. Thinking about adjustable step position too. As yet I have no mast nor sail, the size and cut of the sail will determine the position of centre of effort of the sail. Stepped too far forward and too far back create performance dectractions. I was just wondering if there was a rough rule of thumb to determine the approx position to get a start. Sites on the net show many and varied craft, a lot appear to be home designed, and the mast (step) position seem to vary along the spine, with no apparent ratio. Whereas dimensions for a majority of the craft, including tried and tested designs, seem to have a frame track to base ration of between 1/1:15 and 1/1:25.
Thanks again
Well to give you a rough idea (but make sure you double check this with David Rose or Paul Day "Landyacht" the designer), the wheel base (front axle stubb to rear axle stubb)of a Pacific Magic is 2500mm. From the front axle stubb to the front of the mast step is 885mm and to the rear of the mast step is 1085mm. Depending on the rake of the mast the base of the mast can be anywhere between these two points.
Oops sorry Lachlan, didn't mean to hijack your thread 
Good to see you're putting your blood sweat and tears into it
What hijack Any talk about yachts is okay by me. Im by no way an expert and my designs are made with only a few simple rules Ive picked up across the web. I can testify both landyachts I've built work, that said I wouldn't enter them in a race if I was paid to.
I learnet a lot from a website detailing radio controlled landyacht design. After reading it it seemed pretty common sense stuff, even if it doesn't prove helpfull its a good read (and it has pictures/diagrams).
Ah, here it is:
www.rclandsailing.com/design.html
Scroll past the construction techniques/dinamics bit and check out the design notes. Happy reading, catch you later.
Hey Lachlan,
Been watching your progress of construction. It looks great. I have a bit of doubt about how long your plastic seat is going to last. Especially after reading your heat gun modification description. I know there are millions of those seats around and you can probably pick them up second hand for $1 a piece, however if you find that they are going to fail after short use, here is a suggestion.
I was in the local tinny and outboard shop today and they have a range of plastic seats there that people put in tinnys. Some are just the single piece shell like yours, some are cushioned and some are folding backs but I am sure they are all made of UV resistant material. Unfortunately none of them are cheap, prices range $70-$120. Like I say just a suggestion but a few bucks might save you a lot of aggro.
Quote for the Day:- "Imagination is more important than knowlege."-Albert Einstein.
Live long, have fun, be happy, All the Best, cisco.
Hey cisco, thanks for the thoughts. I probably will need a new one before too long as this one's far from luxury, as well as a little flimsy (the reason the 'tail' going out the back is helping support it. Im pretty sure its UV proofed as its been outside for a while already with no sign of decay. Anyway, I'll see how it goes for now.
If I were to build another it would have seating built into the frame, fold up camping chair style Be going away for the weekend so until I return, Happy designing, building and/or sailing.
Hey Lachlan,
I went out to the Bundaberg Dump today looking for one of those plastic seats for my son's billy cart. Hit the jackpot mate!!! They have about 30 of them out there that can be had for $1 each, all in good condition and not very old by the looks.
I think the metal frames of those particular seats were no good and must have rusted or fallen apart because they only had the plastic seat part of them.
If you are going into production of your yacht, let me know and I will go and get them for you. They are certainly cheaper than the ones in the boat shop.
Thanks for the offer Cisco. Im not sure these seats aren't suitable so if I go into mass production ill be sure to give you a bell
As I said before I got away this weekend holidaying in Warnambool. And yes I did take my creation with me and had a go on a beach down there. Im pretty sure the soft sand was a problem as the thing didn't want to move forward, only roll over 
I think the problem was that the sand was too soft and by the time the sail was producing enough 'thrust' to overcome fricton it was already rolling over. That and the size of the sail made it very 'touchy'. Pulling the sail in even 150mm was enough to go from stationary to forwards movement with an undesirable roll. I hope to try it out on a harder surface soon. As for beaches, I'll leave them to when I holiday again.
Yes mate , even what might look like a perfect place to sail often turns out to be a dud.
There is a big area of tidal flats just outside Gladstone that I thought looked perfect. It only ever gets wet during the highest of the spring tides.
When I tried it out it was well and truly dry, so I get the yacht down on to it and with me in it the weight on the tyres did not break the top dry crust of the surface.
What did happen was that the weight was enough to impress a tyre track into the surface about a quarter of an inch or less deep. This was like riding the yacht over a thin layer of sponge rubber. A sponge is exactly what it was. It just sucked up 90% of the energy that I was catching in the sail.
The closer the surface is to being like smooth concrete or hot mix bitumen the better the ride will be. But you can still have a great ride on sand, grass, gravel or salt as long as it is hard. So don't write off the beaches, you can still have a lot of fun there.
Cheers from cisco
By the way I think the plastic seats are a good cheap alternative to fibreglass when angled the way you have done. Just need to devise some way of preventing feet and legs from touching the ground when moving. Especially for competition.
Thanks for that cisco. I was feeling a little confused that it wanted to move on my paddock with promising style but lacked any cooperation on the beach. When I was trying the beach out it was really too windy for the sail size and as soon as I'd stop i'd wriggle the yacht into the sand 20-30mm. Just goes to show; its easy to underestimate the force required to overcome friction
On a side note, is there anywhere/any post that explains whats required by a homemade landsailer to have some fun at a formal meeting? I dont mean class ruling or racing but just whats required for insurance purposes or some such reason.
I don't know if its the case with all clubs but a social membership with ALYC buys you the 3rd party insurance and the council permission to use the beach at Pt Gawler. I read in another post that someone (Clinton I think) is starting a club in Victoria. See what the deal is with that or else ask the Melbourne Blokat club.
All our yachts in ALSA are home built but they are to a class spec for racing. I don't think they'd have any problems if you wanted to sail a non class spec. Chances are your yacht will be within the specs of one class or another, (might just be a bit too far within spec to be competitive, not that that matters )
So long as I can sail, not necessarily (spelling??) competitively, if I do get to a club meeting/event I'd be more than happy. I doubt anything I'd build would be competivie (within class spec) on a hard flat surface.
That said, I hope one day I can give anyone a go for their money over an uneven terrain or paddock. I have aspirations
Being a rough rider from way back, I couldn't agree with you more Lachlan. If it's rideable I'll ride it and if repairs are necessary afterwards, so be it.
It is the ride that is most important. Experiences have more lasting value than assets.
Ahh. . . . well. Funny story, my girlfriend didn't take any pics with the digital camera, only video 
when we were at the beach. Cant quite get my head round that but she's still beautiful
Coincidentally my father and I are hoping to go to Kerang (lake Cullens) tomorrow to give the two yachts a bit of a dust off. We may not even sail seeing as the lake is clay based and theres rain about. Anyway, theres wind forecast (lots of it) and we want to get away. Even if we cant sail we can have a look around. I guarentee there will be some pics taken if sails do go up.
Stay tuned for another exciting installment next week
EDIT: Sorry for forgetting this but if your out there Inlander feel free to drop out for a look. Not promising much but your welcome to check out our mad max machines I'll confirm tomorrow morning if were coming up or not.
Good to see you back on screen again Lachlan. Been waiting to see you post again.
So watcha been doin'?
This week just gone I started my honours work at uni. Its been a little hectic studying and next week I drop the IQ by getting four wisdom teeth ripped out. Seems as though things in the landsailing shed are going to slow down unfortunately.
On a brighter note, I still want to get supplies together to build another large landyacht. Printed off the Smart Aluminium catalog, still deciding on the advantages of using some Al. Maybe I can start another thread in a bit showing the design I've been tinkering with, I can deal with the ridicule
NEWS FLASH; I wont be tripping up to lake Cullens this weekend 
Dads got some more work on and theres no time. Looks like I'll have to prepare for a trip in a month or two. I knew I'd jinx it.
