Hi,
For starters, a bit of background. I've been wanting to build a landyacht since i first went for a ride in a two seater when i was a kid. Upon finding this forum and a bit of a rummage around my shed I realised i have most of what I need. So it has begun!
I am an Industrial designer by trade, so i have a habbit of trying to "improve" everything. However in this instance i am trying to stick to the LLF design as much as possible for the first build based on that i have not really got a clue about the deisgn intricies of a land yacht! However that being said, due to the availibility of material at hand, and an almost non existant budget there has been some...... comprimises. As a result I need a bit of help digging my way out!
As far as materials, I have an old sail board rig. Not sure of the sail area, (guessing about 5mt). A fiberglass mast about 4400 long. (Beagle shown for scale.)
Instead of the 60mm x 2mm tube I have some 43mm x 3mm seamless tube, (quite a bit actually). I cut a piece of this to length at first and performed a "load test", (i put one end on a brick and jumped on the middle!) seems OK. Also the 35 x 2 SHS is 40 x 3mm SHS. So i have but welded them together. I realise this will likely need bracing and i expect there is quite a bit of torsion at this joint.
Now the bits i'm worried about
1. I have used the same tube as the mast mount. With a bit of heatshrink, the mast will slide over this point quite nicely. Has anyone tries this with any success?
2. With the mast mount positioned as per landyacht's details, it looks to be a too far back. I assume the center of pressure should be just forward of the rear axle's. As well as the boom being too long, it doesn't look right.
3. Can anyone please advise what size wheels should be used. I am intending to run this thing mainly on the beach. It seems that fallshaw poly wheels are the go, but are there any alternatives that work, (Given I am on a budget, as with most people.)
This is where i am up to for the moment. I have an almost full photo log of the process so far if it is of any use to anyone. Just let me know and i can post the build details.
Thanks in advance!
You're making great progress there Grlynch!! We always lke to see build photos!! 
I'll let the LLF designer or one of the many other LLF builders answer your questions, but I expect they might suggest you make some changes to the sail as it does look rather large for a LLF. But hopefully that means you'll be able to cut it to make a perfect LLF sail. 
Looks good, the main spine tube has a twisting force or torsion on it rather than a bending force, Where you have joined it to the back axle it may need some bracing as the LLMini plans (I think) has a cutout where the axle is welded on.
The mast step going inside the may cause a pressure point that may cause damage to the mast and cause splitting. Most tend to put timber inside the mast to above the boom point for additional support. The Sailkart has an internal mast step...
www.seabreeze.com.au/forums/topic.asp?TOPIC_ID=63886
I 'm close to your area if you need some free steel ,a look at my 3 LL minis ,or bat some ideas around
Ian
the sail is a bombora, probably around 6m
is good
the seamless will probaly be fine , but , I think is will flex rather easily. Its hard to be sure, but given the diameter, it is likely. What is the wall thickness of that tube?
I would be inclined to wrap some fibreglass cloth and resin around that mast base to about 0.5m up. none of us have tried the mast step inside, but I recon it would work , with some forethought.
welcome to our obsession, just make sure you keep having fun
wheelwise, the 4.00x8 is basically the best bet, perhaps others in Qld can advise on locally available types
Thanks for the encouragement. It looks as though I'm not too far from the mark yet.
Iand: thanks for the offer, I've not actually seen an llf in the flesh yet. If you and or anyone is heading out for a sail on a weekend I'd like to come and have a look.
Landyacht: the seamless is close to 3mm wall. The sail is quite old, a bit tattered but in not too bad shape. However I think it is considerably smaller that 6mt, maybe about 4-5 by my measurements.
Regarding the mast arrangement I was thinking the same although the wall is quite thick, about 5pm I reason if I can get it to fit quite snug over the mount I shouldn't get too much of a weak point. The mast in a bout 150mm shorter than the sail so I think I'm going to have to trim it anyway.
3mm will be fine , in fact it will be great
I just looked back at theat photo of the sail with the wishbone, i see what you mean
make sure the top of your mast step pipe has well rounded edges
Landyacht, I've got a reasonable radius on the mast step now, about 2mm, but This will increase once I pack it out. The mast step is too small for the mast, about 1.5mm per side. The plan is to use a layer of heatshrink, or two, to pack it out. The advantage is I can slide the mast on whilst it is still hot/warm it it should mould perfectly.
Still not sure about the position, do you think this is a problem with the sail shape, mast step position, mast step angle, or a combination?
It will all look abit different when the yacht is closer to finished with a seat and the sail is reshaped. you going just fine
Thanks Landyacht,
I was considering moving the mast step forward, but i'll leave it for the moment.
I expect the sail mods are going to be challenging. I don't have access to a sewing maching but i'll cross that bridge when i get there!
On a side note, i was lookin at the steering setup, and after a quick trip to "recycle land" at the Victoria Point dump, (love that palce!) i picked up a BMX frame at the right price, (bit hard to haggle him down from nuttin!). It seems like using the goose neck and forks as is woul be the easiest solution. Any reasons why not?
Thanks
you would need to cut and weld the fork to the new angle, or heat ,bend and retemper. maybe Iand could dig up his old posts on doing this as his front end is quite neat. I reckon the handlebars are way to wide , but some people swear by them
here's the link ,and I contacted Glenn to let him know he's welcome to come over and have a look see
www.seabreeze.com.au/forums/topic.asp?TOPIC_ID=39276
and to Paul a link I don't believe we got to hear/see the final result. I think I cracked the mast step mystery, by allowing the rig to lean to leeward it generates downforce to give more traction (ie. the opposite of a windsurfer)
www.seabreeze.com.au/forums/topic.asp?TOPIC_ID=51833
only just realized after suggesting the landyacht register with Phil I never did post any photos of any of mine
Been a bit distracted this weekend. Not much progress.
However i was about to add the bracing to the back axel mount and stopped to wonder why.I'm sure this has been added through experence, however from an engineering perspective (note; i'm no an engineer!) the majority of the force on that joint is torsional. Is it really necesary?
Also i have discovered another couple of small problems. I used 40x40x3 SHS for the axle mounts. Which means finding a standard section to fit into it is a bit difficult. I have at my disposal some old water pipe, which dosn't appear to be rusted on the inside. It measures about 27mm OD, i'm not sure of the wall thicness until i cut it tomorrow. Reackon this will be good enough?
Also i have made the axle with the seam on the SHS on the top without realising, I have a bit of a concern that it will split as i expect this is the side that will experience the most force. Hs anyone lse experienced a problem with this? 
If you don't add the brace imagine the force on that rear weld when you hit even a puddle of water. The brace relocates and lessens that force. Think about leverage
that seam will be fine, i would recommend the brace though.
It will help maintain triangulation in the event of a sudden shock, like hitting something hard
Just a suggestion, use some flat say 30mm x 3mm on both sides for bracing then you can drill holes and also use it to attach the seat...
OK managed to get a bit dne this wekend. Getting further from the original design though. Starting to get a littel nervous!
Build so far
I do not have the right size SHS to suit the 40x40x3 SHS at the base. So i roughed up some axle's from the old water pipe I had. Had to weld a bit of angle to it to get it to fit better, seems OK. Will still need a bit of packing though.
And of course a load test! Dosn't flex much, maybe about 3-5mm. (I should acknowledge my photographer at this point, My 3 and a bit year old Daughter!, No i'm not kidding)
I've succomed to the peer pressure and added the bracing to rear bar. I ender up using some 10mm square solid that i had.
I'm now having to seriously do something about wheels. I think from what i have read the Fallshaws are the go. Dosn't seemt to be much point with anthing else. Can anyone suggest the best place to get these?
Also on the subject of wheels i've noticed a lot of yachts with a small BMX wheel on the front. How does this perform on the beach?
16" bmx is fine on the front.
seeing the rust spiral on the round tube has me wondering if it is galv waterpipe?and not seamless tube?
I would suggest a flat bar strap around the mast step and under the main tube,and a small low brace behind the step
The rust spiral is actually because this pipe was originally the top rail of a wire fence. The rust is a mark from the tie wire? Well spotted though
Will consider the reinforcement on the mast step, but I have to say it's welded on pretty good! Not that I'm much of a boiler maker!
You need something to attach the tack of your sail to so the mast step brace
can do that job as well Apparently some yachts have cracked at the base of the mast step Your query regarding the Bmx wheel on the front We have found them fine Recommend the Fallshaws for the rear though Your build is coming along well Good job there !
I wish i lived in a place where they use seamless tube for fences
oh that right , I do
Starting to shop around for wheels now. I've seen from the Fallshaw website there is several suppliers around brisvegas. I'm assuming the wheel to go for is the 400X8KNO-WB20 (for a 20mm shaft). Can anyone advise what i should be paying for these?
I also se they are not suitable for speeds above 8km/h. Is this really the case?
they are after all a wheelbarrow wheel but they are the toughest plastic wheel Ive found in Oz. ive only got one up to 95 kph , but maybe one day
In Kalgoorlie , we pay just over $60 for a complete wheel. they are made in Brisbane, so it will be interesting to see what price you get
Some more progress. It is starting to come together. I must admit i had to check the dimensions as the proportions don't seem quite right. However i am only 5'6".
Got the steering soted from the BMX frame. Still managed to assemble it after all that welding, so looks like a win. Haven't "Adjusted" the forks yet untill i get some wheels on so i get the angles right.
Started looking at the sail and how i'm going to modify it. That is starting to do my head in. I think it will end up at about a 4.1mt (+ mast pocket) when done. Is this going to be big enough? Am I on thre right track?
Something has just occured to me... and i'm getting that sinking feeling.
In the LLF design is the mast supposed to swivel in the mast step when sheeting? I'm concered that my build with the mast step inside the mast is going to cause me some problems
