Hello land-yachters!

Been following this forum for a while, and finally decided to join, to share with you (and hopefully get some feedback on) my first attempt at a land-yacht build!

The design is essentially a rough approximation of a three-wheeler mini. Since it's not metal, I realize it can't be registered. Which gives me a little more artistic freedom with some of the other design decisions.

So far:
Dimensions (subject to sanding, trimming, and hardware)
Fore-and-aft: about 8 ft
Beam: about 44 in

Wheels: Some wheelbarrow wheels I picked up at the hardware store

Rigging: "borrowed" wholesale from a sunfish. (en.wikipedia.org/wiki/Sunfish_%28sailboat%29)

I have a number of photos of the build so far, to be posted below.

What a way to pass the cold months!


Cheers!

--David

Laying out the first parts...

Cutting the fish-mouth joint

Roughed in

A better idea...




And... that's all for now!

www.seabreeze.com.au/forums/Land-Yacht-Sailing/General/Land-Yachts-from-around-the-World/

Nice! That's what I'd call "artistic freedom". Some really interesting vessels behind that link.

If everything goes reasonably well, though, I'm hoping mine will have more in common with a bamboo bike than with a woven bamboo wall.

Also, sorry for the large-format pics. I'll see if I can't figure out how to make them smaller in the future.

Seriously thick walled bamboo ! Interesting build I am keen to know how you hold the joints together
Keep up the good work I like alternative thinking
Just a thought A hole saw in a wooden jig should make short work of those joints a method used quite a bit by tube fabricators

Unfortunately, the wall-thickness varies quite a bit from pole to pole. I'll probably have to discard about 50% of my stock, which I ordered blind on-line. Next time I'll probably have a longer talk with sales, to let them know what I'm after.

I plan on making the joints using techniques borrowed from carbon-fiber (and, as it turns out bamboo) bikes: laying building up strips of hemp fiber and epoxy. There's a decent tutorial here (bamboobikesupplies.com/pages/hemp-composite-wrapping).

Some friends have suggested that TiteBond III may actually work nearly as well, without the fumes, so I may try that. I'd welcome any feedback on that! My understanding is that epoxy has good compressive strength, the fibers provide torsional strength, and that together they provide a strong joint. I don't know (yet) if the modern wood glues can provide the same (or at lease sufficient) compressive strength to use as a substitute.

Thanks for the tip re the hole saw! I got an interesting lesson in geometry when I realized why my semi-circular templates were leading to elliptical cuts in the poles!

New pics. Finished (finally) the first joint. Not the prettiest bit of fiber joinery, but hopefully strong enough. Next, a friend manufactured some wheels for me. I tried them on for size, seem to fit okay. It was kind of a thrill to wheel the thing around a little -- first time it felt maybe possible...













The plan is to wind/glue more fiber to the ends of the axel (like a Q-tip) to help them fit snug (need calipers to get this part right), treat the metal surfaces to take glue (open to suggestions here), and "permanently" attach the sleeves to the axel with more fiber winding, hopefully gripping the fiber to those weld beads.

You are back! Those joints made of fibre and epoxy should be strong enough
The glue on the metal well I don't have a lot of luck with that but if the bamboo is inside the metal tube and is a tight fit
I would imagine it would not be a problem The axles inside the bamboo should work too
Watching with interest ! Hiko

I hope you are supporting the mast and rear axle by triangular braces and not rely on the bamboo spine to resist twisting. The first photo showing your socks in sandals was a bit hard on my eyes - I think that is ok in the UK but illegal down here in Aussie, we go either barefoot or wear industrial boots !!

Keep going, a very interesting build, it should end up very light weight.

Thanks for the feedback. Yes, definitely planning to add more triangle bracing, pretty much everywhere. Mast stay, spine/axel, steering.

One problem I'm trying to solve is the mast socket. My current design (fig A) has the mast slipped into a bamboo socket, which is in turn attached to the spine. My concern here is that the force between mast and socket is explosive rather than compressive, in contrast with the way the wheels attach to the axel. This is hopefully mitigated by reinforcing the sleeve with tight winding -- probably both wire and fiber.

Another option would be to modify base of the mast to fit over the mast "sleeve" (fig B), same as the wheel/axel fitting. The major downside here is that I no longer be able to use the sail on my Sunfish.

I found this paper about bamboo and thought it was very interesting.
Bamboo Boat Building.

proafile.com/archive/article/bamboo_boatbuilding

Interesting article on bamboo It also mentions a plant based epoxy like resin
Some years ago I came across some locals in the Solomon Islands building dugout canoes
Any flaws in the log they would repair with a black epoxy like stuff they told me was made from two types of plant
material that would harden when mixed. Sorry to go off subject here

a few years ago i read about a US epoxy maker that was selling plant based epoxies in various grades. the colour you got depended on how the variuos elements settled on cooking. sorry cant find the link . i tried to find a supplier in Aus , but no luck

entropyresins.com/?doing_wp_cron=1584717560.7693290710449218750000
ecopoxy.com/
www.supremesilicones.com/Blogs/silicone-bio-epoxy-hybrid-resins/
www.castingabout.co.uk/Eco-Resins.html
just a few i found

Wow -- thanks for the info, guys! It may be too late for this build, but there will be another one. I wonder how structural properties of these epoxies compare to the conventional kind?

Who knows, if I get the design right maybe we can have a new unofficial racing class one day


I'll be back soon with more pictures/updates. It's planting season here, so most of my free time has been spent in the garden. Soon I'll have a short break before weeding season begins.

No time for a full update, but enjoy this pic of progress from a couple of weeks ago. The wheel mounts are only on about 1/4 in this pic. When fully installed the metal sleeve almost totally covers the winding.

Checking the front-end hardware for fit before welding. Silly me, I realized that's an aluminum frame -- I chopped up a steel one instead, last weekend.

If you look closely, you can see the metal hoop where the boom connects to the mast. I plan to weld another steel tube there as a mast-step.

Awww.................we are getting close to a test sail.

Fantastic to see it built out of materials that we don't get here on the south coast of West Australia.

Well done and thanks for the photos along the way.

bamboo has lots and lots of strength ecept when it comes to trist. therefore you need to eliminate the chances of twist , eg ,
make sure all your spars are short and well braced. I would suggest seriously reducing the width and length otherwise its going to sef destruct when sailed. the rig you are using will be perfct with very little heeling moment so width isnt critical . reduce it. the rig will also not be a fast one so you dont need a long class 5 style chassisi with the mast almost 1/2 way back . put it up near the front wheel..
as much as you want to build a super fast yacht the material you are using aint gonna play the game

These are interesting points, and I appreciate the direct advice.

Fortunately, the width is somewhat exaggerated by that last picture -- the metal sleeves that attach the wheels to the rear spar are only partway on. Fully installed, the width is about 2 feet less than shown.

Unfortunately reducing length is not really practical -- the 11' boom already hangs over aft. The mast will actually stepped well forward, as it is on its source boat (a Sunfish), only a couple inches behind the front wheel.

I agree with you about the twist problem, and haven't really been able to come up with a good bracing system to counter it. Right now I'm considering extending the winding along the full length both parts of the frame. This will probably add some stiffness, and may help with the twisting, but we'll see. I'm open to suggestions here...

So, landyacht's last sentence brings up an interesting question: why bamboo? Primarily because it's easy to work with. I'm not actually interested in building a super-fast land yacht -- considering the material, I'm a little terrified of that many splinters moving that fast, should things go wrong. My hope is to bounce along at around 10mph (about 16kph to the rest of the modern world).

Just came across this thread, so how about this:

The Side-Beams on yachts like this take most of the mastloads to the rear-axle.
The Tetrahedron is a great form. The mast-step isn't even welded on.
Did a Kite-Buggy to Landyacht conversion myself, all screwed, easy to break down.
And has ran up to 50kmph....
Cheers, Joe

Select to expand quote

JoeHanson said..
Just came across this thread, so how about this:

The Side-Beams on yachts like this take most of the mastloads to the rear-axle.
The Tetrahedron is a great form. The mast-step isn't even welded on.
Did a Kite-Buggy to Landyacht conversion myself, all screwed, easy to break down.
And has ran up to 50kmph....
Cheers, Joe

A great idea to solve that problem.

from what i recall oof a sunfish rig you could easily have the boom hanging back well behind the yacht and pilot

Well back behind, oh yes!

Sunfish sail is 75sqf, nearly 7sqm! Good for low(!) winds, like my Lateen-sails. Looks probaly similar.
Sail foot is14 ft.
The original Sunfish-boom could be too weak for taking the sheeting point half way. I had to use surfmast-tops plugged together, after bending some alu. Bamboo should be working for this...

Some connections with varialble angles, (two different yachts):

I like the side-beams; I'll try to incorporate them into the current design. The more I read here, compare pictures/designs with what I'm building, I'm more inclined to shorten all dimensions (well, except up I suppose).

That may have to wait for the Mark II, though -- looks like the renter may be mowing the back 40 in the next couple of weeks, leaving me with a nice level patch to play on!