He bought this homebrew landyacht secondhand and has been fixing it up for his clients to use.
It uses wheelbarrow wheels and a windsurfer sail. It carries two people in comfort and comes apart for transport.
In this video the frame twists quite a bit. After that we added two more tubes to triangulate the frame, and it doesn't twist anymore.
Step 1: The Rear Wheels
They are plenty strong and have no trouble with the side forces.
I guess they were made in America by union workers.
I built a landyacht once using cheap imported Harborfreight wheelbarrow wheels. The hubs broke off the wheels after a few minutes. You'd have to weld some braces onto those wheels to make them strong enough.
These axles are stubby things that insert into the rear aluminum tube. The axle nut has a retaining wire to keep it from spinning off.
The rusty tube seen here is one of two braces we added to triangulate the mast support. After that the frame didn't twist anymore.
Step 2: Front Fork and Wheel
One of the steering arms had broken off the fork and got lost. I helped Greg bend and weld a new one from stainless rod. While we were at it we reinforced the other steering arm
The pushrods have small balljoints at each end to connect to the fork and the footbar.
Step 3: Rigging the Sail
The sail is a 6.5 square meter windsurfing sail. It's got battens and "camber inducers" which are forks on the end of the battens that push on the mast.
This is a modern sail, which means you use lots of downhaul force and not much outhaul.
Since the downhaul ring is no the landyacht it's a bit different than rigging a windsurfer. You slide the mast over the stub mast and then downhaul the sail until it looks good. "Looks good" means the top of the sail is flat but not slack, and the sail belly is about 7% of chord.
Step 4: Mast Support
In the second and third photos here I'm showing which parts turn.
I'm grabbing the downhaul ring that's used to downhaul the sail.
The downhaul ring is attached to the stub mast and both turn.
Below that is the mast step. The stub mast fits into the step and is greased so it'll turn.
Above the downhaul ring is a black plastic sleeve over the stub mast. It's free to rotate but it doesn't have to. Above that is the mast support. It's bolted to a couple of tubes that go back to the rear axle.
The mast support looks like it has a fancy bearing in it, but it might just be a plastic ring and some grease.
Above that is the thrust bearing, which is a couple of greased plastic disks. They're pushed up to show what the top of the mast support looks like.
Step 5: Seating Platform
Step 6: Frame
Originally all the frame pieces came apart with clamps as seen in the third picture, so no piece would be more than 8 feet long.
The rear axle is now reinforced with an aluminum channel.
We added the two rusty steel scaffold tubes to keep the frame from twisting.
When you build your frame use lots of triangles. That's called "triangulation" or "triangulationizitionizing"
It's different from "strangulation" which is what happens when the mainsheet wraps around your neck and then you run over it with the rear wheels.
Step 7: Steering and Sheeting
Mainsheet is tied to the chair middle arms and goes up to a pulley on the end of the boom. Pull with your hands, don't get it around your neck.