Land Yacht

For our senior design project, we were tasked with designing, analyzing, and building a land yacht. A land yacht is basically a wind-powered cart that supports a single rider who trims the sail and steers the cart. Our design utilizes a three-wheeled chassis to supports the rider while he/she trims the sail with his hands while steering with his feet. This instructable is a guide to building the land yacht. Once built, it can be used on most terrains, including sand, dirt, grass, or concrete.

Chassis

1 - A500 Hot Roll Pipe (1.25" x Sch 40 x 60")

1 - A500 Hot Roll Pipe (1.25" x Sch 40 x 48")

2 - A500/A513 Hot Rolled Mild Steel Rectangle Tube (1" x 1.5" x 24")

Mast

1 - 6061-T6 Aluminum Pipe (1.25" x Sch 40 x 72")

1 - 6061-T6 Aluminum Pipe (1.25" x Sch 40 x 84")

Mast Collar

1 - Aluminum Pipe (2.0" x Sch 40 x 24")

Mast Base

1 - A500 Hot Roll Pipe (2" x Sch 40 x 12")

Mast/Boom Connector

1 - Model 2T-7 Aluminum-Magnesium Tee (1.25")

Boom

1 - 6061-T6 Aluminum Pipe (1.25" x Sch 40 x 60")

Axle

1 - A36 Hot Rolled Mild Steel Round Bar (0.625" x 48")

Head Tube

1 - Tapered Head Tube

Front Fork

1 - Sunlite Threaded MX Fork

Foot Bar

1 - Mild Steel Round Bar (0.625" x 24")

Pulleys

5 - Rigid Pulleys (1.5")

Bearings

2 - Sealed Ball Bearings (0.625" shaft diameter x 1.375" housing diameter)

Rope

1 - 550 Cord (15')

Wheels

1 - Uline Solid Rubber Wheel (10" OD)

2 - Uline Pneumatic Wheel (10" OD)

Sail

1 - Triangular Sail (5' x 10.5')

Metal Band Saw

Miter Grinder

Drill Press

Bench Grinder

Tap and Die Set

Sewing machine

The first part of this build is preparing the sail for the land yacht. Our land yacht utilizes a sail that has a 5-foot boom and a height of 10.5 feet. This sail height was determined to work with the size of the land yacht. Our team used a much larger sail from a sailboat that will need to be cut to the right dimensions. The first measurement should be 10.5 feet from the top of the sail. The next measurement is 5 feet, horizontally on the sail. You will notice, however, that after you have measured 10.5 feet from the top, there is not enough room to extend 5 feet horizontally on the boom. Therefore, you will need to measure the height of the sail to be more than 10.5 feet until you reach 5 feet in length for the boom. This was accomplished with a sail height of 11.5 feet. Once the measurements are finished, you can now cut the sail. Make a straight, horizontal cut along the foot (bottom) end of the sail.

In order to fit the mast and boom piping onto the sail, a sleeve will need to be created along the luff (height) and foot (bottom) sections of the sail. This sleeve should be measured at 3" in length. To measure, take one section of the sail and fold it over onto itself until you reach 3" in length. Then, mark this length in several sections to make it easier for yourself when sewing.

Once the sail dimensions have been marked and the sleeve has been marked, it is ready to be sewn. The sewing must be done utilizing a sewing machine. If you do not know how to use a sewing machine you can watch videos to understand the process. Taking the bottom section of the sail, fold it back onto itself until it lines up with the marks you created. These marks are your guide as you are sewing the sail. Complete this for the bottom section and the top section of the sail.

Remember that the sail height is currently at 11.5 feet. This needs to be taken down to 10.5 feet. Using scissors, cut off one foot of the top section of the sail. Make a horizontal cut. The top of this sail will now need to be sewn so that the sail threading does not unravel. Make a horizontal stitching at the top of the sail where it was cut. The clew end of the sail is currently open after making the sleeve. This end will need to be sewn shut. Fold the very end of the clew onto itself and sew this section closed. A 4" x 4" square will need to be cut and sewn at the tack end of the sail. This is in order for the mast-boom connector to fit.

Parts: Main tube (A500 Hot Roll Pipe)
Tools: Angle grinder, cutting wheel.

Steps:

1. Using the rear tube as a guide for diameter, remove material from the end of the main tube as to fit the rear tube inside of the notch being created.

End Result: Rear tube fits snug into the main tube at a 90 degree angle ready for a strong weld.

Parts: Main tube (A500 Hot Roll Pipe)

Tools: Horizontal/vertical metal cutting band saw, angle grinder, cutting wheel

Steps:

1. Using the horizontal/vertical metal cutting band saw, cut a 45 degree angle from the front of the main tube. Ensure this operation is done at a 90 degree offset from the rear notching.
2. Notch the 45 degree cut to fit the head tube. This can be done with both the angle grinder and the cutting wheel.

End Result: The head tube fits into the notch ready for a strong weld.

Parts: A36 Hot Rolled Mild Steel Round Bar (0.625" x 48")

Tools: Bench vice, vice grips, 5/8" Hex UNC threading die, cutting oil.

Steps:

1. Place the rear axle in the axle into the bench vice so that it is perpendicular to the ground. Ensure the vice is tightened enough so that the axle does not move or rotates while threading.
2. Grip the 5/8" Hex UNC threading die TIGHTLY with the vice grips.
3. Place the 5/8" Hex UNC threading die over the axle and begin to rotate while applying a large downward force. Apply a generous amount of cutting fluid. (Use a team member to ensure the die is perpendicular to the axle. Once the first few threads have begin to cut, the rest will follow the path that they have made. So any any mistake made in the beginning will not self correct and will ruin the axle)
4. Continue to turn the die until two full inches have been completely threaded. Apply cutting oil often.After every 1/4 turn, counter rotate an 1/8 of a turn to brake the chips that have formed.
5. Repeat for the other side of the axle.

End result: Rear axle threaded 2" on both sides fitting a 5/8" UNC nut.

NOTE: To protect the threads, place a nut on finished threads while storing or working on axle.

Parts: A500 Hot Roll Pipe (rear tube), A36 Hot Rolled Mild Steel Round Bar (threaded axle), 2x Uline Pneumatic Wheel (rear wheel), 2x Sealed Ball Bearings (rear bearings)

Tools: 2x adjustable wrench.

Steps:

1. Remove seam from inside of rear tube. (This seam in is nearly an 1/8 of an inch tall and runs the length of the inside of the rear tube. It must be removed so that the axle bearings can fit inside the rear tube.)
   1. Using a file, remove an inch of this seam until rear axle bearing fits flush into rear tube.
2. Insert threaded axle into to rear tube. There should be 3" of excess axle protruding from each end of the rear tube. (This is where the rear wheels and but will be)
3. Insert rear bearings into the rear tube over the threaded axle. The bearings should be flush with the edge of the rear tube.
4. Place wheels onto the rear axle. Ensure that the the side of the wheels with the bearings (the "long part" is facing inwards touching the rear tube.

End Result: Completed rear axle Assembly with all mentioned parts. Wheels spin freely and do not rattle.

Parts: 2x A500/A513 Hot Rolled Mild Steel Rectangle Tube (1" x 1.5" x 24")

Tools: Horizontal/vertical metal cutting band saw, angle grinder, cutting wheel.

Steps:

1. Cut 45 degree angle on both ends of the brace member using the Horizontal/vertical metal cutting band saw. The cuts should be made, as shown, in an orientation to connect the main and rear tube together.
2. Using the angle grinder and cutting wheel, notch the brace member that that it cups the rear and main tube allowing for a strong weld to be made.
3. Repeat with the second brace member.

End Result:Finished brace members cut and notched to fit into the main and rear tube for extra support.

Parts: Tapered Head Tube, Sunlite Threaded MX Fork, Head Tube Bearing Stack.

Tools: Adjustable wrench.

Steps:

1. Using the instructions that came with the Head Tube Bearing Stack, assemble the first three components (bottom cup, bearing, and washer) onto the fork neck)
2. Place the Tapered Head Tube on the fork neck ensuring that the head tube is seated into the bottom cup pf the bearing stack.
3. Again using the included bearing stack instructions, place the bearing, top cup, and washer onto the fork. Ensure that the head tube is seated in the top cup. (the head tube should only be touching the top and bottom cup's and nothing else)
4. Using the provided head tube nut. Tighten the the bearing stack/head tube assembly onto the threaded fork. The head tube should have no wobble and should be able to easily spin freely.

End Result: Front fork, head tube, and bearing stack all successfully assembled to complete the front end assembly.

Once the head tube has been assembled and the chassis is all ready, it is time to have everything welded. The mast holder can be slid through the 5' chassis pipe. It should be slid 1' back from the front and welded there. The rear of the chassis, where the 5' and 3.5' pipes meet perpendicular, can be welded together. The 2' support beams, as seen in previous pictures, can be welded. The head tube will need to be welded to the front of the chassis at a 45-degree angle. Lastly, the foot bar can then be welded to the top of the fork, seated perpendicular and parallel to the ground.

The seat you choose can be up to you based on your size and comfort needs. For this particular project we chose a typical cheap folding metal chair.

Saw the legs off just below the actual seat portion so that all you have is the back of the chair, and the supports that lead down only as far as the seat. The hinges that allow the chair to fold should also remain included so the back can fold down.

Arrange the chair where you want it to sit on the chassis, centered on the long part of the chassis, above the rear axle and over the supports. Mark out 3-4 spots in a triangle or square shape on the chassis that would fit under the metal seat portion of the chair.

Drill holes through the seat and through the steel chassis. Select a bolt that's long enough to go through the chair and chassis, secure everything together with a washer and nut.

Because the mast is too long and too expensive to ship at its full length of 13 feet, you'll have to put the two pieces together as tightly as possible.

We used an aluminum collar with a 2" inner diameter that was just big enough to hold the outer diameters of the two main mast pieces. Slide both mast pieces into the collar where they meet roughly in the middle. Drill through the aluminum and secure with nuts and bolts that will reach all the way through. One or two bolts per mast piece should do. Try to sand out any sharp edges to avoid cutting your sail.

Similarly for the boom, you will bolt in a t-shaped pipe (mast-boom connector) to one end of the aluminum pipe. Make sure not to push the boom all the way through the intersection. That remaining space in the t-pipe should have an inner diameter significantly larger than the outer diameter of the mast because it will need to be able to swing around.

Before you slide the sail on and put everything together, mark out where on the boom you want to place your Eye Bolts (the bolts with the loop on the end). Then drill through and secure them with a nut. Mark the same spots on your sail where your boom will sit, you will need to cut small holes so the loop end will stick out from under the boom. This is where you will thread your paracord rigging.