When you look at the log in the center of the wheel from afar, it looks like a big bulging eye; When you look closer, the place where the leather is to be wound should show the wooden edge at the end of the log: there is nothing else to imitate this, and it can only be done by fastening. Look at the protrusion at the proximal axis of the outer perimeter of the wheel spoke, and the flea on the inside of the protrusion part should be very positive. If you observe that the buds and fleas of the straight strips connecting the rim (wǎng) and the hub (gǔ) are in a straight line, and there are no unevenness, then the wheels will not be deformed even if they are broken.

To cut down the log in the center of the wheel, it is necessary to mark the shady and sunny sides of the tree. The wood grain on the sunny side is dense and hard, and the wood texture on the sunny side is comb and soft, so the sunny side should be baked with fire, so that the wood becomes as hard as the sunny side, so that even if the log in the center of the wheel is broken, the wood will not shrink and cause the leather wrapped on it to bulge.

The log in the center of the wheel is small and long, and the distance between the straight bar connecting the rim and the hub is narrow, and the large and short wheel is not stable. Therefore I make the rough circumference of the wheel circumference with one-sixth of 6 feet 6 inches in height of the wheel. Two-thirds of the rough circumference of the wheel should be painted. Measure the length of the white paint on both sides of the wheel, and then split it from the middle to use it as the length of the log in the center of the wheel, and the length of the log in the center of the wheel as the circumference of the log. According to one-third of the circumference of the log, the center of the log is dug out and then used as a 薮 (sǒu).

Divide the length of the log into fifths, remove the second part to get the circumference of the virtuous, and the third part of the tune is the circumference of the axle end. When renovating the log in the center of the wheel, it must be straight, the arrangement of the seal book engraved on the log must be correct, the glue coated on the log must be thick, the tendons must be dense, and the wrapped leather must be tightly attached to the log. The wrapped leather is first coated with maru lacquer, and after the maru lacquer is dry, it is polished with stones, and after polishing, the leather will show blue and white, which is called a good log.

I divide the length of the log into three equal parts so that two points are on the outside and one point on the inside, and in the place between the two places place the straight bar connecting the rim and the hub. For straight bars, the width of the straight bar needs to be measured by measuring the depth of the log chisel in the center of the wheel. If the straight bar is wide and shallow, the straight bar will shake, and even a good craftsman will not make it firm; The chisel is deep and the straight bar is narrow, which will make the straight bar more than strong and not strong enough.

Therefore, measure the width of the bar as the size of the bud width, and the end of the bud is cut into a shoot, so that the log in the center of the wheel will not break even if there is a heavy load. Divide the straight bar into 3 equal parts, and then cut the inside of the straight bar close to the outer part of the wheel to a smaller size, even if it encounters deep mud, the straight bar will not stick to the mud. Divide the girth into 3 equal parts, and remove 1 equal part to get the girth of the dice. Straight strips of wood made of coals must be made straight and sunk into the water at a uniform depth.

The straight strip should be pointed directly at the chisel around the outer circumference of the wheel, so that the flea and the chisel are tightly fitted, and it will be firm without adding a wedge (xiē). If the circumference of the wheel does not fit snugly with the flea, a wedge is added, and the end of the wedge will peek out from the gouge on the circumference of the wheel. The wheels are 6 feet 6 inches high, and the protrusions are two-thirds wider, which can be called a strong wheel.

For wheels, the outer circumference of the wheels that run on the swamps should be cut thinner, and the upper and lower circumferences of the wheels that run on the mountains should be equally thick. The circumference of the wheel is thinned so that it travels on the plain land, as if a knife were used to cut wet dirt, so that the wet dirt does not adhere to the wheel; The thickness of the wheel periphery is equal, and when driving in the mountains, it is to use the round and thick wheel periphery to drive on the rocks, so even if the wheel is broken, it will not make the periphery of the wheel of the chiseled hole wear and thin, resulting in the loosening of the straight strip in the chisel.

If the wood on the periphery of the wheel is dried with fire, the grain of the wood on the outward side will not be broken, and the wood on the inward side will not be damaged, and the sides will not swell, which is called being good at using fire. Use gauge measurement to observe whether the wheel is round, use moment measurement to observe whether the intersection of the straight bar and the outer part of the car is at right angles, suspend the line to observe whether the upper and lower straight bars are in a straight line, measure whether the depth of the two wheels sinking into the water is equal with water, use millet to measure whether the hole size of the log in the center of the wheel is the same, and weigh the two wheels to observe whether their weight is equal. Therefore, the wheels made can withstand the inspection of compasses, curved rulers, water, perpendicular lines, millet and weighings, and such craftsmen can be called national workers.

The wheel man makes the car cover, the upper section of the cover handle is 3 inches long, and the lower section of the cover handle is 1 times longer to 6 inches. The diameter of the lid bucket is 6 inches, and the handle under the lid is 2 feet long. The lower section of the lid is 1 time longer than the upper section, which is 4 feet, and the addition of 1 foot is 8 feet. One-tenth of an inch is called a piece, the upper part of the cover bucket is 1 piece higher, the hole of the wooden frame around the cover bucket is 4 pieces larger, the upper edge of the hole is left 2 pieces, the bottom edge of the hole is left 4 pieces, the depth of the hole is 2 and a half inches, the hole is 2 pieces less than the hole hole, and the top of the hole is 1 piece wide.

The bow-shaped wooden frame that supports the canopy is 6 feet long and is called shelter (zhǐ), 5 feet long is called shelter wheel, and 4 feet long is called shelter. Divide the bow into 3 equal parts, and dry the 1 equal near the lid bucket over the fire so that it becomes straight. Divide the girth of the bow strand into 3 equal parts, and remove 1 equal part to get the girth of the bow flea. I divide the bow length into three equal parts, and I divide the one equal part near the cover bucket as the part that is high and stretches out.

The part near the lid bucket should be high, and the curved part should be low. The part near the lid is high and the curved part is low, so the rain flows fast and far. If the canopy is too high, it will be difficult to pass through the gate of the palace, and if the canopy is too high, it will be difficult to pass through the gate of the palace, and if the canopy is too low, it will cover people's vision, so the height of the cover is designed to be 10 feet. Even if there is no curtain on the lid of a good car and no rope is tied to the curtain, the car will not fall off when it is running across the field, and the craftsman with this skill can be called a national worker.