In order to facilitate the storage of the daily skateboard, the surface of the board is transformed into a retractable hollow board surface, and the internal use of the telescopic rod, the hook is added under the hollow circle, and the skateboard can be hung on the wall without touching the bottom of the skateboard.

Step 1: Combination Skateboard Surface

（1）Select the adsorption grid to be 1mm, and

create a rectangular parallelepiped with a length of 52mm, a width of 20.5mm and a height of 1mm.

（2）Establish a stretchable surface as shown in the

parameters, curvature 1:5.2, length 1:10; curvature 2:4.83, length 2:27.01, curve width: 1, height: 20.5

（3）Combine them into the basic shape of the skateboard

Step 2: Finish the Skateboard Surface

（1）Copy the inclined surface, align with the center of the straight plate and then translate it to the sides by 23mm, copy the inclined plate twice and up and down by 0.99mm, and create a rectangular parallelepiped with a width of 30mm, a height of 1mm and a length of 50mm. Move up 0.99mm, move down 0.97mm.

(2)Select holes and combine them

(3)Create a cube with a length and width of 20.5mm and a cylinder with a diameter of 20.5mm and a height of 20.5mm. The cylinders are aligned along the center of the cube, select holes, align with the plates, and combine

Step 3: Build Bottom Accessories1

(1)Create a rectangular parallelepiped 7.5mm long, 5.5mm wide and 0.5mm high, and two cubes with a base of 2.4mm and a height of 2.4 and 2, which are aligned with the bottom cuboid, and are inclined by 8° on the Z axis and - 8°

(2)Establish a diamond shape with a diameter of 2.4 mm and a height of 0.61 mm, and establish a cylinder with a diameter of 2 mm and a height of 2.4 mm, and a tube shape with a diameter of 2.3 mm and a height of 0.2 mm. The diamond shape and the tube type are combined, copied and vertical. Mirror, aligned with the ends of the cylinder

（3）Establish a polygon with a diameter of 1.6mm and a height of 0.3mm, a ring with a diameter of 1.6mm and a height of 0.2mm, and a cylinder with a diameter of 1mm, and align it

Step 4: Build Bottom Accessories2

（1）Connect the combination to the right fitting to create a tube with a diameter of 3.5mm and a height of 0.5mm, raise 4.4mm, align them

（2）Create a cylinder with a diameter of 1.2mm and a height of 5.8mm and align it with the cube.

Step 5: Build Bottom Accessories3

（1）create a cylinder, and copy it to a cylinder with a diameter of 0.7mm, a height of 19mm, a diameter of 1.4mm and a height of 6mm. Rotate 90°, align the combination.

（2）Align with the fitting, place it down in the appropriate position, and align the lower cylinder to create a pyramid with a length of 6mm, a height of 6mm and a width of 1.4mm, which is placed above the cylindrical fitting.

（3）After combining them, tilt it by -16°, make a tubular cylinder, select holes, and combine them.

Step 6: Build Bottom Accessories4

（1）After grouping, copy the fitting ring and scale a tube larger than the original proportional diameter of 5mm and height by 2mm.

（2）Create a 5mm cube, place it in the center of the tube, align, select holes, and combine.

（3）Move the combined tube down to the pyramid, select the holes, copy and shift one by one to the right，Combine them, tilt -20°, ungroup the lower parts and remove the tube shape.

（4）Create a pyramid with a length of 6mm, a width of 1.4mm and a height of 4mm. Enlarge the diameter of the cylinder to 2.3mm and align it in position.

Step 7: Finish Building Bottom Accessories

（1）After adjusting the data, the pyramid is adjusted to have an elongation of 10 mm, a height of 1 mm, a tilt of -2°, a cylinder elongation of 13 mm, a right ring tilt of 5°, and alignment of them.

Step 8: Put on the Wheel

（1）Punch the base to create a cylinder with a diameter of 0.36mm and a height of 0.96mm. Create a hexagon with a length of 0.6mm, a width of 0.6mm and a height of 0.24mm for making screws and putting screws and wheels.

（2）Establish a hemispherical shape with a diameter of 0.8mm and a height of 0.4mm. The diameter of the cylinder is 0.8mm, the height is 1.5mm, the length of the hexagon is 0.8mm, the width is 0.8mm, and the height is 0.4mm. Combine them and align the wheels with the skateboard.

Step 9: Assembly Completed

Assembly completed

Step 10: Change the Skateboard Surface

（1）)Create a sphere with a diameter of 4mm and select the hole, Increase the portable position of the skateboard for easy access

Step 11: Make the Skateboard Surface Retractable

（1）Establish a cylinder with a diameter of 0.1mm, length 39mm, and a spacing of 1mm. Use this as a telescopic rod. The hollow inside the slide plate can be used as a stackable surface for convenient daily storage.

Step 12: Set Up Hook Accessories

（1）A cube with a length of 4 mm and a width of 0.6 mm, and a cylinder with a diameter of 0.8 mm and a length of 4.25 mm, a fitting, and a tube of 5 mm in diameter and 1.4 mm in width are used to make the skateboard become hangable on the wall. And will not touch the bottom of the skateboard to prevent friction damage