Vamp Design Technology

When the standard upper part of the upper part of the upper part is bent to form a curved surface, only a straight middle line style can be used to make a single piece of shoe face part.

Therefore, the flattening process involves straightening the bent line.

Obviously, there are only a few references to the process, so beginners feel that the process is daunting and not surprising.

In the surface design, the center line must be straight to ensure that the overall pattern is cut out.

But how should this process be carried out?

In this part, many styles of cutting are taught to put the upper part of the standard pattern with the center line of the curved surface placed on the straight line which will become the new midline, place the center of the curved line below the straight line, and then place the end part of the two lines above the straight line.

Two alternative ideas are shown.

The location line 1 is similar in size.

Therefore, people will think that when the vamp is molded, the pressure applied to each area is the same.

Line 2 shows an alternative location that is closer to the center of the line and away from the toes.

However, when a straight line is positioned, it is easy to overlook a very important problem if we only pay attention to the toe area and the midline of the curved surface, and this problem will become more obvious later.

When the shape of the design line AB has to be changed, its length must remain unchanged, because the edge of the toe cap should be stitched to the boot of the design line.

The toe area needs to be supported or arched to ensure proper width above the toe.

Because this usually shortens the molding edge, it may be necessary to compensate for it by backing or arching the lower part of the rear edge of the shoe.

We will explain why this causes problems.

general rule

In fact, we can set up some general rules that can be applied to many styles of shoes for the flatten process.

The process can be summarized as the following 3 steps.

1, the line segment C-A: determines the position of the point O, and the part of the design line (A-O) will be arched, while the unaltered part (O-B) will join the line segment X-Y, then determine its location and set it to be a new central line.

2, line segment A-B: from the existing line segment A-O intercept the new line segment A1-O-B.

3, the line segment B-C: determines the position of the support point P, delineating a new toe area to form the sideline.

Mix the border line with the existing line segment C-B.

When the boot surface is flattened, the whole cut surface is produced by the common method. When the style is cut manually, the centerline XY is used as a folding line or as a mirror line, if the computer aided system (CAD) is used.

In step 3, the inner side port is treated similarly with the method outside the C-B.

The following steps will be introduced in more detail in steps 1, 2 and 3, and their working principles will be explained.

In step 1, when measured in a 90 degree direction, the distance from point O to centerline X-Y must be equal to the distance from the nearest point to O in the standard case (Fig. 4). (Fig. 4).

This is because the side stitch A-O-B of the upper part is divided into two parts.

The shape or position of the lower part of the OB has not changed. When it is connected with the boot part, there will be a green drawing line in the picture. The line controls the position of the side surface, or rather, it controls the area or boot of the leg when the surface is molded.

For example, if the O point is closer to the center line X-Y than the surface line C-A, the upper cylinder can not be positioned properly when molding.

If the O point is slightly higher, the shoe barrel is not correct relative to the ground angle.

It is very important to keep the distance between O points and the center line, and if people only pay attention to the middle line of shoe upper when locating the new middle line, this problem is easy to be ignored.

The angle of the line segment is even more difficult to determine, although the angle problem is not particularly critical.

The distance between the straight line and the center line before the O point (a) should not exceed 5-6 millimeters, generally about 3-4 millimeters.

The distance from the toe to the middle of the centerline (b) should be slightly larger than that of the gap (a).

In step 2, the new line segment A1-O-B must be equal to the A-O-B length of the original line segment.

Remember that the line O-B does not change, so the A1-O part must be examined carefully.

The segment A-O of the boot part will be sewn into the side line of the upper A1-O of the shoe, so the distance from any length of the A1-O segment to X-Y must be exactly the same as the distance from the original line A-O to C-A at the 90 degree measurement.

This will ensure that the "tongue piece" of the toe will be equal to the distance from the opposite side to the distance from the shoe side according to the original standard process.

Any difference here will change the fitness of boots.

In step 3, the position of the P point is not important.

It should be located in the middle of the line segment X-Y and the molding edge line. The online segment X-Y passes through the lower point of the center line of the toe surface.

Using P point as the support point, the line segment C-B is moved downward by using line segment C-A in the distance from the new centerline X-Y above the toe.

The line segment is then mixed with the original line segment C-B.

After being supported by the point, the toe may look a little longer, but in fact, the molding line is shortened.

Only the support point P2 can be used to ensure its length is unchanged, but the upper part of the front surface may be too long.

Similarly, if the support point P1 is used, the upper part will usually become too short.

As mentioned earlier, when the toe area moves downward, there is a tendency to shorten the molding line.

It is not recommended to do so, because by moving the rear edge O-B back to O, it becomes the length of the line O-B1, and the length of the molding line will be extended in the wrong position.

The line OB on the boot doesn't change, but if you put the line O-B1 on it, you will see what happens to the centerline.

What is the universality of rules?

These rules apply to all sloping styles that extend to the instep of boots and shoes, and even in a slight preform design.

Indeed, many Gibson shoes and Derby shoes will benefit from using the same boot.

For example, when using linear XY, the absolute tension from point O to center line is much smaller than that of normal black line.

Duplicate key steps

Confirm the O point and draw the middle line.

Establish a new line segment on point O without changing the distance between the distance center line measured at each length and length.

The toe area is formed and moved downwards, blending with the existing molding edge.

Remember that shape retention is the final indicator of quality, and the standard yardstick that is copied along the drawing line of the component style is the key factor to link the above description of the flattening process and good shape retention.