A method for making a horizontal zither

Abstract

The application discloses a making method of a horizontal qin, and relates to the technical field of the horizontal qin, and comprises the following steps: S1, material selection and pretreatment: selecting Chinese tallowwood and red sandalwood as raw materials of a frame, a panel, a rafter and a bridge; drying the wood to a moisture content of 8-12%, and cutting the wood into wood of accurate sizes for standby; S2, frame making: connecting a head, a tail and two side support structures by using a mortise and tenon structure to form a rectangular frame body; S3, rafter installation: arranging a cross beam at 1 / 3 of the distance from the head in the frame, and connecting the cross beam with the frame by using a dovetail tenon; and fixing the spliced upper panel and lower panel on the upper and lower surfaces of the frame by using wood screws. The making method of the horizontal qin selects Chinese tallowwood and red sandalwood as main materials, strictly controls the moisture content of the wood to be between 8-12%, and assembles the frame and the rafter by using traditional crafts such as the mortise and tenon structure and the dovetail tenon, so that the structural stability and acoustic conduction performance of the qin body are enhanced, and the overall sound quality purity and resonance effect of the horizontal qin are improved.

Description

Technical Field

[0001] This invention relates to the field of horizontal harp technology, and specifically to a method for manufacturing a horizontal harp. Background Technology

[0002] The recumbent konghou, a representative of ancient Chinese stringed instruments, has evolved its craftsmanship from the "zhu" of the Han Dynasty to the "konghou" of the Tang and Song Dynasties, forming a technical system centered on wood selection, mortise and tenon joints, and soundboard treatment. The *Kaogongji* (Record of Trades) states, "Examine the shape of the curved surface to regulate the five materials," emphasizing the matching of wood properties with structural design. Modern research shows that the soundboard, as the core component for sound production, directly affects pitch and timbre. Traditionally, the soundboard was often made from a single piece of paulownia wood, carved from a single plank or spliced ​​from two planks, as described in *Mengxi Bitan* (Dream Pool Essays), where "a single piece of wood forms the soundboard, producing a thunderous sound." However, this process has significant structural defects. Due to the shrinkage and expansion characteristics of wood, stress concentration easily occurs at the joints, leading to a cracking rate of over 30% in the soundboard, severely impacting the instrument's lifespan and performance.

[0003] However, in traditional craftsmanship, the panel of the horizontal harp is often made by carving out a single piece of paulownia wood or splicing two pieces of wood together. The joints are only glued with fish glue, lacking a reinforcing structure. In long-term use, due to the shrinkage and expansion characteristics of wood, stress concentration is easily generated at the joints, resulting in a panel cracking rate of over 30%. Therefore, it needs to be improved. Summary of the Invention

[0004] The purpose of this invention is to provide a method for manufacturing a horizontal harp, so as to solve the problem of easy cracking and deformation caused by insufficient reinforcement of panel splicing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for manufacturing a horizontal harp, comprising the following steps:

[0006] S1. Material selection and pretreatment: Select paulownia wood and rosewood as raw materials for the frame, panel, back beam and bridge; dry the wood to a moisture content of 8%-12% and cut it into precise size pieces for later use.

[0007] S2. Frame construction: The headstock, tailstock, and side support structures are connected using mortise and tenon joints to form the main rectangular frame.

[0008] S3. Install the inner beam: Set a crossbeam inside the frame at 1 / 3 of the distance from the headstock, and connect it to the frame with dovetail tenons;

[0009] S4. Spliced ​​Panels: Three 2mm thick paulownia boards are spliced ​​together using a flat-jointing technique, with 3mm wide rosewood strips embedded in the joints for reinforcement; the spliced ​​upper and lower panels are fixed to the upper and lower surfaces of the frame with wood screws.

[0010] S5. String fixing: Use 0.5mm diameter silk strings, fix one end to the string hole of the headstock, go around the nut at the tailstock and back to the headstock, and adjust the tension through the string pin with bearing.

[0011] S6. Install the bridge: A fixed rosewood bridge is glued on at the 5th fret of the soundboard; a movable bridge with a sliding groove is installed at the 12th fret of the soundboard, with a brass track embedded in the groove to ensure stability during movement.

[0012] S7. Tuning and Optimization: Use a tuning fork to calibrate the standard pitch, and adjust the string tension to ±1 cent accuracy via the tuning pins; hand-polish the instrument body and apply natural lacquer.

[0013] Furthermore, in step S4, the three wooden boards are spliced ​​together with staggered joints, and the width of the rosewood strips embedded at the joints is 3mm, with the same thickness as the panels.

[0014] Furthermore, the tuning pins of the tuning device are mounted on the headstock via bronze bearings, and the surface of the tuning pins is engraved with tension markings with an accuracy of 0.1 mm.

[0015] Furthermore, the bottom of the movable bridge is provided with a T-shaped slider, which forms an embedded fit with the trapezoidal groove on the panel to ensure no lateral displacement during movement.

[0016] Compared with the prior art, the present invention provides a method for making a horizontal harp. By selecting paulownia wood and rosewood as the main materials and strictly controlling the moisture content of the wood to be between 8% and 12%, and combining traditional techniques such as mortise and tenon joints and dovetail joints to assemble the frame and the inner beam, the structural stability and acoustic transmission performance of the instrument are enhanced, thereby improving the overall sound purity and resonance effect of the horizontal harp.

[0017] By using three thin paulownia wood boards joined together with flat or finger joints, and reinforcing the joints with rosewood strips, and using bone glue and clamps for pressure curing, the integrity and resistance to deformation of the soundboard are improved. This ensures that the soundboard is not prone to cracking or deformation during long-term use, thus extending the instrument's lifespan.

[0018] By setting up tuning pins with bronze bearings and precise tension scales on their surfaces, combined with the design of the string winding angle and braking device, high-precision (±0.5 cents) adjustment and stable maintenance of string tension are achieved, thereby improving the intonation stability and tuning convenience of the horizontal harp.

[0019] By setting a fixed and movable dual-bridge structure on the panel, the movable bridge uses a T-shaped slider and trapezoidal groove for embedded cooperation, and can be equipped with positioning beads and hemispherical positioning hole system, which realizes flexible adjustment and precise positioning of pitch position, thereby enhancing the adaptability of pitch range and the ability to adjust timbre during performance.

[0020] By using natural lacquer for surface coating and combining it with multiple rounds of hand sanding, the surface smoothness of the instrument reaches Ra≤1.6μm. This not only enhances the appearance and moisture and corrosion resistance, but also optimizes the sound reflection and propagation characteristics, thereby further improving the overall acoustic performance and visual aesthetics of the horizontal harp. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0022] Figure 1 A flowchart illustrating the manufacturing process provided for an embodiment of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] As attached Figure 1 As shown:

[0025] Example 1:

[0026] This invention provides a method for manufacturing a horizontal harp, comprising the following steps:

[0027] Material selection and pretreatment: The frame is made of 12mm thick paulownia wood boards (moisture content strictly controlled at 9%), the inner beam is made of 8mm thick rosewood, and the panel is made of three 2mm thick paulownia wood boards spliced ​​together using a flat-jointing process; all the wood is dried to a moisture content of 8%-12% and then cut to the design dimensions for use. The length of the frame wood is accurate to 180cm and the width is 40cm. The length of the inner beam is consistent with the inner width of the frame.

[0028] Frame construction: The headstock, tailstock, and side support structures are connected using mortise and tenon joints. Specifically, double tenons are set at the ends of the headstock and tailstock, and mortises are made at corresponding positions on the side support structures. A stable connection is achieved through the interference fit between the tenons and mortises, forming a rectangular frame with dimensions of 180cm (length) × 40cm (width) × 15cm (height).

[0029] Installation of the back beam: A crossbeam is installed inside the frame 60cm from the headstock, and connected to the supporting structures on both sides of the frame using dovetail tenons. The ends of the back beam are machined into trapezoidal tenons, and corresponding trapezoidal mortises are made in the frame. After applying bone glue to the mating surfaces of the tenons and mortises, the beam is inserted and fixed to ensure the strength of the connection between the back beam and the frame.

[0030] Panel Assembly: Three paulownia wood panels are joined together using a flat-jointing technique. A 3mm wide strip of rosewood, the same thickness as the panel, is embedded in the joint for reinforcement. During assembly, bone glue is applied to the contact surfaces of the wood strips and panels, and pressure is applied using clamps until the glue layer is 0.1mm thick. After curing for 24 hours, a single panel is formed. The assembled top and bottom panels are then fixed to the upper and lower surfaces of the frame using wood screws spaced 10cm apart and driven in to a depth of 2 / 3 of the panel thickness.

[0031] String fixing: 0.5mm diameter silk strings are used. One end is fixed in the pre-set string hole in the headstock, and the other end goes around the nut at the tailpiece and back to the headstock. Tension is adjusted by tuning pegs with bronze bearings. The tuning pegs are mounted in the headstock via bearings and have tension markings with a precision of 0.1mm. The string wraps around the tuning pegs three times to ensure friction and prevent slippage.

[0032] Bridge Installation: A rosewood bridge, 5mm thick and 8mm wide, is glued and fixed at the 5th fret of the soundboard (30cm from the headstock). It is secured with bone glue applied to the surface in contact with the soundboard. A movable bridge is installed at the 12th fret of the soundboard. The bottom of the bridge has a T-shaped slider that fits snugly into a trapezoidal groove on the soundboard. The groove is 4mm wide and 3mm deep to ensure no lateral shifting during movement.

[0033] Tuning and Optimization: The standard pitch is calibrated using a 440Hz tuning fork, and the string tension is adjusted to ±1 cent accuracy using the tuning peg tension scale. The instrument body is then hand-polished, first with 120-grit sandpaper for rough sanding, then with 240-grit sandpaper for fine sanding. Finally, a layer of natural lacquer is applied, 0.2mm thick, and allowed to cure for 24 hours to complete the process.

[0034] Example 2:

[0035] This embodiment is basically the same as the previous embodiment, except that the fabrication of the modified horizontal harp with a recessed beam structure includes the following steps:

[0036] Material selection and pretreatment: The frame is made of 12mm thick paulownia wood boards (moisture content 9%), the upper and lower layers of the shade beams are made of 6mm thick rosewood; the panels are made of three 2mm thick paulownia wood boards spliced ​​together by finger jointing, with a finger joint length of 15mm; all wood is dried to a moisture content of 8%-12%, cut and ready for use, the frame dimensions are 180cm long × 40cm wide × 15cm high.

[0037] Frame construction: The headstock, tailstock, and side support structures are connected by mortise and tenon joints. The headstock and tailstock have single tenons at their ends, and the side support structures have mortises at corresponding positions. The connection is achieved through the transition between the tenons and mortises, forming the main rectangular frame.

[0038] Installation of the shadow beams: The upper shadow beam is 45cm from the headstock, and the lower shadow beam is 75cm from the headstock. Both are connected to the supporting structures on both sides of the frame using dovetail tenons. The ends of the shadow beams are machined into dovetail tenons, and dovetail mortises are made at the corresponding positions on the frame. After applying bone glue to the mating surfaces of the tenons and mortises, they are inserted and fixed. The two layers of shadow beams intersect at the center of the frame to form an "X"-shaped supporting structure, and the intersection point is reinforced with wooden wedges.

[0039] Panel splicing: Three paulownia wood panels are spliced ​​together using a finger-jointing technique, with a joint length of 15mm. After applying bone glue to the glued surfaces, clamps are used to apply pressure until the glue layer thickness is 0.1mm, and the joints are cured for 24 hours. No wood strips are embedded for reinforcement at the joints. The spliced ​​top and bottom panels are then fixed to the upper and lower surfaces of the frame with wood screws spaced 10cm apart and driven in to a depth of 2 / 3 of the panel thickness.

[0040] String fixing: 0.5mm diameter silk strings are used. One end is fixed to the string hole of the headstock, passes around the nut at the tailstock and returns to the headstock. The tension is adjusted by the tuning peg with bronze bearing. The surface of the tuning peg is engraved with a 0.1mm precision tension scale. The string is wrapped around the tuning peg 3 times to ensure friction.

[0041] Bridge installation: The fixed bridge is located at the 5th fret of the soundboard (30cm from the headstock), and is fixed with rosewood glued on, with a thickness of 5mm and a width of 8mm; the movable bridge is located at the 12th fret, with a T-shaped slider at the bottom that fits into the trapezoidal groove (4mm wide × 3mm deep) on the soundboard to ensure stability during movement.

[0042] Tuning and optimization: The standard pitch is calibrated using a 440Hz tuning fork and adjusted to ±1 cent accuracy using the tension scale on the tuning pins; the body of the instrument is hand-polished with 120-grit and 240-grit sandpaper, then coated with natural lacquer with a lacquer layer thickness of 0.2mm and cured for 24 hours to complete the production.

[0043] Example 3:

[0044] This embodiment is basically the same as the previous embodiment, except that the optimized horizontal harp with a bridge positioning mechanism is manufactured by following these steps:

[0045] Material selection and pretreatment: The frame is made of 12mm thick paulownia wood boards (moisture content precisely controlled at 10%), and the inner beams are made of 8mm thick rosewood; the panels are made of three 2.5mm thick paulownia wood boards spliced ​​together using a flat-jointing technique, with 3.5mm wide rosewood strips embedded in the joints for reinforcement; all wood is dried to a moisture content of 9%-11%, cut and ready for use, and the frame dimensions are 180cm long × 40cm wide × 15cm high.

[0046] Frame construction: The headstock, tailstock, and side support structures are connected by mortise and tenon joints. The headstock and tailstock have double tenons at their ends, and the side support structures have mortises at corresponding positions. The interference fit between the tenons and mortises achieves a stable connection, forming the main rectangular frame.

[0047] Installation of the back beam: A single crossbeam is installed inside the frame, 60cm from the headstock, and connected to the supporting structures on both sides of the frame using dovetail tenons. The ends of the back beam are machined into dovetail tenons, and corresponding dovetail mortises are made in the frame. After applying bone glue to the mating surfaces of the tenons and mortises, they are inserted and fixed in place to ensure connection strength.

[0048] Panel splicing: Three paulownia wood boards are spliced ​​together using a flat-jointing technique. The rosewood strips embedded at the splicing joints are 3.5mm wide and the same thickness as the panels. After applying bone glue to the contact surfaces of the wood strips and boards, clamps are used to apply pressure until the glue layer is 0.15mm thick, and the curing time is 24 hours. The upper and lower panels are fixed to the upper and lower surfaces of the frame with wood screws spaced 8cm apart and driven to a depth of 2 / 3 of the panel thickness.

[0049] String fixing: 0.6mm diameter silk strings are used. One end is fixed in the string hole of the headstock, and the other end goes around the nut at the tailstock and back to the headstock. The tension is adjusted by the tuning peg with double bearings. The tuning peg surface is engraved with tension scale with an accuracy of 0.05mm. The string is wrapped around the tuning peg 4 times to ensure friction.

[0050] Bridge installation: The fixed bridge is located at the 5th fret of the soundboard (30cm from the headstock), and is made of rosewood glued together. It is 5mm thick and 8mm wide, and the surface is engraved with pitch marking grooves (0.5mm deep and 1mm wide). The movable bridge is located at the 12th fret. The bottom has a T-shaped slider that matches the trapezoidal groove on the soundboard (4.5mm wide × 3.5mm deep). Two 2mm diameter positioning beads are embedded at the bottom of the slider, corresponding to the hemispherical positioning holes set every 5mm in the groove on the soundboard, so as to achieve a pitch fine adjustment accuracy of 1 / 4 of the semitone.

[0051] Tuning and optimization: The standard pitch is calibrated using a 442Hz tuning fork and adjusted to ±0.5 cents accuracy via the string tension scale; the body is hand-polished with 180-grit and 320-grit sandpaper, then coated with natural lacquer with a lacquer layer thickness of 0.25mm, and cured for 30 hours to complete the production.

[0052] Example 4:

[0053] This embodiment is basically the same as the previous embodiment, except that the manufacturing of the precision-tuned horizontal harp includes the following steps:

[0054] Material selection and pretreatment: The frame is made of 12mm thick paulownia wood boards (moisture content strictly controlled at 11%), and the inner beam is made of 8mm thick rosewood; the panel is made of three 2mm thick paulownia wood boards spliced ​​together using a flat jointing technique, with 3mm wide rosewood strips embedded in the joints for reinforcement; all wood is dried to a moisture content of 10%-12%, cut and ready for use, the frame dimensions are 180cm long × 40cm wide × 15cm high, and the length of the inner beam is consistent with the inner width of the frame.

[0055] Frame construction: The headstock, tailstock, and side support structures are connected by mortise and tenon joints. The headstock and tailstock have double tenons at their ends, and the side support structures have mortises at corresponding positions. The interference fit between the tenons and mortises achieves a stable connection, forming a rectangular frame body. The diagonal error of the frame is ≤1mm.

[0056] Installation of the back beam: A single crossbeam is installed 60cm from the headstock within the frame, connected to the supporting structures on both sides of the frame via dovetail tenons. The ends of the back beam are machined into dovetail tenons, and corresponding dovetail mortises are made in the frame. Bone glue is applied to the mating surfaces of the tenons and mortises, and the beams are then inserted and fixed. The glue layer is 0.2mm thick. After curing for 24 hours, a connection with a bending strength ≥20MPa is formed.

[0057] Panel splicing: Three paulownia wood boards are spliced ​​together using a flat-jointing technique. The rosewood strips embedded at the splicing joints are 3mm wide and the same thickness as the panels. After applying bone glue to the contact surfaces of the wood strips and boards, clamps are used to apply pressure until the glue layer is 0.1mm thick, and the pressure is maintained for 24 hours. The upper and lower panels are fixed to the upper and lower surfaces of the frame with wood screws spaced 10cm apart, driven to a depth of 2 / 3 of the panel thickness, and the screw heads are sunk 1mm into the panel surface.

[0058] String Fixing: 0.5mm diameter silk strings are used, one end fixed to the string hole in the headstock, the other end looping around the nut at the tailpiece and returning to the headstock. Tension is adjusted via a tuning peg with double bearings. The outer bearing of the tuning peg is made of bronze to withstand radial force; the inner bearing is made of stainless steel to withstand axial force. The tuning peg surface is engraved with tension markings of 0.1mm accuracy. The string wraps around the tuning peg 3 times at a 45° angle to ensure friction ≥5N. A braking device is added to the end of the tuning peg, locking the tension with a micro-bolt; the braking torque is 1.5N·m.

[0059] Bridge installation: Fixed bridge is located at the 5th fret of the soundboard (30cm from the headstock), and is fixed with rosewood glue, 5mm thick and 8mm wide. It is fixed after applying bone glue to the contact surface with the soundboard; movable bridge is located at the 12th fret, with a T-shaped slider at the bottom, which forms an embedded fit with the trapezoidal groove (4mm wide × 3mm deep) on the soundboard. The surface of the slider is polished, with a roughness Ra≤0.8μm.

[0060] Tuning and Optimization: The standard pitch is calibrated using a 442Hz tuning fork, and adjusted to ±0.5 cents accuracy via the string tension scale. During tuning, a digital tension meter is used to monitor string tension in real time, with tension fluctuations controlled within ±2N. After being hand-sanded with 120-grit and 240-grit sandpaper, the instrument is coated with natural lacquer with a thickness of 0.2mm. The lacquer is then cured for 24 hours to complete the process, resulting in a final product surface smoothness ≤Ra1.6μm.

[0061] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for manufacturing a horizontal harp, characterized in that, Includes the following steps: S1. Material selection and pretreatment: Select paulownia wood and rosewood as raw materials for the frame, panel, back beam and bridge; dry the wood to a moisture content of 8%-12% and cut it into precise size pieces for later use. S2. Frame construction: The headstock, tailstock, and side support structures are connected using mortise and tenon joints to form the main rectangular frame. S3. Install the inner beam: Set a crossbeam inside the frame at 1 / 3 of the distance from the headstock, and connect it to the frame with dovetail tenons; S4. Spliced ​​Panels: Three 2mm thick paulownia boards are spliced ​​together using a flat-jointing technique, with 3mm wide rosewood strips embedded in the joints for reinforcement; the spliced ​​upper and lower panels are fixed to the upper and lower surfaces of the frame with wood screws. S5. String fixing: Use 0.5mm diameter silk strings, fix one end to the string hole of the headstock, go around the nut at the tailstock and back to the headstock, and adjust the tension through the string pin with bearing. S6. Install the bridge: A fixed rosewood bridge is glued on at the 5th fret of the soundboard; a movable bridge with a sliding groove is installed at the 12th fret of the soundboard, with a brass track embedded in the groove to ensure stability during movement. S7. Tuning and Optimization: Use a tuning fork to calibrate the standard pitch, and adjust the string tension to ±1 cent accuracy via the tuning pins; hand-polish the instrument body and apply natural lacquer.

2. The method for manufacturing a horizontal harp according to claim 1, characterized in that, In step S4, the three wooden boards are spliced ​​together with staggered joints. The width of the rosewood strips embedded at the splicing joints is 3mm, and the thickness is the same as that of the panels.

3. The method for manufacturing a horizontal harp according to claim 1, characterized in that, The tuning pegs of the tuning device are mounted on the headstock via bronze bearings, and the surface of the tuning pegs is engraved with tension markings with an accuracy of 0.1 mm.

4. A method for manufacturing a horizontal harp according to claim 1, characterized in that, The movable bridge has a T-shaped slider at the bottom, which fits into the trapezoidal groove on the panel to ensure no lateral displacement during movement.

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