V Grooving Machine for Sheet Metal: The Ultimate Guide

What is the use of groover in sheet metal work?

A groover, also known as a V groover or V grooving machine, is a tool used to scribe and slot V-shaped grooves into metal plates. This can reduce the bending radius and improve the appearance of sheet metal workpieces.

The machine is particularly useful in industries requiring high-precision plate processing, such as elevator manufacturing, packaging materials, stainless steel processing, household appliance production, and prop display.

With the development of the economy, places such as hotels, restaurants, shopping malls, banks, and airports have an increasing demand for metal decorative materials with bend forming in middle and high-grade decoration.

• The bending radius of the workpiece should be small;
• The bending angle of the workpiece bending with stainless steel titanium plate or other colored metal plates cannot have great color changes;
• No obvious color difference;
• The curved section of the workpiece is more complicated;
• It can reflect the unique style of the designer.

Traditional bending methods such as forced bending, free bending, and even three-point bending have been unable to meet the above requirements.

In other words, bending the metal sheet with a press brake alone cannot meet the design requirements of the designer and cannot achieve the grade and decorative effect of middle and high-grade decoration.

Therefore, a novel bending technique has been developed, which is V-groove bending technology.

What is the fabrication process of V-groove bend forming?

To put it simply, it is:

First, adopt the V-grooving (or V-cut) method on the metal sheet. Then, bend the grooved sheet metal into various angles and shapes using a press brake with a general mold or special mold.

Such a curved workpiece can meet the special needs of high-end decoration in hotels, restaurants, shopping malls, banks, and airports.

The main equipment of v-groove bending technology is press brake and sheet metal V-groover (also been called V-grooving machine).

The press brake is a traditional plate bending machine, and the thin plate V-grooving machine is a new type of sheet metal processing machinery, which is the key equipment of V-cut bending technology.

To better understand the press brake machine, you can refer to The Ultimate Guide to Press Brake.

So, what is sheet metal V-grooving Machine?

What is a V-grooving machine?

The V-groover is also known as the CNC V-Cutting Machine or V-grooving Machine. It is mainly used to achieve a certain depth of V-cutting on stainless steel plates, ordinary steel plates, aluminum plates, copper plates, and composite plates under 4mm before bend forming.

The workpiece produced with this technique has a small bending radius, no obvious color changes, and small bending force requirements. In addition, it reduces the straightness error of the round edge of narrow long workpieces, and the common press brake and toolings can be used to bend the workpiece with a complicated section shape.

V-grooving machines are widely used in industries such as stainless steel decoration, elevators, security doors, and cabinets.

Before the development of special V-grooving equipment, workshops generally used planers to make V-shaped grooves on metal sheet material. However, because the planer lacks an effective metal sheet pressing device, the V-grooving depth of the metal sheet and the positioning distance of the V groove cannot be precisely controlled. Additionally, planers have high energy consumption and low efficiency.

Currently, V-grooving for metal sheets is accomplished with a new type of metal sheet grooving machine designed and manufactured according to the special needs of the middle and high-end decoration industry and elevator manufacturing industry. This machine can make V-shaped grooves for materials such as stainless steel sheet, iron plate, and copper plate. With the installation of specially dedicated accessories, the metal sheet V-grooving machine can also be used for grinding, polishing, and drawing of metal sheet materials and profiles.

Basic Working Principles of V Grooving Process

The basic principles of the metal sheet grooving process are as follows:

The metal plate is fixed, and the V-groover blade mechanically cuts the metal material on the movement track to form a V-groove.

The size of the bending angle is related to the depth of the V-groove.

The smaller the bending angle, the greater the value of the V-groove depth that needs to be grooved.

There are several technical parameters that have a greater impact on the grooving process.

The following uses the technical parameters of a grooving machine as an example (Figure 2).

Fig.2 Technical parameters of V grooving machine

(1) Maximum width and length of the slotted sheet: This parameter affects the maximum size of the sheet metal that the V-grooving equipment can process.

(2) Maximum thickness of the slotted sheet: This parameter affects the maximum thickness of the sheet metal that the equipment can process.

(3) The minimum distance of the V-shaped groove from the edge: This parameter reflects the minimum distance between the edge of the grooved sheet and the edge of the plate material when processing metal plates. This distance is mainly used for the grooving machine to grip the slot distance. Plus, the safety distance set by the manufacturer, the smaller the minimum distance value of the V-shaped slot from the edge, the smaller the minimum distance value of the slot edge from the plate material edge.

(4) Cutting speed: This parameter reflects the speed of the tool’s linear movement when processing metal plates. The larger the value, the higher the equipment processing efficiency.

(5) Left and right, up and down movement resolution, and positioning accuracy of the tool holder: Each parameter mainly reflects the processing accuracy of the equipment. At present, the minimum positioning accuracy that domestic technology can achieve is ±0.01mm.

In addition to the above-mentioned equipment parameters affecting the grooving process, another important parameter is the blade.

The quality and number of blades directly affect the machining efficiency and the speed of tool wear.

Traditional grooving equipment uses three blades for simultaneous cutting, and current technology uses four blades for simultaneous cutting.

The structure of the blade is shown in Figure 3.

Figure 3 Schematic diagram of the tool structure

There is a distance of 0.1mm between each blade, and the maximum depth of a single groove with four blades can reach 0.6mm.

To ensure the quality of the grooving process and prolong the life of the blade, the depth of a single grooving process set by most companies is 0.4 to 0.5mm.

The latest blades developed in the industry are made of alloy, and each blade can be used to groove 2500 to 3000 meters of stainless steel material.

Classification of Sheet Metal V-groover

Currently, the length of the metal plate for V-grooving is: 2500mm, 3200mm, 4000mm, 5000mm, 6000mm and the processing width of sheet metal mainly is: 1250mm, 1500mm, 2200mm, 2400mm.

The most popular type is 4000×1250 (L*W) V grooving machine.

If classified by the structure style, the sheet metal V-grooving machine can be divided into 4 types:

1. Mobile Worktable Type

The beam structure is fixed, and the tool holder can be positioned on the crossbeam before the groove.

The metal sheet to be processed is fixed on the worktable by a pressing device, and the V-shaped groove is made by moving the worktable back and forth along the long rail. This process is similar to a dedicated planer.

However, the energy consumption is very high during sheet metal V-grooving because the worktable, which is driven by the motor, moves back and forth along the long rail.

2. Beam Move Along Long Rail Type

The worktable is fixed, and the processed sheet is fixed on the worktable by a pressing device. The tool holder is positioned on the crossbeam by moving left and right. The V-grooving is realized by the beam moving back and forth along the long rail on the worktable. During the V-grooving process, the worktable is fixed, but the energy consumption is very high due to the reciprocating motion of the beam along the long rail.

3. Beam Move Along Short Rail Type

The worktable is fixed, and the sheet being processed is fixed on the worktable using a pressing device.

The beam moves back and forth along the short rail of the worktable to conduct pre-grooving positioning.

The tool holder conducts V cutting by moving left and right along the beam.

The energy consumption is low due to the fixed worktable and beam during V-grooving, and the power needed to drive the tool holder’s reciprocating motion along the long rail is much less than the power needed to drive the worktable and beam.

4. Fixed Beam & Worktable Type

Fixed beam and worktable, and the processed sheet is positioned for pre-grooving by the feeding device moving back and forth.

The tool holder conducts the V-cutting with left and right reciprocating motion on the beam.

During V-cutting, it only drives the tool holder to do reciprocating motion along the long rail, and a light-duty feeding device is adopted for pre-grooving positioning without the need to drive a multi-ton beam.

Therefore, it has the lowest energy consumption and the most obvious energy-saving effect.

If classified by the control method, the thin plate V-groover can be divided into:

• Digital Display V-grooving Machine
• CNC V-grooving Machine

The display resolution is 0.01 mm, enough to meet the actual requirements.

Key Features of V-groove Bend Forming Technology

Fig.1 V-grooving bend forming process

1. Small bending force requirement for bending the workpiece

It can be seen from the bending force calculation formula that the bending force required for the workpiece is proportional to its plate thickness.

The bending force is larger for bending thick plates and smaller for thin workpieces.

In V-groove bending technique, the bending force needed is reduced by V-cutting the plate at the bending position, effectively reducing the plate thickness.

As the depth of the V-shaped groove is half of the plate thickness, this can save up to 50% of the bending force.

2. A small bending radius of the workpiece

For free bending, the bending radius is proportional to the V-opening width of the die. The width of the die opening is generally 8 to 12 times the thickness of the plate.

To obtain a smaller bending radius, you need to select a die with a smaller V-opening width.

The thicker the plate, the larger the V-opening width of the die, and the bigger the bending radius.

On the contrary, the thinner the plate, the smaller the V-opening width of the selected die, and the smaller the bending radius.

The thickness of the plate is reduced at the bend position by V-grooving, and the bending radius of the workpiece is naturally proportionally reduced.

In the plate strength range, the thinner the remaining thickness, the smaller the bending radius of the workpiece.

3. Small color changes at the bent round edges of the workpieces

During the V-shape bending process of the plate, the inside of the workpiece’s bending radius is under compressive force and undergoes compression deformation.

The outside of the bending radius is under tensile force and undergoes elongation.

The main factors that influence the color changes of the bent round edge of the workpiece are the elongation deformation caused by the lateral tensile strength.

It can be seen from the V-shape bending process of the sheet that the elongation deformation caused by the lateral tensile force is also related to the thickness of the plate.

By V-grooving the plate, the thickness of the plate at the bending position is reduced and the elongation deformation generated by the lateral tensile force during bending is also reduced, thus achieving the purpose of small color changes at the bent round edges of the workpiece.

4. Small straightness errors of the bent round edge of the narrow long workpiece

In the process of bending a narrow long workpiece, the inside of the bending radius generates compression deformation under compressive force in the width direction, while the deformation materials move at both ends in the length direction. The outside of the bending radius generates elongation under tensile strength in the width direction, with the materials moving towards the center in the length direction.

This results in the bent edge line of the workpiece forming a center-concave shape. The larger the bending deformation, the more severe the center-concave shape of the edge line. Conversely, the smaller the bending deformation, the less severe the center-concave shape of the edge line. Since V-grooving reduces the plate thickness at the bending position, the bending deformation is also reduced.

Therefore, the V-grooving bend forming technique minimizes the straightness errors of the edge line of the narrow long workpiece.

For press brake, only general toolings are needed to conduct the V-grooving bend forming technique.

Some workpieces with complicated or enclosed cross-sections can be bent without special toolings by correctly controlling the grooving depth and edge length (as shown in Fig. 2), which will reduce the expense incurred by complex toolings with special design and shorten the processing cycle.

Fig.2 Workpiece cross-section shape

The Application Prospect of V-grooving Bend Forming Technology

Due to the obvious advantages of V-shaped groove bending technology, and the fact that the traditional bending method and equipment do not need to be changed, only the sheet metal V-grooving machine needs to be added, so V-grooving bend forming technology has been widely used in the emerging middle and high-grade decoration industry in the first place.

It was then adopted in elevator manufacturing.

Next, some experts in medical device manufacturing and electric control cabinet manufacturing industry also showed their interest in V-grooving bend forming technology.

It can be seen that with a deep understanding of the V-grooving bend forming technology, the application field of this technology will be broader.

CNC Auto Metal Sheet V-grooving Machine Operating Instruction

PLC Touch Screen Operation Method

Start the V-grooving machine

Open the air switch on the right side of the electrical box and then turn on the key switch on the front panel.

The entire machine is powered on.

The touch screen will display the initial screen after a three-second delay.

V-grooving monitoring

On the light touchscreen, the whole machine enters operation monitoring, and it displays the following information:

(1) Beam position

This position represents the distance between the beam and the initial point, and it is detected by the screw encoder. The displayed numbers indicate the number of the grooving line.

(2) Target position

The target position of the current moving beam is displayed. If the grooving machine has not started grooving when the beam reaches the target position, press the “beam movement” button, and the machine will not move.

(3) Current distance

This distance is the distance between the current groove and the previous groove.

(4) Blade holder position

The blade holder position is displayed as a 3D point relative to the origin point or the initial point. The position is measured by the stepper motor encoder on the screw rod, and if the position is greater than 29.8mm, the tool holder will not move. The number at the back indicates the number of grooving.

(5) The plate width and plate thickness are set as working parameters.

(6) Press the start button to begin grooving when the position light flashes. When the depth light flashes, press the “Move” button to move to the next position for grooving.

(7) Press “manual operation” to manually control the operation screen.

(8) Press the “open groove preparation” button to move the beam to the front of the platform, and initialize the various grooving parameters to prepare for the grooving of the next metal plate.

The beam will not move if the beam position is less than the initial position offset, but the parameter initialization is normal, and the button should not be pressed during grooving.

(9) To replace the blade, a grooving pause button is set.

When the button is pressed, the grooving machine will stop working, and then press the button to restart the machine.

(10) Press “parameter setting” to jump to the parameter setting screen.

Manual operation

(1) “Beam forward” means moving the beam forward manually, and the moving speed is set in the system parameters.

(2) “Beam backward” means moving the beam back manually, and the moving speed is set in the system parameters.

(3) “Tool holder to the left” means moving the tool holder to the left manually, and the movement speed is set in the system parameters.

(4) “Tool holder to the right” means moving the tool holder to the right manually, and the moving speed is set in the system parameters.

(5) “Tool holder up” means moving the tool holder up manually.

(6) “Tool holder down” means moving the tool holder down manually.

(7) “Operation instructions”: press this button to move the screen to the operation instruction screen.

(8) “Origin alignment”: press this button to perform the function of returning the original to correct the position of the beam.

In general, there is no need to perform the function of returning to the origin (because the computer does not have the function of location memory).

However, if the grooving machine has stopped for more than two days, or if the position is not correct due to some other circumstances, the function of returning to the origin should be performed first after electrification to ensure the normal operation of the machine.

Parameter setting

1. Press the “parameter setting” button to access the parameter setting screen, where the grooving spacing can be set for up to 50 grooves.
2. The first groove can be set with a minimum value of 8mm and a maximum spacing of 1220mm, and there are no limits for the rest of the grooves.
3. After pressing the menu for the parameter you want to set, a digital keyboard will appear on the screen. “ENT” is the input confirmation button, “ES” means the input is canceled, and “CR” is the input reset button. All parameters are positive, and if a negative number is entered, the machine will report an error.
4. Press the “return” button to go back to the setting screen.
5. In the parameter setting, press the “system parameters” button to go back to the system parameters screen.
6. After setting the parameters, check them carefully according to the process sheet to prevent errors.
7. The #1 distance refers to the vertical distance from the 1st groove to the initial point. The #2 distance refers to the vertical distance from the 1st groove to the 2nd groove, and so on, for each of the groove distances.
8. In the parameter setting screen, the current process can be cleared by selecting “parameter full clearance”.

System parameters

The system parameters have several types of buttons:

(1). “Deceleration advance” is the position where the beam decelerates from high speed to a constant speed.

This parameter is crucial for positioning.

If each positioning exceeds the stroke, then increase this parameter, generally set to 8mm, with a maximum setting of 9.999mm.

(2). “Positioning ahead” is the designated pre-stop positioning position.

After the stop, the beam moves to the positioning position under the action of inertia.

If the grooving machine doesn’t stop at the correct position for each stop, it means the parameter setting is too large.

Otherwise, the parameter setting is too small. The maximum data of this parameter can be set to 0.8mm.

(3). “Allowable error” is the allowable error after positioning. It is not allowed to groove if not in this range, and manual correction is required.

(4). “Initial point error” refers to the distance between the blade tip and the edge after correcting the origin.

The minimum setting is 8mm.

Otherwise, the front-positioning proximity switch needs to be adjusted in time.

Grooving (V-cutting)

1). Grooves must meet the following conditions

• The emergency stop switch is not pressed;
• Positioning (indicator light flashing);
• The pressing foot at the side pressed the sheet metal;
• There is no limit on the right or left of the tool holder;
• The beam is not out of stroke range;
• The tool holder stop button is not pressed;
• The longitudinal position of the blade tip ≥ 8mm;

2). Moving beam

When finished with the grooving, press the “Move Beam” button to move the beam to the next grooving position, which is automatically added to the target position by the grooving machine.

After the beam automatically positions itself, a grooving process must be carried out before the beam can move again. This process continues until all the grooving lines have been completed.

3). Conditions for moving beams

• Beam stroke not greater than 1220mm;
• Position positioning does not flash OK;
• The position of the beam is not greater than the target position;
• The follow-up pressing device lifting up;
• The emergency stop switch is not pressed down;
• The beam front limit switch is connected;
• The grooved motor contactor is not pulled in.

4). Press the “Grooving ready” button to move the beam to the front of the platform.

The Grooving Machine Accessories

• Inverter
• Programmable controller
• Step motor
• Step driver
• Encoder
• Proximity switch
• Switch power
• Touchscreen

The Operation Method for Mechanical Grooving

1. Lay the metal sheet flat on the workbench. If the metal sheet has a protective film, then the side with the protective film facing down. One side of the sheet metal clings to the benchmark block in front of the worktable.
2. Press the sheet metal pressing button to tighten the edge of the sheet material and complete the positioning of the sheet material.
3. Adjust the position of the proximity switch limit block at the left and right side of the tool holder slide block properly according to the length of the plate.
4. Determine the spacing of the grooves and the forward and backward adjustment of the beam. Jog the “origin alignment” in the PLC touch screen to realize accurate positioning. That is, the beam displacement to the first groove position, press the follow-up press button to press the plate material tightly.
5. The blade block with a thickness of 35mm is used to set the initial point of the blade, lock the pressing screw, and check the blade block to ensure the height of the blade. This is an important preparatory work to ensure the precise depth of the grooves and the production of safe grooves.
6. Check whether the blade is in good condition and if the blade is badly worn, loosen the blade. Press the screw and rotate the blade 90 degrees, that is, change it to a new blade edge. Or flip the blade and change another blade surface.
7. Press the work-in button on the operation panel of the electrical box to perform the first grooving. Generally, the first grooving depth is 0.3mm, followed by the thickness of the processed plate.
8. After the groove depth meets the requirement, let the grooving blade exit the plate surface. The sliding frame automatically moves to the pre-set right limit position. The PLC controls the beam displacement to the next groove, and then the second grooving is processed. Until the whole grooving process is finished, press the “release button” of the follow-up material’s pressing on the mobile operating station and loosen the follow-up press device. The PLC performs the next groove positioning instruction. The beam immediately moves back to the next groove and repeats until all grooves are finished.
9. After the completion of the grooving work, loosen all the pressing devices, back the beam to the appropriate position, take out the plate materials, and clean the working table.
10. When spray cooling is needed, the switch in the electric cabinet will be opened first, and the cooling system will be automatically lubricated during the cutting process.

Safe Operation Procedure for CNC V-grooving Machine

• CNC Grooving machine should be maintained and operated by the specially-assigned person;
• The operator of CNC V-groover must pass the training of the professional department. After passing the examination and obtaining the qualification certificate, the operator can operate independently;
• Before the operation, wear long-sleeve work clothes (to prevent burning by the grooved debris from splashing), and gloves must be worn when loading and unloading the sheet metal;
• Before starting the V-grooving machine, check whether the machine table is clean, especially between clamps and table;
• Reset the origin after starting up. When working, check whether the workpiece conforms to the process requirements and correctly input the size and grooving depth;
• When the operator is put on the small sheet, remember to handle lightly. Before loading, clean the machine surface and the feeding table, and can not residual grooved wire and other sundries;
• When running the grooving machine, check if the plate is pushing to the origin. The staff shall not extend the head and any part of the body into the machine motor area (to prevent hurt by the machine). The air gun and hand should not be placed under the fixed clamp;
• When the grooving machine is in moving, the operation must be stopped in case of a machine collision or a collision of the materials. First, reset the origin to prevent the moving of the origin at the time of the collision;
• After grooving, gently place the sheet in the designated position to prevent the workpiece from being scratched;
• After the operation, conduct the daily maintenance of the grooving machine, cut off the power supply and clean the workplace.

Gantry (Horizontal) V Grooving Machine vs. Vertical V Grooving Machine: Which One to Choose?

When deciding to purchase a V-grooving machine, you may face the dilemma of choosing between a gantry (horizontal) V-grooving machine and a vertical V-grooving machine. Let me explain the difference between the two.

Currently, there are two types of V-grooving machines on the market: vertical and horizontal.

The structure of the vertical V-groover is similar to that of the door frame type. The fixture is used to position the plate at the corresponding processing position. After clamping, the V-groove is processed by the cutter movement. The tool only performs linear movement of the processing, and the plate is moved to cooperate with the tool processing.

The principle of the horizontal V-groover is opposite to that of the vertical V-groover. It has a large working table, and the plate is fixed on the table by pressure clamps. The cutter is a gantry automatic mechanical structure. The tool moving device on the gantry first locates the machining route on the Y-axis, and then the gantry drives the tool to perform the V-groove machining on the X-axis. The plate is fixed and processed by the movement of the cutter.

Each type of groover has advantages and disadvantages (Table 1).

Table 1 Comparison of vertical and horizontal  V groover technology

The application characteristics of the two can be seen from the comparison items.

The specific choice of equipment for processing needs to be determined according to industry requirements and workpiece characteristics.

Generally, the gantry V-grooving machine has high working efficiency, however, the accuracy of grooving (slotting) is not as good as the vertical V-grooving machine.

Furthermore, if the sheet metal is in a non-specific shape (cut by laser cutting), and more grooving lines will be needed, then we suggest you choose a vertical V-grooving machine.

If the sheet metal is a whole piece or a more symmetrical piece, such as square or rectangular, we recommend choosing the gantry or horizontal type V grooving machine.

In addition, the current price of the gantry type V grooving machine is slightly lower than the vertical V grooving machine, and the gantry type is still the more popular option and is selected by most customers.

Final Thoughts

As customers have higher and higher requirements for the aesthetics of their products, the application of the grooving process is becoming more and more widespread.

It is believed that the grooving process will definitely bring more benefits and contributions to the manufacturing industry in the future.