“I need a CNC machine for processing 100mm thick PET boards and foam boards. Currently, I use a milling machine to process MDF boards, acrylic boards and phenolic boards. The worktable size is 3000x2050mm. Looking forward to your reply.” This is the email sent to us by a customer named Armenio from Portugal. It can be seen that the milling machine he currently uses for MDF, acrylic and phenolic boards cannot meet his needs for cutting thick PET and foam, and his cutting requirements are obviously limited.
In response, we recommended the Trustercnc CNC oscillating knife cutter with a modular integrated tool head system. Since the 3000x2050mm worktable size is not a standard conventional machine size, we need to customize the size for the customer. We also developed a complete set of cutting solutions for the customer, as follows:
For 100mm thick PET and foam: High-frequency pneumatic oscillating knife (0.7-0.8 MPa air pressure, 8-10mm stroke, 120-150 Hz impact frequency) matched with 1.5mm extra-thick cemented carbide long blades, realizing dust-free, zero hot-melt cold cutting with vertical tolerance ≤±0.3 mm.
For MDF, acrylic and phenolic boards: 200W / 24,000 RPM high-precision spindle (dynamic runout TIR <0.003 mm), matched with single-edge mirror O-groove cutter (for acrylic), down-cut double-edge cutter (for MDF) and PCD diamond cutter (for phenolic boards).
Worktable: 3000×2050mm matrix type 6-8 zone vacuum adsorption table, equipped with highly breathable self-healing felt and ≥650 m³/h large-flow variable frequency fan, realizing fast and seamless switching between soft and hard materials.
Why Can a CNC Oscillating Knife Cutting Machine Process PET, Foam, MDF, Acrylic and Phenolic Boards at the Same Time?
The advantage of a CNC oscillating knife cutting machine is that it integrates two completely different cutting mechanisms, “vertical high-frequency micro-shearing” and “high-speed rotary milling”, on the same gantry platform, and intelligently distributes power output through programs to realize different processing technologies.
For flexible materials, the oscillating knife completes shearing through high-speed reciprocating motion, which can avoid the heat generated by long-term friction of traditional rotary tools; for MDF, acrylic and phenolic boards, the spindle-driven milling cutter can complete contour, hole and grooving processing.
The Key Is Not “One Knife for All Materials”, but a Modular Integrated Tool Head System
The core value of the modular tool head system is to concentrate different processing methods on the same CNC platform. For example, install an oscillating knife when processing foam or cuttable PET foam, switch to a cemented carbide milling cutter when processing MDF, use a single-edge or double-edge milling cutter suitable for plastic chip removal when processing acrylic, and use a milling cutter designed for fiber-reinforced materials when processing phenolic boards.
Oscillating Knife and Milling Cutter Undertake Different Processing Tasks
Oscillating knife module: Equipped with a pneumatic large-amplitude tool head, controlled by an independent pneumatic reversing valve and high-frequency micro-stroke controller, specially designed for large-depth cold cutting of 100mm PET/foam; it is also applicable to flexible materials such as EVA, EPE and XPE; some PET foam and flexible PET composite materials; felt, rubber, gaskets and other materials.
Electric spindle module: Equipped with a 200W / 350W high-speed electric spindle, with large-diameter spindle bearing rigidity, specially designed to withstand the strong cutting radial force generated when milling hard plates. It is suitable for MDF, acrylic, phenolic boards and other rigid plastic and composite plates.
For example, in acrylic processing, cutting heat control is very important. Data shows that CNC processing of acrylic usually uses single-edge or few-edge milling cutters, and reasonable feed and chip removal are used to prevent the tool from “friction” rather than cutting in the material. Source: https://www.interstateplastics.com/acrylic-fabrication-machining-guide
What Tool Should Be Used for 100mm Thick PET Board?
For the 100mm thick PET proposed by the customer, we have made important considerations. Because “PET board” may correspond to different forms: solid PET board, PET foam board, PET composite core material, their density, hardness and cutting behavior are very different.
For low-density PET foam or shearable PET composite materials, the oscillating knife can provide low-heat cutting; but for high-density solid PET, 100mm thickness can no longer be simply treated as an ordinary foam board, and a high-frequency pneumatic knife or 400W high-power servo knife may be needed.
Therefore, when selecting equipment, you should first confirm the density, hardness, whether it is closed-cell, whether it is a solid board, and whether the final requirement is contour cutting or complex processing such as grooves, holes and steps. If the material needs a lot of solid material removal, milling may be more suitable than oscillating knife.
What Are the Cutting Difficulties of 100mm PET Board?
After the thickness increases, the biggest change is not simply “longer blade”. The longer the tool extends, the worse the lateral rigidity.
If the blade or tool holder deflects during cutting, the following may occur: correct top size but offset bottom size; non-vertical incision; corner position error; bottom residual material; material driven by the tool.
1. Multi-directional fiber toughness resistance: PET fibers show a disorderly interwoven network structure microscopically, with extremely high tensile strength. During cutting, it is easy to cause fiber stretching along the direction, resulting in edge drawing or delamination.
2. Extremely thick interlayer friction heat: When the tool body reciprocates inside the 100mm material, the side area on both sides reaches 15–20 cm². If chip removal is not smooth or the tool body is too soft, material rebound clamping the knife will cause a sharp increase in friction.
3. Blade deflection: During 100mm cantilever cutting, the tool tip bears huge reverse resistance in the horizontal feed direction, which is very prone to backward bending, resulting in distortion of the bottom size of the workpiece (larger at the top and smaller at the bottom).
Why Is Thick PET Board More Suitable for Cold Cutting with a CNC Oscillating Knife?
Pneumatic oscillating knife cutting belongs to the micro-impact cold shearing mechanism. The blade performs micro-reciprocating punching in the Z-axis direction at a high frequency of more than 8,000 times per minute, and the fibers are forcibly cut off at the moment of compression, with a contact time as short as milliseconds.
Since there is no continuous high-speed rotary friction, the temperature of the cutting area is always maintained at normal temperature (<40°C), which eliminates the disadvantages of material hot melting, tool sticking and coking hardening from the physical source, and achieves almost zero dust emission.
How to Select Blade Length and Tool Specifications for 100mm Thick PET Board?
Overall Length: It is recommended to choose cemented carbide long blades with a total length of 125mm 135mm (reserving 25-35mm clamping and stroke safety distance).
Blade Thickness: Extra-thick blades with thickness ≥1.5 mm must be selected. General thin blades of 0.6mm or 1.0mm are strictly prohibited to provide sufficient transverse bending section modulus.
Blade Geometry Design: Double-sided composite edge micro-serrated blades are recommended. The rake angle is set to 25°, and the micro-serrations can accurately capture and saw off the slipping polyester monofilament during high-frequency punching.
Tip: Too long blade extension will reduce rigidity. Therefore, for thick materials, the blade should be kept at a reasonable extension while meeting the cutting-through requirements, instead of blindly pursuing ultra-long blades.
How to Avoid Melting Edges, Tool Sticking and Incision Deformation During PET Cutting?
1. Pneumatic frequency and pressure lock: The pressure regulating valve pressure is locked at 0.75 0.80 MPa to ensure that the tool head reaches 140 Hz full impact vibration.
2. Feed speed matching: The feed speed is recommended to be set at 4.0 8.0 m/min. Too slow feed (<2 m/min) will cause the tool body to rub and heat in place; too fast feed (>10 m/min) will induce the tool body to bend backward and cut obliquely.
In addition, if PET is a material with strong thermoplasticity, melting edges often mean that too much heat is generated in the cutting area. You can check from four aspects:
1. Check whether the blade has become blunt.
2. Avoid too low feed speed causing long-term friction of the tool.
3. Check whether the vibration frequency matches the feed speed.
4. Check whether the material moves due to insufficient adsorption.
If there is still obvious melting after trial cutting, the material type should be reconfirmed, because this may mean that the current PET is not suitable for direct oscillating knife processing.
How to Use a CNC Oscillating Knife for Thick Board Cutting of Foam Boards?
Foam board is a very typical application of oscillating knife CNC equipment, but “foam” itself is not a single material. EVA, EPE, XPE, IXPE, PU, PET foam and EPS/XPS differ in density, elasticity, pore structure and resilience. Therefore, even for 100mm thick foam, tools and parameters cannot be copied completely.
In actual processing, the blade should be selected first according to foam density and hardness, and then the vibration frequency and feed speed should be determined through trial cutting. For thick foam, special attention should also be paid to blade verticality and bottom cutting-through problems, because the material may rebound after the blade passes, resulting in differences between the incision size and the CAD contour.
What Are the Cutting Difficulties of Different Foam Materials?
EPS (polystyrene foam): Low density, weak particle sintering bonding force. Ordinary mechanical cutting can easily cause foam particles to peel off in clusters (slag dropping), and the cut surface is rough and honeycomb-shaped.
EVA foam (high elastic ethylene-vinyl acetate copolymer): Shore C hardness is between 38°-70°, with extremely fast elastic recovery. During cutting, the material deforms under pressure, and rebounds quickly after the blade slides to clamp the tool body tightly, with huge resistance.
For how to cut EVA with a CNC oscillating knife cutter, please also read: How to Cut EVA Packaging Inserts with a CNC EVA Foam Cutter
EPE pearl cotton (low-density polyethylene foam): High toughness and soft texture. If the blade is not sharp enough or the stroke is too small, the blade will directly deform and stretch the material, resulting in serious drawing and pilling at the bottom of the incision.
How to Select Oscillating Knives for Foam Boards Over 100mm?
Pneumatic Oscillating Tool (POT) must be selected, which is equipped with a large-stroke double-acting cylinder inside.
Stroke length: Must reach 8mm 10mm. The tiny 1-2mm stroke of ordinary electric tool heads cannot form an effective shear fault at a depth of 100mm, and is prone to severe friction deep in the foam.
Cylinder output force: It can output more than 150N high-frequency impact shear force at 0.7 MPa, ensuring smooth and smooth thick board cutting.
For how to cut EPM foam materials over 100mm with a CNC oscillating foam cutting machine, please also read: Cut 100mm+ EPM Foam with a CNC Oscillating Knife Foam Cutter
For how to select tools for CNC oscillating foam cutting machines, please also read: CNC Oscillating Foam Cutting Machine Tool Selection Guide
Why Is Bottom Residue Prone to Occur During Thick Foam Cutting?
Microscopic subsidence of the table: Vacuum adsorption pulls the breathable felt and foam workpiece downward as a whole, resulting in the actual bottom height being lower than the machine calibration height; causing the blade to not really reach the effective cutting depth.
Blade effective stroke blind area: When the oscillating knife is at the top dead center, the tool tip leaves the bottom of the material; if it stops exactly at the bottom surface at the bottom dead center, the cutting time duty cycle is insufficient.
Tool tip end passivation wear: The bottom 3mm of the tool tip is worn and blunt, unable to cut off the cross-linked film at the bottom.
How to Improve Cutting Quality Through Blade Length, Vibration Frequency and Feed Speed?
EPS foam: Blade length 130mm, frequency 110-120 Hz, feed speed increased to 10.0 15.0 m/min. High-speed feed can realize brittle shear with the help of material brittleness, and the cut surface is flat and smooth.
EVA hard foam: Blade length 125mm, frequency 140-150 Hz, feed speed controlled at 6.0 9.0 m/min, air pressure maintained at 0.78 MPa to prevent tool body deflection caused by too fast feed.
CAM corner optimization: The Trustercnc digital control system has the “Over-cut loop” function. The CNC oscillating knife cutting machine will automatically lift the knife at right-angle turns to prevent the tool body from forcibly twisting and tearing the foam at 90° right angles.
Why Does MDF Board Still Need Milling Cutters Instead of Oscillating Knives?
Medium-density fiberboard (MDF) is a dense artificial board made of wood fibers and adhesives such as urea-formaldehyde resin pressed under high temperature and high pressure, with a density usually between 700–850 kg/m³.
Due to its extremely high internal bond strength (Internal Bond Strength >0.55 MPa) and dense homogeneous structure, the reciprocating impact force of the oscillating knife cannot penetrate its dense resin adhesive layer at all; forced cutting with a blade will instantly cause the blade to shatter and damage the connecting rod inside the tool head.
Processing MDF boards must rely on high-speed rotating high-rigidity cemented carbide milling cutters, which cut fibers layer by layer into micron chips and discharge them at high speed through the high-speed circular motion of the blade edge.
Why Do MDF Material Properties Determine That Rotary Milling Is More Suitable?
MDF does not have the grain direction of natural wood, but its surface layer has extremely high density, and the interior is full of hardened resin networks. Rotary milling uses the cutting edge of the milling cutter to continuously impact and peel off the material at a linear speed of 15–25 m/s.
During cutting, the high speed of the tool can provide sufficient cutting kinetic energy, which microscopically quickly overcomes the shear yield limit of the resin adhesive layer, so as to obtain a flat processing section without delamination.
How to Select Milling Cutter Diameter, Number of Edges and Cutting Method for MDF Boards?
Recommended tool structure: Double-edge down-cut spiral milling cutter (Downcut Router Bit) or double-edge positive and negative spiral pressure plate cutter (Compression Bit).
Down-cut cutter principle: The spiral groove discharges chips downward, pressing the vertical cutting component force toward the upper surface of the board, completely eliminating fuzzing and tearing of the top wood fibers.
Tool diameter selection:
For cutting 15-25mm MDF boards, Φ6 mm or Φ8 mm solid cemented carbide milling cutters are recommended.
Thicker tool shanks (above Φ8 mm) have stronger bending rigidity, which can reduce deflection deformation under high feed by 60%.
How to Reduce Burrs, Edge Chipping and Dust in MDF Processing?
Adopt climb milling path: The rotation direction of the tool is consistent with the feed direction, and the cutting thickness of the cutter teeth changes from large to small, which can effectively prevent the wood fibers at the edge of the board from being forcibly picked up and broken outward.
High-power high-pressure dust collection: MDF cutting dust is extremely fine (particle size <10 μm). The spindle end of the Trustercnc CNC oscillating knife cutter is equipped with a fully enclosed pneumatic brush dust hood, connected to a cyclone dust collection system with air volume ≥4000m³/h, which extracts dust the moment it is generated.
Compression cutter for double-sided veneer boards: For MDF with double-sided melamine paper, the upper cutting edge of the compression cutter cuts the lower surface and the lower cutting edge cuts the upper surface. The two forces squeeze toward the middle, ensuring zero burrs on both upper and lower surfaces at the same time.
Why Can’t the Same Set of Parameters Be Used for MDF Cutting and Foam Cutting?
The cutting mechanics models of the two are completely different:
Foam cutting feed speed can reach 15 m/min, cutting resistance is only a few Newtons, and the spindle does not need to rotate.
For MDF milling, the spindle speed should be set to 18,000 22,000 RPM, the feed speed should be controlled at 8.0 12.0 m/min, and the feed per tooth must be strictly maintained at fz=0.2–0.3 mm/tooth. If MDF is pushed at high speed as a soft material, it will cause burning knives or even machine overload shutdown due to chip flute blockage.
How to Configure Milling Cutters for Acrylic Boards to Obtain Flat Cut Edges?
Polymethyl methacrylate (PMMA/acrylic) is a typical thermoplastic amorphous polymer. Its biggest processing problem is not “cannot cut”, but heat management. In CNC processing, the most common problems with acrylic are whitening of cut edges, fish scale wavy patterns on the surface, or cutting chips melting and re-adhering in the cut seam.
In actual processing, cemented carbide single-edge or double-edge milling cutters are usually used, and heat is taken away through sufficient chip load per tooth and good chip removal. The acrylic CNC processing data from Interstate Plastics also emphasizes that the tool should be prevented from “friction” in the material, and sufficient chips should be formed to take away heat.
Source: https://www.interstateplastics.com/acrylic-fabrication-machining-guide
Is the Biggest Difficulty in Acrylic Cutting Melting or Chipping?
Both situations can occur.
Thermal melting: The glass transition temperature of acrylic is only about 105°C. If the tool stays in the same position for too long or the chip flute is blocked, dry friction heat will instantly exceed its melting point, and the chips will melt into glue and weld the tool tightly.
Chipping: Occurs in extruded acrylic or hard modified boards, usually caused by blunt tool edges, low-frequency spindle vibration or brittle impact during up-milling.
Conclusion: The root cause of most processing failures is “secondary overheating melting caused by poor chip removal”. For acrylic, too low feed may instead increase tool residence time and friction heat.
Should Single-Edge or Multi-Edge Milling Cutters Be Selected for Acrylic Processing?
It is recommended to use ultra-fine grain cemented carbide single-edge mirror spiral milling cutter (Single Flute O-Flute Upcut Bit), because the larger chip removal space is conducive to removing acrylic chips.
1. Huge flute volume: Single-edge milling cutters have chip removal groove space of more than 180°, which can form a huge centrifugal chip removal channel during high-speed rotation.
2. Chips take away heat: Acrylic chips are in uniform curly strips. Single-edge tools can quickly throw more than 70% of the cutting heat directly out of the cutting area with the strip chips.
3. Mirror edge (Ra < 0.05μm): Polishing-grade mirror cutting grooves can completely eliminate the micro-mechanical embedding and adhesion of plastic debris on the inner wall of the blade.
Double-edge milling cutters can also be used in some processing scenarios, but the feed per tooth needs to be recalculated according to the spindle, feed and material thickness.
For example, some acrylic processing guides give starting parameters including 6mm single-edge knife, about 12,000–18,000 RPM and corresponding feed range, but also emphasize that specific parameters must be adjusted according to equipment rigidity, tools and materials.
Source: https://www.interstateplastics.com/acrylic-fabrication-machining-guide
How to Control Speed and Feed Speed to Reduce Acrylic Melting Edges?
A very practical concept can be used: Chip Load, feed per tooth.
The basic relationship is: Feed per tooth = Feed speed ÷ (Spindle speed × Number of edges)
For example, if a 6mm single-edge milling cutter runs at 15,000 RPM and 1,200 mm/min, the theoretical feed per tooth is about: 1,200 ÷ 15,000 = 0.08 mm/tooth
This value is only a calculation example and does not mean that this parameter should be used for all acrylics. Actual production must be trial-cut according to tools, board thickness and equipment rigidity.
How to Improve Cut Edge Verticality and Surface Quality for Thick Acrylic Boards?
For 15-20mm cast acrylic thick plates:
1. Step-down DOC: Select Φ6 mm single-edge knife, single-layer cutting depth is controlled at 5.0 6.0 mm, and it is not recommended to cut through 20mm at one time with a single knife.
2. Roughing & Finishing process: Reserve 0.3mm finishing allowance on one side during rough machining; after full-depth forming, the spindle performs a full-height finishing pass at 22,000 RPM and 2.5 m/min feed to completely remove tool marks.
3. Spindle runout control: Use high-precision ER collet with dynamic balance grade G2.5 to strictly limit the overall radial runout of the spindle to <0.003 mm.
The PMMA processing data from Mekanika also recommends starting with more conservative parameters and gradually adjusting according to the actual processing effect.
Source: https://www.mekanika.io/en/blog/material-guides/pmma-cnc-milling-guide
Why Do Phenolic Boards Have Higher Requirements for Tool Rigidity and Processing Stability?
Phenolic laminates (including bakelite boards, phenolic cotton cloth boards, epoxy resin boards FR4) are hard insulating materials made of phenolic resin impregnated paper or cotton cloth hot-pressed. Their physical properties show extremely high hardness (Rockwell M 100-115) and strong anisotropy. After curing, phenolic resin has high wear resistance, and its internal fiber layer is very prone to interlayer peeling and chipping when subjected to transverse alternating shear force.
When ordinary tungsten steel milling cutters cut phenolic boards, the flank wear rate is more than 10 times that of processing aluminum alloys. Therefore, processing phenolic boards not only requires ultra-wear-resistant tool materials, but also puts forward extreme requirements for the low-frequency damping and shock resistance of the machine bed, clamping rigidity and dynamic stiffness of the feed system.
Therefore, for phenolic and fiber-reinforced plastics, some professional tool manufacturers provide special phenolic routing tools, for example, using specific chip breaking structures to reduce vibration and harmonics during processing. Reference: https://products.royceayr.com/products/Precision-CNC-Tooling/Solid-Carbide-Tooling/Phenolic-Upcut
What Impact Do the Hardness and Fiber Structure of Phenolic Boards Have on Milling?
The higher the hardness and the more reinforcing fibers, the more obvious the tool wear.
During processing, the following are prone to occur: tool wear, blade chipping, edge burrs, increased dust, tool temperature rise.
1. High abrasiveness: The resin matrix has extremely high hardness and produces micron-sized hard particles in the cutting area, causing strong abrasive wear on the cutting edge of the tool.
2. Low interlayer shear strength: The transverse interlayer bonding force of the board is much lower than the longitudinal tensile strength. During up-milling, the cutter teeth pry up the material from the inside, which is very easy to tear the upper and lower surface resin layers, causing serious delamination.
3. Extremely high cutting thermal resistance: Phenolic resin has extremely low thermal conductivity (about 0.2 W/(m·K)). A large amount of heat generated by cutting cannot be dissipated from the workpiece, and all concentrates in the tiny area of the tool tip, aggravating tool thermal wear.
How to Select Cemented Carbide Milling Cutters for Processing Phenolic Boards?
It is recommended to prioritize: cemented carbide, sufficient tool rigidity, reasonable number of edges, and tool geometry designed for composite materials.
1. Priority is given to PCD (polycrystalline diamond) insert milling cutters or DLC (diamond-like coating) ultra-fine grain cemented carbide milling cutters. The microhardness of PCD tools can reach 8000 HV, and the wear-resistant life is 20-30 times that of uncoated tungsten steel tools.
2. Tooth structure: Double-edge straight flute or micro-down-cut spiral milling cutters are recommended. Straight flute tools can provide maximum cutting edge support thickness, effectively preventing micro-chipping of diamond blades under impact load.
Professional tool materials do have CNC milling cutter products specially designed for phenolic and fiber-reinforced plastics, which shows that phenolic materials should not simply apply ordinary woodworking tool parameters.
Reference:https://products.royceayr.com/products/Precision-CNC-Tooling/Solid-Carbide-Tooling/Phenolic-Upcut
How to Reduce Tool Wear, Edge Chipping and Board Edge Burrs?
Climb milling entry: The blade cuts into the material from the maximum chip thickness, pressing the board downward on the vacuum table to avoid surface edge chipping.
Layered cutting parameters: Speed controlled at 14,000 16,000 RPM, feed speed set at 3.0 4.5 m/min, single cutting depth (DOC) strictly limited to 3.0 4.0 mm.
Dynamic radius compensation: Set a tool wear compensation program in the background of the numerical control system. Every 50 meters of board processing, automatically compensate the tool offset inward by 0.005mm to ensure that the aperture and shape tolerance are stable within ±0.03 mm.
In addition, if found during processing:
Sudden increase in sound → check tool load
Increased edge burrs → check tool wear
Continuously larger size → check tool diameter and wear
Abnormally increased dust → check tool path and dust collection
How to Deal with Dust and Chips During Phenolic Board Processing?
Phenolic resin dust has a pungent odor and strong insulating abrasiveness, which is harmful to the human body and will seriously wear the machine tool kinematic pairs.
The Trustercnc CNC oscillating knife cutting machine is equipped with an industrial explosion-proof dust collection system with HEPA high-efficiency filtration grade; if you want to further keep the cutting area clean and tidy, you can also choose to install a sealed dust cover at the tool head, matched with a micro-lubrication (MQL) plant-based oil mist system for micro-injection, which can not only suppress dust dispersion, but also significantly reduce the flank temperature of the tool in the cutting area.
How Does One CNC Oscillating Knife Cutter Switch Quickly Between Oscillating Knife and Milling Cutter?
The Trustercnc CNC oscillating knife cutter adopts a modular integrated tool head system, which can integrate different tools on the X-axis, and realizes fast and free switching between oscillating knife and milling cutter through a digital control system.
When processing foam and PET materials suitable for vibration cutting, use the oscillating knife and the milling cutter automatically lifts; when processing MDF, acrylic and phenolic boards, use the milling cutter and the oscillating knife automatically lifts. Truly realize one machine for multiple purposes.
How Does the Modular Integrated Tool Head System Realize Different Tools Sharing One CNC Platform?
In Trustercnc’s modular gantry structure, the spindle and pneumatic oscillating tool head are mounted side by side on independent double Z-axis slides.
Independent servo lifting interlock: When the system executes the oscillating knife path, the milling spindle is automatically lifted to a safe height (moved up by more than 100mm) by the servo system to free up operating space.
Working state switching: The pneumatic oscillating tool head sinks to the working plane, and the high-pressure air valve automatically opens to start vibration; when switching to hard material processing, the pneumatic oscillating knife stops vibrating and returns to the protection cabin, and the electric spindle sinks to start cutting. The entire switching process takes <3 seconds.
Oscillating Knife for PET and Foam, Milling Cutter for MDF, Acrylic and Phenolic Boards
In a single large typesetting operation, you can easily realize composite process operations. For example, when processing a complex luxury packaging box or display stand:
1. The gantry first uses a high-speed milling cutter to blank and mill the edge grooves of the 15mm MDF outer frame.
2. Then, without manual intervention, the system automatically switches to a pneumatic oscillating knife to directly perform one-time fast cold cutting of 100mm EVA buffer liner and PET sound-absorbing backboard on the other side of the same worktable.
3. The whole process is completed in a closed loop in one clamping.
It is emphasized again: 100mm solid PET cannot be judged to use oscillating knife only by the material name, and should be confirmed through material sample testing.
After Tool Replacement, How Does the Software Match Processing Parameters of Different Materials?
The Trustercnc digital control system supports layer-based material macro program management. When drawing in CAD, you only need to assign different layer colors to different materials (for example, green corresponds to 100mm foam, red corresponds to 15mm acrylic):
1. The CAM post-processor will automatically parse the green layer into an oscillating knife path, and automatically mount cutting parameters of 0.75 MPa air pressure command, 10 m/min feed, and Z-axis one-time bottoming.
2. The red layer is automatically parsed into a spindle tool path, and automatically mounts milling codes of 20,000 RPM spindle start, layered 5mm cutting depth, and 5 m/min feed.
Why Are Tool Center Point, Tool Height and Z-Axis Compensation Very Important?
Because the oscillating knife and the spindle are installed at different mechanical physical positions, there is a fixed spatial relative offset vector (ΔX, ΔY, ΔZ) between the two.
TCP Tool Center Point calibration: The machine integrates a high-precision CCD vision industrial camera and laser alignment crosshair, which automatically optically calibrates the center distance of the dual heads at startup, and locks the relative position error compensation within ≤±0.015 mm.
Z-axis independent double tool setting system:
1. The milling cutter spindle adopts a metal contact normally closed tool setter (tool setting repeat accuracy ±0.002 mm).
2. The oscillating knife adopts a non-contact infrared light blocking tool setter (to avoid collision and chipping between sharp thin blades and hard metal), ensuring zero error in the cutting depth of the two tools on the same Z0 reference plane.
How to Configure a 3000×2050mm CNC Oscillating Knife Cutting Machine Suitable for This Customer?
In response to the specific inquiry needs of this Portuguese customer (need to process 100mm thick PET and foam boards, while taking into account the existing MDF, acrylic and phenolic board business, and the table specification must reach 3000×2050mm), standard general-purpose machines cannot meet the requirements.
This specification belongs to the European standard large plate size, which puts forward extremely harsh industrial indicators for the dynamic stiffness of the whole machine gantry structure, the uniform distribution of multi-air circuit vacuum negative pressure on the table, and the load capacity of the composite tool head. Therefore, in order to meet the customer’s requirements, we customized the machine size and developed a complete set of cutting solutions.
3000×2050mm Effective Working Area
The standard machine size of Trustercnc is generally 1625 (1600×2500mm). For the 3000×2050mm effective working area proposed by the customer, we need to specially customize the machine size:
Effective processing stroke: X-axis 3000mm, Y-axis 2050mm, Z-axis effective working clearance needs to reach 200mm 250mm (to ensure safe lifting space for 100mm workpiece thickness + 130mm tool length).
Bed structure: Heavy-duty seamless welded low-carbon steel pipe bed, with internal reinforcing ribs to enhance the tensile strength of the bed body and minimize deformation. After 650°C heat preservation annealing to eliminate internal stress, the bed is finely hand-ground and then milled with a 4300-ton press. The gantry adopts aviation-grade extruded aluminum alloy beams to ensure high-speed movement without sagging vibration under a 2.3-meter large span.
CNC Oscillating Knife System: For 100mm PET Board and Foam Board
Tool: High-frequency pneumatic oscillating knife (Pneumatic Oscillating Tool, POT).
Power parameters: Air pressure 0.7-0.8 MPa, air consumption 120 L/min, vibration stroke 8-10mm, frequency 120-150 Hz.
Tool configuration: Standard 125mm, 135mm cemented carbide serrated long blades (thickness 1.5mm), equipped with pneumatic spring damping presser foot ring to prevent thick plates from jumping up and down during cutting.
Milling Cutter Spindle System: For MDF, Acrylic and Phenolic Boards
Spindle specification: 200W electric spindle, maximum speed 24,000 RPM.
Tool magazine configuration: 8-position linear/disc automatic tool changer (ATC), which can freely load single-edge acrylic mirror knife, double-edge MDF down-cut knife and PCD phenolic special knife, realizing fully automatic program calling.
Dust removal system: Equipped with 5.5kW high-negative pressure industrial dust remover and synchronous pneumatic follow-up sealed dust hood.
Zoned Vacuum Adsorption System
Vacuum pump unit: Equipped with two sets of 7.5kW large-flow high-negative pressure variable frequency vortex air pumps (total suction air volume ≥650m³/h, maximum negative pressure −40 kPa).
Honeycomb worktable: 41.8mm thick honeycomb structure aviation aluminum alloy worktable. The honeycomb structure has leveling function, which can adjust flatness to ensure consistent accuracy. 4mm industrial high-density breathable self-healing special felt is laid on the top.
8-zone independent solenoid valve control: The 3000x2050mm table is divided into 8 independently controlled matrices. When processing small-size hard materials, all negative pressure adsorption forces are concentrated to prevent the workpiece from shifting under high milling load.
CAD/CAM Software and Multi-Tool Path Management
Software platform: Equipped with professional multi-process nesting CAM software system (such as Trocen, Ruida, Zhongrui).
Functional support: Support import of full-format vector files such as DXF/AI/PLT/NC; with automatic nesting, cutting path collision interference check, climb milling / up-milling adaptive designation and oscillating knife corner lift compensation functions.
How to Establish Independent Processing Parameter Libraries for Different Materials?
| Material Type | Tool Selection | Blade Selection | Running Speed / Stroke | Depth and Cutting Strategy | Auxiliary Control |
| 100mm PET sound-absorbing board | Pneumatic oscillating knife (POT) | 125mm×1.5mm serrated cemented carbide blade | Stroke 8mm / feed 6 m/min | Cut through 100mm at one time (overcut 0.3mm) | Air pressure 0.78 MPa fully open |
| 100mm EVA/EPS foam | Pneumatic oscillating knife (POT) | 130mm×1.5mm flat-edge cemented carbide blade | Stroke 10mm / feed 12 m/min | Cut through 100mm at one time (overcut 0.3mm) | Air pressure 0.75 MPa fully open |
| 10-20mm acrylic board | 9kW electric spindle | Φ6 mm single-edge mirror O-groove tungsten steel milling cutter | 20,000 RPM / feed 5.5 m/min | Layered cutting DOC 5mm/layer | 0.3 MPa clean cold air gun for chip blowing |
| 18-25mm MDF board | 9kW electric spindle | Φ8 mm double-edge down-cut spiral cemented carbide knife | 18,000 RPM / feed 10 m/min | Layered cutting DOC 9mm/layer | 5.5kW high-pressure brush dust collection |
| 10-15mm phenolic bakelite board | 9kW electric spindle | Φ6 mm PCD diamond double-edge straight flute milling cutter | 15,000 RPM / feed 3.5 m/min | Layered cutting DOC 3.5mm/layer | Dust collection on + automatic tool offset compensation |
Tip: Different equipment, tools, acrylic grades and plate thicknesses will cause changes in actual parameters, so the parameters in the table should be used as trial cutting starting values, not production guarantee values.
FAQs
Can the existing air compressor in the factory support the pneumatic oscillating knife cutting 100mm thick material? What happens if the air pressure is insufficient?
Pneumatic oscillating knife (POT) cutting 100mm thick material is a “big air consumer”. When the tool head runs at 120-150 Hz high frequency reciprocating, the instantaneous air consumption is about 120–150 L/min, and must maintain a constant dynamic working air pressure of 0.7-0.8 MPa.
If your factory’s air compressor power is lower than 7.5kW (10HP), or the air supply pipeline is too long (large pressure drop), once the air pressure drops below 0.6 MPa during cutting, the impact energy of the oscillating knife will instantly attenuate by more than 40%.
Consequences: The blade cannot cleanly punch off deep fibers, and serious “drawing, gnawing surface, knife jamming or even direct stop alarm” will appear at the bottom of 100mm.
Solution: It is recommended to separately configure an external gas storage tank with a volume of ≥200L for the machine tool, and upgrade the main air supply pipeline from the traditional Φ8mm to Φ12 mm outer diameter polyurethane high-pressure pipe to ensure no pressure drop during high-load continuous cutting.
The table is covered with felt for foam cutting. When switching to milling cutter to cut MDF and acrylic, what if the felt is twisted and broken if the cutting depth is too deep?
Never let the high-speed rotating milling cutter directly cut into the felt, Otherwise, not only will the 4-millimeter-thick breathable felt be instantly torn and pulled into the spindle, but also the entire table will be scrapped.
Protection Scheme 1: In Trustercnc’s control software, the Z-axis safety lower limits of the milling cutter and oscillating knife are physically isolated. During CAM programming, the milling depth reference is strictly calibrated at +0.05 mm above the felt surface (only cut through the plate, not touch the felt).
Protection Scheme 2: If processing large batches of MDF or phenolic boards, there is no need to tear off the felt. Directly lay a 3mm-5mm thick cheap high-density MDF sacrificial board on top of the felt. Vacuum adsorption can directly penetrate the felt and MDF sacrificial board to firmly suck the workpiece. After the milling cutter cuts through the workpiece, it directly cuts into the sacrificial board by 0.5mm, completely isolating felt damage.
When cutting 100mm foam, the top size is very accurate, but when cutting to the bottom, it is found that the top is large and the bottom is small (oblique cut is crooked). How to adjust this?
The essence of “tapering” is the elastic backward bending deformation of the blade under deep cutting resistance. Check and adjust in the following three steps:
1. Replace extra-thick blades: Check the blade thickness. For cutting 100mm, cemented carbide long blades with thickness ≥1.5 mm must be used. Thin blades of 0.6mm or 1.0mm must never be used.
2. Reduce feed speed: If the current feed is 12 m/min, directly reduce it to 6-8 m/min, so that the blade has enough time to crush the resistance through high-frequency vibration, instead of being pushed forward hard by the gantry.
3. Optimize corner path: “Over-cut Loop” must be turned on in the software at right-angle turns, so that the blade is fully lifted to adjust the tool head direction before cutting down, avoiding lateral hard twisting causing tool tip force deflection.
Why is the acrylic cut edge milled by this machine white, melted, and even chips stuck to the knife and cannot be pulled off?
There is only one reason for white melting edges — the heat in the cutting area is not taken away by chips in time, and the heat accumulates sharply at the tool tip, instantly reaching the melting point of acrylic (105°C).
Solutions:
1. Replace with single-edge knife: Immediately stop using any double-edge or multi-edge milling cutters, and replace with a single-edge mirror O-Flute spiral milling cutter. Single-edge knives have a huge unilateral chip flute, which can form uniform strip chips and take away 70% of the heat.
2. Adjust “speed/feed ratio”: Many people have the misunderstanding of “highest speed, slowest feed”, which will cause the cutter teeth to dry grind and slip in the cutting groove. The correct parameters are: reduce the spindle speed to 18,000-20,000 RPM, and at the same time increase the feed speed to 4.5-6.0 m/min, forcibly increase the feed per tooth (fz≈0.2 mm).
3. Turn on cold air gun: Turn on the eddy current cold air gun that comes with the machine, and use 0.3 MPa dry cold air to blow directly at the tool tip to instantly disperse heat and peel off chips.
Tungsten steel milling cutters become blunt after cutting two phenolic boards (bakelite boards), and always have edge chipping. Is it really useful to switch to diamond knives?
It works very well, and it is recommended to replace them. Phenolic resin after curing is a high-hardness thermosetting material, and contains a high-density interwoven fiber matrix, which belongs to extremely fast “micro-abrasive wear” for tungsten steel (tungsten carbide).
For ordinary cemented carbide milling cutters cutting phenolic boards, the flank of the blade will be ground flat after continuous processing of 30-50 meters. After the blade becomes blunt, it can only squeeze the material hard, which immediately causes edge chipping and tearing on the upper and lower surfaces of the board.
After switching to PCD (polycrystalline diamond) or DLC coated milling cutters: The microhardness of PCD blade reaches 8000 HV (tungsten steel is only about 1600 HV), and the continuous cutting life of a single tool can reach more than 1500 meters. Combined with climb milling pressing process and 3-4mm layered cutting depth per layer, the cut edge is flat, smooth and completely burr-free.
100mm thick foamed EPS foam has such good air permeability, the vacuum pump cannot suck it, and the board runs around. How to solve this?
Low-density EPS/EPE foam is full of microscopic pores inside. Conventional high-negative pressure vane pumps (small flow, high negative pressure) will instantly “lose pressure due to air leakage” when encountering breathable materials.
Solutions:
1. Replace with large-flow fan: Large-flow side channel vortex air pumps must be used (air volume ≥650 m³/h, power 7.5kW×2). Using extremely high dynamic air velocity and the pressure difference generated above and below the table, the porous foam is forcibly “pressed” on the felt.
2. Cover with gas barrier film: If the foam density is extremely low and the area is large, directly cover a layer of 0.03mm ultra-thin PE stretch plastic film on the upper surface of the foam. After covering, the vacuum negative pressure cannot leak from the front of the workpiece, and the adsorption force will increase by 3-5 times instantly. The pneumatic blade can directly pierce the film for smooth cutting, and the film can be removed after cutting.
How long can an oscillating blade last for cutting 100mm thick PET polyester fiber sound-absorbing board? When should the knife be changed?
Due to the large number of dense polyester chemical fiber monofilaments inside the PET sound-absorbing board, the passivation speed of the blade is much faster than that of ordinary sponge foam.
Life data: A high-quality 1.5mm extra-thick cemented carbide micro-serrated blade, under standard feed speed (5 m/min), the effective cutting life is usually about 800 1500 linear meters (about 150 250 standard large boards).
Tool change warning signals (change the knife immediately if any of the following occurs):
1. Observe the last 5mm at the bottom of the processed edge, and obvious burrs, drawing or unbroken fiber skin begin to appear.
2. Observe that the load current reading of the machine X/Y axis servo motor increases by more than 25% (indicating that the blade is blunt and the cutting resistance increases significantly).
3. Observe the rake angle of the tool tip with a 30x portable magnifying glass, and there are obvious rounded corners or micro notches (micro chipping).
References and Information Sources
Interstate Plastics. (n.d.). Acrylic fabrication & machining guide. Interstate Plastics – Acrylic Fabrication & Machining Guide
Mekanika. (2024). PMMA (Acrylic) – CNC milling guide. Mekanika – PMMA CNC Milling Guide
Makera. (2026). Acrylic CNC machining guide: Tools, feeds, speeds & best practices. Makera – Acrylic CNC Machining Guide
Royce//Ayr. (n.d.). Phenolic upcut tooling. Royce//Ayr – Phenolic Upcut Tooling
JMJ Profile, Inc. (n.d.). G10, FR4, phenolic & MIL-I-24768/27 machining. JMJ Profile – Phenolic Machining
Erkorkmaz, K., & Altintas, Y. (2001). High speed CNC system design. Part I: jerk limited trajectory generation and quintic spline interpolation. International Journal of Machine Tools and Manufacture, 41(9), 1323-1345.
https://doi.org/10.1016/S0890-6955(01)00002-8
Altintas, Y. (2012). Manufacturing Automation: Metal Cutting Mechanics, Machine Tool Vibrations, and CNC Design (2nd ed.). Cambridge University Press.
https://doi.org/10.1017/CBO9780511843723
