This tooling guide has been put together to help both newcomers and even the more experienced to the CNC machining industry. The purpose is to assist with the selection of cutting tools and clamping systems. The ability to maximize tool life and achieve best possible surface finish is a prerequisite to obtaining the highest return on investment made in a CNC machine. Its efficiency and productivity is only as good as the tooling paired with it, so understanding the most critical aspects of both tooling and accessories is essential.
Precision cutting tools and clamping systems offer a high degree of technical sophistication. There are important characteristics they must possess, which provide the basis for safe, smooth and efficient operation of a CNC machine. Beginning with design, construction, engineering expertise, to the balancing and inspection of the finished product, the selection of tool and clamping system made can have a profound impact on performance and production cost and can have an even greater impact on your bottom line. With the many options and suppliers to chose from, it does require a bit of homework to make the right tooling decisions. Surprisingly, cutting tools are often the last thing thought about when buying a CNC machine…...but consider this: without the cutting tool, your machine won’t produce a single thing!
Cutting tool performance, i.e. tool life and surface finish, is the result of a synergy between cutting tool, clamping system, machine spindle, material hold-down, efficiency of dust extraction, correct machining parameters (i.e. spindle speed and feed rate) and the composition of the material being machined. For best performance, all facets need to be right.
Keeping in mind that a high class, high performance automobile requires high quality, precision-balanced tires to run smooth, the same applies to cutting tools and tool holders used on a CNC machine.
Remember:
…. a CNC machine cannot cut a single panel without the tool. Good tires provide a smooth and safe ride and similarly, high quality, precision balanced tooling is needed to deliver the promise of productivity that comes with a CNC machine.
This presentation will familiarize the CNC novice with the variety of tooling solutions that are available to meet specific cutting, profiling, drilling, grooving and sawing tasks. Furthermore, proper tool selection, material hold down and dust extraction will increase the frequency of the following desirable CNC characteristics:
Using tools within appropriate machining parameters, in particular, correct “chip load”, is important. Simply put, chip load is the size/thickness of the chip being removed per flute/cutting edge with every revolution of the tool. So, going from a 2 flute bit to a 3 flute bit, the size of the chip is reduced by 33% if the feed rate or spindle speed (rpm) is not adjusted accordingly. A smaller chip will increase heat during the cut as the chips cannot be extracted fast enough and are re-cut into yet smaller particles. The resulting heat generated is very detrimental to tool life!
Remember:
Too big a chip load will decrease the finish.Too small a chip will decrease the life.
every field of technology. For the wood/composites industry, it has developed very extensive criteria/norms for the safe and effective operation of manufacturing machinery, cutting tools, clamping systems and many other accessories. It’s closest U.S. counterpart, ANSI (American National Standards Institute), does not have a detailed norm for cutting tools and accessories. When it comes to very specific tool design DIN NORM – abbreviation for Deutsches Institut für Normung (often just referred to as Deutsche Industrienorm) is the German national institute for standardization of almost criteria with details such as minimum acceptable shank diameter based on the mass of the respective tool body being made, maximum knife protrusion beyond tool body (on insert tools) and countless other details that serve to protect both machine operators and the machine itself, in absence of such established norms in the U.S, we look to Germany’s stringent DIN standards to dictate what we do. While today’s CNC machining centers are equipped with state-of-the-art safety features such as curtain guards, contact mats, guard fencing and more, a cutting tool spinning at 16,000+ rpm still poses a risk if sub-standard tools and clamping systems are employed and safety warnings not followed.
Partner with someone who meets the standard!
From left – clockwise
Developed in Germany, the HSK tool holder is the most widely used collet chuck on CNC routers and machining centers in the wood/composite industry today as it provides the highest degree of accuracy for high speed machining. A precision machined interface between spindle and tool, it is balanced to G2.5 spec for 25,000 rpm. Manufactured in accordance with DIN 69893, it is designed for use with automatic tool changers. HSK (Hohl-Schaft-Kegel), translated from the German language means hollow shank taper which is the part of an HSK tool holder that connects to the machine. This taper is machined to the highest precision, both radially and axially, of 0.0001” per DIN Norm. It’s important to purchase only the highest quality tool holders from reputable manufacturers to protect the machine spindle from potential damage.
Understanding the inner workings!
Tool holder styles are interchangeable on any machine that has the HSK-F 63 tool interface.
RDO / SYOZ Style
ER Style
Collets wear out! Over time, the spring steel loses elasticity due to wear and heat. Collets that are not replaced will eventually fail. Collets are inexpensive…. Failure to replace them regularly will increase tool cost due to unnecessary vibration and runout, tool chattering and breakage. They can do considerable damage to a spindle, so adhering to a collet maintenance schedule is preferable to costly repairs.
• Clean collets and collet nuts when changing tools!
• Use proper torque! Investment in a torque wrench to tighten the collet nut is a prerequisite to extending tool life and reducing breakage!
• Pay attention to clamp tool correctly! (see below) With proper tool setup, the collet should be filled to 80% with the tool shank. Shorter will allow deflection.
• Replace collets every 500 machine hours for optimum tool life! Prevent costly spindle repairs!
The collet nut, and accuracy thereof, is an important component of collet tool holder setup. A high precision collet nut will have a ball bearing located at its base which reduces the overall runout and improves clamping force (pictured in photo below on the right). It also prevents tool slippage. The static nut (pictured on the left) does not clamp as accurately as the bearing version. The bearing in the collet nut also facilitates the ability to run either CW or CCW tools in the same tool holder. With a static nut this is not possible….a lefthand toolholder would be needed.
For routine machining of wood and composite materials, the standard collet chuck style
tool holder is an excellent choice. It has an accuracy of .006-0.01mm depending on which
collet style is used. For the more discriminate user and critical machining applications, the
option of a Preziso® Precision Chuck, Hydro Chuck or Heat Shrink chuck is a good option.
STANDARD CHUCK
• Excellent general use choice. This version is supplied with most new machines and adequate for general machining tasks.
PREZISO® CHUCK
• Excellent choice to reduce vibration when cutting very hard materials
• Improved efficiencies over standard tool holders, optimizes tool life.
• Good choice to increase tool life with solid carbide spiral bits.
• No additional equipment needed.
HYDRO CHUCK
• Rigid tool stability
• Extremely high clamping force
• Saves expense of replacing collets regularly.
• Initial higher cost.
HEAT SHRINK CHUCK
• Best for the Spoil Board (Fly) Cutter, all Insert Tools and Diamond Tools.
• Improved efficiencies over standard tool holders, increases tool life and improves finish.
• Not suitable for solid carbide tools and tools requiring frequent change since an additional investment in a heat induction unit is required.
• Saves expense of replacing collets regularly.
• Order Insert tools and diamond tools mounted on heat shrink chucks!
A dust nut can be especially useful if too much dust is remaining on the table. More importantly, it’s a safer and healthier work environment to reduce airborne exposure to dust particles. The Cyclone Dust Nut takes the place of the regular bearing collet nut on the tool holder. Through its geometry, it creates a whirl-wind type effect that sucks the chips out of the cut and into the dust extraction system. The Cyclone must be kept close to the shroud / table to function properly, so best to have shortest possible cut length on the router bit to allow the nut to be positioned as close to the table as possible. Below are photos of the same cut made with a regular collet nut (on the left) and the other, with a cyclone dust nut (on the right). Our company offers a demo/test nut to try so customer knows if it will work in his application before buying.
First, click the collet into position by pressing only one side
Then, pushing down on the other side to lock it in.
To release the collet, use the ball of your hand to push out sideways.
Setup Ffixture with gauge.
Setup Fixture (no gauge) and torque wrench.
Collet Style | Recommended Torque |
---|---|
RDO 35 (SYOZ25) | 59 ft/lbs |
ER 20 | 100 ft/lbs |
ER 32 | 130 ft/lbs |
ER 40 | 90 ft/lbs |
Incorrect torque when tightening the collet nut will result in poor cutting performance, premature collet wear, tool slippage during the cutting process and over-torqueing can often result in tool breakage and chattering. Investment in a torque wrench has paid for itself after the first few bits broken due to over torqueing. Use the torque wrench only for tightening the collet nut. Use a standard wrench to remove it. Otherwise, the torque wrench can lose calibration accuracy.
A setup fixture and torque wrench are a necessary investment to achieve optimum tool life These are necessary to avoid tool breakage, inferior finish, premature wear and a high tooling cost. After spending over six figures on a CNC machine, this is not the time to pinch pennies.
Using typical 10mm shank drill bits with a set-screw flat area on the shank in a collet-style tool holder can result in oval holes. The drill bit shank cannot be clamped evenly around its circumference due to the flat on the tool shank present for set screw tightening. The gap that remains between the collet wall and tool shank in the flat area can cause the bit to deflect, possibly wobble and not provide a good finish. The solution is to get a small and inexpensive drill bit adapter that has a 10mm cylindrical shank (without flat) to go into the collet, and the
female end of the adapter accepts the 10mm drill shank with flat and is tightened in with a set screw. For CNC use, the 70mm drill bit length should be chosen over the 57mm length
From left to right:
For holes that will go through the material, use V-Point Bits (ThruHole Bits) that prevent surface tear-out on the bottom of the cut.
For blind holes, a brad point/dowel bit is required. It has a center point and outside spurs to cut a clean hole. For pilot holes, this bit is available in solid carbide in 1/8” diameter
For hinge pockets, the hinge boring bit is the best option. The center point and outside spurs provide a clean edge hole and prevent the bit from “walking”.
This Universal Drill Adapter is the best and only option if drilling many different cylindrical drill bit sizes for which collets are not always available.
RPM and Feed rate:
When drilling or boring holes on a CNC machine, your spindle
speed and feed rate must be adjusted to within the proper
parameters for drill/boring bits.
Recommended Feed / Speed for Drilling on CNC:
| -- | -- | -- | -- | -- |
| RPM | Feedrate (m/min) |
|3000| 1 - 2 |
|4500| 1.5 - 2.5 |
|6000| 2 - 3.5 |
|9000| 2.5 - 5.5 |
• The best options for CNC machining are either solid carbide bit or PCD
(polycrystalline diamond).
• PCD tooling achieves the best return on investment when it is dedicated to cutting homogeneous material and not interchanged between, for instance, composite and wood. Use dedicated tools per material!
• The only time a carbide-tipped tool is an economical solution for use on a CNC is for cutting a small profiled proto-type (i.e. one-off).
Depending on product and volume being machined, the selection of the most suitable cutting tool requires a bit of homework if best performance and finish relative to investment is desired.
In the following slides we present the most common and cost effective router bit options based on application.
For straight cuts such as sizing, jointing, rebating, grooving and dados, the options available are solid carbide, carbide insert or PCD (polycrystalline diamond).
For profile routing applications, options are either carbide insert or PCD and for proto-type or “one-off” needs, a corrugated head provides a cost-effective solution.
In addition to the many standard tool designs, it is often necessary to customize a tool for a particular requirement in order to provide a more economical option over time.
Many tools styles can effortlessly produce the same cut, so researching cost, time and yield based on tool choice can have a substantial impact on a tooling budget.
Solid carbide router bits come in a variety of tool geometries, number of flutes, and edge grind to include the most popular ones below and described in more detail on the following pages.
• O-Flute, Straight (Soft Wood/Soft Plastic)
• O-Flute, Up Cut (Plastics, Aluminum)
• Up Cut
• Ball Nose Up cut
• Down Cut
• Compression (Mortise Compression)
• Compression Chip Breaker
• Up Cut Chip Breaker
• Down Cut Chip Breaker
• Up Cut Rougher
• Down Cut Rougher
• Single, Two and Three Flutes
Remember: More flutes does not equal better finish! More flutes means you have faster feed rate capability! Refer to the chip load information later in this presentation to calculate your needs.
This image shows a solid carbide, straight O-Flute. The flute shape is ground into what looks like a half-circle. This particular geometry is used for cutting flexible plastics. The flute is straight and helps keep a light weight flexible plastic from moving orlifting on the router table during machining.
Use this tool on materials such as:
The O-Flute upcut bit features the same O-Flute geometry needed for efficient chip removal when routing plastic, and also has an upward shearing angle to bring the chips out of the cut and provide cleanest possible edge finish.
This tool is the preferred router bit for hard and rigid plastic materials, such as:
The up cut spiral bit is used when getting the chips out of the cut is critically important, or when the material is laminated or coated on one side only, and is being machined face down. This tool geometry does present a risk that the top of the material being cut can chip or fray.
This tool is a good choice for mortise and tenon cutting needs and also provides an excellent option for short runs on Corian or phenolic. (longer runs should consider a PCD diamond bit as it is more cost-effective). Upcut bits provide the ability to feed faster than down cut bits as the chips are pulled out of the cut by the upward shearing action and keep the tool running cooler.
A ball nose tool is a great choice for cove and fluting operations, but is also the tool of choice when complex shapes have to be surfaced. A flat bottom bit would leave lines and a poor finish, but a ball nose bit, due to its rounded shape, provides seamless passes.
Another option for this tool is a carbide insert version (pictured below), which is always much more cost effective if the project is ongoing with a continuous tooling need.
The down cut spiral bit provides a superb top surface finish, but it does run the risk, depending on application, of pushing the chips into the cut and bogging down the bit. With good dust extraction and proper chip load, this should not be a problem. It is often selected for doing grooves, dados and rebate cuts . Important to remember, always use the shortest possible cut length for dados, grooves and rebates, as the longer tools will have more deflection and can break more easily or provide poor finish due to deflection when cut length is excessive.
If there is an ongoing dado or rebate cut requirement, an insert bit will decrease cost considerably within a short period of time if the tool is available in the diameter needed. (Image below)
The compression bit is designed to cut materials that have a laminate, melamine, HPL, paint, paper etc. on both top and bottom surface. The cutting flutes have opposite shear angle geometry and cut toward the center of the material, thus providing clean surface top and bottom. This is the most popular style bit used in composite panel processing and is available in many different executions….ranging from a variety of carbide
grades defined for wood, composite material and melamine, and also coated versions. These bits come in multiple carbide grades! Pick the right one for the job!
If using 3/4” or larger compression bits, an insert or a PCD diamond tool offer the lower cost option for any ongoing need.
Insert Bit for >3/4” diameter
PCD bit compression bit
The compression chip breaker is the best choice for cutting plywood and OSB panels where a good surface finish both sides is expected. The chip breakers, which are notches machined in an offset pattern into the flutes, facilitate faster feed rate and breaking up the larger chips created by these materials. While the chip breaker is essentially more of a hogging tool, it does provide excellent machining characteristics as well as a good finish in the compression style.
Below is an insert tool option for high feed speed requirements on plywood panels and other composite materials.
The up or down cut chip breaker is a great choice for cutting composite panels and plywood where a good surface finish on one side is needed. (down cut for best finish on top, and up cut for machining face-down).
The insert option pictured below, features a selection of insert knives that are either straight, up- or down shear or even compression style and can be arranged as needed on the tool body as shown below.. This allows them to be positioned for best possible finish results.
A roughing bit is designed to remove a lot of material quickly, but, as the name implies, it does leave a rough edge which must be cleaned up with a finishing pass using another tool. Typical feed rate for these 3 flute tools is 800”/min and up.
A very cost effective option is an insert roughing tool (pictured below) which is available with either carbide or diamond (PCD) inserts and provides a tremendous cost saving for high volume operations.
Whether diamond tooling should be a consideration for a particular application is discussed in the next few pages. Diamond router bits come in a variety of styles such as high shear, single flute, two flute or three flute disposable, single segment opposite shear etc. Diamond tools are not all equal. Some are designed to be disposable, others can be sharpened one or more times and these factors should be considered when shopping for PCD tooling.
• Always adapt the cutting length of the router tool to the panel thickness, i.e. cutting length should be minimally longer than the panel thickness.
• Always chose the stronger tool, i.e. cut length not too long and diameter not too small.
• Material hold-down must fit the tool. That means, select small diameter tools for parts that are prone to moving.
• Chip clearance is better on larger diameter tools, therefore when running high feed rates and thicker panels, use a diameter of 5/8” or greater.
• Select highest accuracy clamping tools. (Heat shrink, Hydro Chuck or Preziso)
• If using collet chucks, replace collets regularly. (every 500 machine hours!)
There is no debate that PCD (polycrystalline diamond) will outperform solid carbide tooling in wood and composite material by many multiples and be the more economical choice over time. Until recently, there was a good argument to stay away from diamond router bits, because most companies promoting them only offered single flute on diameters of ½” or less. This did not facilitate high feed rates. That has changed with the introduction of 3/8” and ½” PCD bits that are 2-flute!
If you want to achieve the best possible tool life and save substantial amounts of money in the process, you would be remiss to not investigate the cost of running a diamond tool for your biggest projects! Whether sizing or profiling,diamond tooling should always be used on homogeneous material and same panel thickness to maximize the tool life and performance. Most diamond tools can be sharpened a few times and will last longest when paired with a heat shrink tool holder for highest accuracy.
These are circumstances under which solid carbide bits would be the better choice:
• When materials and material thickness varies and having a diamond tool for each operation isn’t feasible.
• If initial cost outlay is critical and a higher upfront tool price isn’t tolerated for cash flow reasons even though it will save much over time.
• If material is prone to inclusion of staples, nails etc. (diamond tools are susceptible to impact damage).
• If the machine is older and has excessive spindle runout, or parts tend to move on the table....stick with carbide.
• If machine operators are poorly disciplined and wouldn’t handle a diamond tool with the gentle respect it deserves.
• If customer is not prepared to invest in a complete setup to insure the diamond tool is capable of performing to expectations, i.e. doesn’t want to replace the collet or invest in a heat shrink tool holder.
• Customer is cutting parts that require plunging straight down into the material (this creates a lot of heat that will cause the PCD tool to wear prematurely.
The below comparison is based on both tools being sharpened twice and does not include setup cost or machine downtime, nor does it factor in that after sharpening a carbide spiral, clearance is lost and thus lower tool life cycle is achieved. Life Cycle estimate 24:1 - a conservative value!
| -- | -- | -- | -- | -- |
| Comparison Data | Carbide | Diamond |
| Initial Tool Cost | $65.00 | $388.00 |
| Sharpening Cost | $16.50 (x2) | $125.00 (x2) |
| Tool Life | 85 panels | 2000 panels |
The next two pages contain information that is critically important to preventing tool breakage and maximizing tool life. Please take the time to review.
Correct chip load is an important factor to extend tool life and avoid premature tool wear! The chip load is the size of the chip the tool makes during the cutting cycle and it is calculated based on the number of flutes on the tool, the spindle speed and the feed progression. The below chart is a starting point reference range only! The below range is based on cutting depth being equal to cutting diameter. For deeper cuts, adjust the chip load as follows: for 2x diameter, reduce by 25%, 3x diameter reduce by 50%.
| -- | -- | -- | -- | -- |
| Tool Diameter | Hardwood | Plywood | MDF / Particleboard | Soft Plastic | Hard Plastic | Acrylic | Solid Surface |
| 1/8" | .003" - .005" | .004" - .006" | .004" - .007" | .003" - .006" | .002" - .004" | .003" - .005" | .002" - .004" |
| 1/4" | .009" - .012" | .011" - .013" | .013" - .016" | .007" - .010" | .006" - .008" | .008" - .009" | .006" - .009" |
| 3/8" | .014" - .018" | .017" - .020" | .020" - .023" | .010" - .012" | .008" - .010" | .010" - .012" | .008" - .010" |
| 1/2" | .019" - .021" | .021" - .023" | .025" - .027" | .012" - .016" | .010" - .012" | .012" - .015" | .010" - .012" |
Calculating Chip Load:
Calculator available here: www.guhdo.com/chipload-calculator
The formula is:
Chip Load = Feed Rate (inches per minute) / (RPM x number of flutes)
Example:
Feed rate of 500” per min / (16,000 rpm x 2 flutes) = 500/32000 = Chip Load is .015”
To calculate feed rate on the fly:
Example: Using a 2 flute 3/8” compression bit cutting MDF, and rpm of 16,000
Your formula is:
(16,000x2) x .023 (chip load per schedule above) = 736”/minute (adjust based on cut depth)
If your machine displays feed rate in metric values, take the metric value, example, 8 meters, and multiply by 39.37 to obtain the inch equivalent for your calculation.
When the chip is too small, the cutting action will generate heat in the cut and will cause the cutting edges of the tool to deteriorate prematurely. A larger generated chip within the reference range for a particular material will achieve the longest tool life.
You can find your optimum chip load, which will allow you to maximize productivity and get the best tool life and lowest cost per panel, if you follow the steps below:
Start using the recommended chip load and slowly increase your feed rate until the finish quality becomes unacceptable. Then slowly decrease feed rate again until desired finish is restored. Make note of your feed rate. Next, decrease the machine RPM's until the finish deteriorates. Once that occurs, increase RPM's until finish is once again restored. At this point, you have found the “sweet spot”
A clean and level spoil board is prerequisite to good vacuum hold-down and machining accuracy. When setting up machining program, the routing tool should extend beyond the work piece and penetrate the spoil board by 0.3 – 0.6mm. Periodic resurfacing of the spoil board to maintain a flat, even surface is most efficiently performed with a large diameter fly cutter. (available in 40mm, 80mm or 100mm diameter).
For best performance these cutters should all be mounted in an HSK heat shrink tool holder
An insert tool with special insert knives and edge radius provides a superb surface finish for applications such as MDF shaker style cabinet door cut outs. Using two additional tools (a 1/2” solid carbide bit and a 1/16” solid carbide bit provide the ability to produce a square corner cutout in MDF doors. For optimum results, this tool should be used on an HSK heat shrink tool holder.
For rebate or deeper surface planing cuts, these insert tools provide a very economic solution as the replacement insert knives, when the tool is dull, usually cost under $6.00/cycle. The solid carbide inserts are available in different carbide grades to facilitate efficient cuts in either wood or composites.
The further the cutting edge of a tool gets away from its clamping source, the more deflection is created and the bigger the risk of tool breakage. Considering the rule of thumb is that cut length shouldn’t exceed three times the cut diameter, that means that cutting a deep mortise pocket can represent a challenge. Special deep pocket mortise bits solve that problem as they are made from a very special high density alloy that prevents deflection and tool breakage despite the depth of cut.
Recommended RPM: 12,000-18,000
Gradual Plunge Feed: 12m/minute (up/down)
Max. Cut Progression: 8-10mm solid wood, 15mm composites
For mitre folds, insert V-Groove Bits are available as standards for 45, 60 and 90 degree (included angle) cuts. Other angles can be produced as custom tools. The insert knives are double sided and provide two life cycles each. Insert V-Groove bits are also a great solution for lettering, engraving and decorative cuts as well as beveling the inside edges of shaker doors and square corner cut-outs.
The following slides show some examples of tooling options for specific materials. A solid carbide tool is often selected for most cutting challenges on a CNC machine. However, this is definitely not always the most cost effective solution. As you will see in the following frames, there are many options to choose from. Therefore, we recommend to look for the most economical option for the job at hand that doesn’t compromise end result. Carbide insert tools or diamond tools offer a lower cost alternative. These options are often overlooked by short-sighted decisions based on initial cost which can be deceptive. In the following slides, we present some examples for slotting, grooving, edging, drilling and profiling in a variety of materials, such as -
Larger profiles and tool assemblies that can provide flexibility such as the ability to machine various door thicknesses or tongue width, are manufactured on arbor adapters as sets with replaceable insert knives.
Caution: Some manufacturers have patented insert tool systems (unique
insert blank) that restricts sourcing and can impact competitive pricing!
Most CNC profile tooling is made-to-order. The process is very simple. A profile drawing or material sample is supplied in order to obtain a firm price quote. Once an order is placed, a dimensioned drawing is submitted for review and revision. Once the drawing is completed to satisfaction a last approval is needed to proceed. Larger profile tools are usually made of an aluminum tool body mounted on an HSK arbor adapter in order to adhere to typical CNC machine spindle weight restrictions.
A corrugated knife adapter fitted with a heat shrink tool holder provides flexibility needed for proto-type production and ”one-off” projects that won’t break the bank. This tool body is made of steel and is available to accept either 8mm , 5/16” ,¼” x 60 degree corrugated knives. This tool is designed to accept knives of length 40, 60 and 80mm corrugated knives. Similar cutters are seen in the market with an aluminum body but we strongly suggest you stay clear of such cutters as the aluminum corrugations in the head will eventually wear out and the tool can become a real danger to operate!
Advantages:
Excellent finish with solid carbide, 4-sided insert knives resulting in considerable savings compared to solid carbide tool. Excellent chip removal and very quiet running due to helical design. Perfect solution for many millwork tasks such as arches and window production. This cutter features scoring (spur) insert knives on the bottom to cut clean corners in a rebate cut.
Depending on blade diameter needed, there are several options for use of sawblades on a CNC machine. The shank style adapter, (on the left), is designed for blades up to 8” (200mm) diameter. Below left is a design with saw collars, which provides blade stability for up to 16” (400mm) diameter blades and the assembly below (right) is for blades up to 14” (350mm) and available in several ”A” dimension lengths.
An aggregate head can provide 5-axis capability with boring/sawing outputs that facilitate horizontal boring and vertical sawing/grooving. Single, double and even four outputs on the same head. Torque arm connections are machine specific and must be verified at the time an
aggregate head is ordered. GDP aggregate heads are manufactured in Germany and adhere to the highest standards of quality and accuracy!
Tool setup fixtures are available in a variety of executions, from the very simple version of a setup tool holder fixture to more expensive and elaborate tool presetters. Regardless of choice, accurate tool setup will save much time and material waste and insure repetitive accuracy of the final product!
A high precision Spindle Calibration Test Bar (pictured left) allows measurement of spindle accuracy which is an important maintenance item of CNC ownership. Indispensable to test runout and alignment after initial machine installation or relocation, after an unexpected ”crash” or simply as a periodic performance test. This will identify spindle issues long before they become bigger and more costly repair items.
Spindle plugs, (pictured below) serve to protect the spindle motor from dust intrusion when the machine is either being moved or the machine is performing a saw/grooving operation or horizontal drilling application. Preventing dust from getting into the spindle motor will insure best maintenance practices and reduction of repair cost.
Tell-tale signs on these photos show us some corrective measures are needed to extend tool life. On the top photo, collet marks are visible on the tool shank. This is an indication that vibration is occurring during the cutting cycle, and it contributes to poor tool life, poor finish quality and can also cause the tool to break at its weakest point, which is right below the shank. Tool breakage is usually the result of one or a combination of: bad/worn collet, poor quality tool holder or collet nut, incorrect torque, vibration during the cut, clamping the tool too high on the shank, too shallow a cut in relation to cut length of the tool, running the tool when it’s dull!
When you see the residue of heat, either black/burned material buildup or a blue discoloration of the carbide or tool body itself, it is time to go over the machining parameters to obtain the correct chip load. This will require one or a combination of:
Possible Cause | Remedy |
---|---|
Deflection – cutting edge too long | Select a tool with cutting edge not more than ¼” longer than material thickness. |
Bad or worn collet | Check tool shank for evidence of chatter marks. When visible, replace collets. |
Over-torqueing | If tool breaks in the shank area, tightening the collet nut to incorrect torque can cause tool breakage. Invest in a setup-fixture and torque wrench. |
Overheating | If signs of heat buildup are in the tool flute, check chip load and adjust feed/speed. |
Part Movement | Improve vacuum hold-down. |
Too much pressure on the tool tip | For rebates, grooves, slots, use the shortest length to avoid tool breakage. |
Tool slippage in the collet | Replace static collet nut with a bearing nut. |