CNC tool maintenance solutions Archives - Edge of Arlington Saw & Tool, Inc.

Tag Archive: CNC tool maintenance solutions

CNC Routers: Things to Avoid
October 18, 2023 5:49 pm Comments Off on CNC Routers: Things to Avoid
Understanding the different variables involved in CNC routing can be overwhelming, especially to anyone new
to CNCs. That is why Edge of Arlington Saw & Tool is here to help you in selecting the proper tool for the job.
Don’t let the complexities involved keep you from maximizing tool life, machine time, and profits—help is only
a phone call away.

• Dead stops, also known as “dwelling in the cut,” can lead to premature tool wear and failure. When
changing directions of travel or when cutting small pieces, a one second stop at 18,000 RPM generates
enormous heat and no means of extraction. Imagine rubbing your hands together 300 times per
second—a sure way to form a blister. This is more of a machinery and software issue. Certain
programming techniques can help to compensate, such as ramping, use of loops at sharp outside
corners, and the use of exit ramps.

• Plunge cutting. While this is the oldest and most widely used method of entering the material, it is not
always the most efficient. Plunge cutting can lead to chips wrapping around the router bit after
repeated plunges. Whenever possible you should Ramp into the cut. This eliminates the heat
generated during the plunging process and can eliminate burn marks at the plunge point. Plunging can
also cause the bit to “walk” because there is no centering point—this will be evident as ovals, holes,
and entry points larger than the diameter of the tool. If you cannot ramp in, a good alternative is to
plunge down outside of the workpiece and enter from the side. Spiraling in can also help. Whatever it
takes to keep the router bit moving.

• Routing holes is never the optimum choice. Use drills for drilling, routers for routing. Drills turn at
much lower RPM than routers do. Router bits generate too much heat when drilling. Drilling just a
couple of holes per sheet will significantly reduce the life of your tooling. In fact, you will dull more
drilling the two holes than cutting the entire piece. If you do not have drill heads to take advantage of
European type boring bits, turn the RPM down as low as possible, 4,000-5,000 RPM at most, and
plunge as fast as possible. An upshear will help to remove the chips if hold-down is not a problem. On
deep holes “pecking” can sometimes help.

• Small parts and scrap pieces can become projectiles if left after the cutting process without sufficient
hold-down. They can also be sucked into the dust collector and cause a blockage. Skin cutting and the
use of tabs can help to hold small parts.

• Over tightening of the collet and collet nut is a common mistake. Most operators assume that the
tighter the better—this is not true and can lead to premature tool and collet wear and tool breakage.
Collets are the most misunderstood and overlooked part of the CNC, often the cause of poor finish,
short tool life, and unnecessary machine wear. Collets are made of spring steel and are subject to
distortion when put under undue pressure. It is highly recommended that collets be tightened to
manufacturers’ specifications with the use of a torque wrench.

• Fires—yes it happens. A tool left in the same place for enough time can and will start a fire. It is
important never to leave a CNC running without an operator. You wouldn’t believe how fast things can
go wrong. The dust collection system and the vacuum system will aid in the fires speedy travel. If this
ever happens to you, beware of flash-back when the vacuum is turned off. When it is safe to do so, it is
important to remove and examine the bleeder board and table underneath, as embers can remain and
once again flair up.

For more, download our free CNC Manual.
Climb Cut vs. Conventional Cut
April 14, 2023 5:38 pm Comments Off on Climb Cut vs. Conventional Cut

Climb and conventional cutting refer to the direction of travel in relation to spindle rotation. In the case of a right-hand rotation spindle, climb cutting (clockwise direction) can produce a different result than conventional cutting (counterclockwise direction).

• In many circumstances conventional (CCW) cutting will provide the best finish, especially in plastics and with larger diameter tools. If the scrap piece has a better finish than the finished part, a change in cutting direction will provide you with the opposite results. Don’t be afraid to experiment with cutting directions or have different cutting directions on the same workpiece.

• There are also left-handed tools and holders available for left-hand rotation—climb cutting would then become counterclockwise and conventional cutting would become clockwise.

• When cutting the interior of a part as opposed to the outside perimeter, conventional cut becomes climb cut and vice versa.

• When cutting two parts with one pass such as when cutting parts that are nested or mirrored, keep in mind that one side of the cut will be conventional cut and the other will be climb cut.

• Climb cutting is more aggressive and can move small parts.

• When cutting hard materials and metals such as aluminum, climb cutting is preferred.

CNC-MANUAL-PDF-Nov-2022
Tips to Safely & Efficiently Prolong the Life of CNC Tooling
November 8, 2021 7:35 pm Comments Off on Tips to Safely & Efficiently Prolong the Life of CNC Tooling

• Dead stops, also known as “dwelling in the cut,” can lead to premature tool wear and failure. When changing directions of travel or when cutting small pieces, a one second stop at 18,000 RPM generates enormous heat and no means of extraction. Imagine rubbing your hands together 300 times per second – a sure way to a blister. This is more of a machinery and software issue. Certain programming techniques can help to compensate, such as ramping, use of loops at sharp outside corners, and the use of exit ramps.
• Plunge cutting, while this is the oldest and most widely used method of entering the material, it is not always the most efficient. Plunge cutting can lead to chips wrapping around the router bit after repeated plunges. Whenever possible you should Ramp into the cut. This eliminates the heat generated during the plunging process and can eliminate burn marks at the plunge point. Plunging can also cause the bit to “walk” because there is no centering point; this will be evident as oval holes and entry points larger than the diameter of the tool. If you cannot ramp in, a good alternative is to plunge down outside of the workpiece and enter from the side. Spiraling in can also help; whatever it takes to keep the router bit moving.
• Routing holes is never the optimum choice. Use drills for drilling, routers for routing. Drills turn at much lower RPM than routers do; router bits generate too much heat when drilling. Drilling just a couple of holes per sheet will significantly reduce the life of your tooling; in fact, you will probably dull more drilling the 2 holes than cutting the entire piece. If you do not have drill heads to take advantage of European type boring bits, turn the RPM down as low as possible, 4-5000 RPM at most, and plunge as fast as possible, an upshear will help to remove the chips if hold down is not a problem. On deep holes “pecking” can sometimes help.
• Small parts and scrap pieces can become projectiles if left after the cutting process without sufficient hold down. They can also be sucked into the dust collector and cause a blockage. Skin cutting and the use of tabs can help to hold small parts.
• Over-tightening of the collet and collet nut is a common mistake. Most operators assume that the tighter the better – this is not true and can lead to premature tool and collet wear and tool breakage. Collets are the most misunderstood and overlooked part of the CNC, often the cause of poor finish, short tool life, and unnecessary machine wear. Collets are made of spring steel and are subject to distortion when put under undue pressure. It is highly recommended that collets be tightened to manufacturers’ specifications with the use of a torque wrench
• Fires, yes it happens. A tool left in the same place for a sufficient amount of time can and will start a fire. It is important never to leave a CNC running without an operator; you wouldn’t believe how fast things can go wrong. The dust collection system and the vacuum system will aid in the fires speedy travel. If this ever happens to you, beware of flash-back when the vacuum is turned off. When it is safe to do so, it is important to remove and examine the bleeder board and table underneath, embers can remain and once again flair up.

Check out our free CNC Manual available at EOASAW.com!

You may also be interested in reading other excerpts from our CNC Manual: Router Bit Tool Geometry, Tool Materials and Their Uses, Factors To Be Considered Before Selecting Your Tool, and Collets & Tool Holders Maintenance.
Factors To Be Considered Before Selecting Your Tool
March 1, 2021 4:52 pm Comments Off on Factors To Be Considered Before Selecting Your Tool
CNC Router Accessories

Many factors need to be considered when evaluating any cutting situation, before selecting a tool. You can find more useful information in our FREE CNC Manual available for download on our site!
- What is the desired finish? Chip-free, hidden part, some minor chips ok, etc. Are both sides (top, bottom) of material of equal importance? The desired finish will often dictate not only what type of tool we can use but also how fast we can cut and whether we must make multiple passes.
- Which is more important, speed or finish? While striving for both, sometimes we must assign priorities or make compromises. Higher quality finish can mean higher machining costs (multiple passes, use of more expensive tooling, slower feed rates, etc.). However, ironically, most people run their tools at too slow a feed rate at too high of a RPM, resulting in heat buildup and premature tool wear.
- What are the machines capabilities and limitations? It is important to know your CNC’s capabilities and limitations. If your machine’s top feed speed is 600 IPM as opposed to a machine capable of feed speeds of 1200 IPM, your tool selection and setup will be quite different. It is important to note here that just because your machine is capable of running at 3400 IPM does not mean you can cut at that rate. When programming any cut for the first time, it is important to ascertain at what feed that part is to be cut. Part size or geometry alone may preclude you from running more than a few hundred IPM.
- Do you have sufficient ability to hold the material you are cutting? If you can’t hold it, you can’t cut it. This is one of the most common problems that I encounter. I am continually amazed how many people will accept minimal feed rates and quality because of chatter and movement. Your ability to make a clean fast cut is related to your ability to hold the material firmly without vibration. Insufficient hold-down can be responsible for everything from premature tool wear and breakage to sub-standard parts, chatter marks, chipping, and material movement. A little planning and effort will give you huge payoffs in productivity and cost savings. When purchasing a CNC router, don’t skimp on the vacuum system. I have never met anyone who said they had too much.
- What is the material you are cutting? Raw particle board, plywood, MDF, single-sided laminate, double-sided laminate, etc. Different materials have different cutting properties and may restrict your tool selection and will often dictate geometries, feed, speed, etc.
- Are there any operations after this one that will cover, conceal, or change the shape of the part being cut? For example, the top edge will be rounded over or the edge will be covered in such a manner so that a small chip would be of no importance.
- Is exact size important? Does another part rely on the accuracy of this part? Maintaining exacting measurements may require multiple passes after a tool is serviced or if the size is non-standard. Edge of Arlington offers insert and diamond tooling designed to solve these types of problems.
  Free! CNC Manual
- Part configuration and size are important considerations. Small parts can be hard to hold. Intricate parts, parts with holes, curves, and short cuts can be challenging due to heat generated because of a machinery’s inability to make instantaneous speed and directional changes. Advances in machine capabilities have greatly improved the speeds associated with travel time and the ability to change direction. However, a bit turning at 18,000 RPM still turns at 300 inches per second and a good Boy Scout can start a campfire with a stick at a much lower RPM.
For more, refer to our CNC Manual.

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