There are two distinct ways to cut materials when CNC milling: Conventional Milling (Up) and Climb Milling (Down). The difference between these two techniques is the relationship of the rotation of the cutter to the direction of feed. In Conventional Milling, the cutter rotates against the direction of the feed. During Climb Milling, the cutter rotates with the feed.

With more modern machines now compensating for backlash or utilize backlash eliminators, it has become a much easier strategy to adopt within shops. While we went over some reasons why climb milling is not an effective strategy above, here are some reasons why a machinist may want to explore climb milling:

2. RC-1142 and RC-1102 – These are both the Insert Carbide 90° v-groove bit, the RC-1142 has a 1/4″ shank while the RC-1102 has a 1/2″ shank, other than that they are the same.  This bit is truly amazing, it can handle small and large details without plunging too deep into your material.  This is definitely my go to bit when doing any sort of V-Carving.

Added uses for conventional cutting: Never climb cut across the end of an upstanding thin rib in aluminum or plastic (You will rip it off). Use reduced feed and conventional cut it or use multiple small depth cuts. Commonly made cutting to length T or L extrusions. You’ll only make this mistake once. It helps to conventional cut torched or burnt out steel plate rough profiles first, then switch to climb cut after you mill through the slag. Same principal as case hardened material. Corn-Cob or serrated cutters work nice here too.

Step millingmachine

“Conventional Milling should be… utilized on casting, forgings” In my head, I logically organize castings as least processed, forgings as most processed, and everything else (hot rolled, cold rolled, extruded) somewhere in between. So to me, that part seems to say ‘use conventional milling for everything’, which is obviously not right. Could you show me where I went wrong,? More specific examples, like case hardening, why a particular direction of cut is preferred for a chunk of metal with unknown provenance.

Great question Graham! There are many factors that go into choosing which method is best for you. Please send an email to [email protected] with all your information and they will be able to help you out as soon as possible.

4. AMS-119 – This 3-Pc set includes the 46202-K 1/4″ down cut, 46200-K 1/8″ down cut and a long lasting RC-1148 60° Insert Carbide v-groove bit.  This is a set that I put together to be a cost effective way to get 3 bits that will allow you to make 85% of the things you’ll want to make when first getting into CNC work.  The 1/4″ bit handles any large pocketing or profile cutting, the 1/8″ bit handles detail pocketing or more detailed profile work, while the 60° v-groove bit handles any v-carving you may want to do.  This is definitely the cost effective set you want to start with when just getting into the CNC world!

In addition, conventional milling should also be utilized on casting, forgings or when the part is case hardened. This is due to the cut beginning under the surface of the material, where it will gradually build a chip. Climb milling into these materials will see maximum chip thickness on engagement, which could lead to premature failure of the cutting edge due to the forces generated. print

Have seen this article several times. One consideration is roughing, my observation is that the load against the cutter when cutting in the conventional direction is lower and reduces the risk of tool breakage. Another is where the tool-paths leave “posts” in corners and so-fourth when hogging out parts, conventional milling will not grab into a post and break the cutter. Another application is when making long thin flats in rod shaped parts either on a indexing head or on a swiss type automatic lathe through a guide bushing, the conventional path will produce less taper and more parallel surfaces. Just a few thoughts.

Millingprocess

As machinists are always trying to find ways to increase efficiency and tool life, climb milling has gotten a lot of recent traction in the space. Less heat is generated within the tool, and friction is more easily mitigated. These two alone lead to longer tool life, allowing for more parts completed per tool, lowering a shops bottom line. Also, climb milling can lead to a better surface finish due to how the chips are formed at the cutting edge.

Great article. I’ve had to use conventional milling when for example, I’d have my thin unsupported part sticking out of work holding with the tool path contouring around the part (think milling end while cutting a part in a lathe) with the material flexing would cause snapping while climbing because it wants to take a large bite as opposed to ramping the cut in. But yeah, 95% or more is climbing.

Thank you for the question Dustin! We would suggest conventional milling when your material has a rough surface, such as cast iron, or is anodized because when conventional milling your cut is scooping underneath the surface to remove your material making it easier on your tool. Also, you want to conventional mill when using a dovetail cutter that has a weak neck diameter because this will help relieve the pressure on the neck of your tool.

I have a Warco 16B milling machine. This is a medium size manual hobby mill. I am confused as people recommend Conventional and Climb milling in about even numbers, this goes for YouTube too. What would you recommend on this type of machine? Your help would be appreciated as I last worked in industry in 1979 so I am extremely out of date. I generally mill Conventionally.

There are many different types of CNC Bits used to cut wood, but Toolstoday’s Matt Plumlee is going to break it down to the 5 most essential bits or bit sets you need for your CNC machine.

It depends on your perspective. Are they showing a view looking down at the work piece or looking up from the workpiece.

Step millingtools

Millingmachine

A 60 year old worn out manual Bridgeport is all I have to work with. (It is in better shape than my 65 year old worn out body.) I rarely climb mill anything, specially not steel. But if the cut is really light, and I want a good finish, I climb mill. , I apply some drag with the table lock screw, and that seems to eliminate the chatter.

ManualMillingMachine for sale

That is not to say there aren’t benefits to climb milling. For example, this strategy offers a machinist more control and less vibration than its climb milling counterpart. Similarly, for materials that traditionally chatter or tear, conventional milling would be the proper strategy to choose. On the other hand, here are some reasons why it might be most beneficial to adopt a climb milling strategy:

However, though Climb Milling is often the current preferred way to machine parts, there are times when Conventional Milling is the necessary milling style. One such example is if your machine does not counteract backlash. In this case, Conventional Milling should be implemented. Without accounting for backlash, breakage can occur due to the forces within the machine during tool engagement.

Conventional Milling is the traditional approach when cutting because the backlash, or the play between the lead screw and the nut in the machine table, is eliminated as seen in Figure 1 below. Recently, however, Climb Milling has been recognized as the preferred way to approach a workpiece since most machines today compensate for backlash or have a backlash eliminator.

I like what you said about chip width working. I need a milling machine for some steel. I’ll have to get a dye-cutter that is discounted.

There can only be one way to interpret the cut because machines only turn in one direction. In the examples the view has to be from under the workpiece looking up at the tool

Types ofmillingprocess

Step millingtechniques

This is great info. I have always conventional milled with face mill to remove the scale off of titanium. Tool life is increased and getting under that scale to machine it off instead of slamming the insert into the scale each time. Once scale has been removed, go back to climb cutting.

As previously stated, traditionally conventional milling has been the common choice for most machinists. This is where the cutting edge of the tool is actually rotating away from the direction of the feed. An example of this is seen in Figure 2 below. Until recently, this has been the common choice due to backlash however, the rise of climb milling has caused machinists or machines to adapt and compensate for this issue.

Sign up to receive a monthly recap of: – The latest machining solutions – Machining tips and tricks – A recap of our most popular posts

I think you left out force vectors during cutting. This can influence tool defection and taper on the side wall on the part. The force vectors are different magnitudes between climb and convectional cutting, so this impacts work holding and this parts or this walls.

This is one of those left hand cutters! How about turning the tool, and cutter the correct direction. G41 climb cutting on the right side. G42 or conventional cutting on the left. Sorry I couldn’t help myself.

Thanks for this very clear and informative explanation. It has been decades since I worked in a factory. Back then the Bridgeport milling machines had terrible backlash. They would chatter or jump when using climb milling. Plus, if one was approaching the end of a cut, one wouldn’t know if the tool would grab at that point and pull the work past the past the desired end point. I almost exclusively used conventional milling and couldn’t understand why many people on YT now talk about using climb milling.

3. Flattening Bit – If you have a machine that will only take up to 1/4″ Shank bits the RC-2265 is the bit for you, if you have a machine that can take a 1/2″ shank the RC-2255 is the one you want!  Whether you’re just flattening your wasteboard or flattening a slab, these bits will always give you super clean results.  With the 3 wing replaceable carbide insert design, they will last you a very long time; each insert can be rotated to get 4 new cutting edges out of a single insert!

In conclusion, we hope that this has helped you decide which wood cutting bits are most important to buy when getting started with a CNC.  We are confident that you will see great results with all bits listed here, just read the reviews on them, you won’t be disappointed!

ManualMilling

Hey there, first of all thank you so much for this post and honestly I was searching for the same information from last few days. Keep posting and keep sharing..

Climb Milling is generally the best way to machine parts today since it reduces the load from the cutting edge, leaves a better surface finish, and improves tool life. During Conventional Milling, the cutter tends to dig into the workpiece and may cause the part to be cut out of tolerance.

5. AMS-177-K – This 8-Pc set includes 45704 90° v-groove, 45705 60° v-groove, 56125 1/8″ radius point roundover, 46376-K 1/4″ diameter ball nose, 46282-K 1/16″ diameter tapered ball nose, 46102-K 1/4″ up cut, 46202-K 1/4″ down cut and 46200-K 1/8″ down cut bit.  This set brings a lot of value for someone just getting into CNC work and will cover many of the projects you will want to make.  This set will cover you from doing some simple profile cuts, detailed pockets, v-carving signs all the way up to doing 3-D designs.  It’s definitely a great well rounded set and one you would really enjoy!

1. 46202-K – No matter the size of your machine a 1/4″ down cut bit like this one will likely be one of your most used bits.  The down cutting action of this bit means that it will leave a clean, chip and tear out free top surface making it perfect for through cuts or pocketing out material.  The size of the bit works well for nesting items as well since it’s not removing as much material as larger bits would.  This bit is definitely a must have!

Top 5 Essential CNC Router Bits for Wood Router Bits June 16th, 2023 3 minute read Listen to article 1x 00:00 Audio generated by DropInBlog's Blog Voice AI™ may have slight pronunciation nuances. Learn more There are many different types of CNC Bits used to cut wood, but Toolstoday’s Matt Plumlee is going to break it down to the 5 most essential bits or bit sets you need for your CNC machine. 1. 46202-K – No matter the size of your machine a 1/4″ down cut bit like this one will likely be one of your most used bits.  The down cutting action of this bit means that it will leave a clean, chip and tear out free top surface making it perfect for through cuts or pocketing out material.  The size of the bit works well for nesting items as well since it’s not removing as much material as larger bits would.  This bit is definitely a must have! 2. RC-1142 and RC-1102 – These are both the Insert Carbide 90° v-groove bit, the RC-1142 has a 1/4″ shank while the RC-1102 has a 1/2″ shank, other than that they are the same.  This bit is truly amazing, it can handle small and large details without plunging too deep into your material.  This is definitely my go to bit when doing any sort of V-Carving. 3. Flattening Bit – If you have a machine that will only take up to 1/4″ Shank bits the RC-2265 is the bit for you, if you have a machine that can take a 1/2″ shank the RC-2255 is the one you want!  Whether you’re just flattening your wasteboard or flattening a slab, these bits will always give you super clean results.  With the 3 wing replaceable carbide insert design, they will last you a very long time; each insert can be rotated to get 4 new cutting edges out of a single insert! 4. AMS-119 – This 3-Pc set includes the 46202-K 1/4″ down cut, 46200-K 1/8″ down cut and a long lasting RC-1148 60° Insert Carbide v-groove bit.  This is a set that I put together to be a cost effective way to get 3 bits that will allow you to make 85% of the things you’ll want to make when first getting into CNC work.  The 1/4″ bit handles any large pocketing or profile cutting, the 1/8″ bit handles detail pocketing or more detailed profile work, while the 60° v-groove bit handles any v-carving you may want to do.  This is definitely the cost effective set you want to start with when just getting into the CNC world! 5. AMS-177-K – This 8-Pc set includes 45704 90° v-groove, 45705 60° v-groove, 56125 1/8″ radius point roundover, 46376-K 1/4″ diameter ball nose, 46282-K 1/16″ diameter tapered ball nose, 46102-K 1/4″ up cut, 46202-K 1/4″ down cut and 46200-K 1/8″ down cut bit.  This set brings a lot of value for someone just getting into CNC work and will cover many of the projects you will want to make.  This set will cover you from doing some simple profile cuts, detailed pockets, v-carving signs all the way up to doing 3-D designs.  It’s definitely a great well rounded set and one you would really enjoy! In conclusion, we hope that this has helped you decide which wood cutting bits are most important to buy when getting started with a CNC.  We are confident that you will see great results with all bits listed here, just read the reviews on them, you won’t be disappointed! « Back to Articles Related Articles Choosing the Right Router Bit for Your CNC 3 minute read June 13th, 2023 Router Bit Maintenance Tips: How to Keep Your Bits Sharp 8 minute read June 23rd, 2023 Top 5 Essential Woodworking Router Bits 3 minute read June 2nd, 2023

Great explanation of the differences between climb milling and conventional milling! I appreciate how you highlighted the advantages of climb milling, especially in reducing tool wear. It’s very informative for someone looking to refine their machining techniques. Thanks for sharing!