How to Improve Your Chip Evacuation Strategy

Have you ever struggled with chip evacuation slowing you down or causing poor surface finishes or possibly even damaging your tools? Today, we’re diving into how to master chip evacuation. Hi, I’m Justin Wiltz, a technical sales engineer with KYOCERA. Hi, I’m Andy Greaves and I’m the East Coast applications engineer for KYOCERA SGS. Chip evacuation improves efficiency, protects tools, and delivers better quality parts. It applies to both indexable and solid round tools. Both types of tools pursue the same goals, so that is controlling the heat, managing the chip formation, improving tool life, and part quality.

But the applications can differ a little bit, right? Indexable tools are ideal for roughing and higher material removal rates in some cases, while solid round tools can excel in finishing and precision-oriented operations. Chip evacuation removes the heat from the cutting zone, which also helps prevent rapid wear, the recutting of chips, and dimensional inaccuracies. So, I also want to talk a little bit about how chip evacuation can be affected in different materials. In tougher materials like stainless steel, you know, poor chip evacuation can lead to that work hardening of that material, which makes everything more difficult the longer the longer you machine and the more cuts that you have to take.

That That also increases cutting force and tool stress. How about in softer materials, though? In ductile materials like aluminum, chips can adhere to the tool if the coolant isn’t properly applied, so the heat isn’t there and the material is effectively sticking back to the tool. How do you recognize the symptoms of poor chip evacuation? Well, some of those can include scratch marks in your workpiece material, chatter, smearing of a workpiece surface, and poor surface finish. Chips can block the cutting zone, especially in slotting or deep pocket milling.

There are several advantages to getting proper chip evacuation from the work area. Proper chip evacuation allows for higher feed rates, longer tool life, and more automation with less downtime because there’s less time for the operator to be going in there cleaning out the chips. But now let’s have a look at some of the more common principles of chip evacuation. So getting the speed and feed right are critical for chip size. Generally larger chips come from higher feed rates and are often easier to manage. However, that’s not always the case. So in heavy materials, dense materials such as molybdenum, they’re a really heavy material, getting a heavy big chip out of there can be difficult.

Sure. In aluminum it’s a completely different story. If you make too fine chips, however, though, they can clog in the cutting zone, get recut, cause jamming, and tool breakages. Another factor in in good chip evacuation has got to be coolant, the use of coolant, and the application of it. So coolant is essential for flushing out chips and preventing things like recutting of chips and tool damage. Chip adhesion can be an issue if there’s not enough lubrication from a cutting lubricant. Now what happens if you have high-pressure coolant? How what kind of advantage to that?

Now high-pressure coolant, let’s say at 1,000 PSI plus, is ideal for deep drilling and high-performance machining, but not always necessary. It’s one of those situations where the more is better. Absolutely, yeah. But not everybody has more. So not everybody has better. A lot of the times flood coolant or mist coolant or even just air blast is all people have. And in those situations, we need to get those nozzles directed directly at the cutting zone to get the air or the coolant into the cutting zone to clear those chips out of the way. On top of that, tool coatings also do provide an excellent addition to help evacuate chips.

So by reducing the friction and heat resistance of the tool, we are able to reduce the potential for chip adhesion and help get those chips out of the cutting zone and away from causing any issues. So, alongside those same benefits in the solid round tool world, let’s talk a little bit about how end users can improve their indexable insert strategies. Inserts are available with different chip breakers to help control that chip size and shape when the workpiece material and feeds and speeds can’t always be dialed in just right. Right. Tight radius chip breakers design and create small curled chips for steels where maybe a wide angle design prevents material pecking in softer materials like like aluminum.

Okay. As far as the types of inserts and where you would want to apply each, like a positive like a high rake or a sharper insert, for example, will typically reduce cutting forces which are especially useful in interrupted cuts to reduce that pressure where the insert reenters the workpiece. How does that factor into the solid tool world? So, in solid round tools, we also have chip breaker options for our cutting tools, and this really does help reduce that spindle load on the tool and help get those chips broken up into smaller pieces which helps get them evacuated, especially in deep pocketing situations.

Geometry is also critical when selecting the right tool for the job. So, when roughing, for example, you want a larger flute opening so that you can take a bigger chip and get that out of the way and evacuate. However, when finishing, we want a more rigid tool that has a more solid core preferably more flutes to get a really high quality surface finish as well. Factoring into that are also helix angles. Helix angles are the angle at which the the flute move up the end mill and drill, but we have many tools in our high performance range which include variable helix angles.

So, here the helix angle changes as it moves up and down the length of the tool, and this really helps suppress chatter, vibration, and controls the cutting forces applied to the tool. Another important feature that’s consistent between both solid round tools and indexables are through coolant designs, which can flush chips out of deep holes, pockets, slots, and other material features, prevent clogging and tool breakage. Another thing that we can take a look at is pecking in a in a drilling application. Now, for holes deeper than five times D, pecking can be an advantage when coolant pressure you might not have that 1,000 PSI or even Yeah.

3 or 500. Yep. Pecking can be an advantage there, and when high pressure isn’t available, or to help clear chips when the holes get extra deep. Mhm. And then, back into milling, we do look at adaptive tool paths to help control the chip formation and the chip distribution and evacuation. So, adaptive tool paths maintain constant cutter radial engagement of the tool. This helps keep the tool loaded up and under cutting pressure, which helps maintain tool life, but it also helps keep those chips in a consistent size being evacuated at the same rate throughout cutting cycle.

So, this is critical for areas such as slotting or high-speed machining, as I mentioned earlier, in pockets, for example. Let’s go over quickly a few final takeaways. Proper chip control manages heat, manages chip flow, and prevents machining disruptions. Also, take into consideration the whole picture, right? We need to match the tool geometry to the material that we’re making. We need to apply the right coating, and we need to make sure that the coolant is best applied for that material, so that we can get those chips cut cleanly and evacuated out the way.

As always, experimentation and optimization are key. What we want to do is get those tools into cut, dialed in, and running as efficiently as possible to maximize tool life and process capability. That’s right, András. If you guys found this video helpful, please be sure to like, subscribe, and hit that notification bell. And if you have any questions or tips that you’d like to share, please leave us a comment below. We’d love to hear your thoughts. Do you guys need help with chip evacuation or tooling challenges? Check the links in the description to contact us or find more resources.

Thanks for joining. See you guys next time on Tips and Chips. And as always, keep those chips flying.