Diameter in a tool isn’t quite the same as diameter in work. The circumference, clearance, and slot dimensions in the tool all vary from the sharpness, the physical characteristics of the work you’re doing for it. In various machining operations, a lot of force and strain is exerted on the whole instrument as a cutter, which chips the material from the cutting edge. While that can sound favorable for the instruments, this procedure results in slower and more work, and increased wear, which makes it an especially unpleasant operation for the best cutters.

If we look at this scale (with reference to this blog, for the reason of which all this material can be considered infinitesimally small), it’s playing with different sized equipment. A thorough treatment of that is entirely different with the form of slotting is discussed on the next page. The tools you use here are absolutely essential to get the job done; pick only the best. Many of the recommendations will sound out of the ordinary, but they have been thoroughly studied, and checked to work better in miniature machining, and so I can guarantee you that you that you can see a marked improvement in your performance rate with this.



Use as many flutes as you can

Proper fluting is often takes into consideration the cutting tooling selection to minimize possible contamination of the cut area from leftover material from the spindle. when it comes to limited keys, you can make sure you use the least number of flutes possible Aluminum and non-ferrous jobs should be achieved with a flat mill and a 2/3 or 3 flute mill. For steel or ferrous applications, we consider a 4 flutes milling bits. Chops which leave space for chips to escape aren’t loaded in deep slots to begin with, so re-cutting the flutes won’t be as bad for the tool as they do on thinner ones.

Before you can use the equipment, you have to make the frame wider, which means greater rigidity, deflection, and core strength is required. The process of micro-slotting is not as above described is very different. Rather, we are “making a slot” Standard slotting allows one to drive a ½-inch into the component to make a complete slot! Using a smaller method, though, is impractical in respect to the complexity of the issue we’re trying to solve.

Take, for example, a.015” end mill. If we’re making a.015″ deep slot with that unit, we’ll probably take a.001″ to.002″ axial depth per pass. Since this is not a conventional slotting toolpath, chips are no longer an issue. Rigidity and core power are now important, so we must add as many flutes as possible! At smaller diameters, 4 or 5 flute tools would be a far safer choice than standard 2/3 flute tools, also in materials like aluminum. Some end users have reported that using a tool with a higher flute count increases tool life by 50 to 100 times over tools with lower flute counts and less rigidity and weight.



When slotting, choose the best corner possible

Aside from ensuring that your miniature tools have a solid core when building a slot, you should also consider your corner power. Adding a corner radius to the tooling is a perfect first step that greatly increases the tool’s corner power over a square profile tool. However, if we want the best tip geometry, we can also start using a ball nose end mill.

A ball nose end mill has the best tip of the three most common profiles. The ball nose end geometry can almost act as a high feed end mill, allowing for higher feed speeds on the light axial passes used for micro-slotting. The lead angle on the ball nose also allows for axial chip thinning, which increases tool life and decreases cycle times.


Choosing the Best Tool for Miniature Slotting Operations

Precision and precision are critical when it comes to miniature tooling, whether you’re slotting, roughing, or merely drilling a hole in a segment. In addition to the recommendations outlined above, it is critical to have a range of tooling tools available to meet your particular slotting requirements. Harvey Tool provides 5 flute end mills as small as.015” in diameter, which are ideal for slotting operations that require a stronger tool with a high flute count.

If you want to improve the power of your corners, Harvey Tool also has a large range of miniature end mills in corner radius and ball nose profiles, with hundreds of scope, length of cut, and flute count choices. Both of these tools’ speeds and feeds are also available, making programming these difficult toolpaths a little bit simpler.



To conclude, when it comes to miniature slotting, there are three main factors to consider: flute count, corner strength, and the width of the axial passes.

It is important to use a corner radius or ball nose tool and to fill the tool with as many flutes as possible. This maintains the tool’s rigidity and prevents deflection while still having superior core strength.

Take light passes with several stepdowns with your axial passes. Even at the smallest diameters, working the tool much like a high feed end mill can result in a successful slotting process.


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