Harmful Dust—How Can You Protect Yourself?

A dust collector in a milling machine—a very important feature
A very important—if not the most important—aspect of professional milling machines is the use of effective dust collection technology.
The dust produced by high-speed milling machines is practically invisible to the human eye.For example, nail technicians who work 8 hours a day without a face mask and without an effective dust extraction system inhale as much as 4 kg of dust in a single year!- provide statistics.
A lack of protection leads to lung diseases, poisoning, and allergies.
Specialists in.Podiatrists often treat patients with foot problems.It is not uncommon for the skin on the feet and the nails to harbor various germs, viruses, bacteria, and fungi.What would happen if they didn't have professional milling machines with a good dust extraction system??The spread of disease would occur without restrictions.

What Features Should a Router with a Dust Collector Have??
Of course, with the greatest possible dust-capturing capacity and an effective filter that traps even the finest dust particles.
The filter should consist of at least several layers of a special nonwoven fabric designed to capture coarse, medium, and fine dust, respectively.The latest filters of this type are manufactured in accordance with the BIA standard.The effectiveness of such filters is estimated to be between 80% and as high as 99%.These filters meet the strict requirements of European classification standards and have been certified for medical use.
Paper filters, which are becoming increasingly rare, are not very effective and are not classified as a medical device.Besides, their capacity is okay.5 times smaller than the aforementioned BIA-standard filters.

Filters Discussed.And now for the most important part—the filter’s dust-capturing capacity.

This refers to a method that involves removing as much dust as possible from the area around a running milling machine in the shortest possible time and directing it to a filter.

When it comes to the dust collection capabilities of milling machines, there are somewhat more significant differences in the technologies used by global manufacturers.

In the past, large, heavy, and fairly noisy motors were used in milling machines equipped with dust collectors.These were electric motors known as brush motors.Motors with carbon brushes had one more drawback.Specifically, they were polluting their immediate surroundings.They have never been classified as a medical device.

The first milling machine with a brushless cascade motor—called the Podolog Nova—was manufactured by RUCK in 2003.Even then, the milling machine had been classified as a medical device, and its technology had been patented.Today, after 12 years, other companies have begun to imitate the RUCK milling machine by using a similar—though not identical—brushless motor.This refers to the main motor located inside the controller housing.The motors in the handle have long been brushless motors.

Although most milling machines with dust collection systems have similar designs, there are still quite significant differences between them.
Many potential customers read the descriptions and technical specifications of individual milling machines.Just as many of them don't understand why this data isn't standardized across all milling machines and why it's so hard to understand.

Below are the units of measurement commonly found in descriptions of milling machines and their translations.

W = Watt. Electric Motor Power Unit.It merely indicates its power, but this in no way corresponds to the volume of the air-dust mixture generated during milling that is absorbed.

mbar (mBar) Millibar (Yuki, Raue) is a former unit of atmospheric pressure , used in the MKSA and CGS systems, according to Wikipedia.
This unit is not used in the latest milling machine technologies.It is also not understandable to the average customer and therefore should not be used as an indicator of the absorption of the air-dust mixture.It does not measure the air flow containing dust, but only the pressure generated by the motor..

Millimeter of water column (mm H₂O) – a non-SI unit of pressure equal to the pressure exerted by a water column one millimeter high at a temperature of 273.16 K (0 °C) under normal gravitational acceleration, according to Wikipedia.
As mentioned above, this unit is not used in the latest milling machine technologies.It is also not understandable to the average customer and therefore should not be used as an indicator of the absorption of the air-dust mixture.It does not measure the air flow containing dust, but only the pressure generated by the motor..
These units are often found in household vacuum cleaners, which currently use noisy brush motors.
Suction pressure, measured in millimeters of water column, can in practice be compared to drawing water from a glass through a straw or emptying a water tank using a submersible pump.
To illustrate the point—in practice, podiatry drills are not applied directly to the skin of the feet to “suck” it.Therefore, these values should not be expressed in units of pressure such as millibars or millimeters of water column, but rather in volumetric units—liters per minute.

l/min.= Liter per minute (RUCK, Baehr, SÜDA, Gerlach) This unit denotes the volumetric air flow rate measured per unit of time.It is converted to standard conditions at with an air inlet at, i.e., from the front part of the milling cutter blade, the so-called "handle.".

This unit represents a specific volumetric flow rate of air containing dust and corresponds to the actual value (power) of dust extraction in milling machines equipped with this function.
The higher the specified value in l/min.This makes the milling machine more efficient—it collects more dust.You could also say that it's better—it protects your health more effectively.
The latest milling machines are rated at exactly this value— l/min.
Although other milling machines are equipped with dust collectors, based on the technical data provided in their specifications (mbar, mm H₂O, watts), it is difficult or even impossible to assess their actual volumetric dust collection capacity. .

The Transition to New Technologies.
Based on observations of RUCK’s podiatry drills—their quiet operation, high performance, and, in short, optimal functionality—other manufacturers of podiatry equipment began to imitate RUCK’s drill technology.They manufacture their own milling machines using similar technology.These companies have implemented their own ideas using brushless motors/suction turbines, specifying their suction power in liters per minute.
And rightly so, because the definition clearly refers to measurements of the incoming air containing dust at the milling machine's air intake, not to the possibility of dust being drawn in by the suction turbines located inside the milling machine's control cabinet.

Why is the measurement taken at the inlet to the handle??
I'll try to explain this as simply and clearly as I can.
Air—and with it, dust—enters right at the beginning of the handle.That's where the dust is absorbed.
The efficiency of the suction turbines located inside the controller housing is always higher when measured directly at the turbine itself.
When the air being drawn in, along with dust, encounters obstacles such as the nooks and crannies of the handle, the long suction hose, and the dust filter, the suction turbines' performance drops dramatically.Therefore, the actual measurement taken at the inlet to the handle is the one that counts..
Most companies that manufacture the latest models of milling machines provide exactly this information and correctly describe it in the machine's technical specifications.

To illustrate the topic even better, I decided to conduct a test on two milling machines.At present, I consider them to be comparable in terms of top quality.
The milling machines being tested are the Baehr TEC A2000 and the RUCK PODOLOG NOVA 3.
Both milling machines were new on the day of the test.Year of manufacture: 2015.
The milling machines were set to full dust collector power, as indicated by the scale on the display.
I conducted the test using a calibrated meter (a device certified for technical compliance)..
Flow rate in liters per minute (l/min).)
The manufacturer of the Baehr Tec A2000 milling machine specifies a capacity of 1,000 (one thousand) l/min.
The manufacturer of the RUCK PODOLOG NOVA 3 milling machine lists its capacity as 280 l/min.
A discrepancy of up to +/-10% in the technical data provided by manufacturers (known as "differences") is permitted..

Test result:
Baehr Tec A2000 milling machine instead of 1,000 L/min.reaches 235 L/min. i.e., —76% less than the manufacturer's figure.
RUCK PODOLOG NOVA 3 Milling Machine instead of 280 L/min.reaches 271 L/min. i.e., —3% less than the manufacturer's stated amount.
The test showed that the RUCK PODOLOG NOVA 3 milling machine is more than 15% more efficient than the Baehr Tec A2000 milling machine.

Summary.
Given the information above, one thing must be said.Milling machines with dust collection systems are getting better and more efficient.Customers have a wide range of options in terms of both quality and price.Not everyone needs to buy the best or most expensive milling machine right away.For beginners, I suggest considering the purchase of less expensive milling machines.However, when it comes to the question of whether to buy a router with or without a dust collector, the answer is clear—YES, with a dust collector.

Also, be sure to read the product descriptions carefully for the equipment you plan to buy, and read the user manuals after you purchase them.This is very important.
And one more thing.For many customers, the most important thing is health—that is, the most effective dust absorption.For others, the number of decibels may be the most important factor.For still others, it's the size of the milling cutter, and for others, it's the price.As I always say—it’s the customer who decides whether to buy a product.All you have to do is provide him with honest and accurate descriptions.

And now, please enjoy this short video: Test of podiatry drills (link).

Author: Marek Cyrulik
Article added10.09.2015

Would you like to find out what Mr. Hellmut Ruck thinks about “wet” milling machines??
Here is a direct link to his reflections  Wet or dry?

Here's more information about milling machines: Which Milling Machine Should You Choose??– Types and Differences Among Milling Machines.