Super Air Wipes Help a Swiss CNC Machine to be More Accurate

Precision Required

As machined parts require tighter tolerances, machine shops are starting to look at Swiss-type CNC machines.  These types of machines are extremely accurate and very fast in producing small parts.  But in order to reach that level of accuracy, the bar stock may have to be pre-treated by a centerless grinder.

Our customer was using Swiss-type CNC machines with guide bushings to produce a very tight-tolerance part.  Because they were using guide bushings, the outside diameter of the bar stock had to be smooth and concentric.  This helps to reduce any vibration when machining.  A centerless grinder was used to accomplish this.  The bar stock that they used was 10 feet long and it was placed into a bar feeder.  They had to grind the bar to an outer diameter of 30mm with a surface finish of 32Ra.  As they were loading the bar stock, they noticed that the surface finish was scuffed and marred.  This was enough to affect the machining process and not meet the tolerance standard.

As they reviewed the possible causes, they found that after the bar was ground, some grinding remnants were sticking to the outside of the bar.  As the rods were leaving the grinder and placed onto a roller-type conveyor, the oily film and metal shavings were sticking to the rollers.  This would scrape and mark the rods as they traveled along the conveyor toward the Swiss-type machining center.  As an attempt to remove this debris, they attached two copper tubes to blow compressed air onto the top and bottom of the bar.   Not only was this loud and inefficient, it was not effective.  They still had a dirty line along the sides of the rod that remained.  They contacted EXAIR to see if we could help them with this dilemma.

In order to get a consistent blow-off force around the entire circumference of the rod, EXAIR Air Wipes were engineered to be an ideal solution for this kind of problem.  I recommended the model 2482 Standard Air Wipe Kit.  The Standard Air Wipe is designed to blow compressed air in a 360 degree flow pattern.  This air pattern is directed at a 30 degree angle toward the center to blow the debris off of the bar stock.  The Coanda effect maximizes the entrainment of ambient air into the compressed air.  This makes the unit very efficient and powerful.  The model 2482 Standard Air Wipe has an I.D. of 2” (51mm) which gives it enough clearance for the 30mm bar stock.  It can be mounted easily near the exit of the centerless grinder to keep the grinding remnants inside the machine.  The kit includes a filter, regulator, and shim set.  The filter will remove contaminants from the compressed air system to keep from introducing any new grime and to keep the inside of the Air Wipe clean and functional.  The shim set and regulator provide the ability to adjust the air to the ideal force level and remove any debris from the surface of the bar.

Standard Air Wipe with Shim Set

As they removed their home-made copper tubes and attached the Standard Air Wipe, they noticed some great improvements.  The dark lines of debris previously along the sides of the bar stock were gone.  The surface was clean around the entire circumference of the bar.  The customer also noticed that the Standard Air Wipe was much quieter than their home-made solution, as it only has a decibel rating of 77 dBA.  As an added benefit, the Standard Air Wipe was using much less compressed air than the copper tubes.  This is due to its design to maximize the amplification ratio.  With more of the “free” ambient air than the compressed air being moved over the target area, it will save money in compressed air usage.  The ROI could be less than four months.

If you have any items that need to have a 360 degree blowing pattern, you can contact an Application Engineer at EXAIR to see if a Standard Air Wipe could work for you.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb
Picture: External-Micrometer-Screw-Gauge by Emilian Robert Vicol.  Creative Commons license

Cold Gun Provides Cooling For CNC Router

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This CNC needs a way to cool the drill and blow away chips created during machining

Precision control with CNC’s means we can achieve a near-identical output in product dimensions and quality.  And, it also means we can create an identical problem every time the machine is used.

Case in point, the CNC shown above is used to machine a 5mm piece of aluminum, but was plagued with problems preventing it from performing to its full potential.  The problem, was that when the machine would plunge into the aluminum, the plunging speed would produce excessive heat leading to a deterioration in performance and quality.  The temporary solution for such a condition is to slow down the machining speeds, but this reduces the efficiency and throughput of the machine.

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A Cold Gun can install directly onto this machine, providing cooling and light chip removal as needed

The real solution for this type of condition is to provide some sort of cooling for the drill head, and if possible, a means to remove the chips and debris from the machining area as well.  Fortunately, both of these are possible through the use of a Cold Gun Aircoolant System.

A Cold Gun in this application will provide cold air at temperatures below freezing to cool the drill, and the airflow from the Cold Gun will simultaneously clear the small chips and debris from the machining area.  And, these improvements to the application keep the workspace completely dry.  There’s no need to add a coolant collection system or to create additional work through cleaning coolant from the machined pieces once they’re complete.

If you have an application in need of a dry-cooling solution, or if you’d like to explore the possibility of removing liquid cooling from your CNC, contact an EXAIR Application Engineer.  We’ll be happy to help.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Line Vac Cleans Up a CNC Sawing Application

A machine shop facility contacted me about an issue they were having with metal chips. Their operation used CNC saw machines to cut metal products of various types and sizes to specific lengths.  They used belt conveyors that were fitting inside the CNC machines to remove the excess chips to a recycle bin.  The cut pieces were then ejected from the CNC machine for the next operation.  The issue was when they would cut tubing.  For the solid pieces, the conveyors inside the CNC machines would work great to remove the chips.  But with hollow stock, the inside of the tube would catch majority of the chips.  So, when the part was ejected, chips would accumulate on the outside of the CNC saw machine.

To solve this problem, I recommended a model 151150 Threaded Heavy Duty Line Vac with a model 9034 solenoid. The reason for the Heavy Duty Line Vac is because it is made of a hardened alloy that is resistant to the abrasion of the metal chips.  The 1 ½” NPT threaded ends made it easy to attach rigid pipe to both ends.  The vacuum end would remove the chips from inside the tube, and the transfer end would send the chips to the recycle bin.  Also, with the controls on the CNC machine, the user could send a signal to the solenoid valve to only operate during cutting operations.  (An added benefit to save on compressed air.)  In his setup, we attached the Heavy Duty Line Vac to the CNC saw machine.  It would ride along with the motion of the saw.  As the saw was cutting, the Heavy Duty Line Vac vacuumed the chips from inside of the tube.  As the saw blade retracted, the Heavy Duty Line Vac would retract as well.  This opened the area for the part to be ejected except now there were no chips accumulating outside of the machine.

Heavy Duty Line Vac
Heavy Duty Line Vac

Keeping work areas clean and recovering debris as it is produced results in a more efficient process and a safer environment. If you every need to bounce some ideas for solving problems like with the customer above, you can always contact an Application Engineer to see if we can help you resolve the issue.

John Ball
Application Engineer
Email: johnball@exair.com
1-800-903-9247
Twitter: @EXAIR_JB

Stories from the past

When I was fresh out of college with very little idea of what I wanted in a career or a job, I landed a job in the machine tool industry.  This was for a small company that was a master distributor of CNC metal-cutting machines.  The job title I had was, Product Specialist.  This job encompassed everything from unloading the machine from the truck, inspecting the machine, adding options / customizing the machine if needed, testing, packaging, and shipping the machine.  I would then go to the customers site, install, test again, train the staff there and then provide on-site and over-the-phone technical support and warranty work.  As the business evolved, the requirements grew and more responsibilities were added.

One of the best parts of the job was trade shows.   It was always hectic, but to see something come together in a small amount of time and see the finished product always made you feel good.   The largest show I would travel to was IMTS, which just happens to be going on in another month.  This is the largest machine technology show in the states.  I would always be running a machine cutting some kind of trinket or sample part.  The main piece I was cutting my first year there was a light bulb out of aluminum.

As my knowledge of the machinery grew, I came to realize the part wasn’t that complicated but it still amazes me to this day.

A lot of our products here at EXAIR do the same thing to people who have never encountered them.  They are absolutely amazed by the Cold Gun’s ability to drop your compressed air temperature by 50° F while having no internal moving parts and only using compressed air.  Just today, I had a customer come in for a demonstration and couldn’t believe he had been struggling with a heat problem for so many years when we were right down the highway from him.

So if you have an application that is impeding your process, or if you have an interesting use for some of our products don’t hesitate to contact us.  Maybe even stop over at our Facebook page and drop us a note or some pictures.  You might be surprised at what you get in return.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF