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

Heavy Duty Dry Vac is a Perfect Fit for This Application

A milling company contacted me for help to improve their scrapping operations.  They had 8 machining stations that were used to machine cast iron.  The chips were removed from the machines by a conveying system and dumped into a wheel barrel next to each machine.  Throughout the day, the CNC operator would have to remove the wheel barrel to the scrap recycling area.  The operator would then shovel the chips from the wheel barrel into 55 gallon drums for storage.  The company had concerns with safety ergonomics, and they wanted to improve the efficiency of the operation.

I suggested the Heavy Duty Dry Vac.  The vacuum generator is made from a hardened steel construction which is very resistant to wear.  It has a higher vacuum level to pick up heavier material at a faster rate.  With the cast iron chips having a bulk density between 130 – 200 lb/ft^3 (2082 – 3204 Kg/m^3), this was the right tool for the right application.  He purchased the model 6297, the Deluxe Heavy Duty Dry Vac System.  It included the 55 gallon lid vacuum system, heavy duty aluminum tools, drum dolly, 10 foot (3 meter) anti-static vacuum hose, and 20 foot (6.1 meter) compressed air hose.  Now, with their new product and new procedure, the CNC operator was able to place the Heavy Duty Dry Vac lid system onto a 55 gallon open drum, turn the unit on, and vacuum the cast iron chips from the wheel barrel.  Once the drum was full, he could swap lids to an empty drum to repeat the operation.

Heavy Duty Dry Vac in operation
Heavy Duty Dry Vac in operation

EXAIR was able to address both concerns.  It was faster, saving them down time and improving operation efficiency; and, it was safer, eliminating the need to shovel and improving health ergonomics.  Because of the wide range of products that EXAIR offers, we can help you with saving money and overall safety.  If you would like to discuss any of your issues with our Application Engineers, you can contact us at your convenience.

John Ball
Application Engineer
email: johnball@exair.com
Twitter: @EXAIR_jb

Vac-u-Gun Improves Valve Cover Machining Operation

A machine shop called looking for a way to vacuum the scrap aluminum chips from their valve cover machining process. They were considering using a Line Vac Air Operated Conveyor to remove the chips, but preferred something hand held, so I recommended our Model # 6192, Vac-u-Gun Collection System.

Vac-u-Gun 6192
Model # 6192 Collection System includes Vac-u-Gun, reusable collection bag, extension wands and tools.

 

The Vac-u-Gun incorporates a nozzle insert where the orientation can be changed, allowing the unit to be used as a vacuum or a blow gun. Using the unit in vacuum mode would allow them to remove the chips and deposit them in the reusable collection bag (included with the system), rather than blow them in an undesired location in the shop. They could then change the direction of the insert and convert the unit to an air gun and blow off any residual cutting oils from the valve cover, reducing their overall process time. Also adding to their plant’s safety as the unit is OSHA compliant per Standard 1910.242(b) for 30 psi dead end pressure (cannot be dead ended) and allowable noise exposure per Standard 29 CFR 1910.95(a).

Vac-u-Gun orientation
Change from vacuum mode to blow mode in seconds!

 

This is another solution that EXAIR had on hand ready to ship same day to fit the customer’s needs.  If you have a similar application where operators are blowing debris into unwanted areas, please give us a call at 1-800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN