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Amarillo Gear Company (Amarillo, Texas) specializes in manufacturing right angle gear drives, spiral bevel gears up to 100-inch diameters, double reduction gear drives and fan drives.
Facing a backlog on their Cincinnati and LeBlond vertical machining centers, the company was looking for a more efficient way to cut the keyways of the different sizes of shafts for the gear drive units. The shafts are made out of various alloy and stainless steels. The company’s tooling was not performing well; it was unable to run the speed and feed needed to produce the parts in a timely manner. Tool life was short, resulting in continual tool change out, machine downtime and a large tooling inventory.
James Baker of Amarillo Gear attended a Milling Technical Training Seminar. “At the seminar, I saw some impressive demonstrations of the product capabilities of Iscar’s solid carbide end mills and Helimills,” he recalls. So he decided to give the company a call.
Dennis Vestal, an Iscar (Arlington, Texas) application specialist, brought in the appropriate tooling to run tests. After testing both Iscar and other suppliers, Amarillo Gear implemented Iscar’s Helimills for roughing the keyways and Iscar’s solid carbide end mills for finishing. On the vertical milling machines, the Helimills used to rough the keyways are running at 650 sfm and 0.004 ipt. The solid carbide end mills used to finish the keyways are running at 400 sfm, 0.004 ipt.
“Their product has given us the ability to actually run faster than we ever could before,” says Mr. Baker. “We actually have been able to realize a 50 percent increase in tool life and reduce our individual tool cost. This greatly reduces our overall cost, if we are actually using fewer tools and are still able to meet and beat production demands.”
Aggressively investigating other alternatives to further enhance both the roughing and finishing applications, Iscar tested the Iscar ShortIn collet chucks and ShrinkIn system.
To justify the cost of Amarillo Gear changing to these products, tool life had to be extended by 20 percent. By running the Helimills in the ShortIn collet chucks with exact size collets, feed rates were increased, improving tool life by as much as 20 percent. Because of the short projection, the new tooling also provided greater rigidity and less runout.
The ShrinkIn collets were set up in the ShortIn holders for the solid carbide end mills. Amarillo Gear was able to almost double its feed rates and achieve surface finishes as good as a 25 RMS, surpassing anything the company had previously achieved. Results went beyond the 20 percent increase in tool life needed to justify switching tooling to reach 60 percent better tool life.
Amarillo Gear has run these tools extensively for 2 years, and the company has experienced cost and time savings. On just one of the vertical milling machines running one of the shafts, the company saved 43 minutes per part, resulting in a savings of $51.48 on each part.
The ShrinkIn system is an enhancement to the existing ER system. The ShrinkIn collets use the Thermal Shrink phenomena for rigid clamping of solid carbide cutters. This system is said to provide higher torque, precision runout and better repeatability.
Among the advantages of ShortIn, according to the company, is the shortest possible overhang. Yet, the product is suitable for both regular and shrink collets. The short collets provide high gripping force, thereby reducing cutting vibrations and improving runout and repeatability. Each chuck is balanced to 2.5 G @ 20,000 rpm, has a symmetrical design for high speed machining and is cost effective. This short holder is now available for ER32 and ER40 spring and shrink collets and TG100 spring collets. These new short holders are said to provide rigidity and better cutting conditions.
Production time at Amarillo Gear has decreased by as much as a 40 hours a week. This results from the reduced cycle time and increased tool life, which have eliminated the machining backlog the company was experiencing. Amarillo Gear is now able to run one shift instead of two to meet production requirements.