Click image to enlarge

Quebec machine shop's focus on complex, tight tolerance work calls for high-end toolholding

As a shop serving the aerospace, defense and high-tech industries, APN Inc., Quebec City, QC, must provide customers with parts that are as close to perfect as possible. Extremely complex, high precision and difficult-to-machine components are APN's specialty. Key to producing such parts to the highest industry standards, as well as faster and more accurately than the competition, is the shop's expertise in high speed, high performance three axis and five axis milling. 

APN has been in business for 42 years and currently has 28 CNC machines, including two high speed three axis machines and five high speed five axis machines. The ISO 9001:2008 and AS 9100-C certified shop has had these machines for some time, but only recently discovered how critical toolholder selection is for such machine tools. 

According to Yves Proteau, vice president of APN, the 100-employee shop always knew high speed, high performance machining required very high precision toolholding. And when the shop first incorporated high speed machining, it relied on shrinkfit toolholding and other standard ER collet holders. The shop "soon realized such toolholding was not proving repeatable enough nor consistent in its performance, especially in the case of holding smaller diameter tools," says Proteau.

These problems, according to Proteau, stemmed from poor holder balance. The shop decided to test a different toolholding system, the Rego-Fix powRgrip, that operates mechanically as opposed to using heat.

"We immediately liked the system because it did not use heat," says Proteau. "But most importantly, we were drawn to the system's extremely high repeatability and balance."  

Short machine setup times are also critical to APN for meeting job delivery times. According to Proteau, the powRgrip holders contribute significantly to shorter overall machine setup times by providing faster tooling set up. Removing a tool from a holder and installing another, for example, takes approximately 10 seconds. The shop's shrinkfit holders, on the other hand, must be heated, the cutter installed, then cooled before the tool can be used. 

APN has one powRgrip tool-changing unit and over 150 powRgrip holders that make up about 60 per cent of the shop's entire tooling. "When we add new machines, we typically add about 40 new powRgrip holders along with it," said Proteau. "Currently, 80 per cent of the tooling we have been purchasing, whether holders or collets, has been Rego-Fix."

APN's powRgrip holders are HSK 63–the shortest length being 3.149 in. (80 mm), the longest 7.875 in. (200 mm)–with 10, 15 and 25 collet sizes. The most beneficial feature is that the toolholders accurately and securely hold tools with shank diameters as small as 0.008 in. (0.203 mm), a tool diameter size that would be tough to hold using shrinkfit tooling.

All of APN's high speed, high performance milling machines now run either powRgrip holders or ER collets. The shop still uses some shrinkfit holders, but only for a few applications involving large diameter tools and other machines. The reason, according to Proteau, is that since the shop had already purchased the shrinkfit holders and heating unit, it would still like to get some return from that investment.

"In our high speed machining operations, we use a lot of smaller tools as well as longer ones. If we had initially incorporated the Rego-Fix powRgrip system for these machines, we likely would have never used any other toolholding system," says Proteau.

Tool sizes at APN are typically 0.1875 in. (4.8 mm), 0.125 in. (3.1 mm) or 0.250 in. (6.35 mm) in diameter, and some of its drills measure down around 0.015 in. (0.381 mm) in diameter. These tiny drills are secured in powRgrip holders with coolant-through-style Rego-Fix ER collets.

Aerospace workpiece materials at APN range from stainless steels, tool steels, Inconels and titanium to copper, plastic and a host of others. Required machining tolerances for most parts are typically 0.0005 in. (0.012 mm), but some can be as tight as 0.0002 in. (0.005 mm). The majority, about 75 per cent, of workpieces measure less than 3 in. sq, and 50 per cent of those are smaller than 1 in. sq. However, on occasion, some measure up to 12 in. sq. 

Job lot sizes vary from five to as many as 1,000 pieces, and the average is about 20. Half of these are regularly scheduled jobs/orders, while the other half are first-run jobs. At any given time, APN can be processing as many as 500 different jobs at one time.

In its three axis and five axis milling operations, APN typically machines parts using fast, light, high speed cuts at spindle speeds applicable to workpiece material and the size of the cutter being used. The shop's three axis milling machines have 18,000 rpm spindles, while the five axis machines have spindles with maximum speeds up to 24,000 rpm. 

When machining with a 0.500 in. diameter cutter in stainless steel, for instance, APN will run at the applicable spindle speeds. However, when it comes to machining aluminum parts, the shop typically runs spindles at maximum speeds. These operations require perfectly balanced toolholding.

When the shop first experienced balance problems with its shrinkfit holders, purchasing a balancing system was considered. That was right around the time when APN decided
to test Rego-Fix holders. 

"We may have benefited from a tool balancing system," commented Proteau. "However, since incorporating the powRgrip holders, the decision to purchase one has been postponed. We no longer see the need for such a system at this time. Our part precision is better than ever, and we no longer experience issues stemming from unbalanced toolholding."

APN situated its powRgrip tool-changing unit near the high speed, high performance machines that use the holders. The machines are arranged in cells, and one employee is in charge of setting up the Rego-Fix tooling. However, all of the shop's machinists know the system and will change their own tooling if necessary. Or, in the case of a part with a long unattended cycle time, a machinist might prepare powRgrip tooling for the other machines while his machine runs on its own.

"After about a week with the system, all our machinists were quite comfortable with changing out tooling using the powRgrip unit. The system is easy to operate and is safe because there is no heat involved," explains Proteau. 

After experiencing the benefits of the powRgrip system, Proteau says the toolholding contributes significantly to one of APN's competitive advantages: the ability to process extremely complex difficult parts, and do so using high speed, high performance machine tools. SMT

APN Inc.

Eego Fix


Machining advanced composites

Lighter and stronger than ever, the new breed of carbon fiber reinforced plastics (CFRP) and laminates are elevating performance levels in applications ranging from downhill skis and tennis rackets to military aircraft and automobiles. Composites technology can help automakers reach their lightweighting goals faster than carbon fiber-reinforced plastics.

Iscar: High speed face milling cutters

Iscar Tool's latest innovations includes new adjustable-pocket face mills in the Alutang family, designed to carry primarily PCD or PCBN tipped inserts for use on cast iron, hardened steel, aluminum or any other non-metallic materials.

In the groove

by Jim Barnes

Focus on the basics for profitable and productive grooving

Grooving is a well-established machining operation, but that does not mean everyone does it as efficiently as possible. Especially in the current economic environment, people may not be paying enough attention to the details.

Sandvik adds more shapes to newest insert grades

Sandvik Coromant has updated its GC4415 and GC4425 steel turning grades with more insert shapes, making them ideal for manufacturers operating in mass and batch production set-ups.

OPEN LETTER COVID-19: Impact on the Aerospace Industry

We are at a critical point in the history of our sector and country

Iscar creates new complex shape for indexable insert

Cemented carbide indexable inserts are an integral part of cutting tools today. Progress on manufacturing technology and design methods has led to important breakthroughs in the production of indexable inserts, says Iscar in this white paper.

Circle segment milling cutters

Walter has introduced two solid carbide circle segment milling cutters, the MD838 Supreme (conical) and the MD839 (tangential) Supreme.

Faster moves

by Jim Barnes

New technology improves tool life and cycle times

Live Tooling Productivity

Getting the most from your lathe live tooling

Skills Training: The Missing Sizzle

If Brian Philip could change education in manufacturing in secondary and post secondary institutions, he would add the missing “sizzle” to the steak.

Automotive Enablers

by Kip Hanson

Competing in today’s automotive market requires high performance tooling

Job Shops Alberta - Growth by Design

by Mary Scianna

Strategy and hard work a winning combination for growing job shop

Rock hard

New generation of tougher cutting tools for hard metals

by Tim Wilson

In the world of cutting tools, hard metals don’t have to be hard-to-cut metals.

Cutting Tool Tips: When to Use Coolants

Coolant can be an effective way to cool a cutting tool, help expel the chip and prevent built up edge.

Cutting Tools: Milling better moulds

The Problem: Improve machining efficiencies

The Solution: High feed milling tools

Ontario mould shop improves productivity using new high feed milling tools

Stay In Touch

twitter facebook linkedIn