Changing Products With Higher Quality And Productivity
Advanced Secondaries Inc. has an unusual position in the marketplace. By making specials from standard screw machine parts or cold-headed parts for the past 30 years, this company has found its comfortable niche.
Advanced Secondaries Inc. has an unusual position in the marketplace. As owner Don Nicholson said, “We really don’t produce anything. We change it.” By making specials from standard screw machine parts or cold-headed parts for the past 30 years, this company has found its comfortable niche.
In a 150-year-old building that started out as a brewery in downtown Cleveland, Ohio, the company primarily does drilling and tapping using automated drilling heads and turning operations to make changes to parts. This business started 40 years ago as an aircraft parts secondary-hole operation. If a customer needed secondary holes drilled in the head for the aircraft fastener industry, the company did the job. Then, it went after cotter pins on bolts, but Lock-Tite took a big chunk of that business. Next, the company went into tapping operations, doing much of it for stamping companies. “But most of our business is for the cold-heading and fastener supply industry that uses mild steels,” Mr. Nicholson remarked. “Somebody sells a fastener or a box of fasteners, but needs something special done to them. Whether it’s a hole in the shank or the knurl on the allen cap screw turned off for a smooth finish, we’ll do it.”
These types of jobs can come in one at a time or 70,000 per week. They keep the company going, but have also led to some quality problems along the way.
A while ago a customer called Advanced and asked them to do changes to 5,000 bolts a week. They put the bolt in a fixture, clamped it and drilled it with an automated drill head. However, in this case, the drill was turning (not the part), and there was a TIR quality issue. Also, the operator had to make sure the part was in the right location for countersinking, and it had to be tapped. From these operations other quality problems arose, and Mr. Nicholson needed to find a better way to produce the parts. To resolve the issues, he bought an OmniTurn GT-Jr. lathe made by Richlin Machinery, Inc. (Farmingdale, New York). Because of how the part is clamped in the machine, the actual cycle time is a bit slower with the lathe. However, it comes out of the machine finished, requiring no secondary operations that could cause other quality issues because of tolerance stack ups.
Mr. Nicholson remarked, “The part’s quality more than justifies having a longer cycle time. Over the course of the day, we’re probably only talking about 200 pieces of lost production. Also, we often had to have a setup man at the drill heads for crashes or tool breaks, and after a crash or broken tool, the fixture or the drill head could move. Then, everything would be off center and the parts scrap until we could get the drill head or fixture set up properly. With the OmniTurn, if a drill breaks, and it will happen, the operator replaces it. As long as they know there were no major problems, they’re right back producing parts again. You’re turning 0.001 inch to 0.003 inch TIR, depending on how the part is in the collet, because we’re talking about cold-headed parts. With the OmniTurn, a setup person doesn’t have to stand around playing with the equipment.”
Mr. Nicholson looked at other competitive lathes to solve the quality issues with the original job. He mentioned that he tries to only buy American-made machines, which limits his choices. However, the OmniTurn worked so well for him that he eventually bought three more. Two of them he has placed in a work cell that can be easily tended by one operator, so he feels that he can double his work output with the same labor he used previously. “It’s like getting parts off the second machine free,” he remarked.
Mr. Nicholson also said purchasing the other three machines was a way to stay competitive and take care of his customers. He stated that with secondary work, he never knows when a job will come in. If it’s a large job, he has to hire extra help, and it could only be for a day or for months at a time. “It was either buy the machines or have customers say, ‘We can’t send it to Advanced because they take too long to produce it.’ Now, when these rush jobs hit my desk at a moment’s notice, I have some flexibility to produce them without getting my customers upset.”
OmniTurn’s GT-Jr. is a gang-tool-style lathe that can easily handle up to eight tools. With special tooling, it can increase the number of operations beyond eight. Travel in the X axis is 12 inches with the Y axis at 9 inches. Rapid travel is 300 ipm with a feed rate of 300 ipm. Precision linear guides are used with zero-backlash ballscrews. The lathe’s frame is composed of an MJ7 composite casting with a cast iron headstock. It offers a 5-hp spindle with 4,000 rpm (6,000 optional). The CNC control is PC-based with special software developed by the company for ease of programming using industry standard G codes. It offers toolpath graphic verification and a word processor program editor. A bar feeder can easily be added to it. With its sturdy frame, the OmniTurn does not require a special foundation. A 4-inch garage floor is sufficient.
Mr. Nicholson mentioned that the gang-style tooling is perfect for his jobs. He has plenty of room for tools, they are easy to change out, and the machine’s overall complexity is reduced without the maintenance demands of a turret or toolchanger.
He added, “All the jobs that I machine are smaller than 1 inch OD and 4 inches or less in length. Most of them are in mild steel. This is our envelope.” According to Mr. Nicholson, programming is easy with the PC-based CNC. Although it’s not conversational, it offers canned program cycles. It can also interface with other programming software. Programming can be done offline on a PC and downloaded with a disk or through an Ethernet.
Hard turning isn’t hard to do. However, it does require an understanding of the process dynamics and a systematic approach to the tooling involved. This article looks at how proper preparation will deliver consistent, predictable hard-turning results.
From watch parts to exotic medical applications, this shop takes on the world of micromachining.
Workholding for turning is usually fairly basic: The selection comes down to chucks or collets. This article looks at when to consider the collet chuck and what kind might be best for a given application.