Better Parts, Better Process

For most of us, a hobby is what we do outside work. Not so for this New York shop. With the application of multi-process machine tools, a successful metalworking business has grown from a love of radio-controlled race cars.

Article From: 1/15/2000 Modern Machine Shop,

Click Image to Enlarge

Hammad Ghuman

Hammad Ghuman holding several packages of RC car parts, which are sold directly on his website (www.1hg.com) and through retail hobby stores.

Former Design

This is an example of making something good, better. The former design is at top and new lighter weight design is at bottom.

Van Svenson

Van Svenson programs DECO 2000 at an off-line PC. The software permits running a simulation while it's being programmed for easy observation and editing.

Milling Center

We have a true milling center inside this machine," says shop founder Hammad Ghuman. The counter spindle slide assembly has X-, Z- and Y-axis motion. The Y axis allows back working tools to be laid out horizontally, rather than vertically, for better tool and chip clearance. All tools are modular, and all axes can have live tooling.

It's not unusual for a hobbyist to morph into an inventor. The natural tendency for tinkering, which defines most hobbyists, can lead to the development of new products.

Once in a while, someone comes along and develops a better process to make parts used in the hobby. And in a few cases, the hobbyist becomes so fascinated with the process that the part becomes secondary to quality engineering and production. And thus, a business is born.

That's the position Hammad Ghuman finds himself in these days. Since high school, Mr. Ghuman has been a radio-controlled car-racing enthusiast. "I guess I was always interested in mechanical things, and radio-controlled cars seemed like an exciting toy to play with," he says.

If It's Broke—Fix It

After breaking critical parts on the cars during races, Mr. Ghuman became frustrated with the way the parts were constructed. Regularly taking a large number of math, science, and technology courses in school, he started to learn how things are made. During his spare time he began making replacement parts for his cars.

Shortly, Mr. Ghuman figured out that the radio control parts he was making virtually by hand could be manufactured more automatically. "I picked up a small CNC lathe. With it I could produce the parts faster and with much tighter tolerances. During the first summer I started making some small parts for myself. Later that summer I made a part that I thought would be sellable."

Other people who raced cars with Mr. Ghuman thought so, too. The first part he tackled was a small axle used for some on-road cars. "It was a relatively simple part and had been made of aluminum by the original manufacturer," he recalls. "I designed one made of graphite, which was a lot lighter and stronger than the stock part." He ran a small ad in an enthusiast's magazine, which resulted in orders and encouragement for the improved part.

He continued development and production during summers while attending college. The second year he added a milling center and designed some new parts using CAD (computer aided design) packages. "With the milling center I was able to do larger parts and some plate-type pieces," he says. "Some of the pieces were fairly complex parts."

In early spring, Mr. Ghuman placed his ads, and production began as soon as classes ended. Working on his own, he discovered that there weren't enough hours in the day.

A Business Is Born

After graduating from college, Mr. Ghuman decided to give the radio-controlled car parts business a one-year full-time trial. Hammad Ghuman, Inc. was launched. He soon found himself backlogged and scrambling to fill orders.

"Customer service definitely needed some work," recalls Mr. Ghuman. The following year, he decided to get some help, so he could keep up with the orders. What had started as a hobby, had now become an all-consuming job. "I needed to find a better way to handle the production levels," says Mr. Ghuman.

He no longer had any time left to even think about racing his own cars. "I spent all the time I had just getting the parts made, packed and shipped out." he says. There had to be more time for creativity.

Hammad Ghuman, Inc.'s first employee, Van Svenson, took over making the parts, giving Mr. Ghuman some time to design new products. But the production process still had its limitations.

The stock for each part had to be hand fed to the machine, then rotated by hand so additional processes could be accomplished. "It was difficult to hold some of the tolerances, too," says Mr. Ghuman. "The tolerances have to be within 0.001 inch or better, and there are many parts, such as ball bearings, that have to fit precisely."

The company advertised quality, and its owner was determined to deliver just that. He started thinking about what could be done to streamline and improve the production. The cost of farming out production did not justify that solution for most parts, although a few high quantity sellers were produced that way in the interim.

The Manufacturing Business

In finding a solution to his production problems, Mr. Ghuman was at a slight disadvantage—he had no prior manufacturing experience. But that ultimately turned out to be a great advantage—he had no preconceived notions about what could or couldn't be done.

"I knew I was looking for some sophisticated equipment," says Mr. Ghuman. "We wanted full milling capabilities with automatic material feeding. We looked at all kinds of machine tools. We even considering building the equipment ourselves."

They were only considering a CNC machine—it had to run by itself. Mr. Ghuman knew that he had to spend more time designing marketable parts. "The way I saw it," he says, "manufacturing was basically a business in itself. I could either spend time learning that, or I could come up with well-designed parts and have a piece of equipment that we could count on to make everything." So the decision was made to get a machine that would make the widest variety of parts, so what they designed could be cost-effectively manufactured.

Finding The Technology

One class of technology, first introduced to Mr. Ghuman as a college freshman, had what turned out to be the closest solution to the shop's manufacturing challenges. It was a Swiss-type or moving headstock lathe.

According to Mr. Ghuman, "I remember the day the brochure showed up. I opened the envelope and instantly knew that this was the machine we needed. Whatever it costs, we need it." The machine he ultimately selected was a DECO 2000 lathe from Tornos Technologies (Brookfield, Connecticut).

"The machine had the potential to do a majority of our interesting parts and allow us to introduce new ones, " says Mr. Ghuman. "All of the axes can have live tooling. All of the tools are modular. So we buy one particular holder to put a tool in, and we can put it wherever we want. We have a true milling center inside this machine."

The machine has 12 axes of movement, with both end attachments and pickoff spindle, and the version Mr. Ghuman selected accommodates stock diameters up to 26 mm and a workpiece length of 200 mm. The counter spindle slide assembly has X-, Z- and Y-axis motion. The Y axis allows back working tools to be laid out horizontally, rather than vertically, for better tool and chip clearance.

"With this design, virtually any part shape may be machined in back working operations," says Mr. Ghuman. "I liked the Windows-based programming, too. Since we had significant experience using high-end CAD packages, we were accustomed to using computers to program every detail graphically."

Doing The Work

Mr. Svenson, now Hammad Ghuman's chief programmer and head of product development, explains how the company is automating the manufacturing process. "First the machining tools are selected, and precisely set up, using the machine's pre-setter. That gives us all the dimensions for the different faces and cutting edges," says Mr. Svenson.

"On our machine, up to 21 tools can be used," he continues. "Each operation has a line of code in the control, and the programmer can stipulate which operation is going to happen when. You can have four tools working simultaneously, so there is ample flexibility."

A case in point is an axle-carrier, which holds a bearing for the rear axle of a radio-controlled car. The part is offset so that it can be turned right-side up or upside down to either raise or lower the axle depending on how high a car owner wants the body to sit off of the ground.

"In another application, we are doing polygon turning where we have a polygon cutter that spins with a synchronized rotation of the part," says Mr. Svenson. "It cuts flat spots while it is turning at about 4,000-5,000 rpm, and on the opposite side there is a turning tool that is contouring the shape."

"Tapping flexibility comes from differential threading, where if the part is spinning at 5,000 rpm, I can spin the tap at 6,000 rpm, and the difference is 1,000 rpm. It will screw in at 1,000 rpm, then I can drop the tap speed to 4,000 rpm and it will back the tap out without reversing either spindle. The control, using what Tornos calls parallel numerical control, synchronizes all these things happening at once, so that nothing crashes. The finished part comes out with three operations done simultaneously."

This PNC software also permits running a simulation while it is being programmed, so any potential problems can be observed and corrected. "It even lets you pause the simulation for a closer look," Mr. Svenson continues.

Learning Together

Since Hammad Ghuman, Inc. was one of the first customers to order the Deco 2000, there was a lot of cooperative learning for both companies. Tornos offered training on running the equipment and Hammad Ghuman, in turn, gave back data on performance.

Says Mr. Ghuman, "We wanted to know what it could do. We kept asking questions, and pushing it to the limit. We asked whether there was a way to do gear hobbing. Tornos told us that a hobbing option was not available yet, but that everything could be synchronized. From what we understood, that was all hobbing required, so we put together our own hobbing tool for the machine."

Mr. Ghuman uses the axle carrier to further explain the complexity of the company's production operations. The carrier is one of the most sophisticated parts the company makes, and even Tornos was concerned that it could be made.

In it is a bearing carrier that supports the rear axle in the cars. Ball bearings go in from both sides, and the axle runs through it. It is critical to get the bearings concentric from both sides so the axle slides in straight.

The previous machining process at the company would be to set up a square block of material, and mill as much as possible without cutting into the fixture. A vise would hold it limiting the access to all sides. Then a mill would execute the bearing bore from one side.

Next the part would be flipped over, lining it up so the second bore was concentric with the first. Problems arose with lining up the bores, making sure the fixture was absolutely free of chips and maintaining the proper tolerances.

"It used to take us 20 minutes to finish just one of these parts," says Mr. Ghuman. "Now we have basically one large 1/2 inch end mill that cuts away most of the material. It roughs out the entire shape in a few passes."

Because it is an off-center part, there was no way to get it to the counter spindle. The problem was overcome by eliminating the turning all together.

"We come in with a counter spindle off center. By simultaneously moving the counter spindle, main spindle and milling tools, we actually mill the curve. We mill the part off, rather than turning it apart. We come in with an end mill to do the bore, and we index the part 180 degrees and mill the other side. That automatically guarantees concentricity in both holes. And," he adds, "not only have our tolerances greatly improved, we can now complete a part in just four minutes."

"Since no one has to handle the part during production, we also added some features to the part," Mr. Ghuman says. "We are using a better quality aluminum and have redesigned the part to make it lighter. It looks better, too."

More Opportunities

Trying new things is what this company is all about. It has become skilled at thinking "out of the box," and is always looking for newer, better ways to design and build parts. Flexible, Swiss-type turning has helped make the parts it designs.

"We like to do things that are different and interesting, as opposed to just being the lowest bidder on a job," says Mr. Ghuman. The company is not particularly interested in everyday machining jobs, but it would be interested in working with someone who has an unusual product, wants to develop it further, and wants to find a better way to produce it.

"We would consider subcontracting on a project that would challenge us," Mr. Ghuman says. "We enjoy taking an idea or an existing product and making it feasible production-wise. If we can make improvements to the product, process, quality, profit margins, or customer satisfaction that's what we enjoy. We are very good at figuring out the best way to do it."

About the author: Paul Casstella is the single spindle product manager for Tornos Technologies U.S. Corporation (Brookfield, Connecticut).

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