CAM keeps spindles turning at Hightown Engineering

Author / Editor: / Rosemarie Stahl

They know it’s corny, but Terry Smith and his partner Steve Browning, owners of Hightown Engineering, like their company motto: “If spindles aren’t turning, we’re not earning." Smith says it keeps them focused every day on what’s most important. That is what they have done for 12 years now: kept spindles turning.

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Dynamic milling toolpath for deep pocket.
Dynamic milling toolpath for deep pocket.
(Source: CNC Software)

To keep pace with the work, they acquired a powerful CAD/CAM system (Mastercam from CNC Software) and developed proficiencies that allowed them to keep equipment fully utilised even though the two partners would be required to create many more CNC programs to produce the same number of parts.

Hightown Engineering is not the first engineering company Terry Smith has operated with a partner. About 20 years ago, he was involved in a similar business, but his partner became disenchanted with the unpredictable and sometimes long hours. So they closed the shop and sold their equipment to a large OEM customer that decided to establish its own manufacturing operations.

When Smith and Browning started their business, they approached this former customer to find out if it might have any overflow work. The OEM liked having its own manufacturing department but wanted to update its manufacturing equipment. Smith and Browning were invited to purchase the old machines and take over manufacturing while they also installed new equipment, designed and built fixtures, and wrote NC programs for the customers’ new high production facility. Within 18 months, Smith and Browning had completed this assignment and, as a result of their good efforts, they were minus their largest customer. However, as they were phasing out production work for customer #1, they were phasing in a lot of jobs from strategically targeted OEMs in the aerospace, defense, medical, and commercial sectors.

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If they were going to have long-term success, the partners knew that they would need better equipment. Although credit was easy to obtain during the first couple of years, they didn't want to be saddled with debt. They only financed their first vertical machining centre. Then, instead of borrowing, they worked long hours, including opposite shifts, saved their earnings, and bought only what they needed most and only with cash. Today, they have 11 CNCs – four vertical machining centres, all with 4th axis (10k RPM), a high-speed cell comprised of three vertical machining centres, all with 4th axis (15k RPM), one CNC vertical mill, three CNC lathes, and a CMM. All were purchased new and are owned outright.

CAM makes the difference

Since CAD/CAM software was not their first priority, it had to wait a couple of years. When they were ready, the partners jumped in with two fully loaded suites of Mastercam Mill Level 3, 5-axis Drill/Curve, Solids, and Lathe. They also have an ongoing maintenance agreement to take full advantage of technical support, provided by dealer 4D Engineering, and free software upgrades. They will soon make the transition to Mastercam 2018. The partners were familiar with Mastercam from their previous employment, but they had been away from it for a couple of years, so there were many more capabilities that they had to learn. A day of training at 4D Engineering provided them with a good refresher course. However, Smith spends many hours every week reviewing Help files or surfing the Mastercam website in search of new and better ways to shave minutes and hours from programming time and CNC cycle times.

The first thing the partners attended to was the last thing that happens in the CAD system, posting the code to the CNC machines. Smith said, “The postprocessor is the most important thing. You can have the best CAM system in the world, but if your postprocessor isn't right, you are just going to get junk code out, make bad parts, and potentially crash a machine. The post is so customisable with Mastercam that if you have the knowledge, you can get the code posted just the way you want it, so that nothing has to be adjusted at the machine.”

Smith and Browning negotiated with their dealer to have some post-modifications included with their original license agreement. When they were manually generating CNC code, they used to spend several hours with every first piece, standing over the machine, first air-cutting the part to confirm the code, then running the part half speed to make sure there were no programming mistakes that might result in a tool or head crash. Today, they use computer simulation (Mastercam's Verify and Backplot features) to weed out human error, making sure that toolpaths are safe, and that material removal is within specifications. Then the code is posted to the machine and used as-is with 100% confidence.

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Three axes for the price of two

The partners needed a small machine to replace their old 2-axis manual mill. They briefly considered a small 3-axis CNC, but they felt that the 3-axis Z (quill) drive restricted the flexibility of the machine too much. Smith didn’t regret the decision to buy a 2-axis CNC mill and then set out investigating how to program 3-axis jobs (one-off prototypes and fixturing, for example) semi-automatically for it.

“I developed this capability by editing the post-processor to the best of my ability. Then I gave it to Phil at 4D and asked him if we could actually do this. Within a week, I got an email from him with the post-modifications that would make it work. For this machine, we program a part normally and generate the machine code from Mastercam. We run the code and when the machine reads a Z-axis command (either feed/rapid up or down), the machine pauses, displaying the required Z movement. The operator manually moves the tool accordingly, presses ‘go’ and the machine continues. This shows the flexibility of Mastercam and the first-rate technical support available.”

Hightown Engineering encourages its customers to submit all work in the form of a CAD file. With nearly 20 years of experience using Mastercam at two companies, there has only been one file that the partners found they couldn’t import cleanly.

“Within the 3D graphics view of Mastercam, we can rotate the part to quickly catch features that may need to be redesigned for manufacturability or determine how the part will be held for manufacturing. These features streamline engineering negotiations and quoting,” says Smith.

Smith is very impressed with Mastercam’s Dynamic high-speed toolpaths, such as OptiRough and Peel Mill, not only because they are so much faster but also because they reduce tooling costs as well as wear and tear on the machine.

“Years ago, using Mastercam X5, we ran a thin sidewall stainless-steel part on the 4th axis, which wasn’t a very rigid set-up, but because the high-speed machining toolpaths produce light cutting forces, we could run at dramatically increased feeds and speeds,” Smith said. “What would have been nearly a three-hour cycle time ‘conventionally’ programmed, took ¾ of an hour thanks to the Peel Mill and Dynamic Mill roughing toolpaths. This was a stainless-steel part and from then onwards, we implemented high speed toolpaths on aluminium parts, which is the bulk of what we do. These paths dramatically reduce our cycle times on our high-speed machine cell – the machines have a #30 taper and thus are not as rigid as our #40 machines, so we Dynamic-toolpath all roughing and the machines excel”.

Once Hightown has settled on a toolpath strategy that works well with a certain type of part, Mastercam gives its user the ability to automatically replicate that strategy for similar parts to eliminate enormous amounts of programming time. Smith calls these features “hidden gems”.

Transform Toolpath is one. “If you want to make multiple parts, program just the one from start to finish, then select transform toolpath. Mastercam then steps in and repeats your part as many times as you have set. This can literally fill your machine table with only a few mouse clicks. We use this feature as much as we can,” Smith said.

Another of these gems is Import Operations. “If you have a tool that's really flying on a part, a real nice flowing toolpath, you can save that operation—the feeds, the speed, the depth of cut and everything—and use it over again on similar jobs. You import the operation into your file, apply it to your CAD geometry, and that's it. You can almost standardise all of your programming just by importing operations”.

Nothing lost in translation

When Hightown Engineering opened its doors, the nature of its business was high production with not much value added. Typical runs were 1,000, 2,000, and even 5,000 pieces, repeating every month. Not much programming work was required at that time. But all that evaporated and the work that replaced it was geometrically complex with production quantities of 25 to 50, developmental quantities of 5 to 10, not to mention the very frequent one-off prototypes.

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Smith concluded, “Mastercam has allowed us to keep up with a geometrically higher engineering workload so that our company can be productive and profitable making parts with much higher value added.” So when he goes home at night, it is almost certain that he will spend at least a little time on Mastercam’s website, looking for what else he can learn and take advantage of. His wife thinks that he is just playing, but it’s much more serious than that.”

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