Shipping around 1,200 different types of part a year, the Aylesbury-based engineering sub-contractor Holm Engineering says its CAD/CAM software is vital in ensuring that a wide range of complex components meets customers’ speedy turn-round requirements, irrespective of whether the production run is large or small.

Scott Holmes, director of the family-run company, says this is achieved because the Alphacam software (www.alphacam.com) “is developed by engineers rather than pure software specialists, so it ‘thinks’ exactly how an engineer works. We draw our shape, pick our offsets and cutters; the system then seamlessly and effortlessly creates the correct NC code.”

Without Alphacam, Mr Holmes says, the biggest challenge of the manufacturing process would be getting work out on time. “We’re coming up against ever-shorter turn-round times, but we can easily produce programs for milling, turning and mill-turn cutting technologies.”

When — some years ago — Holm Engineering was looking to switch from line-by-line programming at the machine to an off-line system, Vero Software’s Alphacam was three-times quicker than its nearest rival in a programming test.

“We had a contract for an airport baggage control component, and we were having real trouble programming it. A number of software companies were invited to show their capabilities. One took two hours, another took an hour; Alphacam took just 15min.”

Today, Holm Engineering uses Alphacam’s CAD and CAM capabilities for all parts (it is the sub-contractor’s only CAD system). Mr Holmes says the company will often use the software at the quoting stage of a contract, before starting work on the actual component.

“If it’s a complicated part with complex machining, I’ll draw up a program to get an idea of how long the job will take, so we can give our customer an accurate quotation.”

Machine variety

Holm Engineering currently uses Alphacam to program eight machines from a range of manufacturers, including Haas, Hardinge Bridgeport, Mori Seiki and Samsung — plus a new high-spec Hurco VMX 30i machining centre with both table- and spindle-mounted probing.

Mr Holmes says: “It is important for me to be able to purchase any machine I wish, without having to worry about the control system. With Alphacam, it is the software that governs what the machines do, rather than the machines themselves.”

If he receives a solid model from a customer, he imports it straight into Alphacam and completes the machining aspects before post-processing it to whichever machine he selects for the job.

“It doesn’t matter which machine it is, or whether the controller is Fanuc, Heidenhain or Hurco; the Alphacam program is simply downloaded, and we start to cut metal immediately, knowing that the program is 100% accurate.”

If the part comes in as a DXF drawing, Mr Holmes uses the draughtsman’s dimensions and machines it from that DXF data; if it is a basic drawing, he redraws it in Alphacam, using the software’s CAD capabilities.

While Holm Engineering uses mainly three-axis machining at the moment, it does have four-axis capability on a Hardinge Bridgeport XR 1000 machining centre; both of the company’s lathes also have a four-axis capability.

“Developing our four-axis work is very important to us. We’ve started taking a different approach to our jobs. Where we would have previously looked at them in a traditional 2-D way, we now think ‘four-axis,’ and it’s opened up a whole new world.”

He has recently made a new fixture plate for four-axis work. “It’s almost like five-axis machining, which is something we will look at in the future, knowing that Alphacam is equally at home producing five-axis programs.”

Part sizes range from pins about 1 x 1mm, through milled components for the medical industry measuring 10 x 10mm and containing a number of holes and profiles, right up to navigational aids such as fog-horns, which are 350mm in diameter and 450mm high. The company also machines large castings.

While Alphacam has come a long way since Mr Holmes started using it in 1995, he well remembers one of the early jobs he did with it.

“My father was trying to improve the look of the original chain case on a 1937 Rudge Rapid 250cc motorcycle. I used the knowledge I’d gained on an Alphacam 3-D modelling course and drew the component, produced all the machine code, and manufactured the part entirely from scratch.”