At its Aerospace AS9100-certified factory in Bracknell, B-Tech Engineering specialises in the manufacture of aerospace parts and assemblies, including galley components and stowable tables for business-class and first-class cabins — all items for which quality and finish are of paramount importance and five-axis machining plays a major role.

Operations director Marc Turner says that an opportunity made possible by the company’s recent introduction of five-axis machining is the manufacture of guitars from solid aluminium.

“One customer is working with some very-high-profile musicians, opening our eyes to other business possibilities created by the technology we have invested in.”

Devotees of aluminium guitars say that these instruments are much more resonant than traditional wooden ones. They are also more durable, and they require virtually no maintenance; there is no truss rod to adjust, and no wooden bits to warp, swell or shrink.

Included in B-Tech’s range of machines are several from Coventry-based DMG Mori UK (www.dmgmori.com).

These include DMG Mori NH5000 horizontal machining centres and a DMU 60 eVo linear five-axis machining centre with CELOS — an app-based interface offering multi-touch operation. The company also has a second similar machine on order; this one will be pallet-changer ready and will be installed shortly.

Managing director Brian Turner said: “We invested in our first DMG Mori NH5000 over five years ago, when we were located in Slough. We have moved to Bracknell since then and doubled in size to 7,500ft² — and we are planning to double in size again as soon as we can.

“We have continued to invest in DMG Mori machines because of their reliability; we are running 24hr a day and cannot afford to have downtime due to machine breakdown.”

As well as machining aerospace parts, B-Tech assembles many of them in a controlled environment (the whole factory is air-conditioned). Some of the assemblies are complex, have up to 90 parts and require skill to achieve the necessary quality standard, with no blemishes on the components, excess adhesive or air bubbles under the laminates.

Working with aerospace customers allows B-Tech to make parts for stock. Mr Turner says: “Our objective is to keep our machines running all the time; and although we may have more stock in finished parts than other companies, we achieve very high levels of machine utilisation and find that this is the most cost-effective and efficient way for us to operate.”

Migrating to five-axis machining with the DMU 60 eVo linear machine was a major step forward for the company, especially for small batch quantities.

Mr Turner says: “Five-axis machining means that set-up times have been virtually eliminated. Furthermore, our use of Lang Makro-Grip vices allows us to clamp securely on a very small section of the billet, machine the complete part in one or two set-ups and break out a finished part from the finish-machined billet.

“With CELOS on the machines and the PC version in the programming office, we can make tooling data, setting data and CNC data available at the machine, thereby allowing operators to check and be sure about the next job before machining starts.

“Moreover, the speed and ease of setting mean that we can cut two or three completely different jobs overnight — and we don’t even require a skilled person to operate the machine.”

Mr Turner says five-axis machining has thrown up some additional benefits. “For example, when using ball-nose cutters, the job can be tipped so that the machine is not cutting with the end of the tool, which can cause ‘pick-up’ and marks on the job.

“Machining with the side of the cutter produces a superior surface finish. We also make use of trochoidal cutting techniques, machining pocket features with the full depth of the heat-shrink tools used.”

The DMU 60 eVo linear is programmed in MasterCAM, but the extra capacity provided by this machine made it necessary to employ an additional CAM programmer.

Mr Turner says: “The DMU 60 eVo linear that we have on order will have 120 tools plus the capacity to add 10 pallets. The extra tool stations will allow us to use sister tooling, while adding the pallets will make it possible to make more parts overnight.”