Billet machining reduces time to market

With the support of Ceratizit UK & Ireland, Techni, a specialist in the design and manufacture of cast iron mounting and drive solutions, has significantly reduced the time to market of its compressor mounting kits used for refrigeration and compressed air units on the van.

The Shrewsbury-based manufacturer’s Techni products are used in many industrial sectors. If you’ve had home delivery from a supermarket, the chilled or frozen goods in the van are most likely kept cool by a refrigerator system using a Techni compressor mounting kit. Or, if you needed a mobile tire fitter or a utility vehicle, their compressors would probably have used Techni equipment.

Typically compressor mounts are machined from ductile iron castings as normal lot sizes make this the most cost effective method. However, driven by the significant increase in home deliveries due to COVID, customers demanded faster turnaround times and much lower volume numbers, but more diverse configurations. This was especially the case for the US market, which has traditionally not had a strong home delivery culture. This increased demand for lower volume and quick turnaround posed challenges for the pour-on production method, which for a new product could take up to six months to come to market.

“We needed to review our methods to minimize these lead times and machining the billets was the logical step,” explains Ali Kerr Techni’s manufacturing engineer who worked on the project. “It’s a new path for us and it’s a path that allows us to produce shorter series, even one-offs, because we eliminate many costs, such as the design and manufacture of the luminaires. Everything we what we need now is a vice and some good tools.

(LR) Operator Carl Brunton, Derrick Jones and Ali Kerr discuss the finished piece

For help with tightening, tooling and methodology, Techni turned to Ceratizit UK & Ireland and sales engineer Derrick Jones. The first step in the process was to perform a 3D scan of the engine compartment of the van to be fitted with the system. CAD was then needed to allow the design engineers to design the mounting brackets. A big advantage with billet machining is that there is no longer any need for the draft angles or slideways needed for castings, making parts much simpler to design.

Typically, brackets can be produced from a billet of aluminum measuring 270mm x 90mm x 180mm. To grip them, a WNT ZSG 4 Centric vise, mounted on a WNT Zero Point MNG Riser bracket is used. With its maximum gripping force of 35Nm, unlike some other systems, the WNT ZSG 4 vise is capable of gripping as little as 3mm of material without any pre-preparation of the billet. By mounting the vise to the MNG Riser Console, access to all five sides of the billet is simple and helps reduce tool overhang, allowing increased cutting data to be applied.

In Techni’s case, 3mm of material is left in situ after machining rather than having to remove it in a second operation, saving additional time.

With the billet seized, up to 90% of the machining, both roughing and finishing, is done using a WNT CircularLine end mill, with Dragonskin DLC (Diamond Like Carbon) coating extremely wear resistant Ceratizit, which provides up to 80% of the hardness of natural diamond to protect against damage from built up edges or abrasive alloy accretions to provide extended tool life and high cutting data.

With Techni, these cutters operate at a conservative surface speed of 450m/minute, 0.2mm/tooth feed, with a 14mm diameter five-flute cutter and 10-20% pitch. On the one hour and 45 minute machining cycle, the Circularline cutter was engaged for approximately 95 minutes and after an initial batch of 50 holders was still delivering the required surface finish results, aided by the innovative geometry of the milling cutter, which is advantageous where the wall thickness is minimal and the requirement for a corner radius of 2 mm is required.

The brackets are machined with the Ceratizit WNT CircularLine end mill
The brackets are machined with the Ceratizit WNT CircularLine end mill

“The help we have received from Ceratizit on this project has been invaluable, and although some elements of billet machining are more important than casting, for example, a casting can cost as little as £20, compared to £80 £ for an aluminum billet, the machining time for a casting is around 20 minutes, not 105 minutes,” says Kerr. “Even with these increased numbers, the argument for billet machining is easily won, simply with the reduced time to market, the initial cost of creating a casting and usually between £2,000 and £10,000 for fitting.

“We can now deliver finished machined parts to customers within a week if required, which would be comparable to four months for a new cast product. This gives us a valuable competitive advantage with new clients or projects. In the future, with batch quantities of up to 300, billet machining will provide a significant advantage and we already have more parts lined up for billet machining.

Working closely with Ceratizit UK & Ireland, Techni has developed a process by which it can respond to new customer demands anywhere in the world in a fast and cost effective manner.

Derrick Jones, Technical Sales Engineer, Ceratizit UK & Ireland explains: “The ZSG 4 vise and MNG zero point system as well as the Circularline DLC cutter are popular standard parts of our product portfolio and provide an excellent example of the how a highly efficient solution for a machining problem can be created with minimum investment or disruption that can take months of production time.

Ceratizit UK and Ireland

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