In 1979, Harlow-based TK Fabrications opened its garage door for business. Today, almost 40 years after the father and son company was conceived, the third-generation family business is filling its impressive new factory with high-end machine tools, the latest addition to which is a Fanuc RoboDrill D21MiA5 five-axis machining centre.

As a manufacturer that exclusively machines plastic and composite materials, TK Fabrications has a machine shop packed with high-end turning centres, machining centres and routing machines. These machines are tasked with manufacturing anything from prototype to 1000+ batch runs that are supplied to customers around the UK, Europe, China, Malaysia and the US. Fanuc has been supporting the growth of the subcontract company since 2002.
Recalling the introduction to Fanuc machine tools, company director Sam Howlett says:
“The first RoboDrill, a T14iB arrived in 2002 with a 4th-axis Nikken rotary unit, which was fantastic. We then bought a used Fanuc and had Fanuc engineers to do some work on the machine to keep it up to the required specifications. We kept that machine for five years. Now, we’ve invested in the new five-axis RoboDrill D21MiA5 and it’s outstanding.”
The reason that TK Fabrications has continually invested in Fanuc technology is two-fold: performance and reliability. Referring to the reliability of the Fanuc brand over the 16-year duration, Howlett says: “Throughout our ongoing growth period, Fanuc has helped our small business to save money, telling us we didn’t need a service contract because the machines don’t breakdown. They were 100% right. After all these years, the machines have never broken down. We’ve had Fanuc come in and do some work, such as lowering a machine after integrating a Microloc work-holding unit. They have also done some other retrofit work, but never attended a breakdown.”
This reliability is a critical aspect to any subcontract manufacturer, as Howlett confirms: “The ability to get finished parts out of the door to meet customer deadlines is a business-critical factor. Failure to meet deadlines has consequences; luckily we buy Fanuc machines so this isn’t an issue. Over the last year, we manufactured over 155,000 components with 98% on-time delivery and the remaining 2% delivered early. Fanuc machines played a considerable role in achieving these statistics by never failing us. Any machine tool failure would be detrimental to these statistics.”
From a productivity perspective, Howlett says that the Fanuc machines have always been streets ahead: “Even the older Fanuc machines have a 15,000 rpm spindle with 54 m/min rapid traverse rate.”

Despite the glowing productivity endorsement of the RoboDrill series, the latest five-axis RoboDrill D21MiA5 has taken TK Fabrications to the next level.
“The D21MiA5 is swallowing work from the other machines on our shop floor,” states Howlett. “It’s giving us more capacity throughout the factory and this is because the new RoboDrill is so much faster than our existing plant list.”
This factor is demonstrated with a plastic component that has a total machining time of 2 minutes 53 seconds, which includes drilling a 170 mm deep hole and then rotating the part to a secondary set-up for machining all faces. The component was previously machined in 6 minutes on an alternate machine, thus cycle times have been cut by over 50%.
Another rectangular plastic part machined on the new D21MiA5 is clamped with two Lang vices and drilled to a depth of 300 mm. This component is being machined in less than 5 minutes, whereas the previous total machining time was over 20 minutes.
The 3+2 configuration of the RoboDrill D21MiA5 is ideal for TK Fabrications as it has no specific requirement for full simultaneous five-axis machining.
“The process to configure the machine from 3+2 to full simultaneous five-axis is simple for Fanuc, and we thought we would have requested it by now,” says Howlett. “However, almost all our jobs only require 3+2 machining, and with the capability of the new Fanuc, it is increasingly close to capacity with no simultaneous five-axis work going through it. This is because it is drawing more work from less productive machines.”
The latest RoboDrill incorporates a Big Plus BBT spindle configuration and more than sufficient capacity in the X, Y and Z axes. In fact, TK Fabrications specified the new addition with a riser block at the rear of the machine to lift the five-axis unit by 50 mm. The purpose of this request was to give the company greater swing capacity, which facilitates the machining of larger components.
Primarily machining plastics and composite materials, TK Fabrications runs every machine without coolant. With the Fanuc RoboDrill, this concept has seen a central dust-extraction system fitted to remove airborne dust.

“The airborne particles are collected via the extraction unit and the machine base is cleaned every 30-40 parts to remove chips,” explains Howlett. “Swarf is automatically blown from the work area as we have a through-tool air blast. This capability keeps the cutting tools at an optimal temperature, clears the work envelope and improves processes such as tapping and deep-hole drilling. The air blast works at 6.2 bar and has been a revelation for us. It stops the tapping process from binding-up, is more productive and delivers extended tool life.”
In conclusion, Howlett says: “Fanuc have been an outstanding machine tool partner. The reliability and machine uptime is amazing, while the service and applications team are extremely helpful and supportive. In short, the technology, speed and capability of the RoboDrill series is perfect for our business.”
For further information www.fanuc.eu

Almost 78 years after Tenable Screw was founded by a Swiss watchmaker as a manufacturer of screws, the company has become one of the UK’s largest subcontract producers of turned parts.
With three manufacturing sites in Marlborough, Coventry and its headquarters in Wimbledon, Tenable has more than 250 machine tools that include 71 coil-fed Escomatics, 26 multi-spindle machines, 56 sliding-head turning centres and four fixed-head turning centres. The machines produce millions of components every month.

Committed to an ongoing culture of quality-assured engineering, Tenable Screw invests 10% of annual turnover in the latest technology to support its live base of over 250 customers. Part of this investment strategy has seen the arrival of a Tornos MultiSwiss 6X14.
The modern face of Tenable Screw sees the company manufacture everything from connector pins and sockets through to bolts, screws and much more for the electronics, instrumentation and control, automotive, aerospace, medical, defence, transport and telecommunications sectors in quantities that range from prototypes and small batch production up to runs of more than 100,000. With London property at a premium and the 45,000 sq ft Wimbledon headquarters packed with machine tools, the philosophy behind the MultiSwiss 6X14 purchase was to add flexibility and capacity to a business with limited floor space.
Commenting upon the arrival of the Tornos MultiSwiss 6X14, Tenable Screw commercial director Nigel Schlaefli says: “We initially acquired the MultiSwiss to alleviate capacity issues on our single-spindle sliding-head machines, while having the production capacity of multiple single-spindle machines in a floor area significantly smaller than five-to-six single-spindle machines. Although we initially used the MultiSwiss as a flexible centre that was supporting our single-spindle machines, like any subcontract manufacturer that has a fluid workflow, customer base and component types, the MultiSwiss is now dedicated to producing just one component family. Despite being restricted to a single family of parts, the productivity, precision, cost reduction and floor area benefits are evident.”
Just a few months after installing the MultiSwiss 6X14, Tenable Screw won a long-term automotive contract. The family of parts comprises stainless-steel pins that require numerous external turning processes, as well as knurling, drilling and parting off. The UK contract demands 1,500,000 parts every year, a quantity equal to 30,000 parts per week. Tenable Screw trialled the automotive part on one of its sliding-head turning centres and the cycle time was 1.5 parts per minute. In stark contrast, the MultiSwiss 6X14 was capable of producing 9 parts per minute – an output equal to six sliding-head turning centres.
“We calculated that we would have needed to run six single-spindle turning centres for 24 hours a day to meet the contract capacity level,” says Schlaefli. “In comparison, the MultiSwiss 6X14 hits the same output by just running for 17-18 hours a day. This means we can run the machine during a day shift, change tools and re-stock the barfeed at the end of the shift, and then run for an extra 8-9 hours unmanned.

As with all manufacturers with relentless quality standards, Tenable Screw has a dedicated quality control department and its production adheres to ISO9001. With regard to production, Tenable applies SPC and CPK procedures to its manufacturing processes. The CNC manager responsible for more than 60 CNC machine tools at Tenable Screw, Paul Kelley, says: “If we were producing this automotive part on six machines there would inevitably be a variation in CPK values between them. Although the part has an average tolerance band of ±20 µm, the MultiSwiss easily maintains a band of less than ±10 µm, and this improves our CPK and SPC values considerably.
“What we have also found is that each spindle on the MultiSwiss works independently, unlike conventional multi-spindle or CAM-auto machines. This allows us to change the spindle speeds for each spindle and operation, which in turn considerably improves surface finishes and contributes to extended tool life compared with other production machines.”
Contributing to both quality and tool life is the hydrostatic spindle technology integrated into the Tornos MultiSwiss 6X14.
“Over an extended period of time, roller bearing technology on machine tools will generate wear and this results in diminishing component quality,” explains Kelley. “However, the hydrostatic spindle technology on the Tornos eliminates wear; this means precision and consistency will not reduce. The hydrostatic spindle also eliminates vibration in the spindle head and this enhances component quality and surface finishes.”
Referring to the tool life on the machine, Kelley says: “The MultiSwiss will run for two days without any need for tool changes. Even then, we are only changing inserts as a precautionary measure. The only tool we change on a daily basis is the knurling tool. To put this in context, we are producing 18,000 stainless steel parts before we change inserts. The MultiSwiss is achieving at least double the tool life of the single-spindle machines.”
The MultiSwiss at Tenable Screw has demonstrated how it can lower floor-space requirements and reduce power consumption, tooling and general running costs compared with five or six single-spindle machine tools offering a similar production output.

Concluding upon the CNC control and ease-of-use characteristics of the MultiSwiss, Kelley says: “The MultiSwiss has 14 linear axes and seven C axes with up to 18 tool stations. Despite the number of axes and tool positions, the machine is significantly easier to program than single-spindle sliding-head machines. We apply G-code programming and determine the number of operations for each spindle. Combining these features with a well-lit and easy-to-access work envelope, the MultiSwiss is easier and faster to set-up than single-spindle machines.
“This ease-of-programming is certainly beneficial; but one equally important factor is the operator,” he adds. “There is a distinct lack of skilled CNC machine operators and programmers in the UK. Combining the ease-of-use characteristics with the facility to be as productive as six alternate machines, the MultiSwiss reduces the reliance and requirement for highly-skilled staff.”
For further information www.tornos.com