When BCT Engineering Ltd opened its doors for business over 30 years ago, the Woking Company revved up its revenue from producing performance parts for motorcycles. Over the last three decades, this has evolved into the automotive, automation, offshore, aerospace and motorsport industries. With a concerted effort to speed-up productivity, the Surrey subcontractor has enlisted the support of Tamworth cutting tool specialists Industrial Tooling Corporation (ITC).
Simply stating the impact ITC has had on the subcontract business, BCT Engineering Ltd Managing Director, Mr Tony Ryan says: “The help we’ve had from ITC has been invaluable.” Referring to a particular product that is being manufactured at the company, Mr Ryan continues: “We have one product that is part of a modern ‘touch-button’ domestic tap for boiled or chilled water and we were initially making the parts from plate material. However, we had problems that were down to both the type of material we were using and the machining methods we were applying. ITC came along, had a look at the way we were machining the parts and they changed the tools and the machining strategy. This has saved at least an hour on each component.”
“To achieve this, we are using a combination of tooling that includes high feed tip tools to go around the outside of the part and then a solid carbide end mill to go through the centre of the part. When we started to machine the part, we were going far too cautiously with the speeds and feeds, as we didn’t realise the performance parameters of the tools. Now, we have evolved the situation and we have drastically reduced the cycle times and improved the process reliability.”
Commenting upon the domestic tap component, ITC’s Application Engineer, Matt White says: “The task for the tap components was for them to be machined in a shorter time whilst maintaining a safe and reliable process. Tony had the idea to change from making one part at a time to machining two at a time. We looked at the job in some depth and recognised that applying a combination of indexable tipped tools and solid carbide end mills was the best route forward. In this case, we applied the WIDIA M370 high feed indexable end mill to machine the profile of the parts and then used an ITC 20mm diameter solid carbide 5 flute 5021 cutter to rough machine the slotted form in the centre of the parts. The final step was the application of an ITC solid carbide 6 flute 6051 long series finishing tool.”
From a process stability perspective, Matt continues: “We are now looking at machining 5 billets per indexable edge of the high-feed WIDIA M370 on 316 stainless. With a 0.6mm depth of cut and 180m/min spindle speed, with a feed rate of 0.5mm/tooth, this is a very productive run time. What Tony now knows is that he can let the job run and leave the machine to do other tasks; guaranteed to return to the machine at a later time with five billets reliably machined.”
These stainless steel tap components are machined in batch sizes of 50 off pairs/sets and the machining time of four hours per pair/set has been reduced from four hours to two hours, a 50% cycle time reduction for BCT Engineering.
Looking at another component, an aluminium laser casing that is produced in batches of 20off, the application expertise of ITC’s Matt White once again managed to reduce cycle times; this time by over two hours per part. Referring to the opportunity to work on this project, Matt says: “After successes on stainless machining at BCT, I had the chance to run the 40mm diameter VHSC WIDIA cutter to rough-out pockets on large aluminium casings.
“Previously, BCT was using a slightly different tool on the job and we were only able to run at a feed in the region of F2000. With the new ITC WIDIA VHSC tool, we can run at F3500 whilst doubling the depth of cut. This is saving us at least an hour per component, just from the pocket machining. This is significant, as we machine a relatively large quantity of these parts and we had the opportunity to create further savings with other tools on this project.”
With regard to the tool life and performance, Matt says: “Using the 3-tipped WIDIA VHSC indexable tool, the parallelism has improved, the tool life is much better and the performance is fantastic. BCT has some very good aluminium casing type jobs that we needed to take some time out of, the WIDIA VHSC Series has been very successful at doing this.”
Regarding the cutting parameters, ITC’s Matt says: “The cutting data on this job is dictated by the maximum spindle speed restriction of 8000rpm. However, we have managed to run the VHSC at 7,000rpm with a 5 degree ramp down angle to a 3mm depth of cut and then we run around the pocket at almost 3500mm/min.
“Previously BCT was utilising the conventional WIDIA VSM11 tools, which is like the APKT style insert. The trouble with these standard 90 degree shoulder mill tools is that they inherently cannot be fed very fast on aluminium. So, in the past it may have been better to run with a larger solid carbide multi-flute tool than to go with indexable tools. With the new VHSC, we have the option to run much faster. For example, you can go from 0.1mm per tooth for a standard shoulder mill to 0.3mm per tooth and beyond with the WIDIA VHSC. Furthermore, you can really get the spindle speed up; we are looking to run a 50mm diameter tool at speeds around 12,000rpm with 6000mm/min feeds for machine tools capable of operating at these parameters.”
Despite removing the material much faster, the surface finish is actually improved, considerably. As Matt continues: “The more you push these tools by running higher feeds and higher revolutions, the better the surface finish. From a tool life perspective, BCT haven’t changed an insert edge yet. This may not be good news for our area sales representative Dave Cleeve, but it’s certainly good news for Tony and BCT.”
Concluding on the service from Tamworth based ITC, Mr Ryan says: “With all the help we’ve had from ITC, we now buy virtually all of our cutting tools from them. Most cutting tool manufacturers would not be able to give us the service that ITC has provided. Matt White and Dave Cleeve have spent upwards of two to three days initially sorting these two jobs for us, with continued follow up visits to further improve performance. The results have been fantastic and we are delighted by their commitment to help our business.”