Workholding technology Fast and precise changeover: This is how JWA increases productivity
UK — The subcontract manufacturer JWA Tooling opted for workholding technology from Hainbuch to ensure quick tool changes on several different turning centres, thus increasing overall productivity.
JWA Tooling has grown exponentially since its inception in 1985 when founder John Wood set the company up from his loft, designing special purpose machines and subcontracting the work out. The company quickly bought its first factory and manual machines and subsequently CNC machine tools. More recently, the company has added a new facility and invested heavily to fill the site with new technology. The investment strategy has reaped rewards with the Leicester business growing by 150 % with a 40 % increase in the workforce and the new investments boosting machining capacity by 60 % in recent years.
The company has a plant list of over 20 CNC machine tools that includes a multitude of wire EDM, machining and mill/turn centres, grinding and manual lathes as well as moulding, laser marking and automation technology that are all complemented with an inspection department primarily kitted out by Mitutoyo. Residing in this machine shop is equipment from brands such as HAAS, Spinner, Hardinge and Miyano.
Adding to the plant list, the company has invested more than £ 2.5 million in an additional factory, three new Fanuc EDM machines, three new automation-ready Mazak machining centres that includes the company’s first dedicated 5-axis machine, a Doosan cobot, a Doosan Lynx turning centre and a Colchester Harrison Alpha 1400XC. The link that is increasingly tying more of these machines together is the workholding and clamping technology from Hainbuch. The reason for investing in quick changeover workholding from Hainbuch is borne out of the workflow that passes through the company — it has an annual product spread of more than 8000 different part types with batches frequently less than 5-off.
Commenting on this situation, JWA Tooling founder, John Wood says: “If you analysed our company, you’d see that we have lots of machines and lots of setup times, which means the machines can be stopped for longer than they are running. We have chosen to address this issue by investing in new workholding systems.”
The workholding experts from Hainbuch were introduced to JWA Tooling when the company invested in a Colchester Harrison Alpha 1400XC manual and semi-CNC turning centre. The decision to invest in the Hainbuch Torok 65 manual chuck was influenced by the ability of the innovative chuck to offer extremely fast and precise changeovers. The flexibility of the Hainbuch Torok 65 also permits the fast changeover from I.D clamping to O.D jaw clamping of components. Furthermore, it can be used on turning centres without a clamping cylinder.
The flexible Torok system can be supplied with a selection of O.D and I.D clamping heads, jaw clamping adaptations, face drivers and morse tapers as well as magnet modules and flanges, which offers JWA complete flexibility for its existing and future turning requirements. The Hainbuch Torok is capable of clamping components from 3 to 65 mm in diameter with an actuating torque of 90 Nm and a maximum radial clamping force of 105 kN. However, jaw adaptions permit clamping far beyond the 65 mm diameter of the clamping heads.
Easy removal of collets
So, when the company decided to install a Doosan Lynx 2100LY turning centre more recently, the subcontract manufacturer once again opted for workholding technology from Hainbuch with the Top Plus 65 combi pull-back collet chuck. Commenting upon this, Wood continues: “The reason for picking this particular design of chuck is quite critical, as we have been well established with round collets over the years. But if you look at the modern machines with live tooling and C-axis configurations, you need to index accurately and know where the component faces and locations are. So, with the Hainbuch system and its hexagonal fitting, you can identify your mark on the chuck and the collet and you can put the collet back in the identical position.”
As a machinist at JWA Tooling, Harry discussed and demonstrated the changeover from a Hainbuch Top Plus 65 combi pull-back collet chuck to a Hainbuch 215 jaw module system. Using a single clamping tool to grip the collet, the collet is removed in a matter of seconds. Referring to this, Harry exclaims: “This clamping tool is unique and it’s the easiest tool I have used for removing collets. Previous collet systems that we used are held in place by a thread and locking bolt and this takes time to release and it can get gummed up quite easily with swarf ingress. The Hainbuch collet system relies on the pressure of the collet expanding on the outside of the holder. To release the collet, all I have to do is relieve that pressure with the Hainbuch trigger tool and remove the collet, a task that takes less than 30 seconds.”
The next step of changing from a collet configuration to a 3-jaw chuck is an equally simple process. As Harry continues: “The first step is to use an Allen key to release the central locking mechanism in the chuck. Once the Allen key unlocks the locking mechanism, it cannot be removed from the chuck for safety purposes. The Hainbuch Top Plus 215 jaw module system is then mounted on the machine spindle, three screws on the face of the chuck are tightened and the billets are then ready to be loaded to the 3-jaw interface — this process takes less than 3 minutes.”
Reduced setup times and increased machine uptime
JWA Tooling conducts a significant amount of low-volume fast turnaround work — for this, the Hainbuch system is perfect. The subcontracting company manufactures components from a range of material types and when it comes to the machining of plastic and other lightweight materials, the Hainbuch system is creating benefits beyond the realms of reduced setup times and increased machine uptime. As Harry continues: “When machining plastics with a chuck, the process can create a vortex that pulls the swarf into the chuck and spindle. However, with the Hainbuch collet chuck system, it is a totally sealed unit that eliminates the vortex effect, so the chips drop straight into the base of the machine.”
Alluding to the set-up savings achieved through the Hainbuch system, Harry says: “In our particular case where we are using chuck jaws, the set-up time isn’t measured in minutes it can sometimes be hours. This is because, with several machines, we have two separate systems for jaws and collets. So, not only do we have to change between the two systems by removing all the housing and the internal workings, but we also have to clock everything up true, put it on the machine and then re-bore the jaws. With the Hainbuch system, we can easily change from collets to jaws, but we can also change from one machine to the next. This creates interchangeability between the machines.”
From a precision and repeatability perspective, Harry continues: “This is another key benefit of the Hainbuch system. I can take the jaws off one machine today and load it onto another machine and it will still run true. From a repeatability standpoint, we can accurately predict what is going to happen. The way we programme a lot of components, we use CAD models and because of that predictability in the dimensions when we are refitting collets or jaws, we can accurately predict where our datums will be and this saves even more machining and set-up time.”
Reinforcing the flexibility attributes of the Hainbuch system, Mr Wood continues: “My section lead in the turning department was amazed when he put the Hainbuch chuck back on the machine after stripping down the conventional chuck and the concentricity and repeatability was running better than 5 µm. With regards to clamping force, a traditional CNC machine has a hydraulic clamping mechanism, which can be quite savage. With the Hainbuch system, you can have a device that plugs into the collet and measures the clamping force. We also have the expanding mandrels for I.D clamping and this can be changed over in less than a minute, just like all the other Hainbuch products.”
“At present, we have invested in a range of Hainbuch collets and chucks for two turning machines and we have a decision to make regarding taking existing collets and chucks off other turning centres. If we do invest in more new turning centres, they will automatically have the Hainbuch collet chuck system installed. It really is a game-changer for our business,” concludes Wood.