OPEN MIND Pushes Dormer Tools to the MAXX
Since re-locating to its new facility over two years ago, Sheffield based Dormer Tools has invested considerable time, resources and expertise into selecting ‘Technology Partners’ to enhance the capabilities of its Productivity Centre department. Among the technology partners are Sandvik Coromant, Kelch, System 3R, Heller, Hexagon Metrology and OPEN MIND. This culmination of leading manufacturers enables Dormer to solve the cutting tool and production issues of its customers and the partners’ customers by implementing a combination of cutting edge technologies from each partner.
The company has three technical engineers in the Productivity Centre with an additional ten on the road that are imbued in customer surgeries, technical projects and customer and staff training. Always at the forefront of technology, the Dormer engineers were flabbergasted by the new hyperMAXX® roughing cycle from OPEN MIND. As Dormer Tools Machining Applications Engineer, Mr Matt Johnson comments: “I was invited by an OPEN MIND engineer to supply tooling for a demonstration piece at Warwick University and witness the benefits of the new hyperMAXX® package. Using OPEN MIND’s hyperMILL®, the previous machining time for the 18mm deep pocket in the 316 stainless steel part was 25 minutes. I supplied our S356 solid carbide end mill and changed the cutting parameters to slightly reduce feeds and speeds, but machine the full 18mm depth in one pass as opposed to the previous program that used three 6mm deep passes. This strategy reduced the cycle time. Then the OPEN MIND engineer turned on the hyperMAXX® roughing cycle and asked me to treble the recommended Dormer feed and almost double the speed rates for the cutter. My apprehension was quelled by the confidence of the OPEN MIND engineer and we immediately witnessed a staggering result.”
Calculating the QMax value for the machining cycle. Most cutting tool manufacturers measure productivity benefits by calculating the QMax value for the machining cycle, this cubic (cm/min) value is the Depth of Cut X Step Over X Feed divided by 1000. “In this demo the original QMax value was 17.1ccm/min, using the Dormer 12mm cutter at the recommended parameters resulted in a QMax value of 30ccm/min, a significant gain. However, when the hyperMAXX® module was turned on, it gave us a value of 108ccm/min, a staggering 280% improvement on the combined use of hyperMILL® and Dormer tooling. Compared to the first test piece, the result was a 630% improvement,” says Mr Johnson.
Considering the drastic improvement in productivity, the Dormer engineer expected the tool life to be significantly reduced. However, cutter wear was less than the previous cycle. To demonstrate the reduction in cutter wear, Mr Johnson continues: “We are currently machining a structural wing component from titanium for an OPEN MIND and Dormer customer. Like the OPEN MIND customer, we are using the same Dormer S357 12mm carbide cutter with a 3mm radius and X-Ceed coating and we have extended tool life from 30 minutes to over 2 hours – a tool life improvement of over 200%. The only difference is that we are using hyperMAXX®.”
Reduce stress on the cutting tool. The Dormer engineer recognises that the hyperMAXX® tool paths are generated to reduce stress on the cutting tool whilst continually calculating the optimal speed and feed for each cut. hyperMAXX® reduces the forces on the cutting tool by eliminating sharp directional changes in the tool path. As Mr Johnson continues: “hyperMAXX® maintains a constant load on the tool and eliminates sharp directional changes. It is the directional changes in alternate CAM packages that cause stress and contribute to the sudden failure of cutting tools. With hyperMAXX® our tools are changed because they wear out, with alternate CAM packages our cutting tools, like all cutting tools undergo considerably greater stress that results in sudden breakages that are never an exact constant.”
With regard to the production of the structural aerospace part, the customer was taking 40 hours to machine two sides of the component; Dormer has reduced the machining time to 10 hours with hyperMAXX®. As Mr Johnson states: “The aerospace subcontractor has a contract to produce over 150 parts that was taking a week to machine each part, we have now cut that production time to one day! The component has a number of pockets on each side and to demonstrate cycle time reduction with hyperMAXX®, one pocket was previously machined in 40minutes. Dormer is now milling the pocket in 3 minutes. To achieve such a result and simultaneously improve tool life is exceptional.”
Mr Johnson concludes: “The OPEN MIND team is extremely supportive and the technical team is always on hand for our queries. Added to this, OPEN MIND always appears a step ahead of its competition. Nobody has anything that can compare to hyperMILL® and by the time they do, OPEN MIND will have launched the next development. We are having a ‘Challenge Dormer’ Open Event in July; with hyperMAXX® I’m sure we’ll be giving subcontractors and OEM’s alike, a major productivity boost!”