Getting into gear with new mandrel

Hard work and first-class teamwork between gear manufacturer Hänel and Hainbuch has certainly paid-off. The new Mando G211 mandrel for gear manufacturers is particularly suitable for gear hobbing, cutting and grinding, and this has been demonstrated at Hänel. Now available as a standard mandrel from stock, this solution for gear cutting has optimised the manufacturing process, reduced set-up times and improved gear quality, largely credit to the stable clamping features that dampen vibration.

When a new product like the Mando G211 mandrel is launched, it must be tested thoroughly under real-world conditions. In this case, Hainbuch was looking for a reliable partner capable of testing a prototype, and the company approached Hänel GmbH & Co KG from Bad Friedrichshall, Germany.
Commenting on its willingness to participate, Jürgen Renner, the production manager at Hänel GmbH, says: “We already had positive experiences with Hainbuch clamping devices, so for us, the whole thing sounded promising from the very beginning. We saw the potential for improvements in our manufacturing and processes – that’s why we agreed. I must add, our management is very open to such partnerships and, if it results in rewarding optimisation and keeps investments manageable, nothing stands in the way of such a project.”
Hänel initially received two prototypes of the Mando G211 mandrel in sizes zero and two. The mandrels were tested on a Richardon R400 manual loading machine and a Gleason-Pfauter GP200 hobbing machine with automatic loading to see if they would be compatible.

“For our employees, this new clamping system was very strange, as for 20 years they worked with a clamping system from the machine manufacturer without radial clamping, which worked fine to date,“ admits Renner. “Initially, we had to make some adjustments to the machine and, in addition, we did not reach our zero-line on the Gleasen-Pfauter machine because the mandrel was too tall. As a result, adjustments to the machine and loading system were required. What followed were conversations with the responsible designers at Hainbuch. We have diligently tested and passed on all the information needed to further optimise the mandrel – all design changes were implemented by Hainbuch.”
The revised second prototypes were subsequently made available, undergoing field trials before a few minor adjustments to the machine were made. It was evident that the stiff and slender mandrel could go into series production and be produced for stock.

At Hänel, batch sizes are between 30 and 1000 pieces, which customers specify because of the precision. As a rule, the high-quality gears are hardened and ground, so reworking is not an option.
“With the current clamping system, we couldn‘t achieve good concentricity,” says Renner. “The workpiece was pressed axially downwards. Now it is clamped with the mandrel from the inside, radially outwards. Thus, we have higher clamping stability. This eliminates the reworking of certain components. For some of our orders, the old clamping system was good, because the concentricity was not so important. But basically, the better the concentricity, the easier it works later. With a normal hardened gear, the bore still needs to be reworked, but all the workpieces that are fully geared can now be reduced to one operation.”
Hänel has also improved set-up times with the new mandrel. This time reduction is because when using the Mando G211 mandrel, only the segmented clamping bushing and not the entire clamping system has to be changed. Use of the G211 also eliminates the need for alignment, which of course saves time. Even if the mandrel and segmented clamping bushing have to be changed to a different size, it is still faster. There are only three screws on the mandrel for the support and a screw on the segmented clamping bushing.
“If everything is prepared optimally, and the part family is in stock and can be processed one after the other, we will certainly save 50% of the set-up time,” says Renner. “Not only is the set up faster, but the process is more stable and safer.”
Andreas Hoffmann, head of toolmaking, sees even more benefits: “Thanks to better stability, we can drive higher feed rates. Even tool wear is reduced because we have less vibration.”
Hänel now has six Mando G211 mandrels, the two prototypes and four standard mandrels in sizes zero to four.

Hoffmann explains: “All new components have been manufactured with the mandrel ever since. Even with older components, we try to change over to the mandrel clamping because the segmented clamping bushings from Hainbuch can be delivered within one day. That’s a huge advantage for us.”
“For me, it is incomprehensible that we have not worked with Hainbuch before,” Renner concludes.
For further information www.hainbuch.com

Vigilance Group expands UK operations

The Vigilance Group has announced a significant expansion of its operations in Bristol and the opening of a new showroom facility in the East Midlands.

Vigilance, the engineering specialist holding company that incorporates under its corporate banner – Machine Tool Sales Online (MTSO); MACH Machine Tools; and Vigilance Engineering Safety Products – says the move will ensure the group’s long-term growth and future prosperity by providing customers with more choice and improved access to its technologies and solutions.
With regard to the Bristol facility, premises adjacent to the site recently became available and so Vigilance grabbed the opportunity to virtually double its floor space to 21,000 sq ft. The move will see the company create a new and larger customer showroom and demonstration facility, and enable more new and used machine tools to be held in stock. The group has also acquired 5000 sq ft premises previously leased by DRMT Solutions Ltd in Leicester, which has closed following the retirement of one of its directors.
For further information www.machmt.co.uk

Studer S41 ticks Magellan’s boxes

The Bournemouth facility of Magellan Aerospace manufactures items such as pintle pins, undercarriage pins and split chrome halves, all of which need high-precision grinding to achieve the required standards of accuracy and surface finish.

Here, the company has recently installed a Studer S41 CNC universal cylindrical grinding machine from Advanced Grinding Supplies.
“Having been enthusiastic users of Studer S30 and S21 grinders, purchased from Advanced Grinding Supplies Ltd, not only have we been delighted with the performance of these machines, we have also been impressed by the support and advice received from the supplier,” says Keith Summers, engineering manager, special projects European operations.
“I was able to visit the Studer factory in Switzerland and witness in-depth grinding trials that confirmed the performance of the S41 on our parts, and its ability to deliver improvements in cycle times. As a result of the S41’s suitability, and given the guarantee of continued support from Advanced Grinding Supplies, we were happy to place an order.
“The help of Advanced Grinding Supplies was invaluable when we were specifying the machine and its accessories and consumables, such as dressing tools, grinding wheels and coolant,” continues Summers. “We believe that these important add-ons will help us to realise the full productive potential of our new grinder.
“The speed and flexibility of our Studer S41 is already helping in our ongoing quest for productivity improvements. As well as increasing our current component grinding capacity, the S41’s between centres and centre height capacities, in addition to its large weight bearing capability, will ensure that it is able to undertake the precision grinding of all future components.”
For further information www.adgrind.co.uk

Master launches ceramic discs for angle grinders

Master Abrasives has introduced a range of ceramic abrasive discs for angle grinders. Unlike conventional discs, the grain in Master Ultra Ceramic discs fractures to form new points that are sharp and precise.

This functionality maintains a cooler cutting action and long product life, making the discs suitable for aggressive grinding and blending applications. The discs also require less pressure, resulting in reduced operator fatigue.
Initially available from stock in 36 and 60 grit for 50 and 75 mm diameter discs, additional options for the Ultra Ceramic range are set to follow. The discs from stock have the MRD threaded screw-type mounting system, which makes them suitable for high-volume, high-production operations. Ultra Ceramic discs are packaged in the trademark Master branded blue boxes, and will also be available from distributors of the Master brand.
Andy Wright, national sales manager, says: “We’ve already experienced exceptional results in various customer applications when using ZIPP high-power angle grinders with Master Ultra Ceramic discs, and are now finding new opportunities to improve productivity in aerospace, fabrication and foundry markets.”
The ZDG-302 air angle die grinder by ZIPP, which is suitable for many high-speed grinding and finishing applications, is compatible with Master quick-change holders and discs. The grinder can be used on finishing dies, metal moulds and cast-iron workpieces.
For further information www.master-abrasives.co.uk

Precision required for rotor grinding

Thanks to the technologies of Holroyd Precision, a major industrial group in northern China will soon embark on the production of its own range of air ends, helical rotors and screw compressors.

A £1.4m order was secured recently that requires Holroyd Precision to supply one of its helical rotor and thread grinding machines to the customer. The machine, a Holroyd TG 350E, is set for delivery in early 2019, when it will be used to precision-grind helical components of up to 350 mm in diameter and 1795 mm in length.
“We are delighted to have secured this significant order,” comments Holroyd regional sales director, Steven Benn. “Although for commercially sensitive reasons we cannot name the customer, it is particularly rewarding to know that in their quest to achieve the highest levels of precision in rotor manufacture, they recognised the uncompromising levels of accuracy that our technologies offer.
“As we are members of the Manchester-China Forum,” he continues, “securing this significant order also underpins our ongoing drive to strengthen ties between the city and China.”
Equally suited to prototyping, batch and volume production, TG series machines are designed primarily for the finish-grinding of helical screw components such as worm screws and rotors after they have been milled to a rough or semi-finished state. Fully automated on-machine probing provides closed-loop feedback of corrections to the dresser wheel and does not require a high level of operator skill.
For further information www.holroyd.com