The sharp end

In many ways throughout most civilised countries in the world, we've become something of a throwaway society. As market pressures force the price of many everyday commodities down, the tendency is to replace rather than refurbish or repair, but is this always the most cost-effective option? In manufacturing circles, drills are often discarded once they become worn, but there is an alternative as Dave Tudor found out when he spoke to Darex's Lorelei Frye-Wiltrout at MACH 2010.

Headquartered in Ashland, Oregon, USA and represented in the UK by Salisbury, Wiltshire-based 1st Machine Tool Accessories (1st MTA), Darex is a family-run specialist manufacturer of drill sharpening machines and has been in business for 35 years. Broadly, its global customer base comprises two distinct areas – those companies purchasing machines to sharpen their own drill bits and organisations providing a regrinding service on a subcontract basis.

The cost savings obtainable through regrinding can be considerable as Ms Frye-Wiltrout reveals. “We carried out a cost analysis on a cross-section of commonly used drills that would typically be used by any manufacturing company. We purchased these drills from the catalogue of a tooling supplier in a variety of sizes, diameters and materials until we had enough to fill a 1lb coffee can. We then added up the total cost of all the drills.

“The results surprised us all,” she declares. “For the cumulative price of the drills in a relatively small coffee can, companies could purchase our V391 precision drill sharpener – and still get change.”

Return on investment

The benefits of being able to grind your own tools will of course be dependent on application but as well as the having the convenience of grinding drills quickly onsite, an additional plus point is the capability of being able to produce bespoke tool geometries for trialling purposes prior to actually purchasing a tool. “This is one of the major benefits of our tool sharpeners,” Ms Frye-Wiltrout emphasises. “Once the machine has been purchased, companies can produce their own helixes and geometries at virtually no cost. Operationally, tools can be tweaked to produce optimum results.”

For customers considering the capability of carrying out their own drill grinding and regrinding, Darex offers a user friendly ‘Return on Investment' calculator on its website. As Ms Frye-Wiltrout explains, this tool is ideal for applications engineers needing the hard facts necessary to convince cautious financial controllers deliberating over whether to make the investment or not.

“It's a very simple tool that calculates when machine payback will be realised,” she advises. “The customer simply inputs how much money is currently being spent on new drills; if applicable, how much is being spent on regrinding and then the particular machine model they're interested in. In seconds the payback time is calculated and presented to the user.

Something for everyone

Visitors to the 1st MTA/Kitagawa stand at MACH were able to get up close and personal with a cross-section of the Darex range under power and in action. As we'll see, the products on offer cover a multitude of uses and applications.

The V391 drill grinder and sharpener is aimed specifically at small machine shops with relatively low volume drill sharpening requirements. Fast and simple to use, Darex claim that common drills can be sharpened quickly and accurately in less than one minute which means that productivity is kept at optimum levels. “To get some idea of price perspective here – for the cost of less than 100 drills, users can purchase a V391 sharpener,” Ms Frye-Wiltrout reveals. “The Darex V391 incorporates some of the same technology used in our more advanced machines and is the perfect choice for shops that need a sharpener for intermittent use. Its simple, intuitive design give everyone access to sharp drills when you need them.”

The V391 incorporates two wheels in its design – a sharpening wheel and a split point wheel. CBN for HSS or diamond wheels for carbide are available and no tools are necessary for adjustment. Featuring EZ adjustable split depth, split angle and adjustable point splitting and adjustable point relief, the machine can handle drill diameters from 3mm to 19mm and 118° to 140° point angles. With a weight of 11kg and footprint of 30mm x 28mm x 23mm, the machine can be integrated into machine shops where space is at a premium.

Moving up the product range to accommodate organisations that need more robust and heavy-duty equipment, the XT3000 expandable drill grinder and sharpener is designed for high volume/high variety environments. “The XT3000 is ideal for companies that use tool cribs,” Ms Frye-Wiltrout advises. “It not only sharpens drill bits but also countersinks, step drills, 90° spotting drills and Brad point drills. It's versatile too – it can handle miniature drills down to 1.5mm diameter and up to 30mm.”

Described by Ms Frye-Wiltrout as a ‘workhorse' the XT3000 is ideal for shops that sharpen a variety of drill sizes and styles and want the advantages of an advanced manual drill and tool sharpener. Point angles of 118° to 150° with a 90° option can be accommodated and again the user has a choice of grinding wheels available – Borazon CBN for HSS and cobalt and diamond for carbide. 

Top of the tree

With the XPS16 drill grinder and sharpener, things start getting serious. It's a full 4-axis, high precision CNC sharpener designed for high volume applications and targeted primarily at the carbide market. Effectively however, its USP is the ability to hone as well as grind, providing the ultra precise cutting edges critical to cutting performance and prolonging tool life.

The honing feature can be activated after the machine sharpens and splits the drill bit. An additional feature is the ability to disable the grinding process completely and use the machine solely for honing operations.

Drill capacity ranges from 3mm to 16mm diameter and a variety of point styles can be sharpened including standard conic, four facet, standard and radius split point. Dimensionally, the machine occupies a footprint of 660mm x 560mm x 300mm with a number of options available including 260-grit and 320-grit diamond wheels, 120-grit brush diamond hone and a 90° point angle package.

A company that listens to its customers, Darex is constantly looking to improve its product range and welcomes feedback from its clients. A recent example of this is with the XT3000. “The XT3000 is a manual machine, but we had a number of requests from customers who asked if the process could be automated,” Ms Frye-Wiltrout affirms.
“We took their comments on board and designed an automated sharpening system which can be purchased as a complete system or integrated to existing machines as a retrofit option.”

Added value

Darex's association with 1st MTA and Kitagawa began way back in 1992 when the company was looking to expand its products into global markets. The distribution agreement was initially established that year at the EMO exhibition in Hannover.

“We're very selective about our distribution partners,” Ms Frye-Wiltrout explains, “but what we particularly like about 1st MTA is the fact that they're happy to carry stock not only of our products, but also of our vast range of accessories. From a technical aspect the company is well versed on our entire product portfolio and provides exemplary service and support to our users in the UK.

“It's also worth pointing out that during 2009 when world markets were down, 1st MTA maintained healthy business levels which is commendable in such tough operating conditions,” she concludes. “We look on the company more as applications partners rather than simply distributors. We regularly have 1st MTA staff over to Oregon for training and are confident that they can match our products with any drill sharpening application that may arise.”

Darex
www.darex.com 1st MTA
www.1mta.com