Edwards Precision Saws Services (EPSS) has been manufacturing wide bandsaw blades for more than 20 years from its base in Somerset and in that time has built up a considerable customer base among sawmills both at home and in Europe.
Focusing particularly on bandsaw blades, EPSS was the first company in the UK to introduce the higher strength 170 grade steel. Having seen the benefits of higher wear resistance and improved mechanical strength that this new material could offer, the company brought in its first batch of 170 steel from Sweden’s Uddeholm in the early 1990s. Since then it has taken delivery of more than 200 tonnes of the material to make bandsaw blades and blade service life of two to three shifts is now fairly common. Uddeholm 170 is especially good for Stellite-tipping and blades can be re-tipped several times.
EPSS has two modern press lines producing toothed steel and its ability to punch a variety of tooth shapes allows it to meet every customer’s requirement. Two plasma-arc Stelliting lines provide high quality Stellite tipping while hydraulic swaging is used for non-tipped blades. On site at Taunton the company has automatic hydraulic tensioning machinery which can be programmed to meet every blade application, while final tooth and side grinding is undertaken on one of its Vollmer wet grinding machines, including the state-of-the-art CNC CA300 camless grinder which can handle over 60 different tooth shapes, including a whole range of vari-pitch formats.
Edwards was the first company in the UK to install one of Vollmer’s RC100 bandsaw grinding machines which was specifically designed to automatically level, tension and straighten wide bandsaw blades. This process is often referred to as the ‘black art’ of saw doctoring but anyone who has seen it carried out will know that it relies on years of experience and an innate understanding of the blade and its planned use. Akin to a juggling act, the blade first has to be evaluated to identify defects before a decision can be taken about what corrective action is required to produce the desired blade. The processes of levelling, tensioning and straightening all involve deforming the steel so each process has a bearing on the other, although each has to be carried out separately.
Storing details
One of the benefits of the new Vollmer machine is that its programmable memory can store details of all EPSS customers’ blades so regrinding becomes a more straightforward operation. What once took a saw doctor many hours to carry out can now be recreated mechanically and left to run overnight, for example – although this does not mean that the operation has been de-skilled. While the hard work and complex calculations are now carried out by the RC100, operators still have to program the software to take account of the type of material, end-use, and levelling tolerances among other parameters.
By using the Uddeholm 170 grade high-strain Swedish steel and specialist vari-pitch grinding on the Vollmer CA300 and CA200 CNC grinders, EPSS can tailor specially spaced tooth pitches to individual requirements and sawmills report consistently improved throughput as well as quieter running as a result.
Edwards can also offer Uddeholm Ankar-R steel for applications where Stellite tips remain sharp for long periods of time. Considerable savings in downtime and servicing can more than justify the higher initial cost, especially when the steel is coupled with vari-pitch technology.
