Power Equipment Australasia

TEST PREPARATIONS To achieve the most accurate performance comparisons, all test wood was selected from the same 30 year old Douglas fir plantation in northwest Washington State, USA. Several larger trees were harvested and milled into 10-in. by 10-in. timbers that ranged from 10- to 16-feet in length. These timbers would provide a uniform test material for timed cuts. About half the lineal measure of these timbers was unusable, due to knot whorls and the harder wood adjacent to them. All test cuts were made in knot-free, clear sections only. To compare stay-sharp characteristics, we felled a group of Douglas fir trees with similar diameters at breast height. All were the same age and growing in the same area. They were transported with an excavator to keep them clean, and cut into 32-ft. lengths. The volume of each log was calculated, and the three most identical logs were selected for the stay-sharp cutting test—one for each brand of chain. TEST PROCEDURES The same gas-powered chain saw was used throughout the testing—a one-year-old Stihl MS261 C-M that was fitted with a new 18-in. guide bar and drive sprocket. This 50.2 cc 4 HP profes- sional model has an electronic engine management system. Its no-load RPM is around 14,000 RPM. Engine speed in the cut is 9,500-10,000 RPM. The chains in this test were evaluated on the following criteria: 1. Cutting speed, new; 2. Cutting speed, used; 3. Cutting speed, after sharpening; and 4. Boring ease. To pinpoint cutting speed, each chain was timed in five separate cuts and the times were averaged. Then each chain was used to make three, timed boring cuts through an 8-in. diameter log section. These times were also averaged. Next, each chain was used to make 239 cuts in one of the 32-ft., stay-sharp test logs using this sequence: 11 firewood rounds off the butt end, and 228 one-inch rounds off the small end. Two cups of forest dirt were spread evenly across the final 48-in. (about 20 per cent of total cuts) to simulate typical abrasive conditions. These 32-ft. test logs each contained about 10 cu. ft. of wood. The 239 stay- sharp cuts would be equivalent to bucking about nine such logs into firewood lengths. When split and stacked, it would come close to a cord in volume. After completing the 239-cut gauntlet, the chain was re-tested on the same 10-in. by 10-in. timber used to determine its cutting speed when new. As before, five cuts were made and averaged, so cutting speed-new vs. cutting speed-used could be measured accurately. After dulling, each chain in the test sequence described above was hand- sharpened using a Vallorbe plate-type filing guide and retested in a 10-in. by 10-in. timber. Again, five cuts were made and the times were averaged and then compared to the new-condition cutting times. Other perfor- mance factors were considered, but proved irrelevant. For example, we monitored chain stretch, but none of the three chains stretched beyond what would normally be expected. TEST RESULTS In the 2015 test, the new loop of Archer .325-in. semi-chisel chain trailed its USA competition, but caught up significantly in the post-sharpening round. In this current test, the Archer .325-in. chisel chain was very fast... straight out of the box. Its average cutting time was just 0.11 of a second behind the leader, US-1. It beat US-2 by 0.81 of a second. The Archer .325 chisel excelled in stay-sharp ability, turning in the fastest time of all after the stay-sharp cutting test—a loss of just 11.6 per cent compared to its new-condition cutting time. US-2 lost 16.1 per cent compared to new, while US-1 dropped a whopping 22.4 per cent compared to new. All three chains cut faster than new after sharpening, but Archer gained more ground on US-1, reducing the gap to just 0.05 of a second—a virtual tie. US-2 lagged behind by a full second. As this test involved professional-use chains, they all bored readily.However, Archer enjoyed a clear lead in this category, surpassing US-1 in boring speed by 16 per cent andUS-2 by 29 per cent. In 2015, we were somewhat surprised to see how well Archer chain performed compared to the old-line leaders in the field. However, while doing that project it became evident that PMD was genuinely committed to making high quality, competi- tive products. So, the strong showing in this evaluation was not too surprising. EXTENDED TESTING The test data reported above relate to chains that were new or almost new. But, how do they perform in extended use? This is, perhaps, a more important criteria, especially to a professional user. With their many decades of field experience, the durability and reliability of the US-1 and US-2 chains were well- documented. Could the upstart Archer .325 chisel chain last as long and maintain its excellent cutting characteristics through weeks of use and abuse? To find out, we committed one of the Archer test loops to an extended work detail on that small tree farminWashington, USA. We focused on thinning, which, in this case, entailed falling cull trees, de-limbing and topping, skidding to a landing and bucking into firewood. Our extended test criteria was not determined by time or number of work sessions. Our plan was to use this one loop until it failed or its cutters were filed all the way back. We put in a month’s worth of work with this chain, sharpening and adjusting depth gauges as needed along the way. It remained a pleasure to use, cutting fast and straight until the end. Average speed was 6.81 seconds, which was faster than all three test chains when they were brand new! In addition to its impressive ongoing cutting capability, the chain’s frame held up very well, with no cracks or excessive wear, and it did not stretch at all. The test loop proved beyond a doubt, that Archer’s .325-in. chisel is as fast AND durable as the best-known brands. The only thing it doesn’t match is their high price! Ken Morrison Industry journalist Ken Morrison has researched and reviewed portable power equipment technology for 30+ years. This article originally appeared in the July edition of PowerView. PRODUCT REVIEW 18 | POWER EQUIPMENT AUSTRALASIA | DECEMBER - JANUARY 2018