Woodworker's Journal 1985-9-6, страница 72

jmi.iIM link I vcaliher had very little li.tw.iiil tuning action on the down-n.iK although the aggressiveness of . til was .ilmut till, same as the llegner.

What To Ijook For

l thration—Because scroll saws cut with a reciprocating (up-and-down) motion. rather than a continuous cutting action like a hand saw. you can expect a certain amount of vibration—it's just the nature of the beast. However, better saw s are engineered to keep vibration to a minimum, which results in greater cutting accuracy, prolonged blade lite, reduced operator fatigue, and less wear on bearings and other moving parts.

A number of factors contribute to saw vibration: sloppy or oul-of-round bearings or bushings, misalignment of upper and lower arms, or a poorly balanced drive system, to name a few. Some saws.

Photo 3: Delta 40-601

such as the Delta, overcome vibration problems largely by sheer mass alone: the siurdv cast-iron arms and base make this saw as sturdy as a rock. Lighter-weight saws, such as the Hcgncr Multi-max 18V, Excaliber EX II, and both the RBI saws, rely on precision machining to keep vibration to a minimum. (This is not to say that the Delia is poorly machined, by any means). The llegner and Excaliber. by the way. showed ihe leasi amount ot vibration in my tests; they were a joy to use. In comparison, the IX-li.i and RBI saws had some vibration, but not enough to affect cutting performance or lo he particularly annoying, flic Shopsmith vibrated ihe most -a bii too much, in my opinion. Ii did perform satisfactorily in my culling tesls. but the vibration was irritating.

The way the saw is mounted also has a lot to do with vibration. Most of (lie

Photo 5: H eg tier Multimax IS I

saws tested have sturdy stands, either as standard or optional equipment. W hile testing one of the saws, it was making an irritating rattling noise. Upon closer inspection. I noticed that I hadn't fully tightened one of the bolls on ihe stand. As an aside, a dab of silicone seal placed in the hole around each bolt during siand assembly will further reduce the likelihood of stand vibration. Also, make sure you install the leveling feet (hat come with the siand and adjust them properly. You can mount any of these saws on a bench, but on most benches, you'll find that the saw w ill vibrate more than when mounted on a siand. We'll have more on stands later.

A final word on vibration: even with the best saws, you may receive a unit that has excessive \ i brat ion: the cause is usually due to nuis, bolts or screws thai work their way loose during shipping.

Phot,, 7: KHI Hawk 220VS

Photo 4: I i ratthrr EX II

Photo 6: RBI Hawk 2I6YS

Photo 8: Shopsmith 555272.

IV Woodworker's Journal