Creative Woodworks & crafts 2001-01, страница 59

) D GMD, Good,

IBM, A TIONS

by Frank Pozsgai I cannot tell a lie, I was strongly influenced by the 1966 Beach Boys® No. 1 hit, "Good Vibrations "©!

Let's talk about saw vibration

Bui enough of playing Name That Tune . . . We need to talk about vibration as it pertains to a scroll saw—what are the causes, what's an acceptable amount, and what can wc do about it!

Over the coursc of the last several years, 1 have demonstrated every scroll saw on the market. It never ceases to amaze mc when someone walks up to the saw and puts their hand on the table to chcck the level of vibration, but never asks about the scroll saw itself. I've come to the conclusion that they sure aren't genuine woodworkers, or they'd know that their "touch test" isn't accomplishing much.

It's not rocket science... is it?

Vibration occurs when the moving masses (parallel saw arms and counterweight) arc not perfectly balanced. According to Sir Isaac Newton, for every action there is an equal and opposite reaction. In your scroll saw, the force exerted by the saw arms is opposed by an equal force exerted by the counterbalance weight. If these two components are perfectly balanced, there will be very little vibration to be felt. However, if they are NOT balanced relative to each other, you will feel vibration. Let's face it, in the real world of mass-produced equipment, nothing is ever perfectly balanced. So this is the reason you are likely to feel vibration.

Dealing with it

The acceptable level of vibration actually depends on each individual scroller and what they can tolerate. Playing heavily into this is the tendency to have the preconceived notion that vibration of any degree will lessen one's ability to use a scroll saw successfully.

What, then, should we do to deal with vibration? Here arc some ideas to choose from: A. Increase the mass of your base. B. Use an appropriate anti-vibration pad- not loo thick or too thin. C. Those who have aluminum table lops can purchase a spray can of insulation foam, turn the saw over, and till the entire underside of the table with the foam. This will reduce the noise level, as well as some of the vibration.

D. For those saws yielding acccss to the main pivot bolls: remove and grease (yes, GRF.ASE) them on a regular, as-nceded basis. The typical scroll saw uses an oil-impregnated Hushing in which the medium carbon pivot bolts ride, and as the steel wears and elongates the brass bushing, the grease helps to fill the void and reduce the vibration. \ \ E. Bolt your saw down to your work bench, and also use a n isolation barrier between the saw and the table.

F. Research and alter the dynamic vibration characteristic of your particular scroll saw. However, you could expend most of your natural life developing this process!