How a Foot-Power Scroll Saw Works.
—If you will look again at Figs. 13 and 14 you will see that the scroll saws shown have saw frames very like a hand saw frame. The lower part of the frame is connected with a crank on the end of a spindle, which has a small grooved wheel fixed to it, by a pitman or rod and the treadle is connected with the large drive wheel by another pitman; finally the drive wheel is belted to the small grooved wheel.
Now when you work the treadle with your foot it produces a reciprocating motion and this is changed by the pitman into rotary motion which it imparts to the drive wheel. Since the grooved, or driven, wheel is smaller than the drive wheel it revolves faster and this gives the pitman connected with it a very rapid rotary motion on one end but as it is pivoted to the frame which in turn is pivoted at the rear end it is changed into an up and down or reciprocating motion exactly like the treadle but many times faster.
The Fleetwood works a little differently, in that instead of a frame the pitman is connected with a metal block that slides in a guide. The lower end of the saw is fastened to the upper end of this sliding block and the top of the saw blade is fixed to the end of a long, curved spring whose elasticity tends to make it fly up.
This action keeps the saw blade always taut and pulls it up except when the pitman pulls the block down and the saw with it. This is the principle on which large power jig saws used in shops are worked.
How to Saw on a Foot-Power Scroll Saw.
—Lay the board you are going to saw flat on the table of the machine and put your finger tips of both hands on top of the board; when possible keep one hand on one side of the saw and the other hand on the opposite side of it.
Press down hard enough on the work to keep it on the table against the up strokes of the saw; as the top of the table is polished it is easy to slide the work around and keep the saw on the line. Run the saw at an even speed and do not feed the wood against the blade too fast.
TABLE OF SCROLL SAW WOODS
| Name | Price per foot planed to a thickness of | ||
|---|---|---|---|
| ¹⁄₁₆ to ¹⁄₈ in. | ³⁄₁₆ in. | ¹⁄₄ in. | |
| Poplar, or White Wood or Bass | $0.07 | $0.08 | $0.09 |
| Spanish Cedar | .10 | .12 | .14 |
| White Maple | .10 | .12 | .15 |
| Sycamore | .11 | .13 | .15 |
| Hazel Wood | .11 | .13 | .15 |
| Oak or White Ash | .11 | .13 | .15 |
| White Holly | .12 | .14 | .16 |
| Black Walnut | .14 | .16 | .18 |
| Bird’s Eye Maple | .14 | .16 | .18 |
| Mahogany | .14 | .16 | .18 |
| Cocobola | .20 | .25 | .30 |
| Amaranth | .20 | .25 | .30 |
| Rosewood | .25 | .30 | .40 |
| Satin Wood | .30 | .35 | .40 |
| Tulip | .50 | .60 | .75 |
| Real Ebony | .50 | .50 | .50 |