Before you start
Both manuals require the saw to be secured to a workbench or stand — DEWALT through the three holes in its base, WEN with wood screws or bolts, washers and nuts — so it cannot move while running. Clear the table of everything but the work. Every step below that touches the blade, the clamps or the table is done with the saw switched off and unplugged. If the saw is new to you, the scroll saw guide explains its parts, and choosing a scroll saw covers what to compare before buying one.
Fit the blade
A plain-end blade (DEWALT DW788)
Unplug the saw
DEWALT's first instruction for fitting a blade.
Release the tension
Move the blade tension lever fully to the right, and loosen — but do not unscrew — the top and bottom thumbscrews.
Thread and clamp the bottom
Pass the blade through the hole in the table with the teeth facing the front of the saw and pointing down, and tighten the bottom thumbscrew.
Clamp the top and tension
Fit the top of the blade into the top clamp, tighten its thumbscrew, then set the tension before switching on.
A saw that takes pinned blades works differently. On the WEN 3921, the blade's pin hooks into a recess in the lower holder; you push down on the upper holder to slip the top pin into its slot, then lower the tension lever and check both pins are seated. Its pinned blades can go in either of two slots, turning the blade 90° — to accommodate a wider variety of workpieces, as WEN puts it. Pinless blades on the WEN are clamped into separate blade attachments that hook onto the holders. Whatever the saw, the teeth point down: WEN states that the teeth cut only on the downstroke.
Set the tension
- On the DW788, moving the lever to the left increases tension. DEWALT says the right tension varies with the blade's size, that you should reduce it if blades break often, and that you will get better at judging it with practice on scrap.
- On the WEN, the lever applies tension and a knob adjusts it: clockwise tightens, counterclockwise loosens.
- Olson's check: pushed with reasonable force, the middle of the blade should not move more than 1/8 in front to back. Olson adds that too little tension weakens performance.
- After work, DEWALT says to remove the blade or release its tension when the saw will stand unused for a long time.
Set the hold-down and the speed
DEWALT's material hold-down should touch the top of the work; WEN's guard foot should just rest on it. Neither is removed: DEWALT says its hold-down is also a barrier between fingers and blade. When the table is tilted for a bevel, both are re-set parallel to it. On the DW788 the speed knob is turned with the saw running. DEWALT recommends slower speeds for metals, plastics, harder woods and very thin materials; for anything else, try the cut on scrap and adjust.
A reverse-tooth blade has a few teeth near its lower end pointing up, to cut on the upstroke and stop the underside tearing. Olson says these work best with 1 to 2 reverse teeth showing above the table on the upstroke, adjusting the blade in its holder, or trimming it, when necessary.
Outside cuts and curves
Cutting to a line
Start clear of the blade
WEN says not to start the saw with the work pressing on the blade: switch on, then bring the work slowly to it.
Hold it down, feed gently
Hold the work firmly on the table and feed it only as fast as the saw cuts. DEWALT says to feed fast enough for the blade to cut but never to force the work; WEN says forcing it deflects the blade.
Steer by turning the work
Turn the work, not the blade, to follow the line, keeping your fingers out of the blade's path if the work slips. WEN warns the blade tends to follow the grain, so be ready to correct for it.
Relieve long curves
DEWALT says to make relief cuts before cutting long curves, so waste falls away as you go.
Back out with care
If the work resists being backed out of an unfinished cut, DEWALT says to switch the motor off first.
If the cut edges scorch, Olson's advice is to slow the feed and let the blade cut, and to use a lube stick on the blade or clear shipping tape on the work. Blades dull quickly — WEN gives 1/2 hour to 2 hours of cutting — and a beginner should expect some to break while learning.
Inside cuts
Inside cuts are what a scroll saw does that most saws cannot: the blade is freed at one end, passed through a starter hole and re-clamped, as the drawing at the top of this page shows.
An inside cut (DEWALT DW788)
Drill the starter hole
Drill a hole in the waste, close to the line. Make it the pilot hole the blade's maker lists: Olson gives 3/64 in for its #5 reverse-tooth FR44602 and 3/16 in for every one of its pin-end blades.
Free the blade's top
With the saw unplugged, move the tension lever fully right, loosen the top thumbscrew and lift the top arm, leaving the blade in the bottom clamp.
Thread the work
Lower the work over the blade so it passes up through the starter hole, then re-clamp the top of the blade.
Re-tension and cut
Re-set the tension, plug in, and cut the opening. When the loop closes, the waste falls free; release the blade again to lift the work off.
DEWALT also allows the reverse: free the bottom of the blade and thread it down through the work. On the WEN with pinless blades, the blade goes through the table insert slot and the work's pilot hole before the upper attachment is tightened. Cut all the inside openings of a piece before its outline, so you are holding a large, stiff board while doing the fine work — the order both builds in scroll saw projects follow.
When a blade jams
WEN says a jam is usually sawdust clogging the cut. Switch the saw off and unplug it, wedge the cut open, and back the blade out. DEWALT adds never to remove jammed or cut-off pieces until the power is off and the blade has stopped, and never to reach under the table while the saw runs.
Safety— Small pieces and fingers
Do not cut a piece too small to hold safely, and keep your fingers out of any line a slip would carry them along. Wear eye protection and, as DEWALT advises, a dust mask. More in woodworking safety rules and woodworking safety equipment.
Before each cut
- Saw secured; unplugged while the blade is fitted
- Teeth pointing down; tension set and checked
- Hold-down or guard foot resting on the work
- Starter holes drilled for inside cuts
- Speed set on scrap
- Fingers clear of the blade's path
Put it into practice with scroll saw projects for beginners, which use outside cuts only, then the inside cuts in scroll saw projects.
Sources
The setup follows the DEWALT DW788 manual because it gives one complete sequence for a plain-end saw; WEN's steps for a saw that takes pinned and pinless blades are given beside it. Tension is described only as the makers describe it; no tension figure is given. Pilot-hole sizes are Olson's for its own blades. Nothing was tested.
- 1.
DW788 20" (508 mm) Heavy Duty Variable Speed Scroll Saw instruction manual. DEWALT.
Used for: Unplugging before fitting a blade; the tension lever moved fully right, thumbscrews loosened but not removed, the blade threaded through the table teeth forward and down and clamped bottom then top; tension increased by moving the lever left, varying with blade size, reduced if blades break often, released when the saw is not in use; the hold-down touching the work and set parallel to a tilted table; slower speeds for metals, plastics, harder woods and very thin materials; feeding fast enough to cut but not forcing; relief cuts before long curves; switching off if the work resists being backed out; the inside-cut sequence through a pilot hole.
- 2.
3921 16" Variable Speed Scroll Saw operator's manual. WEN Products.
Used for: Fitting pinned blades in either of two slots, turning the blade 90°, and pinless blades in their own attachments threaded through the table insert and the work's pilot hole; tension by a lever and a knob turned clockwise to tighten; the guard foot just resting on the work; not starting the saw with the work against the blade; feeding only as fast as the saw cuts; compensating for the blade's tendency to follow the grain; a blade jammed by sawdust in the cut freed with the saw off and unplugged by wedging the cut open; expecting some broken blades while learning.
- 3.
Scroll Saw Blade Selection Chart. Olson Saw Company, 2020.
Used for: A tension check — with reasonable force the middle of the blade should not move more than 1/8 in front to back; reverse-tooth blades set with 1 to 2 reverse teeth above the table on the upstroke; slowing the feed and using a lube stick or clear shipping tape to reduce burning; a pilot hole for each blade, 3/64 in for its #5 reverse-tooth FR44602 and 3/16 in for its pin-end blades.
About this tutorial
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