Excalibur Scroll Saw EX21

This article of mine was first published late last year in The Australian Wood Review, and so I can now reprint it here on Stu’s Shed (as per a specific arrangement with AWR).

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It is a well-known aphorism that first-impressions count, and both the designers, and manufacturers of the Excalibur EX21 Scroll saw knew this very, very well.

A scroll saw is not something that needs to look like a prop from Star Trek, or  encased in plastic to such a degree it disguises its real form. This scroll saw looks, and feels serious, and it has a price tag to prove it.  The whole unit has a very utilitarian design:  you need a flat working surface, so there’s a large flat surface of plate steel.  A frame and base – more plate steel bolted together.  A rack and pinion system to make angled cuts – even more plate steel.  The machine is solid, and well engineered.

Excalibur

For angled cuts, the EX21 uses the same concept as a increasing number of scroll saws, in that it tilts the blade (and mechanism) over, rather than angling the base.  From an operator’s point of view, this means your workpiece remains on a large horizontal work surface providing ideal access and control, even when performing cuts up to 45 degrees to either side.

Angled Cuts

To tilt the assembly over, the EX21 uses not one, but two rack and pinion mechanisms at either end of the tool so the mechanism is smooth and solid.

Rack and Pinion Mechanism

Underside Showing Tilt Mechanism Rod

The motor protrudes out of the side of the tool, and connects directly into the oscillating mechanism, rather than relying on belts to transfer the power from the motor. The motor is also direct current, so it retains full torque throughout the variable speed range of 400 – 1550 strokes / minute.

Protruding Motor

Direct Drive

If you strip a scroll saw down to its fundamental principle, it is to take a fine blade, and oscillate it rapidly up and down, and even here the EX21 is a superior machine.  The drive is transferred to the blade via a twin parallel link drive, so instead of having a long arm top and bottom that oscillates (and due to that length sacrifices a huge amount of the power developed by the motor in getting it to the blade), this has two links – one for the top of the blade, one for the bottom that delivers the power right to the end of the arm before it is converted at that point through a couple of very short arms to produce the oscillating blade.

Upper Blade Arms

The actual speed of oscillations is the same as other machines, but the difference in developed power is substantial.  For an operator, this means a difference between stalling the machine, or having it to continue cutting even in trying circumstances (such as thick stock (up to 53mm), and/or tight corners) and in difficult timbers.  Also, it is claimed to reduce overall vibration of the machine, and while this is true throughout the majority of the oscillating speeds, vibration became quite noticeable at the highest speed settings.  Having the scroll saw clamped down to a solid bench, or the separately available stand should reduce that considerably.

A obviously common task when using a scroll saw is changing the blade, and particularly feeding the blade into the middle of a pattern for an internal cut.  The blade clamping mechanism and independent tensioning mechanism makes this task a breeze.  The overall blade tension is set by the knob at the back of the machine, and it allows a significant amount of tension to be exerted on the blade, which will optimise its performance, both in quality of the cut, as well as its ability remain on track and cut straight (vertically), without the blade trying to squirm during the cut.  However, there is no need to wind off that tension for a blade change, as the blade clamping mechanism independently releases and reapplies that tension with its “flip tensioner” during a blade change.

Flip Tensioner

The actual clamp itself is also very simple, and importantly, tool-less.  Finally, the top arm lifts well clear of the work (still with the blade attached at the top point), making it very easy to feed into the next hole for another internal cut.

Raised Arm

The arm can remain in the raised position, but I did find the method to achieve that a little questionable.  It relies simply on a bolt passing through the housing to rub on the arm, and the friction to keep the arm up.  I would have thought a more positive method for locking the arm in the upper position would have been preferable, and sometimes found that resorting to a block of wood provided a more positive (although undesirable) solution.  If the arm is lifted too high, it actually impacts on the threads of another bolt that holds a side-cover on.  Do this too hard (or incorrectly lift the saw by the top arm), and there is a risk of damaging the threads of this access bolt.

Raised Arm Restraining Bolt

The work-holddown seems to have been a bit of an afterthought – not that it is incorrectly positioned, but it has not had the same amount of precision engineering treatment that the rest of the saw has benefited from.  Also too, the very standard concept of the air pump produces very little airflow (no worse than other scroll saws), but again I would have liked to have seen a better solution.  A light source may have also been a sensible inclusion, particularly if it was on a flexible arm utilising fibre optics, or modern LED light sources so it can be positioned where required.  At least there is no laser!

Blower & Holddown

The bottom line: This is a well engineered tool, and really sets the standards for scroll saws.  It is a very expensive bit of kit, but if you are serious about using a scroll saw, this is a serious, uncompromising machine.