Infinity Dadonator — and the Amazon Alternative
Infinity sells direct. The Freud SD508 is the stacked dado set you can order today, and it does the same job: flat bottoms, clean walls.
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Infinity’s Dadonator is sold by Infinity Cutting Tools direct at infinitytools.com. It is not an Amazon product. The Freud SD508 scored here is the equivalent you can order today, and the rest of this page is about what a stacked dado set does and whether you can use one.
Stacked versus wobble
A wobble dado is a single blade mounted on an angled hub, sweeping side to side as it turns. It is cheap, it is adjustable by rotating a dial, and it cuts a dado with a slightly curved bottom, because the blade is describing an arc.
A stacked set is two outer blades with chippers between them. Everything turns in the same plane, so the bottom of the cut is flat. For a shelf housing where the shelf must sit down properly, or a groove a drawer bottom slides in, flat matters.
Shims are the real feature
Plywood is never its nominal thickness. “3/4 in” ply is usually around 23 mm — and the next sheet may be different again.
A stacked set comes with shims, thin washers that go between the chippers. Measure the actual sheet with a caliper, shim the stack to match, and the dado fits the ply exactly rather than needing packing or being sloppy. That is the difference between a cabinet that goes together and one that needs fixing.
Check your saw first
This is the part that catches people outside North America. A dado stack needs enough arbor length to take the full width, and many saws sold in the UK, EU and Australia have short arbors specifically because dado stacks are not permitted under the machinery standards those saws are built to. The riving knife also has to come off, which is a regulated safety device on those machines.
If your saw takes a stack, this is a great way to cut housings. If it does not, a router with a straight bit and a guide does the same job safely — slower, and with a cleaner result in veneered ply.
The throat plate
A stacked dado needs a dado throat plate with a wide opening. That is a separate purchase or a shop-made one, and it is not optional: running a stack through a standard zero-clearance plate will destroy the plate and possibly more.
What works
- A stacked set cuts a genuinely flat-bottomed dado, which a wobble dado cannot do and which matters when a shelf has to seat properly
- Shims let you dial the width to match actual plywood thickness, which is never the nominal figure and varies sheet to sheet
- Scoring-style outer blades keep the shoulders of the dado crisp in veneered ply, where a cheap set tears the top veneer
What doesn't
- Dado stacks are illegal or unusable on many saws outside North America — short arbors and riving-knife regulations mean the stack physically will not fit
- Changing to a dado stack means removing the riving knife and fitting a dado throat plate, which is a real safety step and a real hassle
- An 8 in stack cuts a shallower maximum depth than a 10 in blade, which occasionally matters on deep rebates