Custom saw blade for quick boxes and drawers
May 29, 2015 12:34 PM   Subscribe

Andrew Klein demonstrates his custom saw blade designed for quickly making boxes and drawers. There's also a photo gallery if you want to skip the video.
posted by Nonsteroidal Anti-Inflammatory Drug (33 comments total) 24 users marked this as a favorite
Pretty cool. I'm curious about the strength of the joint. I imagine for things like drawers and boxes it's sufficient, but for anything structural I'd like some testing to see if it's as good as a biscuit or a peg joint. Still, I can see this being hella handy. If it goes into production I'll add one to my dream wood shop list.
posted by gauche at 12:41 PM on May 29, 2015

posted by resurrexit at 12:48 PM on May 29, 2015 [1 favorite]

Biscuits are mostly for alignment while gluing and don't provide that much strength. Straight edge glued boards are very strong, the main reason for dadoes, biscuits, and dowels are that it makes gluing up casework way easier.

Actual tenons might give more structural support. They also help with some problems that are more common in solid woods due to expansion and contraction over time.

I feel like I've seen this exact thing before as a router bit... it's a cool idea though.
posted by RustyBrooks at 12:48 PM on May 29, 2015 [2 favorites]

Yeah, so this is similar

What it lacks is the one-cut aspect where the single cut makes 2 edges at once. I'm not sure how much that would really be a game changer though.
posted by RustyBrooks at 12:50 PM on May 29, 2015 [2 favorites]

I'm curious about the strength of the joint.

He stands one one of the drawer faces (~200 lbs.) and it doesn't break, the he turns and kind of stomps it. It took two "stomps" to break it, and a lot of it was plywood failure rather than glue. In other words, strong enough to do what it needs to do, and definitely strong enough when you factor in the ease of making these joints compared to what he acknowledges are far stronger, but more complicated, joints.

That said, this isn't idiot-proof. Still have to be precise on blade height, fence depth, etc. But then again anyone who's making furniture is probably already on that....
posted by resurrexit at 12:50 PM on May 29, 2015

Yeah, I think I have a shaper blade that's similar -- but as one person said, there are multiple ways to do the same job, and there are some woodworkers who can do just about everything with their table saw and no other tools. (eg he had a 1/4" table saw blade - beat any other way to cut a 1/4" groove.)

That said, still pretty neat.
posted by k5.user at 12:53 PM on May 29, 2015

I had to go back and rewatch the first pass over the blade, I thought the had his hand right on top of the board.
posted by synthetik at 12:59 PM on May 29, 2015

Oh, this is really neat. The custom carbide blade is very interesting, although the technique relies on the sturdy dado set. Custom carbide blades are a semi-secret weapon for furniture makers -- you can find many tool shops that will shape a carbide blade for you, although many dadoes are meant for intricate molding.

I'm not trying to minimize the achievement here: There's a unique combination of tool and material here that takes a very flexible mind to visualize. This type of joint usually takes a pass with a table saw, and then several passes with a router. This is a pain in the ass and fraught with fuckuppery. Cabinetry is a precision skill and it's the bane of otherwise talented woodworkers.

By reducing the task to a minimal number of passes in the saw and -- please appreciate this is just as important as reducing passes -- keeping the cabinet pieces in one piece Klein has a very nearly foolproof system for basic cabinetry.

gauche: "I'm curious about the strength of the joint."

Ehhh. For drawers, the strength isn't a huge concern. It's interesting in an academic sense, but there's no strain against those edges in the typical use case beyond what he demonstrated. If it was a concern (why?) I could easily see some refinements to his custom blade profile that would interlock better. Alternately, just pop in a few finishing nails and you'll be good. He contrasts his jointery with finger joints. Those are the best way to get strength in the sense I think you mean. But they're also a pain in the ass timesink even if you have a jig to make them. The real dazzler is the "it just falls into the clamps!" aspect of it.

I think my only concern is how well this would work with non-veeners. His demonstrations were plywood sheets, which are very forgiving of the kind of creasing and mechanical tolerance he's working at. If you have some hardwood, it might splinter or blow out.
posted by boo_radley at 1:38 PM on May 29, 2015 [6 favorites]

RustyBrooks: "What it lacks is the one-cut aspect where the single cut makes 2 edges at once. I'm not sure how much that would really be a game changer though."

Here's an example of Rockler working with a rail and stile router bits.

Here's what you should take away:
The router bit needs to be adjusted depending on the depth of the pieces. At 2:43, the joint is dry fitted and you'll see that they're not quite flush with each other. But juuuuuuuust barely. Do you sand the joint flush? Maybe take a second pass on the router? Maybe you'll screw it up again and remove too much material. Then you'll have to start over. This is the kind of fuck-uppery that I mentioned above. Note as well that there's two bits involved: one for the walls of the drawer and a second type for the bottom. Often this bottom is a blind joint for simplicity.

The advantage is that you get more choices in your material and design: if you want 1/2" oak sides and 1/8" black maple face and back, you can do that. Klein's system locks you into a consistent size throughout the piece. If you're interested in doing fancier work of different woods, you might not be able to do it with Klein's system.
posted by boo_radley at 1:52 PM on May 29, 2015 [2 favorites]

America, fuck yeah.
We do something like this on cored composite panels. We call it Coragami

Here is some precedent using a very similar joint: Northwest Native bentwood boxes.
posted by Mei's lost sandal at 2:10 PM on May 29, 2015 [3 favorites]

Impressive shop.
posted by notyou at 2:18 PM on May 29, 2015

I like the idea of just doing 45° cuts and then flipping the other side. It has the advantage of minimal wastage and it's self-correctling if the angle is slightly off, e.g. 44 + 46 is still 90.
posted by w0mbat at 2:26 PM on May 29, 2015 [1 favorite]

I came in to talk about what I see as the limitations of this genuinely rather clever solution, but boo_radley already covered that much better than I could've. I'll note though that a lot of those caveats are irrelevant in the presented context. Klein presents this as a technique for quickly busting out shop drawers, not as a solution for fine cabinetry. In that context, being limited to half-inch plywood and producing drawers that are functional if not necessarily pretty is totally fine.

The creator intends this for utilitarian work that will be used in-house for making workbenches and such, something that professional woodworkers spend a surprising amount of time doing. Woodworkers are constantly having to build and/or modify bits of their workshops to accomodate the needs of whatever project they happen to be working on—when you work in wood, making your own tools, jigs, and shop furniture is second nature. Time spent doing that sort of thing is time not spent making saleable items, however. If a cabinetmaker can save a few hours of tedious gruntwork building a new set of shop drawers, that's time that can be put toward doing something more rewarding and lucrative. So in that sense, I think this innovation is absolutely worthwhile.

Plus, designing a custom dado that allows him to do plywood origami was probably a lot more fun than making the drawers the regular way. He probably spent more time designing, building, testing, and refining his system than he'll ever save using it, but it was surely much more satisfying.
posted by Anticipation Of A New Lover's Arrival, The at 2:31 PM on May 29, 2015 [9 favorites]

One other downside here is if you are doing a metric fuck-ton of drawers, you'd regret having the bottoms the same thickness as the sides, instead of the more typical 4 or 5mm ply. That's a lot of 12mm ply you wouldn't have to consume.
posted by Mei's lost sandal at 2:50 PM on May 29, 2015

He shows a method to make multiple drawers of the same size in one go with thinner bottoms.
posted by ssg at 3:12 PM on May 29, 2015

Biscuits are mostly for alignment while gluing and don't provide that much strength. Straight edge glued boards are very strong, the main reason for dadoes, biscuits, and dowels are that it makes gluing up casework way easier.

In edge-to-edge gluing, e.g. a plank tabletop, this is all true. In casework, where joints inevitably involve right-angle joints, it's not true at all.
posted by jon1270 at 3:52 PM on May 29, 2015

Router bits for making locking miter joints work on a similar-ish principle but you couldn't cut them out out one piece of wood like this. This was a very clever piece of design.
posted by middleclasstool at 3:54 PM on May 29, 2015

Derp. I just realized y'all already brought those up. Never mind.
posted by middleclasstool at 3:59 PM on May 29, 2015

Well, I admit a few things:
* I've never done my own tests with biscuits vs no biscuits
* I've mostly heard from people that they don't really help that much
some googling around gives mixed results, but the biscuits-help side seems stronger than my statement above evidentially, so, let's go with that.

(fwiw my workbench, which I inherited, has drawers that are just rabbeted on the front and back and glued together. They're probably 30 years old, used frequently, and abused, and they're doing just fine)
posted by RustyBrooks at 4:14 PM on May 29, 2015

It's safe to categorically say that a butt joint, with the end of a board glued to the face of another board without any other joinery or fasteners, is very weak. Once you start throwing in nails, screws, rabbets, dados, dowels, biscuits, box joints, dominoes, floating tenons, integral tenons or dovetails, it gets much harder to say anything categorically. There are just too many variables in play, including the care and precision of the workmanship, to say that X is always better than Y... unless Y is a butt joint.

As to the joint shown in the video, he's edited out a lot of time spent fine-tuning the setups. He also waves away the gap in the joint as being caused by his custom blade's being a bit too small in diameter, but I suspect fit problems there would be persistent if this is meant to be paired with a standard dado set because not all dado sets of the same nominal diameter are precisely the same size when manufactured, and they all shrink in diameter when sharpened. And then there's the question of how much it will cost, and whether that cost can be justified for the sake of a few (or even a few dozen) utility drawers.

I guess I'm rather GetOffMyLawn about stuff like this, but one of my peeves in woodworking is the perennial proliferation of whiz-bang gadgets that tend to be expensive, do a so-so job of an extremely specialized task, and then clutter up the shop for years, doing nothing.
posted by jon1270 at 5:35 PM on May 29, 2015

I feel like I've seen something very similar on Lumberjocks, done with a 90 degree V groove router bit, but I can't find it offhand. It works the same way, although you get a simple miter joint rather than the more complex locking joint this produces. On plywood I don't think a V groove would give you very good glue surfaces, but for non-structural boxes it's a nice approach.
posted by srt19170 at 8:01 PM on May 29, 2015

I have been putting off making drawers and cabinets for ages. I'd love to try this out as an option.
posted by Dip Flash at 9:02 PM on May 29, 2015

I'm impressed by the guy's ability to think up such a cool thing. I'm just a hand tool hobbyist, so not really in his target market but I'll just say that measuring to get all those cuts in precisely the right spot must require a ton of trial and error. It seem too me that he could demo a less finicky application; making wide flat drawers with thin bottoms, if he'd just concentrated on using it to trim the sides to the required length and focused less on elaborate setups for the foldy aspect. But then, I guess it's the gee whiz that sells it.
posted by bonobothegreat at 10:10 PM on May 29, 2015

This is a neat idea.

And I didn't know that you could get custom saw blades just like that. I wonder what the prototype cost him?
posted by Harald74 at 3:17 AM on May 30, 2015

BTW, dado blades are prohibited in Europe, so I won't (legally) be able to try out his invention when it goes to market.
posted by Harald74 at 3:18 AM on May 30, 2015

BTW, dado blades are prohibited in Europe,

Is this true? Why?
posted by Mei's lost sandal at 8:37 AM on May 30, 2015

People sawing their bits off apparently
posted by fullerine at 8:54 AM on May 30, 2015

Wow that seems... crazy. I wonder how that affects woodworking techniques? I mean I don't use mine a LOT but it probably gets pulled out every 3rd or 4th time I make something. I wonder how europe feels about my radial arm saw, which even I feel leery of?
posted by RustyBrooks at 9:08 AM on May 30, 2015

Weird. What is it about dado blades that makes them so horrifyingly dangerous that Europeans cannot be trusted to own them? I mean, a table saw is already a pretty scary tool, one that demands a lot of respect and attention, but nobody prohibits them. Why does mounting a blade with an extra-wide kerf make it suddenly so dangerous that such blades must be prohibited by law? Are they more dangerous than, say, a chainsaw? A welding torch? I can't quite fathom this.
posted by Anticipation Of A New Lover's Arrival, The at 10:12 AM on May 30, 2015

Well, dado blades were apparently overrepresented on the accident statistics. I have no more information than fullerine's link above.

BTW, I develop software for digital finishing machines (remember old flatbed plotters? Strap a vibrating knife or a router spindle to your old plotter's 2-ton cousin and let rip.) Our American competitors strap a emergency stop button on their machine and call it a day. We have several layers of photo sensors on both side of the traverse, and mechanical collision detection on the traverse end panels in addition to several emergency stop buttons. The Americans however have a very important thing; the liability-canceling safety sticker...

I sense there's a difference in culture.
posted by Harald74 at 12:16 PM on May 30, 2015 [2 favorites]

Rather than stacking a bunch of blades including one that has been custom ground you can just get a set of knives for a shaper head cut. Mine is an ancient unit without over feed protection but the blades are just flat pieces of carbide and quite reasonable.
posted by Mitheral at 12:18 PM on May 30, 2015

What is it about dado blades that makes them so horrifyingly dangerous

The only thing that occurs to me is that with a dado blade, you're generally putting a groove into the face of a relatively thin board or sheet. It's important to keep the workpiece held down flat to the table to keep the groove at a consistent depth. So if you're an absolute moron, you press down on the piece with your hand directly above the blade, then push your hand down on to the blade when the piece moves off.

Push sticks, people. You can make a dozen in an hour from crap you have in the cutoff barrel. Keep the meat behind the metal.
posted by echo target at 12:22 PM on May 30, 2015 [2 favorites]

I looked around a little earlier, and though I've lost the links, there seemed to be some kind of European safety standard where a sawblade has to come to a complete stop within so many seconds of the power being cut, and dado blades often don't conform because of the weight?
posted by rifflesby at 3:57 PM on May 30, 2015

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