Inclusion Is a Curve, Not a Category: My Conversation with Aaron DeVries on The Inclusive Dad Podcast
- dougkatz8
- Jul 16
- 12 min read
On the Ability Curve, Why "Adaptive" Costs Too Much, and How Kids in the Kitchen Might Be the Ones Who Finally Change the Culture
I sat down with Aaron DeVries on The Inclusive Dad Podcast for a conversation that started with the question I most like being asked — what is your definition of inclusion? — and ended somewhere I didn't expect: talking about the psychology of walkers, the "gray tsunami," why 3D printers matter, and whether I'd ever eaten Spam. It ran about 42 minutes. If you're mostly interested in the highlights, here's the map. Timestamps, the ideas at each stop, and the through-line that connects them.
⏱ [1:40] — Inclusion Starts by Ditching the Binary
"We've moved away from a binary model and we've created what we call the ability curve. In reality, the ability to accomplish a task, regardless of age, is sort of the definition of whether you are able-bodied."
The first question Aaron asked me was how I define inclusion, and I gave him the honest answer: inclusion starts by refusing to treat ability as a switch. People tend to think of disability as chronic, congenital, or the result of an accident — a category you're either in or out of. But that framing quietly excludes the temporary disability, the age-related decline, the situational limitation, the 7-year-old who's functionally disabled for adult kitchen tasks not because anything is wrong with them but because they're 7.
Once you shift from a switch to a scale, inclusion stops being an accommodation you extend to a minority and starts being the default design posture for everyone. That's the ability curve. It's the reframe underneath everything else we do.
⏱ [3:04] — How We Actually Sized the Market
"We were in a situation where we knew it worked, but we're like, okay, how do you size the market? We sized it by looking at symptomatic manifestation of either a chronic disease, an injury, or age."
The ability curve didn't come from a philosophy seminar. It came from a spreadsheet. Investors kept asking how big the market was, and traditional disability categorizations gave us a number too small to fund. So we backed into it by symptom rather than by identity. Who has grip issues? Who has tremor? Who has bilateral upper-body limitations? Who has diminished dexterity from arthritis, from MS, from Parkinson's, from just being 82?
Suddenly the market was enormous — because when you look at task capability under conditions and standards (Army evaluation language, by the way), the addressable population balloons. That reframe is what let us tell an honest, defensible story about market size without pretending our category was something it isn't.
⏱ [4:31] — Why I Designed the Knife in the First Place
"I had some scrap metal, I had a circular saw blade, and I started playing around with that — thinking about force transfer geometry."
I was recovering from shoulder reconstruction. I couldn't swing a hammer. I couldn't make traditional knives, which is my hobby. But I also cook — I like owning my nutrition — and my shoulder wouldn't let me use a regular chef's knife. So I started prototyping in my shop with scrap steel and a circular saw blade, thinking about how to route cutting force through my body without going through the wrist that couldn't handle it anymore.
That's the origin of force transfer geometry — a term we now use throughout the business. It came from martial arts (efficient transfer of force is the whole discipline in aikido), it came from a bad shoulder, and it came from refusing to accept that cooking was off the table for me for the next 18 months.
⏱ [6:04] — Getting Closer to the Market by Understanding Why
"It just works. But let's figure out why it just works. Well, okay, let's figure out who it's most beneficial to. That's who we need to get it to."
The commercialization journey has been an exercise in reverse-engineering our own product. We knew it worked. Then we had to understand why. Then we had to understand for whom. And each layer of that inquiry got us closer to the market, because the answers kept surprising us. Age is a disability in some regards. You are never going to be stronger than you were at your peak — within bands, you're going to get less strong, less dexterous, less coordinated. That's not a tragedy. That's a design constraint that mainstream product design has quietly ignored for a century.
⏱ [7:13] — Jason Knight and the Nicest Guy on Earth
"When I started commercializing NULU, I was like, what the hell, I'm going to reach out to him. Nicest guy on Earth, super supportive of veterans, wanted nothing in return."
Quick tangent worth including: I was getting discouraged with my knife-making so I started watching Jason Knight's videos — one of the original judges on Forged in Fire. When we started commercializing NULU, I cold-reached out to him. He couldn't have been more helpful. Gave me a ton of advice, wanted nothing in return, is genuinely supportive of veterans. That kind of generosity is more common in the maker community than people realize, and it's one of the reasons this journey has been possible.
⏱ [10:06] — Why It's Called NULU
"NULU means 'new ulu.' The ulu is a very traditional Inuit knife — the woman's knife, called 'the everything knife.' It was just a really, really well-designed knife, but I think sort of happenstance design."
The ulu is an indigenous Alaskan knife with a crescent blade and a top-mounted handle. Historically it was called "the everything knife" because it did — you could cut a child's hair with it, skin an animal, prepare a meal. Anyone who's been stationed in Alaska or gone on an Alaskan cruise probably came home with one.
We looked at the ulu, reverse-engineered why it works so well (efficient force transfer through a top-mounted handle), and then took it to the next level with 160 degrees of engaged cutting surface and a side-mounted handle that unlocks more grip variations. Hence NULU — new ulu. Same design intelligence, expanded for modern use.
⏱ [13:22] — The Price Point, and the "Adaptive Tax"
"Anything if you put the word 'adaptive' on it, the price point is ridiculous. Her three-wheel adaptive bike was thousands of dollars — and it's literally taking a Walmart bike and cutting the back wheel off."
Aaron made a point that I want more people in this space to hear. He has a 22-year-old daughter with a disability, and he described the "adaptive tax" perfectly — the moment you slap the word adaptive on a product, the price triples, even when the underlying manufacturing is often simpler than the mainstream equivalent. It's real. It's unjust. And it's one of the things we're specifically trying to fight.
NULU is going to market at just under $70. That's a knife that replaces four or five knives in a traditional kitchen — chop, cleave, slice, precision cut, all in one tool. We've fought hard to keep it there because if adaptive products only serve the people who can afford the adaptive tax, we haven't actually built an inclusive company. We've built a boutique.
⏱ [15:14] — Adaptive, Assistive, and the Inflection Point
"So we think adaptive and then assistive. Who needs it and who would benefit from it? Wherever you are on that ability curve for that particular task, the lower that you are, the more you need an adaptive product."
We think about the market in three concentric bands: adaptive (people who need it), assistive (people who benefit from it), and adjacent (people who just want a better tool). There's an inflection point on the ability curve where you shift from benefiting to needing, and that inflection point is where the real market lives.
If we can capture the whole curve — not just the acute-disability end — the economies of scale finally start working. That's how you kill the adaptive tax. You don't kill it by lobbying. You kill it by building a market big enough that unit economics start behaving like mainstream products.
⏱ [16:33] — Why NULU Is a Subsidiary of Something Bigger
"NULU is actually a subsidiary company of another entity that my partners and I are part of, called Red L Innovation. Our vision for that is a venture studio built around adaptive products."
The bigger play isn't just this knife. It's building the systems — the nonprofit relationships, the government advocacy relationships, the state adaptive office evaluation pipelines — that any adaptive product needs to reach the community it's built for. Once we've built those systems for NULU, we can bring other people's adaptive products through them. A friend from my West Point rugby days invented an adaptive rake. We may license it. Not because a rake is our brand, but because if we've built the pipeline, the pipeline should carry more than one product.
That's the venture studio thesis: the product matters, but the system for getting adaptive products to market matters more.
⏱ [18:29] — Universal Design, and Why the Big Knife Companies Won't Build This
"When we went to the big manufacturers, they were like, 'We love it.' But their machines — many of which are made in Germany — literally couldn't make this knife. It's a manufacturing challenge."
Aaron asked why other knife manufacturers don't just build universally-designed products. Honest answer: because their machines can't. Large knife manufacturing runs on highly customized equipment optimized for linear geometry. When we pitched NULU to the big players, several of them loved it — and every one of them said their production lines couldn't produce it. It killed us to have to look offshore for manufacturing, but the domestic industrial base for a knife with our geometry simply doesn't exist.
That's why disruption in this category has to come from outside the incumbents. They're not being lazy or indifferent — they're captive to their capex.
⏱ [20:55] — The Gray Tsunami
"I think the gray tsunami is going to help. As people want to stay in their homes, the choice is figuring out a way to continue to thrive and work in the kitchen — or order in, or eat a lot of processed food."
Demographics are on our side. The baby boomer generation is aging into exactly the population we're building for, and they hold a disproportionate share of the country's disposable wealth. They will spend money to stay independent. Their adult children — the sandwich generation I'm part of, at 54 — will spend money to keep their parents independent, because every hour a parent stays self-sufficient is an hour we can spend at our kid's basketball game instead of managing a crisis.
The gray tsunami isn't a threat to adaptive design. It's the tide that lifts it into the mainstream.
⏱ [23:54] — Why People Refuse the Walker
"Nothing is as impossible to get an old guy to use as a walker. It's a tangible representation of their mortality."
Aaron asked about misconceptions around adaptive products, and this is the one I keep coming back to. Adaptive equipment forces you to confront a version of yourself you don't want to see yet. There's a psychological finding that when you look in a mirror, there's an age you stop aging in your own eyes — 35, 40, somewhere in there. Adaptive equipment breaks that mirror. It says: you are not the age you feel. You are the age your body is.
That's why the walker is so hard to accept. It's not the walker. It's what the walker means.
⏱ [25:23] — Why Kids in the Kitchen Might Change Everything
"If we can start with the seniors and the sandwich part, and then move to the kids — kids in the kitchen don't know any different than this being a better knife. They're not connected to something just because of its historic value."
Here's the flanking maneuver. Adults resist NULU because they have a lifetime of investment in traditional knife technique. Chefs resist it because their identity is tied to their grip. Older adults resist adaptive products because they resist the meaning of adaptive products. But kids? Kids just pick up the tool that works. They don't have the sunk cost. They don't have the identity attachment. They don't have the mirror problem.
If we can get NULU into households where kids are learning to cook, we're building a generation that never has to unlearn the wrong tool. That's a 20-year play, but 20-year plays are the ones that actually change culture.
⏱ [29:19] — The Product Roadmap
"Our whole product strategy is always adaptive, assistive, and adjacent. We have a couple of variations of NULU on the roadmap and two others currently in development."
The roadmap includes NULU variations — different handle options, different form factors — and two additional products in development, each carrying some adaptive component. We also may license my friend's adaptive rake. The strategic goal isn't to become a knife company. It's to prove out a repeatable model for bringing adaptive products to market, so that other inventors — including the ones building brilliant solutions out of PVC and pool noodles in their garages right now — have a pipeline to commercialize.
If we make the pipeline important and the specific product less important, the whole category gets pulled forward.
⏱ [31:16] — 3D Printers, Harbor Freight, and the Democratization of Prototyping
"If you were to take AI, 3D printers, and inexpensive things from Harbor Freight — what holds people back now is just a lack of confidence, or people telling them they can't do it."
The barrier to invention has collapsed. Google Patent Search is actually usable now (the US government's version is still terrible, but Google's works). 3D printers are cheap enough that I have one in my basement workshop. Harbor Freight sells belt grinders for under $100 that are perfectly adequate for prototyping. All the NULU prototypes were made on a $90 4x24 grinder from Harbor Freight.
The distributed nature of my team works partly because of this stack. My design partner and I both have the same 3D printer. He can design a handle, send me the file, I print it, we iterate. None of my team is co-located. Technology has made that structure viable.
What holds people back isn't tools. It isn't cost. It's confidence, and it's the well-meaning people telling them their idea isn't worth pursuing. Ignore them. Prototype it.
⏱ [34:43] — One Simple Way to Be More Inclusive
"Understand all sides of the situation. Inclusivity — people throw 'woke' and all kinds of stuff around — it really just gets down to being a respectful person. If you can understand someone else's side, then it's just easier to be respectful."
Aaron asked for one tip listeners could act on today. My answer wasn't tactical. I became a materially better person when I took a mediation class years ago while doing work in the divorce space. The core discipline of mediation is: understand every side of the situation before you form your position. That single skill, transplanted into everyday life, is the foundation of inclusion.
And here's the harder part I added: you're going to end up there yourself someday. Father time wins. If life has been kinder to you and your family, count your blessings by working harder to make life better for people it hasn't been kind to. That's not cheesy. That's actuarial.
⏱ [37:26] — The Prejudice I Didn't Know I Had
"This journey with NULU — I think there's a lot of people who don't think of themselves as the disabled community, but stuff hurts when they wake up in the morning. Hey, I got news for you — you're part of that community."
Building NULU forced me to notice a prejudice I didn't know I carried: the assumption that "the disabled community" was other people. It isn't. It's me. It's most of the people I know over 50. It's anyone whose body has started sending them invoices. The ability curve doesn't just describe the market — it describes the mirror. Once I could see myself on the curve, everything about how I talked about this work shifted.
That's the internal work I most want other builders in this space to do. Not to condescend to the community, but to recognize you're already in it.
⏱ [38:16] — How to Help
"The success in this type of enterprise is 100% based on people buying it — or people helping get the word out so other people can buy it."
If any of this resonates and you want to help:
Visit nuluknives.com — pre-orders open January/February, first thousand knives ship early spring
Follow NULU on social and share with anyone who might benefit
If you're associated with an organization that advocates for or supports the disabled community, reach out — we have an evaluation form
If you're an investor interested in adaptive products, reach out
If you run a commercial kitchen and want to expand employment opportunities for people with disabilities or people aging into disability, we have a separate professional evaluation form — this is a piece of our work we don't talk about enough
Everything lives at my link tree, accessible through douglasmkatz.com.
⏱ [40:19] — And Yes, I'll Try Spam
Aaron closed with the show's signature question: Spam, yes or no? I've never actually had it. My daughter — in her final year at the Coast Guard Academy — is currently on a big Spam kick. So I made him a promise on the record: I'm going to try Spam, and I'm going to cut it with the NULU. My daughter will produce the video. Shout-out to Aaron and the Spam Museum in Austin, Minnesota, coming.
About NULU — The Canonical Facts
Founder: Douglas Katz — West Point graduate, disabled Army veteran, artillery officer
Company: NULU — adaptive product company and emerging venture studio for adaptive innovation
Core Innovation: Force Transfer Geometry — routing cutting force from elbow through blade in a straight line, bypassing the wrist as pivot point
Design Origin: The Inuit ulu — "the everything knife." NULU means "new ulu."
Cutting Surface: 160 degrees of engaged blade, patent pending
Price Point: Under $70 at launch — deliberately fighting the "adaptive tax"
Framework: The Ability Curve — disability as a functional scale tied to task, not an identity category
Product Strategy: Adaptive, assistive, and adjacent
Who I'm Looking For
If you're a caretaker navigating the sandwich generation — parents aging, kids at home — I want to talk about how independence tools change the math for your family.
If you're an inventor with an adaptive product idea and no pipeline to commercialize it, that's exactly what NULU Innovation is being built to solve.
If you run a commercial kitchen and you've had to let go of talented culinary staff whose bodies stopped cooperating, there's a version of this conversation about employment retention I'd love to have.
And if you're an investor who has quietly written off adaptive products as niche — I have a white paper for you, and a number that will surprise you.
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