Product Genius, the Podcast for Inventors, Entrepreneurs, and Startups
Honest advice for inventors—with obscure cultural references included at no extra charge.
Episode
214
Additive, Subtractive, and Multiplicative Manufacturing
What do 3D printers, CNC machines, and a little math have in common? Steven challenges Noah to explain additive, subtractive, and ‘multiplication’ manufacturing, showing inventors when to move from one-off prototypes to scalable production and how to choose the right manufacturing process.
Core Topics for this episode:
- Manufacturing
- Manufacturing Methods
Key Takeaways Include:
Listen here:
Episode Blog
Why Inventors Need to Think Beyond 3D Printing
Additive manufacturing and subtractive manufacturing sound like intimidating engineering jargon, but the concepts are surprisingly simple. Additive manufacturing builds parts by adding material, while subtractive manufacturing removes material from a larger piece.
Both are excellent prototyping methods, but Noah explains that most inventors should ultimately be thinking about something else entirely: scalable production. His joking term, ‘multiplication manufacturing,’ captures the real goal—creating hundreds or thousands of parts efficiently using manufacturing processes such as injection molding or casting.
The best process depends on production volume, tooling costs, and business goals. Some products make perfect sense to continue producing with 3D printing, while others quickly justify investing in tooling.
Product Genius Take
Don’t choose a manufacturing process because it’s trendy. Choose the process that fits your product, your market, and your long-term business strategy.
Or, read the full transcript here:
Steven Julian
Additive manufacturing, subtractive manufacturing. What the heck is going on around here and no one told me there'd be math with my manufacturing? Next on Flash of Genius. Slightly annoying co-host Steven Julian with the co-host of Product Genius, Noah McNeely for a Flash of Genius.
Noah McNeely
I am so excited to be here because I was told last time that I did not have the charisma or I had the charisma of an engineer on the opening topic.
Steven Julian
You have the charisma of an engineer today. Right.
Noah McNeely
An engineer who is- I'm analyzing my charisma. Yeah. So that's how engineers do it. There you go.
Steven Julian
We're going to talk about additive manufacturing and subtractive manufacturing, which made our producer, Jody, like really ask a ton of questions because it's a buzzword that I've never heard of. He's never heard of.
Noah McNeely
Tell us about it. It was an inquisition on Jody's part.
Steven Julian
No one expects the additive inquisition.
Noah McNeely
So these are buzzwords. You do hear them. And if you're an inventor, you probably run across them in an article and they're real simple. Additive manufacturing is the idea of you start with nothing and you add stuff to it until you. have what you want. That's essentially 3D printing, which is all different. We talked about that before. It's all different types. Subtractive manufacturing is the other end of the spectrum where you start with a big block of stuff and you cut away everything you don't want. So that's like CNC machine.
And, you know, things like that.
Steven Julian
And you said that it's a kind of a current buzzword. Is it a war of whether I use additive or subtractive? Is it people get hung up on it?
Noah McNeely
Well, no, they're both very useful for very different things. It's not that one is better or worse than the other. They have different purposes. There you go. But what I don't like is a lot of people use the phrase manufacturing at the end of them. They say additive manufacturing, subtractive manufacturing. Yes. In theory, you can 3D print product and sell that. And I actually know people that do that. They run businesses. That's all they do. And then you can actually machine items and sell those. That's also done. However, what I think most of our listeners want to get to is they want to get away from addition.
They want to get away from subtraction. They want to get to multiplication. And that's where you're actually working with a factory that's making thousands or tens of thousands of these items for you at a time. Rather than 3D printing or CNC where you're just making one or two items at a time typically. Now there is manufacturing level CNC where you're doing that.
Steven Julian
So what we're talking about is making sure that, and again, there are certain scenarios where you have to do it as additive or subtracted.
Noah McNeely
Well, it's a prototyping process typically.
Steven Julian
So what you're trying to help your clients get to is where they can multiply the amount of product they're creating to therefore lower the cost. Create better margins, all that kind of stuff.
Noah McNeely
Right. If you're 3D printing, maybe you make a part an hour. But if you're manufacturing, you're making 500 parts an hour. That's a totally different ballgame.
Steven Julian
Can you give a quick example of something you've seen, a product that you saw, that you saw the opportunity to go from? Additive to multiplication and kind of getting them through that process. Give an example. Sure.
Noah McNeely
I actually do run into. people that have started their businesses and they are 3D printing product and they're selling on Etsy or wherever and they're actually doing a good business. But eventually they reach that point where they just can't 3D print fast enough to keep up with demand. And that's the point where we need to go into making a mold and actually molding this out of plastic on the factory level. So instead of tying up. 50 3D printers for a week to make or run a product, they're basically tying up a factory for an hour and a half to make an entire pallet full of product.
Steven Julian
Do you find in those kind of scenarios, a lot of times they're aware that they want to get to multiplication, but they're just wondering what's the break-even point? And probably it's an example of both. It depends on the person. Yeah, you've probably come across some people that just, oh, the 3D printer is the only way I can do this. Well, no, you really need to learn how the process works and I can help you with that.
Noah McNeely
Yeah, so there's really a couple of questions. Number one, is my market big? enough to support the investment in that mold or those fixtures or whatever it is to go into multiplication level manufacturing? Or am I pretty well tapped out this market? Like I'm selling 100 of these a month and that's really all I'm ever going to sell. Well, 3D printing might be an appropriate solution for you. There are some other processes that are kind of halfway between. So I would say every...
Steven Julian
It depends.
Noah McNeely
Yeah, of course. Everything depends. Every situation is unique. And I'm working with a client right now that we're going to go into a process using... A wider form of manufacturing called urethane casting for this particular individual because they do need to sell like $200 or $300 a month. They're not selling thousands. That's appropriate for that particular product.
Steven Julian
And I guess that's where your expertise and your years in the business and your staying on top of what's currently going on in the new technologies. because it depends on what they're trying to do. And you need to, yeah, so they may just think, oh, I can only do it on a 3D printer. Well, no. And like you said. Is it worth? paying for the casting to get that yield on the end, if I can use that term?
Noah McNeely
Right.
Steven Julian
So let me have a little fun with it and ask one last question. What about division? Are we leaving out the fourth horseman of the mathpocalypse?
Noah McNeely
I suppose if you were making a rather controversial product, it might be considered divisive manufacturing. Nice. But I don't know how profitable that is.
Steven Julian
Ah, well done. I set it up on a tee, and actually it really wasn't that good of a tee. He knocked it out of the park. Noah McNeely from Product Genius, thank you for bringing up additive manufacturing, subtractive manufacturing. We did not use the word you would like to, I think, get into the jargon, which is multiplicative.
Noah McNeely
The reason we didn't use that is because I was having trouble figuring out how to pronounce it. So I went multiplication instead.
Steven Julian
Thankfully, you have a slightly annoying co-host who did put it in the lexicon, at least in this example. So whatever your manufacturing needs.
Noah McNeely
If you would like the list of words I cannot pronounce, I will provide one.
Steven Julian
Ooh, just go to productquickstart.com, put it in. the contact us and say, give me the list of words you don't feel comfortable saying, and Noah will send that to you. He'll also help you develop your product. For Noah McNeely and our producer, Jody Smith, this is your slightly annoying multiplicative co-host, Steven Julian, saying, we'll catch you next time on Flash of Genius.