Welcome to The Engineering Triangle podcast!
Our maiden episode kicks off as our host, engineer, and managing director Ayrton Sue and senior mechanical engineer Daniel Berti discussed best practices for Design for Manufacture (DFM). Ayrton and Daniel looked at some great and not-so-great examples of DFM around the world as well as Koodaideri Innovation and Technology's HydraTune, a product we designed and manufacture here at Element Engineering Australia, and the ongoing progress of our very own Cranio Pro-IO product line.
You can stream it on Spotify, YouTube, and all your favourite podcast apps of choice!
For those who would prefer to read rather than listen, here is a summary of our conversation:
Design For Manufacture
Ayrton: To start off, what's your favourite product that's been very well designed for manufacture?
Daniel: IKEA furniture is a big one. Yes, it's only mechanical, but all the thought is going into making sure they can be built cost effectively at huge scale. And they can be used and set up and installed by anyone in the world.
Ayrton: IKEA's insane, the scale that they're at. They've got some specific manufacturing processes to be able to pump out furniture at that scale, so the designs that they're doing are actually specific to the manufacturing processes that they've got in house.
You've got melamine and laminated chipboard furniture, things like that. You must be able to put things together with very minimal tools that come in the box. And some of those fastens and things like that are made so you don't need special tools.
Daniel: From the get-go they would have had the intent of selling at huge volumes, because to make the processes work that way and to bring the cost down, they must have an eye on volume. It's something you've got to consider from the start.
Ayrton: Apple products are produced in the tens of millions per model year. I think the newest iPhone's got a titanium machined shell. You know, CNC machined titanium billets that get cored out and reach very fine thicknesses.
They’ve gone for high-end elegant materials, and they've created the manufacturing process that gives them the advantage they want - a beautiful product that's as lightweight as possible. Because it could be anodised aluminium, it could be steel, it could be plastic. But it might not have the feel that they want.
Daniel: Lego is another one. Yes, it's very simple, but they do it better than anyone else at scale. Like anyone that's played with Lego knows how well they fit together.
Ayrton: Tolerances on those things is insane. They're one of the biggest and best companies in the world doing injection moulding, so they have to understand their manufacturing process intimately and design their products around it.
My kids have got all the different versions. You know, the little dollhouse things and whatever. And they're not just the regular Lego bricks anymore. They're all different shapes, like a little car or Mr. Whippy van. They've made some very special Lego bricks that have to be specifically designed around the injection moulding process.
Daniel: I think I saw there was a tolerance on their moulds is 0.02mm. And then eight out of every million parts get thrown in the bin. That's their QA, eight out of a million is their rejection rate. They've got it nailed down.
Ayrton: I'd love to work for Lego one day.
There's lots of other ones as well, like when you're manufacturing a million vehicles of the same model. It's just insane. The number of different manufacturing processes that go into a car. Plastic injection moulding two-meter-wide bumpers is a monster job.
Just going from a design that someone's thought up in their head, going through the process and interfacing with engineers or CAD designers or whatever, being able to actually then create things that are manufacturable within tolerance. It's insane what they do.
And there's, what, hundreds of thousands of individual parts, if not high hundreds of thousands of parts in a single car? Then we all take it for granted and go down and buy a cheap one for $20,000-30,000? It's insane the amount of effort and quality that's put into these things.
Terrible Designs
Ayrton: How about the worst-case scenario, a terrible design that should have never gone ahead into manufacturing?
Daniel: Two things just jumped to me. And it was really the Samsung Galaxy Fold that they released a few years ago. I'm a Samsung owner, so...
Ayrton: Yeah, you've always been a Samsung guy.
Daniel: But it kind of just goes to show how difficult it can be to scale and do things right. I think they hadn't properly tested then screens. They ended up getting creases and failing.
Ayrton: I guess the technology isn't or wasn't there at the time. The crease thing would drive me insane.
Most products that you interface with day to day are not great products. One thing that really annoys me is 3L milk cartons. They obviously serve the purpose of putting three litres of milk into a single carton that's made out of recycled PET. It could be recycled, all that type of stuff.
But man, you can never pour the first cup of tea without spilling it. That thing needs to be totally redesigned. And then the kids can't use it either because, you know, the thing is 3 litres.
Daniel: It's the most awkward thing. What annoys me is, I'm used to them having a seal. But if you buy it from IGA, for example, it doesn't have the seal. We go through a lot of milk, so I'll have, like, 2-3 litres at any one time. One's always sitting lying down. But if we buy the brand without the seal...
Ayrton: Everywhere. Stinking.
Daniel: So I've worked it out now. It's a three and a two, fits perfectly in my door.
Ayrton: But I think it's one of those things where the design or the economies of scale have compromised on the milks, right? You go to America and their gallon, they're 3.8 or 4 litres, you always see in the movies people trying to pour them.
But it's the economies of scale. And obviously people want to buy that thing. But the downside to it is that you can't pour it. You just have to deal with the spill, you know. Or you get really good at it, unlike us.
Most things are pretty average. Everything has an issue to it.
Daniel: It's a trade-off cost. But you have to think when you're going through the process of designing something, who are you doing it for?
Ayrton: But that's a lesson that we've learned along the way, especially with startups or new customers that we have come in the door. You don't have to have a perfect product. Because how many products do you use every single day that you go, wow, this is phenomenal? You know what I mean?
Design for manufacture is basically trying to get this thing to the vision that you've got. And it doesn't have to be perfect.
The Key to Good DFM
Ayrton: What do you think is the key to really good design for manufacture?
Daniel: Personally, I think it comes down to considering the entire life cycle of the product. You need to understand what it has to achieve, who it's being sold to, what it's going to be used for, and how it might be abused. You also need to consider how easy and serviceable it needs to be for the user.
Volume affects the cost and processes at play. Manufacturing methods are critical, but the approach changes based on how many you're going to sell.
Ayrton: People need to understand it's not only Design For Manufacture. Designing for the complete product life cycle is important. You have to manufacture the parts, assemble them, calibrate or program if they're smart products, and ensure they survive storage and shipping. Then there's installation, operation, servicing, and disposal.
Most people mainly think about the use phase and manufacturing processes but miss out on other stages. For example, an IoT device with a battery might sit on a shelf for a year. How does its battery state affect user experience? Do you have to do something special when you get it out of the box?
A big one we discuss with clients is volumes. The price point for the end user and the expected sales volume dictate the manufacturing process. For a cheap IoT device, plastic injection moulding is common. For a premium product, it might be CNC machined, anodised aluminium.
You can find a factory quickly, but building a supplier relationship is a long process. Depending on the supplier's capabilities and communication, you might choose a different process.
At Element, we've taken many manufacturing processes in-house to get closer to them. Machining, anodising, plastic injection moulding, and liquid silicon rubber injection moulding were challenging. Only a few factories in the world handle it, and the costs were high. Bringing processes in-house helps us design better and get closer to manufacturing.
Daniel: Part availability is a huge issue, especially with electronics. Future-proofing if parts become obsolete is often overlooked. We've experienced this.
Ayrton: Covid was horrible for that. Electronics components became unavailable, and we had to redesign products due to one chip being out of stock.
Daniel: It happens a lot on the mechanical side too. Supplier websites list many structural sections, but most aren't readily available. We've built relationships with suppliers to know what we can and can't get.
Ayrton: Did that come down to relationships?
Daniel: Yes, working with them is key. Mistakes happen, but addressing them is important. Availability is massive, especially when you want to move quickly. Designing something without considering part availability isn't good for us.
Speedy Manufacturability
Ayrton: How do you quickly make something manufacturable?
Daniel: Prototyping is different from production runs. Even when designing, you can optimise the time it takes to assemble and sell. Reduce unnecessary customisation and leverage off-the-shelf parts and components. Simplify the design where possible. Our approach is to prototype and test efficiently to avoid wasting money on something that doesn't work or perform.
Using 3D printers can help you gauge how something might feel before moving to machining or injection moulding. Each step, like injection moulding, is a bigger investment, so speeding up the process helps.
Ayrton: For high-volume products, injection moulding is essential, especially for plastics. 3D printing can help with initial prototypes. You might also use vacuum casting to produce 20 units more cost-effectively than 3D printing, with a similar look and feel to injection moulding. Understanding these processes is crucial.
Daniel: We've faced challenges with offshoring, especially for prototyping. Communication issues, such as language barriers and misinterpretation of specifications, can arise. Clear drawings and explicit QA standards are essential. Inexperienced designers may overlook these details, leading to costly mistakes or mismatches with the final product.
Ayrton: The outcomes can be costly: either an expensive quote due to incorrect specifications or a product that doesn’t match your design. Having a good relationship with your supplier helps. Being able to discuss and refine designs together can improve the outcome.
Daniel: Exactly. QA is crucial. It's easy to overlook critical issues like seal performance if not properly checked. We now ensure that critical components are thoroughly tested before proceeding too far.
Cost Reduction
Ayrton: If you don’t know your volumes and price points, you’re kind of in a wasteland. And if you're designing for manufacture, don’t add more complexity than needed.
Daniel: Right. Don’t specify tolerances like 0.01mm if they’re not necessary. Your machinist might just give you a high quote if the specs are too tight.
Ayrton: Most suppliers will find ways to work around issues and manage costs, but simpler designs are generally cheaper and faster.
Daniel: We’ve experienced this with our suppliers, like for the sapphire lenses in an ongoing oil and gas project. The initial quote was for a lower class rating, but we needed a higher one. The supplier agreed to add extra QA processes and provide certificates. We use the units within spec and include that in the costs.
Ayrton: For higher volume products, like SRAM TyreWiz, we cut costs by removing subsystems. We used internal sensors instead of external ones, which weren’t available during COVID. Although the upfront engineering effort was higher, it led to overall cost reductions, especially with large volumes. The NRE costs, though higher initially, were offset by lower bill of material costs over time.
Daniel: Sometimes you launch a product and then refine the design later to reduce costs.
Ayrton: For TyreWiz, eliminating components made the board smaller and improved manufacturability. The NRE cost is high for small quantities but lower for larger volumes. I heard Apple has a nearly infinite R&D budget because the NRE cost is spread across so many products, though that might be exaggerated.
Daniel: The cost becomes negligible with scale.
Ayrton: Probably. You have to consider and amortise NRE costs. You need to sell the product; you can’t spend forever on R&D.
Daniel: You’ve got to call it a day at some point.
HydraTune
Ayrton: We designed and manufactured Koodaideri's HydraTune system for technicians to remotely perform maintenance on dangerous hydraulics in the field. We CNC machine, anodise, and assemble the satellite pod and battery charger modules right here in our workshop.
It was one of our larger end-to-end projects, and they have products out in the field now being tested with some major companies.
It was a challenging project because it's a safety-critical device. HydraTune eliminates the need for technicians to adjust hydraulic valves in risky conditions. Normally, adjusting a hydraulic valve involves reaching into a machine that might be running. If something goes wrong, high-pressure hydraulic fluid could spray out, potentially penetrating protective clothing and causing serious harm.
Daniel: You’d be in trouble.
Ayrton: Exactly. Developing a safety-critical IoT device controlled via Bluetooth on a tablet was challenging. The environment where the device is used also presented difficulties. You have a steel structure with big cast iron machines and sheet metal covers. Good RF performance was crucial.
We knew it could be done. Our Cranio system handles the core firmware, Bluetooth communications, and app functionality. Implementing this robustly over long distances to a rugged tablet required a big antenna. The design includes a removable battery, a stepper motor controller with a Bluetooth antenna, and a 4 to 20mA pressure sensor. It could have been a plastic injection-moulded box or something sleek, but we're not talking about tens of thousands of devices. Plus, the environment is rugged and the device will be handled roughly.
Shane was keen on a CNC machined aluminium with an anodised finish. We explored industrial design options, focusing on form, fit, and function. Nicole did an excellent job with various designs in Blender. Nicole and Minh worked closely together to ensure manufacturability. Nicole focused on making the design look and feel right, while Minh tackled making it manufacturable.
Daniel: Always known from the start.
Ayrton: Yeah, from the very start.
Daniel: It’s important because the design would be very different if it were injection moulded.
Ayrton: Exactly. Injection moulding requires draft angles and thinner walls. The product was designed around the manufacturing processes we chose, which were aligned with the expected field volumes.
It was a great project that showcased all our skills at Element, including our Cranio ecosystem, which sped up HydraTune’s market launch. The licensing agreement provides access to ongoing updates, such as over-the-air firmware updates, improvements, and security patches—things we previously struggled to offer individually for each customer.
We handled all the manufacturing and prototyping in-house. After COVID halted offshore production, we decided to invest in our own machines. We offered the customer the option to manufacture with us, and we successfully completed the first batch of devices. We aim to keep our manufacturing sharp for future batches.
Daniel: It was quite collaborative too, right? Without that, you might have gone down the wrong path or left them unhappy. It was a big project, involving manufacturing designs, mechanical designs, and electronics integration.
Ayrton: That’s something we deliberately set up in the business. Mechanical and electronics teams work closely together, as do firmware with electronics, and web with firmware. Industrial design also works directly with mechanical.
It’s a circular process where different pieces of the puzzle come together. Having everyone in the same office allows for direct communication and faster problem-solving.
Daniel: For HydraTune, changes from the first prototypes were minimal because of this close collaboration. Mechanical engineers worked directly with machinists, allowing for quick feedback and adjustments.
Ayrton: If you’re trying to emulate this with another business, make sure you have a supplier close by or can visit them. In-person conversations are crucial. You can’t get the same insight over Teams or email—you just get a huge '**** off' quote.
Cranio
Ayrton: We’re currently working on our own data logging and control system, Cranio. A major part of the system is the Pro-IO devices. We're CNC machining the housings and injection moulding LSR seals right in our workshop.
Cranio is my pet project that Dan has supported me and the business on. I’ve had the chance to learn production-grade electronics and IoT while Dan has managed the business. This has allowed us to develop some cool IoT technology.
The Cranio Pro-IO system is interesting because it fulfils a niche: rugged embedded devices that don’t need a traditional control cabinet. Usually, a remote device would require a control cabinet with glands, seals, and electronic components. I wanted to simplify this.
Cranio Pro-IO is configurable with various communication options like cellular, Wi-Fi, long-range RF, and Bluetooth. It supports different I/O types, including analog and digital sensors, outputs, relays, and stepper motors.
It’s designed to be easily mounted on a pole in the field with a solar panel. Cables from sensors and actuators pass through liquid silicone rubber glands, eliminating the need for special connectors. Instead of expensive connectors and crimping tools, we’ve aimed to make it user-friendly for anyone technically capable. The CNC-machined aluminium housings are rugged, and the plastic top ensures Bluetooth communication. It’s stackable and durable.
This project is a passion of mine, and we’re getting closer to bringing it to market. The manufacturing processes are chosen based on the volumes we aim to produce, with a goal of a few thousand units for rugged environments like mining and oil and gas.
Liquid silicone rubber presents challenges but offers advantages. For instance, using an LSR button cover is more cost-effective and compact than off-the-shelf alternatives. It improves both the product’s functionality and its user experience.
Doing this internally has been a valuable learning experience, helping us become a better manufacturing supplier with high precision and quality. It also allows us to manage risks with our own product.
Daniel: We’ve had a few mechanical guys dedicated to it over time, and it’s been a great learning experience for them. It’s nice to work on something at the cutting edge of technology, compared to the more routine steel projects.
Ayrton: IoT is complex because it involves integrating mechanical, electronics, firmware, and software. Industrial design is also important for functionality and aesthetics. Bringing it in-house has helped us learn and improve for our customers.
We’re confident this will become a successful product. It needs a user-friendly front-end system and seamless setup to stand out. We aim to make setup easy, avoiding complex commands and competing with platforms like Arduino and Raspberry Pi. Designing all these components for IoT is challenging.
Smart machines also add complexity, like adding sensors and control systems to previously mechanical machines. Effective communication between teams is crucial, ensuring everyone is on the same page and using communication efficiently.
Daniel: It’s about balancing good, fast, and cost. Achieving all three requires experience.
Ayrton: Exactly. The engineering triangle highlights this. Design for Manufacture (DFM) is both a science and an art, developed through experience. Having trusted people to discuss pain points with is the key to successful DFM.
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