This article, based on an interview with Charles Day, Macfab’s manager of research and development, describes one of Macfab’s longstanding customer relationships – with the University of Toronto Institute for Aerospace Studies.
High precision components, mission-critical assembly and quality management systems – and as a matter of fact, this actually IS rocket science…
The University of Toronto Institute of Aerospace Studies (UTIAS) is one of North America’s largest aerospace engineering educational and research organizations. Its Space Flight Laboratory (SFL) builds low-cost microsatellites and nanosatellites for space flight organizations throughout the world. SFL arranges launches through its Nanosatellite Launch Service and provides customizable separation systems called XPODs, which are designed to contain the satellite and to then eject it from the capsule.
The Space Flight Lab has been a Macfab customer for over a decade. During that time, Charles Day, has worked on virtually all of Macfab’s SFL projects, notably for the XPOD systems, for which Macfab provides what has become a complete turnkey solution, including:
- Manufacturing of structural panels, door and pusher plates
- Nickel plating – performed by a specialty firm and managed by Macfab
- Pre- and post-plating measurement and cleaning
- Assembly and sub-assembly of components
- Documentation support, including measurement data and verification of each assembly step
“Initially we would produce the components and they would assemble them in their clean room facility. Over time, they gained confidence that we had the ability to do that for them. What was key in this is that we have the facilities to properly handle and clean these components, and also perform the final assembly as well."
– Charles Day, R&D manager
“There are several points at which you’ve cleaned them before, but then they get dirty to some degree during some of the processes, so then they get re-cleaned to maintain the surface integrity. And when you’re doing things like tapping holes, you have to use lubricating oils, and these need to be completely removed before you proceed to install anything like helicoils or send them for plating. The important thing is, when these things go into the space vehicle, if there’s anything at all in there that’s going to vaporize, it’ll end up condensing on your components, or somebody else’s and potentially foiling a mission – so the off-gas situation is very important.
“We do all that here. We machine the components, we maintain the integrity of them – the high-level speciality cleaning that’s required, the actual chemicals that are used for cleaning, and the processes used for applying them – and then, every step along the way, using whatever process needed, we have the facilities for that, which they don’t necessarily have themselves.”
For obvious reasons, the Space Flight Lab’s cost of failure is extremely high. And considering that launch costs are based on mass, component weight is indeed a mission-critical factor. One of Macfab’s major contributions in this area was in moving from aluminum to a less dense alloy, which provides weight reduction and maintains structural integrity, but from a manufacturing standpoint, is also much more challenging.
“There are very few shops in North America that can machine this alloy, because it can be very dangerous, and there are many issues around maintaining the surface integrity. For example, if it comes into contact with water or any water-based compounds it will oxidize, pitting the surface as it dissociates water, forming oxygen and hydrogen. Now you’ve got an explosive condition, and the machining waste can very easily be ignited. So you either need to use special coolants to machine it, or you machine it dry. You also have to deal with the inherent stresses in the material, so the order in which we do manufacturing steps is very important as well. Through a lot of trial and error, we’ve worked out the machining process so we don’t have those issues.”
The SFL’s XPOD systems are manufactured in very low quantities, including many one-off orders, and the specialization involved often requires a significant degree of interaction. Macfab’s experience in machining and assembly in general, and with SFL’s products in particular, has played a key role in custom-tailoring the system to meet new users’ needs.
“Every time we do these, there’s some difference, some unique purpose – for example, in the measuring instrumentation that’s going to be used in the satellites themselves – so we’re constantly dealing with modifications. They might be building these for a client in Europe, for instance, so we’re waiting for feedback from that client to come back through U of T to us, to actually modify some of these components to fit specialized devices that they will house – and we’ve gone through some rev changes as well. On the larger XPOD, there has been a radical structural change. That was initiated by them, but then there’s manufacturability issues at our end as well, which we review and handle for them.
"We select the tooling and make the specialized fixturing, and we develop the CNC programs for manufacturing. Some of the process steps are done with more traditional manual machines, and others are CNC."
Quality management, literally and figuratively
Charles Day came to Macfab nearly 20 years ago with an analytical laboratory background that started in the pharmaceutical industry, where, as he puts it, “record-keeping and compliance were always an element of my day-to-day life.” From day one, he worked with SFL to develop their manufacturing control document that provides work instructions and records of Macfab’s work on the project. That continuity, and the level of rapport that comes with it, pays dividends in all kinds of ways, large and small.
“On this last assembly that we made, in reviewing and using the assembly instructions in the document, I saw an opportunity for improvement, to clarify the linkage between the process steps and the actual graphics that were there. They were kind of out of sync, and there was a chance for confusion for new assembly staff. In the operating document, I would usually make handwritten notes on it for our people to follow for clarification, so I provided that feedback to the U of T, to update the document and include my notes as changes. And we have that kind of dialog with them all the time.
“Sometimes they’ll have an issue with one of the other components we make for this assembly and they’ll sit down with us and we’ll look at possible alternatives in how we could manufacture it and make it work for them. So we have that level of dialogue.
“The thing that’s important for U of T is that we’ve been doing this for over a decade. Their project staff can change over time, but we are a consistency for them, so that when it comes to doing that assembly, we have that tribal knowledge. So they know, ‘let Macfab do it, it’s going to be the same as last time’, and we move forward.”
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