My understanding of manufacturing has grown considerably during my time running Tuff Writer. Our pens have evolved from just a twinkle in my eye to an actual product and continued to evolve as our knowledge of design and manufacturing processes has matured. The funny thing is that the more we learn (it's definitely "we" now, Tuff Writer has grown beyond just me), the more processes we bring in-house, the more experience we gain... the more we realize that there's so much more left to learn.
In fact, we've added flashlights, carabiners and various other gadgets to our catalog. All the while, something we've never lost sight of is the pursuit of quality. We've worked hard to develop a keen eye for detail in the shop and an appetite for, if not the achievement of at least the pursuit of, perfection. That's not to say that we're perfect or that nothing ever gets past us (although we take it as a personal affront when it does and do everything in our power to make it right) but everyone in the shop takes great pride is making something special, something a cut above.
To that end, this seems to be a never ending education. I don't think we had any idea when we started purchasing our own CNC equipment what a wonderful and deep rabbit hole we were jumping into. That said, it's given me a fundamentally better understanding on what it means to make quality products.
You see... quality isn't just about hand finishing and hand assembly. The process starts all the way at the beginning during the initial design. So many components and products are beautifully designed and meticulously dimensioned for manufacturing processes that don't even exist yet. In other words, you can't expect a greater fidelity of the finished product than the resolution which the actual shaping process can deliver.
"Awesome, Jack... you wanna try talking English for a change maybe?" Hm... ok, let's try this.
Imagine that you're making a perfectly square internal hole in a 1" titanium plate which needs to slip fit a square block and hold .001" tolerances. In short, you're not going to machine this because a square internal corner simply isn't possible with an end-mill (remember, the mill is hold spinning cutters that are round and always leave an internal radius). You could waterjet the part but the kerf on the waterjet means that at 1" depth you're going to have tapered walls, no dice. A saw won't work because you can't get the saw blade into the square interior. 3D metal printing (i.e. DMLS - Direct Metal Laser Sintering) can make create geometry and thickness no problem but... with a tolerance of .003 on the high-end, there's just no way to hold the necessary tolerances. Grinding can easily hold the tolerances but it's not going to work for the internal square and the hole is just too small anyway. You're left with wire EDM (electrical Discharge Machining) which will use a very, very thin metal wire to cut through the metal.
And if you decided to design this out of Carbon Fiber... well, best of luck as EDM wouldn't work as it requires a conductive material (actually, I have no clue how the hell you'd make this out of CF but I'm sure someone smarter / more experienced could figure it out).
Now, if you can machine the 1" block to fit a square hole instead all of a sudden things become so much easier as you could loosen up the internal square hole tolerances and control the block instead. A 1" square block of titanium can easily be machined or honed to within .001" tolerances all day long. Heck, do you even need perfectly square internal corners or did the designer just think it looked pretty that way on the model?
All of this became especially apparent as we worked on the 416SS pen advancing mechanism. The dimensions were smaller and tolerances were tighter than anything I had worked on before. Fortunately, my buddy Chris was here (el hefe at Automatic Precision Inc. in Illinois) to help me understand what Swiss-type lathe turning was capable of. Even then, it took months of design work and modeling. Then we had to actually run the part and get the tolerancing right. In the end, we decided to have a custom ground shoulder end-mill made to be able to machine the race like we wanted it (bit of a risk, we didn't know if it would work like we hoped and still aren't sure how many parts we'll get out of the tool).
In other words, we've done our best to design quality into the mechanism and then continue to keep an eye on it through the entire manufacturing and assembly process. We've designed the new mechanism around the manufacturing processes available to us and sized it to fit within the performance envelope of the equipment we have access to (which, is admittedly pretty impressive).
Where does this all get us? For the moment we're golden (seriously though, have I mentioned just how awesome this thing is?) but then quality is a bit of a moving target. Just as cars have become much more reliable over the past few decades (remember the days when 100K miles meant the wheels were about to fall off and the engine needed a rebuild? No? I must be getting old) so will our expectations of quality continue to progress as time goes on. Without careful attention and constant vigilance, it's also possible to backslide (ever driven a Jeep Compass or Jeep Patriot?).
So what's next? We keep moving, keep learning. The more we keep our hands dirty and the more tools we add to our design and manufacturing arsenal, the more cool $h!t we can design, manufacture and ultimately delivery.
Guess this means we keep adding toys to the shop and then figuring out what the hell we can do with them.
I'm in if you are.
-jack
