Like many stories, this one started on the roof. This particular roof is located in Michigan and keeps the rain and snow off of the i3Detroit hackerspace. Being an old industrial building, things up on the roof can start getting creaky, and when an almighty screech started coming from one of the rooftop vents as it swiveled in the wind, Nate, one of the group’s coordinators, knew it was time to do something about it.
Previous attempts to silence the banshee with the usual libations had failed, so Nate climbed up to effect a proper repair with real bearings. He dug into the unit, measured for the bearing, and came down to order the correct items. That’s when it struck him: How many should I order? After all, bearings are useful devices, not just to repair a wonky vent but especially handy in a hackerspace, where they can be put to all sorts of uses. Would extra bearings be put to good use, or would they just sit on a shelf gathering dust?
That’s when Nate dropped us a line and asked a question that raises some interesting possibilities, and one which we couldn’t answer offhand: Is there a readily accessible online library of common mechanical parts?
Not All The Parts
My first reaction to Nate’s question was, “Sure there is — it’s called the McMaster-Carr catalog.” The voluminous gold and green dead-tree version and its online equivalent are valuable references for anything and everything mechanical. But McMaster’s stock really represents more of the universe of parts as opposed to a well-defined list of commonly specified parts. If a part exists, it’s likely in the catalog, but just because it exists doesn’t mean it’s generally useful. So much for the wisecrack.
It turns out that Nate has something else far more interesting in mind, and it’s based more on his experiences with electronics parts ordering. He’s thinking about something along the lines of Octopart’s Common Parts Library, Macrofab’s House Parts, or Seeed Studio’s Open Parts Library. These repositories allow designers to see what components are currently being used for various applications. The aim is to ease the design process by limiting choices to just a few widely available parts. Start there, and if your needs aren’t met with some of them, branch out, spending extra time on only the parts that actually call for it.
Say you’re working on a circuit and need an op-amp. Searching through every op-amp available can be a daunting task. Having a concise list of the devices broken into a few general categories helps to ensure you don’t get bogged down with each part choice when your design constraints aren’t very particular. Pick your bandwidth, pick your package, and move on with things. In the case of Contract Manufacturers, the added benefit is that you won’t need to source the parts for the production run and their familiarity with the components helps avoid problems when the pick and place machines are fired up.
An equivalent library for mechanical parts would be a boon to all designers. The line between electronics and mechanical design has always been a blurry one at best, and with more and more products interacting with the real world through servos, steppers, and actuators, specifying mechanical components is just another part of the job for electronics designers. Making that process easier would be a win for both the designers and the suppliers that will get the business through quick and simple one-click ordering.
Where Do We Find the Common Mechanical Parts?
And yet, to the best of my knowledge, no such Common Mechanical Parts library exists. I could be wrong, of course, and we’d love to hear from the readers if they know of any such services. But we’d also like to brainstorm what just such a library would look like, and how it would be executed. For my money, I’d start with the McMaster-Carr catalog, since if they don’t have it, you don’t need it. One must assume that they have an API for their catalog; after all, Fusion 360 has a searchable catalog of parts so that you can drop CAD drawings for McMaster parts right into your mechanical designs. A little Googling around suggests that the API is private, though.
So what do you think? Would a Common Mechanical Parts Library be useful? Does one already exist? What would you want to see in terms of features from such a product? Sound off in the comments section below.
And thanks to Nate for the tip on this and the useful discussion.