Via Gary Stevens/Flickr and Alexis Madrigal.
It's worth reading the wikipedia entry on QSL cards - it's an interesting and bizarre idea.
Manufacturing guy-at-large.
Ceiling
A while back.
Yes.
I love working on projects where it’s not a given that the idea is even possible.
— Jonnie Hallman (@destroytoday) January 8, 2014My steez.
Public Radio progress
The latest rev (v1.1) of The Public Radio:
The current state is:
- Arduino Pro Mini
- Si4703 breakout
- Mono audio amp breakout
- VREG
- A bunch of screw terminals
The next rev will be a little PCB that the Pro Mini can mount to, and on the back will be all discrete components comprising our own FM tuner & amplifier. This will reduce the cost of the assembly by a *lot* (these Sparkfun boards are easy to work with but silly expensive), and will allow us to play with the circuits a bit.
The incredible thing is really how cheap the Pro Mini is. These things cost under $9 (cheaper on eBay) and have a lot more features than we'd ever need. Eventually we'll strip that off too and run the whole thing off of an ATTiny (or similar) but for now there's no point in getting ahead of ourselves - the Pro Mini is cheap enough and requires very little work on our part to get our MVP out quickly.
We should have the updated circuit done tomorrow and will be working on board layouts over the weekend :)
Dance dance
Burritos
Craig Cannon, from his poignant 2013 recap:
I’ve found it dangerously easy to mistake industry-defined success with what I actually want, which is, as always, more burritos.
True.
The Lady's Harp
I've been working with Daniel Fishkin on a electronic sound art project called The Lady's Harp. It's a large scale installation that uses acoustic feedback (from guitar pickups) looped back through contact transducers, which induce vibration on piano strings. Daniel has installed this instrument in a few other settings, but needs it to be easier to set up & tear down, so I'm helping with some basic mechanical design. We're using mostly off-the-shelf components - primarily 8020 extrusion - and a few laser cut acrylic parts.
We're mocking the components up in the next few days, and Daniel will be installing the Lady's Harp in Nothing Space later this month. I'll have more updates soon, but Daniel's description of the project is much more elegant and informative :)
Writer's Block
From Jerry Seinfeld's recent AMA:
Q: How do you deal with writers block?
A: Writer's block is a phony, made up, BS excuse for not doing your work.
:)
Schematic & Plans
One more report from our Hacknight: The Public Radio's schematic.
We'll use a Pro Mini for this next rev (the one after that will likely get an ATTiny), but will be using discrete ICs for both the FM receiver chip (Si4703 for this rev, though we'll eventually transition to Si4702 as we're not using the RDS features the 4703 offers) and the amplifier.
This schematic got a little sloppy at the end (after all, I was drawing it :/). I'll probably redraw it once more on paper just to make it pretty, and then we'll punch it down into Eagle and build a board file off of it.
There are probably a few mistakes here so if anyone's got a sharp eye, let me know :)
And lastly, our tasklist for the next few days:
Most of this doesn't bear much comment... The next rev will likely get laser cut acrylic lids, which I kind of hate but which should be significantly more economical (and quicker to procure). Eventually we'll do stamped stainless steel lids, but that's a ways off. We also need to do a bit more digging on active antennas, as the telescoping RC antennas we're using here leave much to be desired. We've also got to look into other wire-to-board connection options; the screw terminals we're using (.1 spaced) are still a bit bulky, and we'd really like to avoid soldering wire directly to the PCB...
More soon.
Symbols
This is a poorly formatted quote.
A week or two ago I posted a really great quote that I received on MFG. This one is on the opposite end of the spectrum.
Note that although I specified DDP terms, the supplier (a middleman for overseas outsourcing) has quoted FOB China.
The price is also totally noncompetitive. I hope to purchase these parts from a US supplier for under $3 apiece at this quantity - and I don't want to be waiting 6 weeks for a boat to show up, either. At larger quantities (1000s) I'd hope to be paying more like $1.75 to my door.
MFG RFQ View rates
For traditionally manufactured parts, MFG has a large enough supplier network that you almost always get a handful of good quotes. My rack end, for instance, went out to over a thousand suppliers. About 75 viewed the RFQ, and to date I've received 7 bids. Another dozen or so suppliers are apparently "preparing quotes."
When you shrink the pool down, though, the rates matter a lot more. There are a *lot* of swiss turning shops in the US, but very few that can produce DMLS titanium parts. So when I posted my seatmast topper, I tracked the results with a lot more interest.
The RFQ went out to 110 suppliers. 8 viewed it, and I have yet to receive a single quote.
Incidentally, there is at least one supplier on this list who did *not* view the RFQ but whom I found separately via Google.
The thing that really strikes me here is MFG's total incapacity to move my project forward - quotes or not. In optimal situations, MFG is an effective marketplace to compare quotes for manufactured parts. What it's not good at, however, is the broader function of connecting designers with manufacturers. Anything I want to learn about the DMLS process - information that inevitably is going to come directly from the engineers and operations managers that are quoting and building my parts - is totally missing from the MFG experience. Instead, I'm left to do leather-to-the-ground work the same way I always have: an afternoon spent with Google + a phone line.
There's definitely a place in the world for a manufacturing marketplace, but I'm pretty sure this could be better.
Regardless, I'm beginning to develop a few old-fashioned leads on good DMLS job shops, and I hope to have some real - and reasonable - pricing in the next few days.
Documentation
Note: This is old, and too complicated/obscure to explain here. I still like it tho :)
Snowdog
A couple days ago.
A good idea that we're not ready for
A vending machine in Bushwick, via Ana Andjelic:
I think this is a great, great idea. But I suspect that for most cyclists, it doesn't actually eliminate a pain point - which presumably, in this case, is having a flat tire and not being able to fix it.
That's because access to supplies isn't really the issue with that pain point. For the vast majority of cyclists, the issue is not knowing how or not wanting to fix it yourself.
Take the issue of knowing which tube to buy. QBP (the most ubiquitous of all bicycle parts distributors, and the manufacturer of most of the tubes shown in this photo) sells literally dozens of SKUs of just inner tubes. Knowing which one to use requires a bit of knowledge, especially when you consider that many cyclists (a disproportionate number of whom probably live in Bushwick) are riding mostly obsolete tire sizes, e.g. 26x1-3/8" (an old Raleigh variant), which can easily be confused with incompatible alternatives (e.g. 26"x1.375").
But there are other possible issues here - being late for work and needing the service to be done as quickly as possible. Wearing clothing that isn't conducive to kneeling on the sidewalk. Maybe the issue isn't in the tube but in the tire itself - a blown sidewall, say.
Now, I'm *not* a booster of bike shops - I think that they provide pretty poor value to the vast majority of customers. But the way to fix that isn't through direct-to-consumer sales, whether online or via unmanned kiosks. Instead, we need a new way to provide customers with the information and service they need. We need to empower cyclists to choose between a variety of good options, for example:
- Affordable repair parts + clear & detailed education on how to perform basic services
- A basic way to store, access & understand information about your bike and its specs/requirements (e.g. tire size, brake pad style, etc)
- On-demand Uber-style repair service, anywhere/anytime
- The ability to lock your bike up wherever you are, and queue a mechanic to come by, unlock it, perform the service and drop the bike off at your home/work
Without a complete transformation of the way we think of bicycle repairs, I worry that services like the one in the photo will be wasting sidewalk space. I like the idea, but I need more execution to get behind it.
Also: Rim strips? Really? No regular consumer is buying those.
File conversion woes
This is why dimensioned PDF drawings are so extensively used in procurement. The top photo is from a supplier from MFG.com; the bottom one is the STEP that I originally uploaded to MFG.
This supplier has obviously downloaded my STEP and performed some translation or conversion on it, and in the process has deleted a few faces (you can see the difference in the foreground of the part, and in the areas he's highlighted in red). This is clearly an inexperienced supplier, and one that I would ultimately have a *really* hard time choosing. I'm not sure what he did or how he did it, but the fact that he made this mistake is an indicator that we'd have issues down the road.
(To his credit: the photo came from a message he wrote me saying that he "noticed some missing surfaces on the part file," and asking me to fix them. So he knew that there was a problem, but didn't understand what it was and wasn't able to troubleshoot it himself.)
In traditional manufacturing, 3D part files are created and edited in a program like Inventor or SolidWorks. The parts are then brought into a separate environment in the same application and drawn and annotated in multiple 2D views on a "paperspace." The resulting drawing file (.IDW for Inventor) is a dynamic representation of the original part; if you modify the part file, the drawing will update automatically.
You *never* submit drawing files directly to a manufacturer. Instead, you export PDFs of the dimensioned drawings, and *optionally* include STEP files (which are essentially cross-platform 3D files) as a courtesy. The STEPs can be used to help the manufacturer set up their CNC machines, but they're for reference only; the PDFs (with all their dimensions and annotations) are what you're buying.
"Organic" shapes - like those that 3D printing is so well equipped to make - don't fit into this process well. Complex surfaces are *really* difficult to define clearly and completely in two dimensions, and so most 3D printed parts are built from solid files. In this case I submitted a STEP, which manufacturers will convert to an STL and then run through a slicer and feed into their machines.
The problem is that STEP files aren't immutable, and the supplier in this case has apparently deleted a feature from the part. In this case the result was obvious, but there are a lot of features that he could modify or delete that would be a lot more difficult for him to detect, and my QC job would be accordingly tricky.
This process should be better. The PDF workflow is inconvenient, but at least it's an effective barrier to issues like this one.
Also, we need more, and more *good*, DMLS suppliers.
Kevin Lynch
From The Perceptual Form of the City, Lynch's classic text on urban planning and "imageability." Via Bostonography; emphasis mine.
A highly imageable city… would seem well formed, distinct, remarkable, it would invite the eye and the ear to greater attention and participation. The sensuous grasp upon such surroundings would not merely be simplified, but also extended and deepened. Such a city would be one that could be apprehended over time as a pattern of high continuity with many distinctive parts clearly interconnected. The perceptive and familiar observer could absorb new sensuous impacts without disruption of his basic image, and each new impact would touch upon many previous elements. He would be well oriented, and he could move easily. He would be highly aware of his environment.
The Shortest Pencil
From the archives :)
The Public Radio assembly
A few days ago Zach and I assembled the lids on the newest version of The Public Radio.
I had spent a bit of time thinking of how we'd streamline the process, and had purchased a round punch and some foam tape to make an adhesive backed spacer for the speaker. For production we'll get these die cut by a job shop, but for prototyping this worked very well.
I was trying out two different varieties of mounting screws for this version. In order to make the lid cost effective, I designed it with countersunk thru holes and am mounting the speaker from above. That meant finding screws that would bite into the plastic speaker body well, and I bought a selection of thread-forming screws for that purpose. They've got cute little torx heads which - if I spend a little more time organizing the speaker perforations - will look pretty nice on a stamped (as opposed to this SLA printed) stainless steel lids.
Overall, the assembly worked very well. Honestly I'd prefer to nix the screws, but that's impractical... it's possible that I would design the lids in two parts (like a clamshell) instead, so that the mounting hardware could be hidden from view. We'll see :)
We should be receiving new PCBs on Monday, and will be assembling a few v1.1s ASAP. Expect updates.
Strategy Tax
From the second of Ben Thompson's posts on Microsoft's recent reorganization. Emphasis mine.
Let’s follow the typical path: Company A makes an amazing product, finds a great market fit, and starts to make a lot of money. They IPO. They continue to grow, and the stock goes up. And then the stock stops going up, because it’s not clear how they will continue to grow. A stock’s worth, after all, is simply the discounted sum of future earnings.
And so the company looks for another avenue of growth. They diversify, maybe successfully, but now they have two products. And soon, like DuPont, they see the wisdom in having two divisions.
Of course, those divisions are certainly related in some way, and it’s inevitable that considerations are given – or dictated, from the CEO – that decisions in one divisions favor the other division whenever possible. This consideration is called a strategy tax, and it’s a hindrance to product quality. So is the inevitable competition for resources, and the increasingly divided attention of the CEO.