Topic: Making

KQ Button Tester; nee Turbo Button

2017-11-16 22:19 - Making

My KQ Turbo Button device, on a messy desk.

I've never posted here about this device I made. I made it earlier this year, mostly as a joke. On the right, now mostly hidden by the fan, is a solenoid. It sits poised above a yellow arcade button, also mostly hidden by the fan. On the front of this view is the electronics and the controls are on the top, all glued to a huge 12 volt lead acid battery.

The original point was to be able to press that button with inhuman speed and accuracy. I managed to leverage that to contribute to some of my videos about Killer Queen. More recently I've been interested in figuring out how to pick good arcade hardware. The moving parts wear out and need replacing. Which ones to buy as replacements?

So I updated the device, not only can it push the button — normally the one in the real arcade, now (in the extra little bit of wood it's sitting on) a dedicated one — it can read its value. So it can be used to derive fine details about the performance of the button, when pressed. I want to do quite a bit with this. Here's one example:

ED 0
D 12272
U 12280
D 12284
U 12540
D 12832
U 12836
D 12844
EU 0
U 8364

That starts ED 0 for "event down zero". Then a bunch of lines D and U indicate the timing of "down" and "up" events observed, in microseconds since we started the "down" event. All real mechanical switches "bounce" a bit when activated (and deactivated, usually). In this case, the button first went down about 12 milliseconds after we started (it takes some time for the solenoid coil to charge up, then to physically move) and the switch contacts bounced apart and back together three times after that, taking just over half a millisecond to settle down into its final resting state. And in this case when it came back up, there were no bounces. In my limited experience so far, this looks like good performance for such switches.

This is just one bit of data but we can compare quality in the "bounciness" category pretty easily: how many bounces, and how long before the last one is done? I intend to follow this with a post containing a detailed summary of this, for several switches. I need to make a final call on exactly what I want to measure, and make sure my tool will do that if at all possible, so it will take a little time.

PCB Prototyping Service Review: JLCPCB

2017-10-01 10:46 - Making

Scan of a board produced by JLCPCB.

Disclaimer: the PCBs pictured and discussed in this article were provided to me at no cost, in return for writing this review. I've received no other compensation and this is my own personal un-altered opinion.

Recently I was contacted about a new PCB prototyping service called JLCPCB and asked to do a review. I've done a few of these over time, and this is much the same. Pictured at left is four copies, two front and two back, of the board that I had made for this review.

It's a simple board so I can't comment on high density pads, but all of the traces, holes, and solder mask appear to be well aligned. The silkscreen is solid and legible everywhere. Overall, I would say these are perfectly fine boards.

I got ten copies, and they were all generally fine. Look (very) closely at the far bottom right of the image, though. You'll have to go full resolution to see it, but there's some scuffing around the pads near the bottom middle and bottom right. Cosmetic only, it seems, and the other nine boards had no issues or only even more minor scuffs/scrapes.


JLCPCB's claim to fame appears to be their $2 minimum cost. This applies only to the first board in any given order, and shipping from China applies to any order. So really you can get a few copies of one board made for $2, but you can only get it delivered for more like $12. Add a second board to the same order (e.g. to share the shipping overhead) and it will be $5.

Customer Numbers

Just like EasyEDA, this is some sort of batching service, which adds customer numbers in the silkscreen. They do say this ahead of time, but as I've called out in earlier reviews, I really don't like it. Especially here. I explicitly put in the in the "remark" box that I'd prefer this number to be located under U2 or U1. It would fit in either place. But instead, it was put out near the edge in the most visible place.

Final Call

These are fine boards, there's (almost) nothing wrong with them. But if I'm going to pay a couple bucks for the boards, plus $10 to $15 for shipping, I'd rather go with Elecrow's "special" service, ten copies up to 10x10cm for $5 — with no extra customer number printed.

Quarto Game Board

2017-08-11 12:57 - Making

I recently discovered (via the awesomely named YouTube channel I Like To Make Stuff) of a board game called Quarto. It's got simple rules and it's pretty easy to make a set yourself. I'm visiting my Mom in New Jersey, and that means access to some tools I couldn't keep in the city.

Rounding the material for half the pieces. The pieces are all rough cut out.
The board is a grid routed into some already-finished wood. Complete!

I picked some already-one-inch-square scrap available, it seems to be PVC. I rounded off the corners on the router table, then cut out eight short pieces and eight tall pieces, half of each from the rounded over section and half from some raw square section. Then half of the pieces got holes drilled in the top, and half got spray painted black.

The board is another scrap piece, of wood that was already finished. A grid of shallow lines, again with the router table, formed the play spaces. I chamfered the edges and with the paint dry, it was done!

This was a quick and dirty project. The grid lines were not routed the best, and the spray paint leaves a lot to be desired. But they're definitely good enough to play with. So I'll give that a try, and then decide if it's worth trying again, with perhaps better materials and more care.

Killer Queen Berry Flower Plush

2017-07-29 12:04 - Making

An in-game berry flower, full of berries. An in-game berry flower, picked clean. I've hardly posted about it, besides the tapper buttons I made last year, but since early 2016 I've been spending a lot of time playing an arcade game called Killer Queen. It's played by ten people at once, in two teams of five. The social aspect of working with your team to outplay the other one turns a fantastic game into an addictive one. At left and right here are two pictures of one of the key parts of the game: these yellow flowers are scattered around the play area. They start, like at left, full of six berries and often end up like at right, plucked clean. The berries are central to play, being a direct path to one of the win conditions and also the means by which players upgrade themselves to pursue the others.

One of the very dedicated players that I know thanks to this game is pregnant, with her baby due in just a few weeks. A coworker and fellow player had the wonderful idea to give a Killer Queen themed baby gift, and one was a plush berry flower toy. I was excited from the moment I heard the idea. I finished making it, and gifted it, this week. Here's a photo gallery plus some explanation of the build process.

Some fuzzy pom-poms will be the berries. A plush berry pile, on a flower-to-be.

First was gathering materials. There's some yellow felt here for the flower, and some fuzzy pom-poms of just the right color to stand in for the berries. I had to make two orders of these. At first I just got six, because that's how many there are in game. Once I saw them in person though, I realized I'd need to make a pyramid in three dimensions for this to make sense as a physical object.

The first of the petals, top and bottom, being stitched together. Using printed paper templates, I cut four petals out of yellow felt, and sewed two layers together.

I found what seemed like a reasonable petal shape and drew it out on the computer, then printed it out on paper for templates. These were traced onto yellow felt which was sewed and trimmed into the final outer shape. It took two tries to get the size right. This worked out great: though I wanted the profile of the smaller size, using the larger size ended up being just the right amount of extra material to wrap around the depth I wanted. So I sewed and cut the outer shape of all four petals. Each was one sheet of felt, cut in half and stitched together into a pocket.

An early step of sewing the separate petals into one flower, two seams join one petal to either side of a third.. Continuing the process of flower assembly, all four petals are either sewn together already, or pinned in place for sewing. The first half of flower assembly complete:  All four petals are sewn together on one side.  The other side

With all four separate petals prepared, the next step was to start sewing them together into one flower. This involved pinning the remaining flaps in place, stitching from the outer corner of two petals down to the middle, and repeating three more times. When done one side of the flower was sewed up, with flaps remaining on the other side.

A piece of upholstery foam is cut into the flower shape. The foam is stuffed into the flower, by flipping it inside out over the foam. After fit was confirmed, a few last seams were done by machine, leaving the smallest flap open for stuffing the foam through while inverting the felt flower around it.

The plan is to flip the felt flower inside out around a piece of upholstery foam, leaving it stuffed and plush, with the seams hidden inside. This was tested first, and the fit was fine. So the foam came back out and two of the four remaining seams were done by machine, again on what would be the inside. With a smaller open hole left, the flower was stuffed again, leaving just a few loose flaps.

Stitching the second of the remaining seams by hand, from the outside. Last seams of the flower complete, foam stuffed inside.

The remaining two seams were stitched by hand. This leaves a raised seam, but they'll be hidden shortly.

A green pistil and some berries are laid out to plan their placement. The pistil is stitched in place.

I had hardly noticed despite playing the game for over a year, until I looked closely for this project: There's a green structure that holds the berries. I'm choosing to call this the pistil (a discrete organ in the center of a flower capable of receiving pollen and producing a fruit). So I made a simple cone out of green felt and stuffed with a bit more foam, with the intent that it holds up the higher layers of berries without crushing the lower ones. I laid the bottom layer of berries in an arrangement that would mostly cover the raised seams, and leave room for the pistil in the middle. Then stitched the pistil in place, again by hand.

The petal The lower layer of berries were stitched onto the petals. The lower layer of berries are all in place.

Next I added the vein pattern onto the top of the flowers. I found a reasonable image online, then traced out the main structure and stretched and tweaked it to fit my exact petal shape. I printed this out onto paper and cut out the shape to form a stencil, which was drawn over with a marker. With that done, the first layer of berries were stitched onto the petals in a triangle shape, around the pistil.

Two more layers of berries are stitched onto the pistil, to form a tetrahedral shape. The finished flower, shot one. The finished flower, shot two.

All that remained was to attach the final four berries. These went onto the pistil, using its structure to help with the shape. Which did not end up perfect. There was more slack than I hoped for, but I'm still very happy with the final result!

Cable Hangers

2017-04-09 18:53 - Making

The first cable hanger, holding mostly micro- and mini-USB cables.

The second cable hanger, holding mostly portable game system charging adapters, and a few miscellaneous things.

A while ago I came up with an idea which I finally brought to fruition this weekend. I've got a lot of cables, mostly USB cables. They generally sit in messy piles and are difficult to find. This is a system to hang the cables on the wall so they remain out of the way, but also easily found.

There are two locations with plenty of wall space in my apartment which are also very out of the way, and they now both hold one of these three foot long organizers, for a total of just over sixty spaces to hold cables. Most of which are full!

It started with some very cheap mini clothespin style clips. Then a one-by-two board with a small groove routed into it. The clips are glued into that groove, then the board is screwed to the wall with a couple drywall anchors. That's it!

One (pictured left) holds mostly micro USB and mini USB cables, with a couple USB extensions and full size USB cables. The other (pictured right) holds mostly charging adapters for various portable game systems, but also some wall adapters, earbud headphones and a couple USB C cables as well.

Now I just need to come up with a way to straighten all those cables, so that it looks neater!

PCB Fab Review: EasyEDA

2017-03-30 22:39 - Making

Following my two previous such posts, EasyEDA reached out to me requesting a review of their service. Disclaimers up front: First, they offered a $50 coupon so I paid only the shipping for these boards, but this article remains my own unvarnished opinion. Second: I did not use their design tools, I already know KiCad and can't spend the time to learn a new one. This is review is about only the PCB fab service, so point one is that they support both modes (use their design tools, or upload your own produced separately).

Three revisions of my wi_ther board.  Rev A by Elecrow, rev B by Seeed, Rev C by EasyEDA.

To the right is a comparison of three revisions of the same board. The green board on the right is the back and front of the board made by EasyEDA, with a PCB ruler showing centimeters besides that. Click to embiggen, open in a new tab to go even bigger.

The Good

The quality of the boards I received was very consistent. And quite good overall. There was the occasional light scratch, and a semi-consistent sort of wrinkle in the solder mask, but they are only evident under close inspection, never deep enough to cut through the solder mask. The silkscreen is bold and legible, even under a microscope it's consistent and solid. Compare especially the line around U4 to the rev B board in the middle, whose silkscreen is spotty and hard to read. Routing of the internal cutouts is also quite good (although I intentionally rounded as many corners as I could in this version, after experiencing this in rev B). The square corner cutouts around U3 show the worst, still minor, issue here: one corner has a bit of over-cutting.

The Bad

There's a fair deal of dust, especially visible along the right side of M1 on the front-up board at far right. Easy enough to wipe off before assembly. Then of course those darn added part numbers! I specifically put instructions to place the number inside the outline of M1. That will be covered by a part once assembled, becoming invisible. Instead they put it right smack along the edge of the front layer. There's hardly a more visible spot.


Cost was very good. I also got a stencil, which due to size/weight forced express shipping. So I'll do a separate cost comparison, for this 99x33mm board, cheapest options including shipping:

QuantityEasyEDASeeed Fusion 1Elecrow 2Dirty PCBs

1 Seeed had a (temporary?) $5 off shipping special, in these prices.

2 Always the "special two layer, 10qty" service. Edit to multiple quantity of that in the cart for 20/50 total quantity.

When I first put this chart together, EasyEDA had the best price after shipping at anything but quantity 10, for this board. I then had the idea to use multiples of Elecrow's "special" service, which brought them down to the same price range. It's worth noting that isn't clever enough to try this. If you're cost sensitive, invest a little time into exploring all the options offered from several fabs.

I've got a different larger board that I'm working on (149x68mm) and I only need one of it. In this case five from EasyEDA is easily the least expensive among several fabs (coming in about 25% cheaper than the next lowest option). Once again it's worth checking several sources, and even designing to fit into a particular envelope which is efficiently priced if you can. For this larger board, it has to be that size.


These boards are perfectly good, and also very inexpensive. They match or beat the quality of the previous revisions from other fabs, for similar or lower costs. I'm very happy with this service. That said, when I'm not getting the service for free I'll probably pay the premium to not get extra part numbers added to hardly-controllable usually-too-visible parts of my boards.

Remapcro: A Hardware Keyboard Macro Recorder

2017-01-21 15:39 - Making

The assembled boards, with keys, top view. The assembled boards, with keys, bottom view.

I posted once recently about the prototype of this project, but as of today I've finished the first real one. The name Remapcro is a portmanteau of remap and macro, because that's what it does. It's an array of extra keys onto which macros can be stored, and then replayed at a touch. It works by sitting between your keyboard and computer. Normally key presses are passed straight through, but when recording a macro they are stored and then later replayed.

I made a handful of small errors along the way, but none were fatal. The worst is in the picture on the right, above. There are two PCBs to hold the electronics. On top one holds the key switches and the diodes which help make the keyboard matrix easy to read and error free. Then a second smaller one, holding the "smarts". There are a couple connections between the two of them, and the cross-wise one (top to bottom, at the edge of the smaller board) is off by one space. I ended up mounting the smaller board "upside down" and even though I thought I had the connector perfectly centered, it was off by a tenth of an inch. Thanks to the size of the key caps, there was already some extra room in the case I designed, and cutting a bit of the corner off the smaller board helped squeeze everything in anyway.

There's also one LED tucked into the top-left key (bottom left in the left picture above). It's actually three LEDs (red, green, and blue). And specially designed to fit exactly into these key caps. I could only find it in a lot of 50 from China, and I was too impatient to wait for it to arrive (and carefully check my design against it) before I ordered the PCBs. I ended up needing to put it in backwards, trim off a bit of the bulge that now sticks out rather than into the slot it's designed for, and re-wire the connections a bit.

Fully assembled Remapcro, front side view. Fully assembled Remapcro, rear view. Fully assembled Remapcro, rear side view.

The case the boards fit into was a challenge both to design and to produce with my 3D printer. But (perhaps aside from the screaming orange color, that's what was easily on hand for this first test run) I'm quite happy with it. A couple pieces slot together at the front, then a screw holds the back on, wedging everything together. The only problem was getting the back piece sized correctly, especially with all those holes. It's still not perfect, but it's functional. And if you were curious about the shape and arrangement of keys:

The first Remapcro, in-situ.

Of course, it's designed to look like it belongs, sitting next to a standard PC keyboard. I hope to re-design the case, ideally with more rounded corners and tweaking the alignment of a few things. Plus, supporting the insides better: right now it's only supported at the extreme front and back edge. This is mostly fine, but it can flex when pressing the keys towards the middle, which would be nice to avoid. I'd really like to fit everything onto a single board. That little space between the top and second rows could probably just fit all the electronics, but the problem is the connectors. With all the keys poking holes everywhere, not much room is left to mount the USB in and out ports. Who knows, maybe I'll come up with a brainstorm.

Geeetech G2S Pro Power Supply Cover

2017-01-16 17:12 - Making

The cover which I designed and printed for the power supply for my 3D printer.

Back in October I finally decided to get a 3D printer. I got a low cost kit, and one of the glaring issues is the power supply. As shipped, there were loose wires between the plug, the switch, and the supply. No bare conductors, but still not awesome. The switch would just flap in the breeze. I saw some similar designs already made online but none of them really satisfied me. I decided to design my own. It took some time before I could successfully print it, but it's finally done, much safer now not to mention easier to use!

I've shared the design files on Thingiverse. The set of hexagon holes were designed partially to save material, but mostly to try to reduce curling. They weren't sufficient, which is why I only now finally got it printed successfully. I had to get my bed leveled very well plus use a brim, to get this successful print in ABS. The PEI print surface was probably also required; it helped at least.

PCB Fab Review: Seeed Studio's Fusion

2017-01-08 23:20 - Making

In early November, Seeed Studio contacted in regards to my PCB fab comparison post from 2015, asking that I also review them. After a short discussion they agreed to give me a $50 service credit in exchange for a review. This post is that review, of the Fusion PCB Prototyping Service.

Board One

Several copies of a simple square PCB manufactured by Seeed Studio's Fusion service, with issues marked.

I had two boards fabbed, plus a metal solder paste stencil. Let's get into the first board. This is for an incomplete project which I won't describe yet here, instead just covering the quality of the PCB.

They're fully routed, which seems to be common from Chinese fabs. There's one tiny "nipple" of extra FR4 consistently in one spot. I assume this is the very end of the tool path which somehow isn't quite completed. This seems to be common for individually routed boards, as I've seen this sort of issue from three separate (low-cost) fabs.

The good: there's both plated slots and non-plated holes, and they came out as desired.

The bad: a few boards have extra blobs of silkscreen scattered about, see the left two. In consistent locations, and there's two more boards (not pictured) with slightly more faint spots but again in the same locations. Those two I might have missed if it weren't for these very obvious two pointing out the locations. Several of the boards have scratches, more visible in person than in the scanned image here. One of them has a bit of solder mask missing from a spot over one of the traces. There are several blemishes in the solder mask, most too subtle to notice in the scan but one (on the bottom right pictured board) is severe. Perhaps one or two of the ten boards arrived without some form of blemish or scratch.

The ugly: order numbers added to the silkscreen layer. On this board, it's at the top right of the front layer, near the power connector. It seems they put a tiny bit of effort into hiding it under a component, but the presence at all is disappointing. I'd normally check this sort of thing ahead of time, but I selected Seeed because they approached me, not because of my normal evaluation process. I only got to it now that I have the boards and I'm taking the time to write a review. I went looking, and I found as the last entry in their FAQ the Seeed Production Code will be printed on empty space of your PCB page. Certainly could have been more up front with it. I didn't mind when Dirty PCBs did this, they're transparent about it. A way to hint to them where the printing would be least obtrusive would be an improvement. (In this case the fat DIP pads in the middle will be fully covered by a part, and anywhere on the back would be better than almost anywhere on the front.)

Board Two

Another more complex board, manufactured by Seeed Studio's Fusion service.  Again, issues highlighted.

This second board is a revision of my environmental sensor project. It's mostly the same, but a USB/UART chip was added along with a few other small tweaks. I'm putting a front and back copy each of the first revision into the picture, for comparison. They're in the bottom right, clearly identifiable as the pair with a different color.

The good: Seeed's blue solder mask is actually blue! More of these boards came out okay: I put four of ten in my defect-free pile, as I was laying the rest on the scanner bed to show. All the issues I've got to bring up next are generally minor.

The bad: Still several defects, including scratches on lots of boards. One, pictured in the mid right, goes across several holes, deep enough to expose copper. Two of the boards, but one really in particular, had a surface finish issue, the whole thing being mottled. The silkscreen shows stippling everywhere on this board. Side-by-side with the rev A board (the bottom-right two) it's nearly unreadable by comparison. One of the boards has a stray speck of metal (solder, surely) sitting off in the middle of nowhere. Thank goodness it's not shorting something. Another has a foreign object in one of the through holes.

The ugly: this board cares about thermal properties, so it has several internal cutouts to help limit heat transfer. The Seeed boards are all routed sloppily. Most of the inner holes have at least one corner where the cut goes a bit too far, creating an extra divot. And still those order numbers in the silkscreen. Again sort of hidden under a part, at least they tried.

A curiosity: Silkscreen between fine pitch pads. Both rev A and B as well as my old prototype include the exact same TSSOP part (U3), with 0.65mm between pins (center to center, 0.40 wide). As best I can tell, the silkscreen gerber specifies one wide empty area across these pins in both revisions. But:

Comparison of the fabbing of the same footprint by three PCB fabs.  Left to right: OSH Park, Elecrow, and Seeed Studio's Fusion.

That's the same footprint manufactured thrice by three different fabs. On the left is the prototype by OSH Park, in the middle rev A by Elecrow, and on the right rev B by Seeed. It's the same "Housings_SSOP:TSSOP-8_3x3mm_Pitch0.65mm" default KiCad footprint in all three cases, with no custom clearance setting. The mask clearance ends up overlapping into one large rectangle covering each of the four pins on either side. That's just how OSH and Seeed fabbed it. But Elecrow actually filled in the mask between these pins anyway. I can't fault Seeed for fabbing the board as specified. Overall I'm not excited about the idea of the fab changing the design on my behalf. In this particular case, I like what Elecrow did, however. Perhaps I'd never have noticed if I wasn't scrutinizing the boards for this review, as I never had any trouble soldering them, even completely by hand.


A close-up view of the silkscreening on a PCB fabricated by Seed Studio's Fusion service.

I've laser cut my own stencils out of plastic before, but they've only worked okay. For roughly $20, and with a $50 coupon, I decided to order a metal one to see what that was like. Board two has several surface mount parts, and I added a QFN part in this revision.

There's not actually a lot to say here. The measurements were listed online in the order page (28 x 30 cm) but it was a case of ordering sight unseen over the internet and not truly understanding the size. I ended up cutting it down to make it practical to use by hand, and then it worked very well.

I have now used it once, and it was a fine experience. Especially including the narrow pitch QFN leads, which worked great the first time. But then, once I was done, I whipped the board under the microscope to check my joints. The soldering was fine, but up close, the silkscreen's quality issues were clearly revealed. Was the inkjet under-extruding? I can see that it's a bunch of separate dots, which do not connect to form any sort of line. The upper case letter "I" in "IO" is especially bad, sometimes one-and-a-half sometimes just one row of dots not quite making a line. (This is visible in the comparison shot of U3 above, as well.)


The order I made for everything reviewed above was two PCBs, 10 qty each, and one metal stencil. That's $9.90 x 2 plus $19.90 which seemed a reasonable $39.70. But that weight/size came to $84.20 total after shipping (!). If I try again without the stencil I get $34.89 total. The same no-stencil order comes out $32.84 at Elecrow.

For an order of just board one, Seeed quotes $9.90 for a basic board (1.6mm FR-4, 2 layer, qty 10, green mask, HASL, 1 oz copper). Great. But go through checkout and you'll discover that the cheapest shipping is $12.68, for 10-18 day service (3-5 day costs $19.43). Elecrow charges $11.50 for their 5x10cm service with otherwise identical specs, but they have a shipping option at only $6.60 (their 2-3 day costs $18.05). If you're patient that's $22.58 from Seeed, or $18.10 from Elecrow, and a wider difference if you're impatient. And if I were ordering there, I'd have squeezed into 5x5cm and saved another $2.

Which is another subtler issue. Elecrow puts their size-based pricing right up front. I've definitely designed to a 5x5 or 5x10 cm envelope before. But Seeed just has you type in your size and only then tells you the cost. It might be that this gives you more/better choice for what to do and what it will cost, but it's very hard to know what your board will cost ahead of time, or to know how to focus the design phase to optimize cost. Where is the line? Let's compare some known prices at Elecrow to what Seeed would charge:

Size (cm)ElecrowSeeed

A lot of data to say that they're both competitive, always within a few dollars of each other. When I use Elecrow's size increments. I've got another practical board in progress, it's 41 x 130 mm and external concerns force this particular size. At Elecrow I'd need to buy the 5x15 cm service at $23.48 for five copies. For five copies at this size Seeed charges $16.84, which is a significant difference (roughly 28%). But since Seeed will only tell me the final cost of a board after selecting all options, it's hard for me to take advantage of these possible savings.


For this review I've pulled out another set of two boards I ordered from Elecrow in late 2015. (A failed (suspended?) project which I won't go into...) They're of similar sizes to the Seeed boards reviewed here, and when looking at them with as critical an eye as I did when I started writing this detailed review, I did find two small scratches, out of eleven boards. But I did not find any other issues, most importantly no order numbers added to the silkscreen. The prices are very similar, and I can predict the price easily ahead of time.

If I don't need more than three and my boards are small, I'll definitely go for OSH Park. If I've got bigger boards or I want more than three copies though, Seeed probably won't be my go to in the future.