I’m angry (again)

It’s been quite a bit of time since I’ve posted here, so quick update on what’s happening.

It’s mothers’ day soon (it happens that this day is not the same depending on the country, so i’m hoping to be spammed twice as much) and I got spammed to “think about my mother and get her the latest kitchen appliance”. First, I think it’s awfully sexist to consider that my mom would be happy to have a new mixer or vacuum cleaner. I’m pretty sure she’d prefer a good science fiction book. Second, my mother died 3 years ago and that’s a painful topic for me. I do think about my mother and I don’t need to be reminded by random strangers for marketing purpose. It’s slightly too late for this year, but I plan public shaming on the topic next year.

I’m French, I could vote for the presidential election. First round was April 23rd, second round was May 7th. I received the place I could vote by mail (woohoo for snail mail) on May 4th (star wars day). The paper was originated from Paris on April 24th, so after the first round but it’s supposedly from the consulate of Geneva. More fun, I couldn’t change the location for my wife, so my wife and I were allocated to different locations (300 km apart). Of course, if I wanted to vote, I’d have to commute for more than 90 minutes and queue for more than one hour outside. I’m not sure if it’s on purpose or not, but I call that a scandal and not democracy. Of course, I could still vote at the same time because I never managed to get unregistered from metropolitan France when I moved abroad 12 years ago and I’m still receiving this at my parents, which is another scandal by itself (even better, the consulate told me once it’s work as intended  because I can’t vote for municipal elections s they don’t exist here, so I must be registered in France to be able to vote…) Of course, if I vote twice as the government offers me too, I’d be committing major fraud and be legally responsible, confirmed by the consulate as well. That block might end up translated and shared with the government to foster visibility if I get to find time.

I’ve restarted playing World of Warcraft, after a 6 years break. Stuff has really changed, often for the best. The game is much more casual now, it’s super easy to level up, earn money, much less grinding is required. The universe seem pretty empty: despite having a new extension, it’s clear the game is coming to end of life and struggling to keep players. Most of the game and UI by itself evolved quite a lot, much of what was before provided through addons is now embedded into the core game. While it’s feasible to play casually (we play 2 accounts with my wife), it’s still super easy to sink hours in it. Especially if you have a slightly addictive behavior and have to discover 4 extensions at once. The environment is even bigger than before, nicer. I however really don’t like the concept of pet battles, I don’t really get this in-game pokemon. Some new professions are really looking like useless grinding (thinking about archaeology) while some other mechanisms have been revamped for the best: I love the concept of garrison and wish I could customize it a bit more.

I’ve recently doused myself with some gifts: I upgraded my computer for new graphic card (from GTX 560Ti to GTX 1060), new screen (Ultra wide curved 34 inches screen for a whopping 3440×1440 resolution). I wished I’d done it earlier, the price step is steep but the comfort is just 10 times better. Got some new tools as well, so I’m pretty much setup now (sewing machine, belt sander, jigsaw and best of all, chisels from my great-grandfather). Time for some new hacks soon.

My website is currently hosted on google cloud for free (perks of working for them, I had a coupon). This coupon however is expiring, I need to either pay or switch providers. I was looking for a simple solution that would allow me to serve this simple blog with what I thought was some very easy requirements:

  • As managed as possible, I’m too old to do basic sysadmin myself (and I’m kinda already doing that very day at a slightly larger scale). Especially doing kernel updates and maintaining apache configuration is not what I want to spend my week-ends doing.
  • Https support: cause I’m paranoid (It’s not because you’re paranoid that there is not someone out there trying to kill you)
  • Vanity domain support: I have my domain, I don’t want to be on florent123.wordpress.net or foobar.blogger.net
  • Easy to update and maintain: auto-update, from web UI customization / updates (wordpress, despite not being super secure
  • Cheap and mostly powerful enough to handle a few hundred queries per day.

To my utter surprise, it’s not so easy to find and align all requirements. I’m almost thinking about serving from home…


End of march check – goals 2017


I had some goals / hopes for 2017, It’s currently end of 1st quarter and a good time to look back on how I’m faring.

  • Posting technical stuff on blog : mostly on track. Nothing in March (I’ve been travelling) but lots in January and February
  • Posting non-technical stuff: a few posts, not that many. Half-success
  • Doing technical stuff: some cool projects (lamp) done, with logbook. Some other have been made but badly documented (toy sword) and not published. Overall, I got the feeling I didn’t really change my methodology  or focused on smaller project, so not really a success so far.
  • Reading books: I’v read way more than I was expecting (Goodreads challenge). 12 books and clearly a stretch on some of them (trainingg cats, 2 autobiographies). I still need to interleave some more serious reading in the middle of this HF/SF I’m constantly reading. some progress, could do better.
  • Wellbeing: complete failure. I didn’t lose weight, I took weight (each trip to the US is a nightmare, I might blame the 24oz steaks – yes, that’s 750g). Didn’t train and spent my whole winter commuting by mass transportation, only minor activities (mostly skiing with the kids)

Overall, I got the feeling I could do better.

There are some stuff I did I’m happy about however:

  • I’m upgrading my video setup at home, learning and training to be sure I can make decent videos, especially for tutorials. I discovered I actually love sharing stuff I know how to do and I’m emphasizing this topic.
  • I id some real woodworking, despite my limited amount of HW/space. I’m actually quite proud I helped the kids with repairing, making toys.
  • I’ve restarted playing WoW, after a 6 years break. The feeling is weird, like rediscovering a place you lived when you were young. The game I changed very much, I’m playing casually in this reroll (and with people I know IRL). Anyway, this is really great.

Create a video lamp

I’m doing quite a lot of video conferences from home and I’ve decided to improve my setup, to have better quality, and ideally, at some point, be able to use it for some Youtube tutorials. I still somehow naively think I’ll eventually find some time to do that…

Anyway, as I’ve discovered recently and explained in my last post, it happens my light setup is sub-optimal. I’ve looked at theory and at option for buying lamps, but I couldn’t found anything satisfying. My main reproaches were:

  • boo bulky, too professional: I don’t have much space and I definitely don’t want to have stands (or drill too many holes in my walls)
  • awfully expensive: I’m not ready to invest several hundreds of francs/dollars in this topic, and this seems to be the starting price
  • disputable quality: I found some cheap solutions for filming with DSLR in China, but they require batteries to run. This is not eco-friendly (I got 230V at home) and the few which had technical specs were indicating currents in volts… Too shady for me.

I happened to have a 30W LED R7s lamp that I bought to replace an halogen and we ended up not using, because it was not enough brights nor dimmable.

Time to hit the workshop and make stuff happen. I scavenged the cable from a broken lamp that was lying around and as usual, got some wood tiles from my trusted IKEA RUNNEN stash. Here is a quick run of the project. As usual, pictures can be seen in original size by clicking them.

As a quick note, I used very little hardware:

  • oscillating tool (FEIN-like) for cutting
  • power drill for drilling / screwing
  • soldering station
  • hot glue gun

First step is to build the lamp holder: cut a tile in 2, drill a 10mm hole, affix to the other with screws. A nail is used on each side to hold the bulb in place and ensure connectivity

Bulb is held in place by 2 10mm holes in the horizontal tabs and a nail on each side
Back plate holds the 2 tabs with glue and 2 screws
Detail on the back and other side

Next step is to connect the wires to the nails. Some simple soldering: put soldering on the wire, bend in place, then solder to the nail. Surprisingly, the nail had no issue properly holding the solder. Then, isolate with tape and cut to have it look cleaner.

Solder the wire to the nail
Hide the metal under isolating tape
and cut the tape to have a cleaner finish

Next step is to affix diffusers, to have a nice and smooth light. The power supply wire is held in place with a nail and hot glue. I cut pieces of disks from mdf (the back of an old billy shelf) then nailed them on top and bottom. One of them had to have a small hole for the cable and I broke one of my small file 🙁 Next time, I’ll pull the dremel. I used cooking paper (sulfur paper) as diffuser: I’m a bit scared about the fire hazard and I want to make sure it doesn’t produce too much heat. The diffusing paper is held in place by the engineer best friend, tape. This will have to be reworked.

the 2 diffusers holders in place
Diffuser in place

The lamp is held in place with 2 powerful magnets (1cmx1cmx1cm neodymium), on the chassis of my desk

Detail on magnets holding the lamp. it connects to the screws heads.
Lamp in place and working

Lessons learnt:

  • I need a second lamp for testing, this is so powerful, this completely breaks the balance of my setup
  • Baking paper is very brittle and super hard to work with
  • Hot glue is evil, each time I’m using it, it’s worse. But it pulls me. So evil.
  • Lamp is too powerful, I should use a stronger diffuser, further away (bigger disks). Maybe a simple piece of white paper will do
  • Some solder drop on my pant, I now have a hole :-/
  • Simple projects like that are better done by trying in the workshop rather than trying to do plan, I actually tried and failed a 3D model on wednesday evening to do with the laser cutter. The result would have been nicer and more reproductible, but I had way more fun prototyping 🙂
  • The heat is under control, less scary than expected


Overall, this is worsening my current setup but I’m pretty happy. This was a quick hack (2.5 hours end-to-end) and this worked as expected, with very little to update. I’ll definitely order a new bulb and build a second lamp.

From better video to better still pictures

Earlier today, I was in a meeting and I was thinking how to improve the quality of my video conference that I often do from home. I was at the time especially focussed on how to improve the sound quality. After some Nerd Sniping from my boss, I ended up reading about some internal document that basically describe the following steps:

  • get a decent webcam: done
  • get some proper lighting: I thought it was ok for my home setup, but some tests proved I need some improvement. More later.
  • get a good microphone: well, this is 3rd step and I got sidetracked

About the lighting, the theory explains that you need 3 lights. I’m not an expert so I’ll just link the video I just watched on the topic and that sums up the totality of my knowledge:

My current lighting strategy involves 2 IKEA LED lights (they seem to be named JANSJÖ) that I use as indirect light, hitting a white paper and on my right and a wall. I don’t have a hair light but I have a GU10 spotlight that I can redirect so I’ll focus on this later. As I discovered this lightning is far from being powerful enough, I scrambled and found some other LED lights we used when the kids were babies. They seem to be named DIODER but we have only 3 heads remaining. Each head has 6 LED and some more basic tests showed they were providing correct power at roughly 1/3 of the distance I could use them. As amortization is quadratic, it happens I need something like 54 LEDs to have proper lighting. As 48 LEDs seems to be a good standard, I’ll probably buy 2 sets in the near future, when I find them at an agreeable price (read cheap knock off from aliexpress).

Anyway, I was back to square 1: my video conference did not improve but I now had spare lights (and some stuff in my office). Then, it hit me: I had issue taking picture in the evening when I did my last laser-cutter build (free teaser: it’s a gopro box and you can find all the glory details in the relevant post). So, I got my hot glue gun, some cardboard (it happens that a empty litter package was available) and started to build.

The build is pretty straightforward: Cutting, hot-glueing, double-side tape. It’s called an ugly prototype :-). Some pictures of the process (just click to enlarge).

Glue the sides
Adapt the roof
Add the lights
Professional shooting set!
go pro box
laser-cut cube

After 2 hours, it’s time for a small conclusion:

  • To have enough Depth of Field when shooting macro, you need to close like crazy (technical term). These pictures are typically f/25 and 10s exposure
  • When using 10s exposure in a flat, you don’t move. And you don’t breathe. Actually, you even hold the cat to prevent vibrations.
  • Your best friend when shooting long-ish exposure on the fly (i.e. holding your camera and shooting 1/8th) is your worst enemy here: disable Image stabilization and the pictures are going to be sharper.
  • Don’t press the button: use a remote or the timer from the camera and walk back as far as you can
  • This is studio time, pick your lens carefully. You don’t care about aperture, you care about piqué  (or whatever it’s called in English, optical sharpness?)
  • Shooting macro will actually give you 24MPixels to look at your stuff. Most of the pictures didn’t make it just because I was ashamed of them (my wedding ring is actually disgusting when I look at it from close)

Anyway, my video conference setup did not improve (yet) but I’m researching about microphones, so expect more on the topic soon.

New zoom lens

RC car drifting in snow, with my boy driving

There are currently 2 topics I wanted to talk about, the first one is the situation in the US, the second one is photography. I feel there is enough depression and sadness around there to skip the first topic and focus on the second for now. And I’ll soon be travelling to the states and I’d rather avoid having an advanced screening when landing, let’s be honest, there are more interesting prospects, like a fresh beer.

I recently upgraded my telephoto lens to a canon EF 70-300mm F/4-5.6L. My current camera body is an EOS 80D, which means the crop sensor is giving me an actual 100-480mm range which is a really powerful zoom. I ended up putting a Hoya UV filter on it to protect the entry lens.

I’ve been fumbling with it for a few weeks and had a mitigated Point of view on the resulting pictures: some of them were awesome, some of them were barely medium, quite fuzzy. This week end, I decided to give it a better shot and spent a few hours playing with it, first in the city then with my boy playing with his RC car. The initial idea was to get a set of raw picture to do some post-processing using lightroom and actually start to be able to use it, but the jpeg from the camera were mostly good enough that I decided to post them.

It’s time for some conclusions about this new lens:

Detail of Zurich main train station (crop)
  • the lens is long and heavy, there is no point denying it. You can’t hold the camera with a single hand, the total body + lens is more than 1.5kg. Be ready for your back, neck and hands. I currently have a camera dedicated backpack and I end up picking the right subset of gear depending on where I’m going and what I plan to shoot.
  • 480mm (300mm * 1.6 due to crop sensor) is a very long equivalent focal. Even with f/5.6 and an impressive IS (stabilisator), it’s easy to have fuzzy pictures due to shaking.
  • IS has 2 modes: 1 is for all direction stabilization, 2 is for vertical only. Choosing the right one is key if you want to have a decent picture (the stabilisator will actually kill a smooth horizontal movement and make a moving subject fuzzy). Typical example would be the RC car, travelling pretty darn fast.
  • it has a really nice bokeh
  • it’s weather sealed, so no issue going outside in a drizzle (not that you want to shoot picture in these conditions usually unless you’re in the gloomy grey style…)
  • It’s NOT compatible with focal multiplier from Canon, so don’t expect a cheap super long zoom on full frame
  • it has no ring to attach to a tripod, this is an optional accessory that canon is selling independently. That’s quite cheap from Canon IMHO and this ring is nigh impossible to find in Switzerland. It however comes with lens hood and a nice pouch for storage, albeit not really protective (no foam or dampening material)
  • It’s not constant aperture, which is a pain when shooting manual (need to tune speed when changing zoom) but what you lose in feature, you gain in weight, size and money.
  • this lens is full-frame compatible and is my first step toward that direction.

I managed to shoot a few decent pictures (actually, more than I expected), but mostly:

pigeon head (crop)
  • even in broad daylight, don’t hesitate to crank up ISO. I often ended up at 250/320 which allows to reduce the exposure. With zoom fully extended, shooting at slower speed than 1/250 always almost lead to not perfectly focused pictures (hopefully, not because I have Parkinson disease)
  • 300mm and f/5.6 gives a very shallow field of depth. That can be good for portraits (especially due to the nice bokeh) but you definitely want to close a bit if you’re unsure about focus (and there you go, boosting ISO again then)
  • shooting inside is mostly a no go (aperture is not bright enough) but using an indirect flash, it actually produce marvels.

Pictures here are some examples (cropped or reduced in size), a much bigger set can be found in the dedicated google photo album. I would not call this article a review as the issues I’ve had are mostly from the operator, not the hardware, but I’m definitely super happy about the purchase and the result I have with it, highly recommended. Despite the price ticket, this has convinced me to focus on the “L” lenses for future purchases.



I’ve been following the #joinindaily tag on G+ for a while and I’ve decided to try to participate.

The concept is simple: each day, a single theme is announced, you have the day to post (or not) a picture related to the theme. It’s not a competition, mostly a just for fun event.

I’ve done it for a few days and I have found 3 different usages:

  • theme interpretation: trying to bend the word into something different. One of the best example was the theme “star”, which had a bunch of night skies but also a lot of creative approaches (starfish e.g.)
  • tell a story: that’s currently what I’m doing, finding a picture and telling a story around it, being personal story around the picture taking (this picture reminds me of blah…) or story around what is in the picture  (this is a picture of a battlefield where this event happened…)
  • technical prowess: basically, anything from editing, post-processing, technicalities behind the picture.

To help me, I’ve uploaded my picture to google photos which allows me to search with the power of AI and find random themes. As AI is only partially smart, sometime, you’ll have to bend the wording to find the pictures, but I think that’s part of the fun. This allows me to tap into ~14 years of pictures and several GiB, which gives me lots of chances to find something.

As a personal constraint, I want to keep posting pictures without private information (faces you could recognize for example) in it, which makes it more challenging for some theme. For people interested in this but not in my rantings, you can follow this collection on Google+.

I don’t know for how long I’ll be doing that and how assiduous I’ll be, but for now, this is a great fun and this gives me ideas on new pictures and allows me to think creatively.

In the meantime, I’ve decided to upgrade my photo gear and I’m now the proud owner of an awesome new zoom lens that I plan to use soon. I’ve also started to shoot raw + jpeg, which enables me to post-process (so far, I really suck at it though, but I’m trying to learn). Thanks for everyone (Inês, Allen, Miso 🙂 ) who proved me it was useful and gave me advices, I’m now using lightroom and I’m happy with the situation. Quite a lot of work currently and I mostly use the JPEG from the camera but I’ve seen the kind of improvement I can get from the raw version and this convinced me. One of the most obvious being light balance correction: the 2 pictures below have been made with the same lens (my new shiny), smae day but one with indirect flash and the other one with electric light. Shooting raw allows to have the same tone (and actually pick the one most relevant) for the picture. (pictures here are jpeg from camera).

When (If?) I manage to progress on the topic, I’ll try to share my tips and tricks on this topics as this is very much non trivial to start but the potential gain is huge (especially thinking about landscape pictures which can’t be really awesome without some post-processing)

Our cat – Canon EOS 80D – f/4.5 – 1/15 – 108mm – ISO200 – indirect flash (ceiling)
Our cat (Canon EOS 80D – f/5 – 1/15 – 155mm – ISO200 – electric lights)

from 2016 to 2017

So 2016 has come and gone, it’s time for some post-mortem / retrospective and dive into the wonderful world of 2017. I must say that this post is the perfect example of what I should avoid as I started it roughly mid december and I realize that January is mostly gone and this is still not published (and becoming less and less relevant).


The world is more and more scarily broken. I feel sad just thinking about it, not that there is much I can do. Extreme right wing, religion, terrorism, war, genocides, I think most of the tick box can be checked, sadly.

It pains me to see how the future is shaping more and more like the grimiest forecast of the 60s science fiction and less and less like a happy fantasy. Even when the future is coming (google self-driving car, I’m looking at you), it gets boring.

On the other hand, it could have been worse. Austria chose greens instead of extreme right wing, we had no major nuclear incident, Switzerland is still a wealthy and mostly safe place to live.

That said, 2016 was an awful year for arts: Carrie Fisher, Leonard Cohen, David Bowie…

In summary, bad year, better forgive about it and hope for better.

Me and myself

I had a few resolutions last year and it’s time for a retrospective

Post on blog

I wanted to post at least once a month: I posted ~18 blog posts (of different quality, true) over last year, with an emphasis on begin of year and big gaping holes in some months (november, september). Currently, blog is read mostly by people I know / friends and has very low traction. Most of the external traffic is in French for HR related stuff I posted ~10 years ago.

Not too bad on this topic (70%?), but some clear axis of improvement:

  • More engagement, post twice per month seem to be a good cadence, ideally at fixed time/day
  • Finish stuff that I started : I have ~5 blog posts in various state of draft that could have easily filled the gaps I had provided I gave them a bit more log

For 2017:

  • Post at least once a month something technical, this can be a tutorial, a thing I realized, either soft or hard. lower bar would be typically building lego. In case of big projects, any significant milestone should be an independent post and count. Should be in english.
  • Stretch, post once a month on non-technical stuff, in french or english depending on the topic.

Do technical stuff

I wanted to do a technical hack per month. Scope and exact definition of technical were purposely left fuzzy.

I clearly did a lot of technical stuff and posted quite a bit of them, so a clear improvement on the topic. Especially, I got the feeling:

  • I clearly improved and learnt stuff in mechanical design / tinkering: learnt to use fusion 360, to do parametrical design, first 3D printer usage, lots of complex lasercutter designs that I mostly posted
  • Had some lego, not really technical but fun-ish and good with kids
  • Did some human-size furniture for the birds
  • Broke and repaired my drone

I also failed on various other stuff:

  • almost no electronic work. The stuff I tried stayed on breadboard and never really worked
  • got pwned on a server
  • couldn’t not really keep up with advent of code
  • broke an RC car

Overall, I’m super happy on the topic, I have identified a few axis of improvements:

  • When doing stuff, start a log (picture, video) early as backtracking the history is painful. Start early by defining goals follow up with pictures for any interesting step (better to have too many than too few). Start writing early and publish even if it’s a failure.
  • definition of technical is super fuzzy and covered stuff which is only technical as a stretch
  • no formal logbook

For 2017:

  • Do the technical things to feed the blog 🙂
  • Some stuff I would like to do will have to be postponed due to constraints, so focus on things which are achievable (I want a forge, but living in a flat, that does not sound realistic)

Read books

I read 32 out of the 20 books I had pledged to read, so clear achievement (details in goodreads challenge). However quality is still quite dubious.

Most of the books I read are teenagers’ books, of very low interest from a literacy stand point. There are however a few outliers that stand out:

The things to improve is obvious here: read more of the outliers and less of the other (as in aim for quality, not quantity)

For 2017:

  • Well, let’s restart goodread challenge for 20 books, but aiming at at least 5 books which are neither heroic-fantasy nor science-fiction.


Being 36, I’m putting weight. Reasonably, but even so, it’s quite noticeable. I wanted to restart sport and get more healthy habits. This topic has been a complete failure:

  • I exactly commuted 0 time by bike and ~4 times using rollerblades
  • I started twice YAYOG and never went past the first week
  • I’ve been exactly once at the fitness room at work (while it’s free)
  • I’ve steadily gain weight, despite not tracking properly
  • I’m still eating candies (too many, in the evening), drinking too much beer and whisky and having too many snacks
  • I’ve tried counting calories and failed, I’m obviously getting way too many

I managed to partially:

  • cut on caffeine: I’ve managed to go to 2 coffee a day, no coke or other source of caffeine
  • get sleep habit under control: managed to sleep more and better, at least over some period of time

So, complete fail on that one, need to tune it a lot for next year

For 2017:

  • Train twice per week, even some light training (going to work rollerblading or skiing rover WE)
  • Improve overall fitness and reduce weight (aiming at back to 68kg?, which would be minus 5 stabilized)


For 2017, kids are getting bigger and we can have more and more shared activity:

  • Focus on better splitting couple / kids / family / personal time and keep enough for each bucket.
  • [family] go skying, ice-skating, hiking, biking…
  • [family] schedule summer vacation for family, ideally some eastern / fall break as well
  • [couple] Get 2 week-end for us, without the kids or work
  • [kids] Build lego with the kids, involve in projects


Overall, having these “personal” targets helped me focus and prioritize over the last year. I’m trying to go one step further this year and actually make them public, hoping it will help me focus on them. Let’s see how it goes, I aim at reviewing this on a quarterly basis

LePin, Lego and Porsche

I’ve been a fan of Lego for ages and my only limiting factors are the place it takes and the cost.

Being a car fan, I was pretty excited by the release of the ego 911 GT3RS (Lego 42056). However, this model was not stocked much and is overly expensive, probably to account for the Porsche copyright. This model is one of the biggest Lego Technics set to date (3rd I think) and is also one of the most complex in terms of mechanics, with a 4 speed sequential gearbox and a realistic look and feel.

Deciding that 300+ swiss francs was too much for a toy, I skipped this model…. until a colleague pointed me to LePin.

Until now, I’ve only and ever bough real Legos. My kids got some BanBao bricks which were definitely of lesser quality compared to the danish originals. Some colleagues told me that LePin quality is much higher, on par with original Lego. I used the 11/11 (the Chinese equivalent of black friday or cyber monday) to order a set to try and picked the Porsche model for ~80 dollars (USD, roughly 1/4th of the Swiss price for original lego)

After building it, here are my first thoughts:

  • The set is a 1:1 copy of the Lego set, the instruction is a leaner version (without all the shininess and pictures from real porsche) of the Lego one, based on an older version (with bugs). This is a clear clone and I don’t know how this can be legal and not infringe copyrights… Just to be clear, it’s free for sale online, you don’t have to go into the deeper parts of the undernet to find it and it ships with dhl/goes through custom without problems.
  • The quality of the pieces is really good, almost impossible to differentiate from real Legos. The model I picked is a known stretch for Legos (way too many gears and way too much friction) and ends up a good test: if this one is working, almost any Lego set must be working.
  • Assuming I didn’t mess up with the montage, I had way more spare parts (connectors especially) than on a standard Lego set. I however ended up with a spare bar of length 4 and a missing one of length 5. I can’t really say who is responsible for that.
  • Chiral components are clearly identified on real Legos with an embedded number, LePin are not
  • Some pages of the manual are not printed to scale, so you can’t use the 1:1 size picture to measure (not a problem if you’re experience, might be an issue for beginners)
  • The set itself is astonishing: huge, realistic, bright orange, it really looks like a masterpiece and has overly complex mechanics carefully hidden 🙂
  • some tolerances might be slightly worse than lego: the clear disks used for lights tend to fall, some connections are overly loose while other required some force to actually snap (including some connectors)

My final conclusion is that I would not buy LePin on a standard set, the price difference is not enough to account for the lack of innovation. I’m fine if a group creates alternative original models and cheaper bricks on the ones where the patent expired (I guess it’s not the case for studless). In case of Lepin, the quality is really good (almost the same as Lego, at least in terms of tolerance, I don’t know about time resilience) but he legal aspect seem quite shady.

Building a microscope


I recently bought on aliexpress a powerful (and cheap) microscope. For 15 bucks however, the feature set is quite limited and it has no autofocus, meaning the body needs to be moved to put things in focus. As the official support has 2 ball joints, it’s almost impossible to be accurate : when moving focus, you end up moving the sample and must restart. On top of this, it’s almost impossible to do any kind of fine tuning and the microscope has very low depth of field, requiring displacement in 10th of mm for focus.

I decided that building a body where I can accurately change focus would be my October monthly hack. It was completed in October and was super late for posting… Let’s call it a Novctober hack.


As usual, I’ll be using a share laser-cutter and 3mm thick mdf. The laser cutter is free for use at work and mdf is the cheapest material you can find for hacking around.

My idea is to lock the body of the microscope into 2 rings and use a carriage that can slide on vertical rails. Actual movement will be done using a threaded rod. Looking at my stash of junk, I’ve seen that I have a 1m long M6 rod. I also happen to have a set of M6 nut from a previous project that I can easily embed. To avoid putting too many constraint on carriage, a single nut will be used to do the translation, from the bottom.

For reference, this means that:

  • the hole must be 6mm diameter
  • the equivalent nut is an hexagon, 10mm flat to flat
  • the thread is 1mm per rotation

Open questions:

  • The amount of space needed for the carriage to properly slide is quite unknown to me. As the mdf is actually slighrly thinner than 3mm, I’m going for 3mm and no margin, and will sand/grind the relevant pieces if required.
  • not sure the amount of force (torque) required on thread to move the carriage and device. Assuming I won’t need additional torque and can directly turn the raw rod with finger. Some lubrification might be needed at some point

First prototype

The first prototype proved it was a viable concept, it however showed some limitations.For reference, it’s based on v10 of the fusion 360 file

  • the amount the carriage can travel is too small, the body needs to be much bigger
  • the lack of back plate means the body was not sturdy enough and could shake / shift (parallelogram disortion)
  • the holding ring are not compelled to stay horizontal, need to add orthogonal pieces
  • Having a removable support for sample would be nice
  • One of the component was badly extruded and lacked a hole

What confirmed worked well:

  • the carriage slides without issue
  • the hole is the correct size
  • the overall concept works

Second prototype

Rework is implemented in v14 of fusion 360 model, the actual printing can be found in this commit on the usual bitbucket repository, in this file. The print uses roughly an A4-sized sheet of mdf, all included.

img_20161014_140214 img_20161014_140325 img_20161011_145901

After building, quick summary:

  • despite having longer range of motion, still unable to focus at lower zoom, would need several more centimeters
  • the back plate has 2 holes which are not the same side, forgot a constraint in the design (just an aesthetic issue)
  • the carriage works fine with the redesigned model, the nut needs to be glued though because it’s not heavy enough to go down with gravity
  • while glueing the sliding bar, I pressed them too much and the carriage could not slide any more. had to sand quite a bit of material to make it work
  • the holding tray worked well

Reference for assembling

I decided to sand all pieces, to give a smoother feeling. I sued Grit 600 for starting then finished with Grit 1000.

Pay attention to the following tricks for glueing / assembling:

  • sliding bar needs to stay parallel, don’t over-constraint while glueing
  • to help aligning the 2 bottom plates, use the vertical sliders
  • Don’t glue the full body before inserting the sliding part
  • I used 2 nuts locked against each other to prevent the threaded rod from moving

Some more

After a few minutes of usage, the lighting of the microscope failed probably linked to a deficient solder. Wiggling the cable helped for a while, but I have limited hopes. However, worst case, it’s still possible to use external lighting so it’s still usable.

The device itself exposes as a video device, I could use it from Linux (/dev/video) and Windows (as a directX  input device). The pictures below have been taken using VLC (open capture device in the file menu) then use video/snapshot to get pictures.

Some pictures for reference, overview of a feather from my bird.

 View of the feather, for scale.
This is a standard post-it and a standard sd card
 Minimal zoom, I didn’t have enough distance for focus, so I used the empty bottom of the microscope to actually make it higher  vlcsnap-2016-10-14-15h50m57s657
Some more zoom on the top of the feather vlcsnap-2016-10-14-15h53m00s405
Maximal zoom on the tip of feather, using the removal tray.

The background is wood fiber from mdf, field of depth is super short.


Lessons learnt

  • despite having a full 3D model, 2 iterations were required and it’s not perfect, dynamic mechanics is (unsurprisingly) much hard than static
  • the reliability of a component sourced from China for 15$ is on-par with expectations

Some more pictures

The following pictures are, in this order:

  • a 1 dolalr us bill, zoom on washington’s head
  • the backplate of my phone
  • a mechanical watch
  • the atmega328 on an arduino mini
  • a SMC resistor from an ESP8266



This post and the related original works and pictures are covered by the creative common licence, CC-BY-SA.

Some random thoughts

I realized I’ve been pretty idle and did not post over the last month. September is gone, and that blog stayed empty. I did not really do anything technical last month (I mostly blame work and laziness), but I have a few random and unorganized thoughts I wanted to post.

  • I have finally seen the move “Rush (2013)” and I only regret not seeing it earlier. I was not born at this epic age of formula one racing, I knew about Lauda (ofc) but nothing about Hunt.The movie is great, it really shows what I imagined the 70s to be about racing: different philosophies battling on the grid, the begin of professionalism, the death at each corner. I can only recommend the movie, even if you’re not a petrol head.
  • Speaking about Petrol Heads, a friend of mine drove me last week in California in a Tesla X. This car is impressive. Performance wise, it would made cry my sportly german 6-inline, at least on straight line. Actually, the car itself is a mix between a tank and a sports car. It seems to be a californian hipster version of the muscle car, weighting tons but compensating by sheer goodwill horsepowers. Calling that an eco friendly car is definitely an overstatement. Outside of the pure performance part, the car itself is quite disruptive on the technoologies it uses: ~20 inches embedded touch screen controlling everything, 7 seaters, falcon wings, everything electrified. I can’t help but be scared about the future of this car. It’s definitely a cobblestone in the world of car making, with the equilibrium slowly shifting and newcomers finally challenging the establishment. However, my cell phone lasts in average 2 years, my computer up to 5. I’m pretty sure the supply line is not made in a way that this car will be maintainable in the long term. Which means that this car is likely going to be a myth, but a myth that will die in less than 10 years.and won’t ever make it to collection. You can still drive a 1923 Bugatti or a 300SL gullwing (at least if you have a few spare dollars), I fear modern cars won’t have that fate and will end up discarded (which is an interesting problem for an eco-friendly care)
  • I’ve read slingshot, by a former colleague of mine. The book is awesome, don’t hesitate, buy it read it, share it if you like SF. Second book got published in August and is my (big) pile of stuff to read, but failry high priority.
  • I’ve finished (and went above) my goodreads challenge and retrospectively, I’m not proud: I’ve read chick litt, bit lit but really only a few books of higher value. I’ll try to focus more on content and less on quantity next year.
  • I’ve seen the latest x-men, it’s good to see such a talented young actress playing someone else than Sansa and moving to the big screen. The movie is quite good as well. I would not say the same about Batman v. Superman: I happily slept in front of it and found it awfully boring. I didn’t know about Deadpool, foun dit was a nice way of spending an evening (or a quarter of a transatlantic flight)
  • I’ve flown again with SAS (Scandinavian Airlines) : that company has cheap business flights with good quality, but comfort in eco is awful. So Good for business, Ok for Eco+, avoid for Eco in the future.
  • This blog is now served over https or http, still tuning the details, so edges might be rough. I’ve also put some monitoring in place with uptime.com and tuned the apache configuration, so things should be slightly more stable and have elss downtime than previously.
  • Mandatory picture : my last business trip had a nicer weather than the grey sky of  september in Switzerland
From the SF office
From the SF office