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Some links about me. Many of my 3D designs are free. I also post on Google+ and in another blog, oz4.us

Thursday, August 18, 2016

A huge and unique cross-cultural fablab in Europe!

I was wondering what +Florian Horsch was doing lately. If you are a reader of this blog and do not know already about this great person, you may remember him because he kindly invited me the Fabcon conference for a speech about the businessman and the maker in Germany, 2014. I would have bet he was on a novel and useful project, but I did not expect it to be this big and humanist.
One of the biggest European fablab (725m²), and most probably the most inter-cultural one!

Thursday, June 2, 2016

3D printing nozzle characteristics

Nozzle shapes and nozzle materials

Obviously the nozzle diameter is one of the major parameters when 3D printing. But you may have wondered about the many nozzle shapes that are available on the market. Some brands have preferred shapes. And, even though will not have a drastic impact on the print, they may be significant and worth a post.

Overall length of the nozzle?

Marketbot vs Ultimaker nozzles.
Both are quite long, but the former has a
bigger flat ring around the nozzle hole.
In my opinion, long nozzles are more convenient for cleaning, and they let more cooling air flow around.

Shorter nozzles reduce heat loss a bit and they probably give a better control and reading of the temperature (remember: the sensor is on the heating block, not on the output).
They could arguably help to reduce the overall length of the hot end, so they reduce could positioning error slightly. And they may spare a few grams... But this is marginal and for the most hard core players: they will not help make a bad design better!

Friday, May 27, 2016

PC crash: back to a working state in 5 minutes!

For the last 15 years, both my hardware and system upgrades always evolved AROUND my work, and not the opposite! The overwhelming majority of configuration files, preferences and application shortcuts survive through both system software and hardware upgrades for decades... when you are running Linux.

linux beats them all - crashed my pc had urgent work to do moved 2 hard drives took me 5 minutes back to work
Linux is never putting its foot in the door. Focus on your work, it even keeps your preferences and settings.
Yesterday night my motherboard died without warning (hopefully it is not my high end i7 CPU!). I had work in process to deliver, and some of it was not synchronized with my remote servers yet.
No biggie! I brought my 4-year old old Core2 duo Desktop back from the dust in the garage, I plugged my hard drives into it, and I booted.

Bang, back to work in 5 minutes in the exact same state. Linux is so useful and so efficient!

So why is it so easy to change your computer on Linux without impacting any of your own data and preferences?


Wednesday, May 18, 2016

Cooling 3D prints with an aquarium pump

3D printing cooled with an aquarium pump!
It works well and it cannot be quieter. Even tough
the pump is bulky, it is does not pollute the hot end.
(the above was a preliminary experiment)
Interestingly, while this trick is not new, very few people seem to use it. For years I had an air pump on a shelf for this purpose. Only recently did I use it, and I really like it better than fan on the hot end.

The good thing is that aquarium pumps do build some pressure in order to pump air down into water. No regular radial or axial fan can do this, they only move air around. Do not get me wrong: regular fans works well, but the smaller the fan the noisier and the shorter its lifespan. And they are bulky anyhow and obstruct the view.

Actually, I printed almost years without fans attached to the hot end at all. Instead, I used a large, powerful and silent 120mm PC fan on the printer chassis. It blows a lot of air on the whole part, which is often even better, but it fails to cool down tiny towers or islands when the hot end never move aside (flowing air is very lazy and will not reach tortuous parts). Also, the big fan blows air only from one direction, which shows up on opposite sides.

So I still needed air again on the head....



Monday, April 18, 2016

Being a contractor or a full-time employee?

Working as a contractor versus regular employment?

I regularly see the fear about working as a contractor. Lately I was part of a discussion that started like: could it be risky for any subsequent 9-to-5 career? I strongly disagree: being a contractor is interestingly a warranty for me to find again a new job in case I fail as a contractor! In my opinion, it will indeed help most careers, as I an employer I would favor people that took the risk to try, whether they were successful or not. Contracting both provides and requires skills at the same time, more than any regular 9-to-5 job.

I feel like I can handle all sorts of professional blows, like being fired. And first of all, well, I will not be fired as long as I am my own boss! This is because I feel each day insured by varied and evolving professional experiences together with a growing professional network.

Here is a post about how I ended up as being a very happy contractor, after having been a state employee, a full time engineer in a small family-owned company, then in a stock-valued much larger company, then a CEO and a CTO in a start-up (silly names), and a very well-paid part-time employee in a startup... before I flew on my own in the naked simplicity of a contractor in a cooperative, with no mess.

Disclaimer: my experience is all in the so-called "new" technologies, but it may still help beyond.

Friday, April 15, 2016

3D printing sponsorship: getting hired and getting fired ... as with any other job? :(

A blow to Octoprint and to the 3D printing community? May be not.

This short post is triggered by the recent lay off of Gina Häußge by BQ, its sponsor and maker of some opensource 3D printers (notably the witbox and hephestos). And by the fact she goes with a few others, more recently hired, well-known people like Thomas Sanladerer (a well known high-quality educational video blogger on youtube) or Nils Hitze (currently an evangelist for rent, and a pillar in the largest 3D printing community on Google Plus). The are part of a massive lay off, so it shall not be felt as specifically related to individuals or to the open source movement (in my opinion).

But why does it matter to the average 3D printer user? Easy one: Gina is the founder and main developer of Octoprint, a "baby monitor for 3D printers", or more technically a massively popular and very useful software which runs on a Raspberry Pi and which lets you remotely control 3D printers. It can be used on BQ 3D printers as other brands, and many companies even ship it with their own printers (when they are not just stealing it!).

No more sponsorship equals less features and less maintenance.

Octoprint is a milestone in usability as a remote control, just like Cura simplified slicing 3D models.
Both are free and open-sourced, initially made by smart developers on their free time,
and who later got sponsored for keeping on doing their good work.
(hey I realize only now they were printing one of my early designs in 2012 for this action shot!)

Saturday, December 19, 2015

Tribed: a fully automatic bed leveling and tool height adjustment, with FSR and 3 Z screws

This post is the continuation of my preliminary analysis regarding bed tramming and automatic tool height adjustment. So far I never made the step to redo my bed, even though it was on my wish list for years. Now it is a reality :)

Early testing of the complete setup : starting with a properly calibrated bed,
corrupting it manually, and letting the system auto-calibrate it again.
A faster / realistic movement is here, since speed was not a concern above.

So why now? A few months ago, someone came and talked to me about his wish to design a new, open source, user-friendly printer for the prosumer market. Please check this as your opinion counts!

All in all, it was an excellent reason to realize my idea of a fully automatic bed leveling. And since the new printer will also be opensource, here is the work, design and my analysis. How nice: not only I was given the possibility, but I was asked to do so!

As said, this improvement is part of a longer effort towards a user-friendly printer, for more reliability and less manual tweaking. My Ultimaker itself may eventually be ditched one day. Huh. No, I am joking. Well.. unless the new one is really is obviously better... Damn, that's exactly what it is all about :/

Friday, December 18, 2015

Sensors and issues for automatic bed leveling and height adjustment

My printer eventually has a fully automatic and hardware bed leveling (aka tramming), and bed height (aka Z-offset). Yes, it now handles any tool height without any user action, in addition to a long-wished automatic leveling of the bed.
This is part of preliminary studies for a prosumer open-source printer, for which you are more than welcome to give your opinion! The entire bed structure was entirely revamped, as one important point in my former wish list.
Revised heated bed with automatic tramming and tool height compensation.
Since I wanted to document both the new bed but also why I wanted it this way, this first post addresses usual sensors and strategies used to deal with the bed calibration. The deal is to make a bed level and to start printing at a proper height, and there are many ways to do so, but not as conveniently as I wanted (which will be documented in a subsequent post). The second post will show more precisely what and how I did it.


Friday, October 30, 2015

Preliminary expectations and design options for a prosumer, fully opensource 3D printer. Your opinion matters!

Call for feedback: designing an opensource, prosumer-grade 3D printer

We are currently designing a 3D printer for advanced, serious, or professional usage.

The main target is reliability. The price tag is secondary, but we expect it to be $3 to 5K. Would you help us with this short survey? Being open source, the preferences of the community is very valuable to us, and we think it may be a win-win strategy.

Update: as an example of a forthcoming growing list of publication, here is an automatic bed leveling and head height adjustment.

Please feel free to share the link, every opinion counts: https://jeremiefrancois.typeform.com/to/xbuY9S


Friday, October 2, 2015

"It is better for your safety that we are opaque" (Volkswagate)







"It is better for your safety that we are opaque"

I just read an article on the BBC related to Volkswagen and the "(...) argument for stopping people fiddling with those systems, because if you don't know what you are doing - or even worse do know and have malicious intent - you could create genuine safety issues."
Volkswagen in 1969 by John Muir
But are we still complete idiots?
This post not only relate to Volkswagen, but to any big company using proprietary stuff and saying it is good for you. You can replace "car" with any non-open piece of software or hardware alike. Transparency is just so hard to depreciate, especially when you are talking to your own customers.

Saturday, May 16, 2015

Messy code, branches with a lack of guidelines and comments are killing Marlin!

Marlin no more exists as a single, readable, common branch!

Where shall I go now?

In a previous post, I described a tiny contribution I made to the 3D printer firmware Marlin. The deal was to help with the calibration of a Delta printer thanks to a manual Z-probe (calibration really is the drawback of Delta printers, due to their weird geometry as compared to easier cartesian X-Y bots like the usual printers). It was already painful for such a small, one-time improvement to the code source, and given the invested time, I tried to make it broader by implementing multi-line comments (and to learn about git by the way).
http://www.dailymotion.com/video/x2gp98t_hal-fixing-a-light-bulb_fun


This is how I feel when I want to code something in Marlin!
(Malcom in the Middle, fixing a light bulb)

So I worked in mainstream Marlin. My idea was that it could benefit to existing variants of Marlin as well, when they decide to get changes from the "official" parent. But it does not work so well in reality.

This experience unveiled another, deeper, issue related to the many Marlin variants, and I think it is due to the fundamental way github works, in addition to git own complexity. In my opinion, Marlin is just dying because of this, together with the limits of the Arduino platform.


Tuesday, April 21, 2015

Headlines again... 3D printing guns, a passion?

Headlines again: 3D printing yet another part of a gun. So what?

Please Cody, yes, you the guy with big stainless-steel thermoplastic bollocks, please, now I want new stuff, like 3D printing bazookas, ammo or landmines!

I already tackled the subject it in this older post but telling that a 3D printer is probably not the best tool to use is not even my point here. Using a 3D printer to print more guns is no surprise, but I wish headlines focus more on noble usage like e-NABLE prosthetics. It is an excellent project, where volunteers 3D print free upper-limb prosthetics, like artificial hands for others. If your printer is idle, you should go and read about them!
E-NABLE: is this not a better use for 3D printing, according to you?
This way we have people printing tools that may harm people, while other people do repair them. Nice absurd world.

Here is my point for once: why do the words gun and freedom have to be put in the same sentence almost each time pro-gunners start to argue? What the heck?

Sunday, April 5, 2015

3D printer survival kit: a comprehensive set of 3D printer tools and tips.


Survival kit: tools for the 3D printers


This post started as early as September 2013, and it eventually ends here, may 2015! At least, you can be sure I heavily made my opinion and I have feedback on the tools I list here.

All included, a nicely packed Ultimaker 100% ready for travel.
I keep nearly all my tools in a dedicated box, that matches well the bottom of my printer. You will read in this post about each of the tools, slightly sorted in different categories and even though some tools are used for multiple tasks.

I attached a note after each of the items, where 5/5 is a must in my opinion, and 0/5 a luxury or a useless tools. Of course there are no 0/5 in my box as I want only a (comfortable) survival kit in the end. Read more...


Monday, March 30, 2015

CNC fail? 3D printed design blows my ears instead of the dust

I bought a well-built Chinese CNC machine last year, namely a 4 axis CNC3040Z-DQ router/engraver, for about €1000 (as far as I remember).

Milling a PCB with a low cost CNC router/engraver controlled by LinuxCNC.
My initial need was to "etch" electronics PCB boards at home, to get rid of so called proto- and perf boards. This machine is overkill for the job, but I do not regret my purchase since it can do much more than PCB milling...

But only recently did I spend enough time to use it. Even though the reliability and consistency of a CNC milling machine is way better than that of a 3D printer, the whole process is cumbersome. It takes a lot of time to get used to the software, which is a decade behind the ergonomics of more intuitive 3D printing software. Worst, the controlling software like linuxCNC or Mach3 still require a parallel port and a special real-time distribution of linux. Both are a real pain because you need a dedicated and obsolete machine just to drive the CNC. Recent projects like GRBL are knocking at the door though, as an alternative to parallel port hardware: they rely on Arduinos, but are limited by the power of this platform. ARM-based boards are more promising, especially for fast machines, or when you have more than 3 axis of freedom (e.g. see 6DoF)

Note: I may write more about CNC machining at home, its software and process in other posts. But I start here with a quick, funny, and miserable failure of mine, that was meant to be an improvement in the first place. And, well, it mixes printing and milling so it is a good transition.


Tuesday, January 27, 2015

Contributing to projects hosted on github: a step by step howto, and an illustration with Marlin (3D printer firmware).

Git is powerful... and very painful the first time! / Github contribution howto / Tweaking Marlin for better 3D printer menus.

Git mess, only partially resumed by Oliver Steele.
Indeed, the upstream higher repository is not shown here,
as seen on this other bigger, clean and useful cheat sheet.
I eventually wrote a feature to fix something that annoyed me for years: allow multi-line commands in the LCD menus of Marlin, a very well known firmware for 3D printer.

I needed it for my Delta printer: these printer do require precise calibration, often with a sequence of gcode commands (check the end of this post for more and why I wanted these to be in my menus and not as initialization files on all my SD cards nor on a PC over a USB cable).

Now, Marlin is hosted on github, a community front end to many other open source projects. Actually, the linux kernel itself is developed with git so it works, for sure.

I often tried to use github, but I never went past a simple git clone of a repository. It was still better than to download a zip archive, because you can easily get the new stuff with a git pull. But here and partially out of curiosity, I wanted to try and contribute to a project at the source.

Now... what a huge and painful procedure just to give a hand! Seriously, it is mind boggling how much crap and megabytes need to be handled just to help and submit a few dozen f*king lines of code to an opensource project hosted on github. This is too bad since I am sure many programmers would be glad to give a hand to project they stumble upon (like me, often), but without this need to become administrators of complex and shared projects themselves!

This article is all about posting and contributing to a project hosted on github. You'll get the calibration g-code line I used at the end of the post if you really ask yourself.

Thursday, January 8, 2015

Sad day for intelligence and respect.



David Pope
I can't even blame those stupid murderers at Charlie Hebdo. They just are not worth the intelligence nature gives us. If at least it was for money or power, there would be some sort of "justification". But no, this is the most profound proof that some individual are able to deny their own free will, curiosity and intelligence to some obscure ideology. Why on earth would someone who is saying or drawing something would do with your very own religion? Faith has no proof and need no proof. Faith without respect is blind stupidity.

And let me be clear, now every racist will exult with this opportunity to prove they are not better at trying to live in peace altogether.

Sunday, November 23, 2014

How to use Openscad (4): children and advanced topics

Part 4/5: children, factorized placement and chained hulls

Yes, it was made with Openscad and it is parametric!
(extreme collaborative work, picture by N.Goodger)
Previously in this tutorial for the Openscad CAD software, we talked only about modules that behaved as shapes.


A powerful and often ignored feature of Openscad is that modules can also behave as if they were operators, exactly like the translate()or color() operators. They do not create shapes on their own, but they modify the subsequent commands.

In Openscad, it is possible through the use of children. But first, let us create and discuss a bit about a common-case example.



Saturday, November 22, 2014

How to use Openscad (3): iterations, extrusions and more modularity!

Part 3/5: iteration, extrusion and useful parametrized CSG techniques

Repeating shapes

As we saw in the previous article, repeating a shape by copy/pasting its Openscad definition is a bad practice. It increases the risk of mistakes just because of the slight changes that have to be made on each of the copies. And any "regularity" should be factorized: let the computer do our work!


The former way we built a (partially) rounded cube. Four copy/pastes? Boo!

See how the four columns really are all the same cylinder, where only the position changes? This is where we can and we should use loops instead. And once again there are different ways to do so.


Thursday, November 6, 2014

Fortune 500 teller? 3D printing trends, reports, analyses and business intelligence...

Are the "high-level strategically analyzed reports" worth something?

Hey, could my blog be so informative? :)

I am regularly contacted, mostly on linkedIn, by experts that seek data. The last time it was for a company that compiles data and trends "for the Fortune 500 companies". Which does not excite me more than that, and here is why.

Such data are usually sold at an incredible price to managers that think they would get a better clue at the market, with the idea that they would be more profitable. But there are two traps here.

The first one is: am I really enough of an expert to give clues to Fortune 500 companies? I am mostly an iconoclast, e.g. when I say not to invest in Makerbot at all (neither as a customer nor as an investor, but I have a full-length analysis why I say so), or when I explain why, imho, "pro/expensive" FDM printers are almost a scam nowadays. OK, I may be better than a monkey and provide a few useful reviews (e.g. materials for artists, or what cannot be 3D printed...). But still, asking my opinion on the market trends could cast a doubt on the forthcoming corresponding report. Oh, well, may be they also want data from makers -- why not after all.

As a manager, do you really need accurate trends and data?
Or do you need only the feeling that you have some?
Secondly and as importantly, the reviews are most often never used in reality. Once bought, they are dropped on the desk of a subordinate in the company, with the advice to get some insight from the document. The underlying idea is: since it is expensive it must be valuable...

Thursday, September 11, 2014

How to use Openscad (2): variables and modules for parametric designs

Part 2/5: Variable and parametric design

The previous part addressed the basics of Openscad. It relied mostly on "immediate values": we were providing dimensions as explicit numbers. If you want to tweak the design dimensions, then you need to parse the scad source code and fix the numbers all everywhere.

In fact "hard coded" numbers must be avoided. As opposed to "static" designs, parametric designs give the flexibility to tune the numbers very efficiently at one place only. The good point is that Openscad is one of the best tool to do so.

A larger mug by using the scale operator (from the "basic" tutorial).
This is still not parametric, as numbers are hard-coded (a bad practice).
See how the numbers in our mug design above depends on each other? If the cube is to be made taller for any reason, then the intersecting sphere and hollow cylinder must be tuned accordingly in the source code. And this is exactly something a computer can do better than us.

So let us first convert this design to a parametric version, i.e. a design that can be tweaked with a small set of parameters that all have a clear role (width, height and so).


About Me

My photo

If you know me and you cannot tell exactly what my real job is, then you probably found the right Jeremie. Check zax.fr for some pointers.

I am self-employed and I help start-ups, research centers, small companies with their needs related to computers, sensors, data processing and mechatronics. If you have a project and know what "R&D" is, then you already sparked my interest ;)