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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

Saturday, November 5, 2016

Filament switch: close up shots that highlights further the complexity of extruding plastics

I stumbled upon this old picture while looking for another one. It shows tiny carbon fibers embedded in crystal-clear polycarbonate, that happened when I switched from CFPLA to a crystal-clear polycarbonate (hellish stuff to print btw). Looking at it a second time makes me realize how complex extrusion is (more after the break).

A microphotography that shows carbon fibers during a transition from CFPLA to polycarbonate.

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. The pump is bulky,
but the overall is a very compact 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!)

About Me

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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 ;)