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Some links about me. Many of my 3D designs are free, but I can also be contracted to design yours !

Thursday, September 11, 2014

How to use Openscad: variables and modules for parametric designs

Part 2/3: Variable and parametric design

So far we used only "hard coded" numbers (see the previous part regarding the basics of Openscad).
Hard coded numbers are mostly always bad. Seriously: when you use Openscad you probably want NOT to use hard coded numbers, but variables instead, as you get lots of advantages in doing 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).
For example, the mug above has lots of annoying dependencies: whenever the cube is made taller, the sphere and cylinder parameters must also be updated accordingly.


How to use Openscad, tricks and tips to design a parametric 3D object

Part 1/3: Introduction to constructive solid geometry with Openscad

Some technical and non-technical people keep asking me how I create new designs. As often, after a few personal replies, I end up heading to the blog to share the answer as they keep asking for more.

Also I long wanted to write a pragmatic and step-by-step introduction to Openscad. The idea is to help people even with no programming skills (mostly in this part) and to bring newcomers to a point that they can design their own 3D objects (part two).
If only a few readers switch to "designers" by reading this I will be quite happy. Meanwhile I will have given a detailed answer to my friends and contacts!

A non-obvious GoPro mount that is fully customizable thanks to Openscad.
It looks complex, but it is still exclusively made of spheres, cylinders and cubes with a few basic "joints".
A forthcoming last part will deal with the complex features of Openscad. This one is for people that either learn fast or for those that are already proficient with the usual features of Openscad.

So first, what is Openscad? Within the CAD family, it is a 3D modeler: a software that helps you to create 3D objects. There are many such tools, but this one is used extensively in the 3D printing community, not only because it is free but because is it really efficient for some kind of objects.

It may or may not suit your mind, but with time I am able to "see" the shape I describe, not as text but directly as shapes. I guess it depends on people, but I am sure there are people that are not programmers that can think alike. And if you are already a programmer with no industrial goal then you really should give it a try. It will be a breeze to use up to a productive level, especially if you do not want to invest time in a new and hellish interactive user interface!

The official manual is OK but it does not really work as an introduction. The navigation is also sometimes difficult to the point goggle is more useful. There is a nice raw cheat sheet also but it has no link to the respective functions (what a pity!). In any case these fail to help learning Openscad quickly in my humble opinion.


Thursday, August 14, 2014

Home made filament drying box

How to make a simple dehydrator (drying box) with a solar vacuum tube

A short and probably overkill post for a passive and zero carbon footprint drying box (not counting the required one to make the tube).

I use a spare, high tech and powerful vacuum solar tube, but it is easy to make something with a copper or steel tube painted in black, around which you slide larger transparent plastic bottles. Such insulation is required to avoid the ambient air temperature from cooling your own heated air.

The second required item is a brand used low-tech cardboard box.


Sunday, August 10, 2014

E3D v6 hot end: ideas and assembly tricks

Assembled E3D v6 with a few particularities
You may remember that I wrote broadly about hot ends in an another post, but this short new one is specifically about the sixth revision of the E3D family (E3Dv6).

This is probably the best hot end on the market right now (in my opinion -- and I did not check them all). It is not cheap, hence expensive as all the good quality hot ends. But this is a critical part where you cannot really lose money if you value your time...

However there are still some room for some improvements. 







Sunday, July 6, 2014

Material for artists: 3D printing wood, chalk, and eventually metal with bronze


A gorgeous dual material and well
polished bronze ring by foehnsturm

Important materials for artists


Still today, the visual quality of 3D printed objects is far from perfect. Of course, a stringy or bumpy surface does not mean the part will not work: you can get a visibly ugly part that still works well enough as a mechanical connector for example. But an artist will certainly not like it.

This post tries to list the main filaments that artists would look for first. Many other filaments are listed in a former post about materials that can be printed (without artistic consideration).

It also talks about the brand new bronzeFill filament from ColorFabb. Yes it does contain bronze. No, we are not yet printing metal really. But certainly it is a major and very welcome addition to the list of interesting materials to 3D print.






Friday, June 27, 2014

Four in the morning. Just had a few tweaks to finish my upgrade...

Eventually "implemented" my upgrade! I certainly did not think it would take me so long, but once you start to sort the mess that's below a 3D printer you just can spend days on it! There is a brief list after the break.


I am sure a lot of 3D printer owners share the "two minutes into two hours" syndrome.

Monday, June 2, 2014

Why you should not buy Makerbot 3D printers!

Avoid Makerbot and its 3D printers, they are both wrong.

Really! And there are many reasons not to buy: cost, reliability, human values, innovation and so.

I endorse even less Makerbot business
than I already trusted their products !
But enough is enough, this time I say why.
Seriously, Makerbot Industries care more about money than 3D printers. They so badly want your money that they start using dirty business practices. As a client, their overall strategy is simple: you will increasingly pay more to get less. The quality of the product is less important as long as you sell it, using marketing or so.

Do not think this is a biased joke, neither only a maker's rant. I really want to warn would-be customers that they should not buy, and try to stay objective.

Their latest violent business strategy makes this clear beyond doubt. I cannot think of any other motive than greed, or may be also for the inflating ego of Bre Pettis, its director. By the way, 3D printing certainly never was invented by Makerbot -- this is pure usurpation. Please do not fall in the trap of old and dirty business practices.


Tuesday, May 20, 2014

The businessman and the maker

The Businessman and the Maker

Businessman v.s. Maker (although Dilbert is certainly not a maker!)
At Fabcon 2014 3D print fair (my feedback is here), I gave a speech entitled "Make it yourself: it can be better than what the industry sells you!".

It was insipred by this former post on the same vein, which rang a bell in Florian Horsh head (so much he very kindly invited me).




3D print fair at Fabcon 2014: feelings and people

Fabcon 2014 - was worth 2575 kilometers and 31 hours on a motorbike!

So I was kindly offered to give the closing talk of the 2014 edition of Fabcon 3.D in Erfurt, Germany.

My talk is now available online as slides, and also as a youtube video (for some unknown reason I cannot embed it here).

Note that I added a short separate post that resumes it, with a few new ideas: The businessman and the maker. This one is about the people and projects I met there.

My spoken English should definitely be improved (and I was half sick half exhausted), but it will spare you pushes on the space bar for the next slide, and more importantly, you still get details in the 25 minutes not-so-lively speech. My apologies, as it was the first time I spoke in public for years (back to my time at the long-gone Palm company, and more significantly during my PhD, huh, 14 year ago!). Please read ahead.

Tuesday, March 25, 2014

Quick comparison: pro versus low cost FDM 3D printers

Are so-called "professional" entry-level 3D FDM printers worth their price?


A LinkedIn user in my network asked for more data when I said that "low cost" FDM printers could compare favorably to "professional" (and expensive) printers. Sure, it is a bold statement, and it does not hold for every of the many "levels of quality", as there are just too numerous. But let me get into more details.
In my opinion, an Ultimaker rev. 2 (~2K€) compares very nicely to a Stratasys UPrint-Se (~23K€)
I certainly do not want to say the "pro" printers are crappy, nor that any brand is crappier than the other, but I had the chance to compare my Ultimaker prints with a "professional" Stratasys entry-level printer (i.e. 1200€ versus 23K€). The outcome is that I just would never swap the two even if I was offered the "pro" one for free! Huh.

Now I am a power tinkerer, I know how to print, I prototype the printer itself, and I cherish freedom, but I tried to keep this bias out of the following arguments.

Thursday, March 20, 2014

Thoughts and hints around hot ends

This post finally documents ideas and hints I had during the design of two hot ends I made last year.
My extremely small "cheesy hot end" (all-metal and actively-cooled), here with an Ultimaker printed support.
This hot end was very easy to make (only used basic tools) and also because the barrel is quite short.
At the time I already had ordered an E3D hot end, but the lead time was so big that I decided to give it try myself. Actually, since I attached it with this tiny E3D support on my Ultimaker, I almost never swapped my hot ends anymore because it is just so reliable... The only drawback is that the efficient heatsink could be made almost half the size for more Z space, less vibrations and less weight (hence my smaller, low cost --and low quality-- copycat by the way, see below). And it does not mean I stop thinking ;)

Tuesday, January 28, 2014

Features and improvements for a would-be homemade Ultimaker 3D printer

How would I re-design the original Ultimaker?

Quite some changes on the back of
my Ultimaker Original (aka v.1)!
The Ultimaker 1 (aka Original) is a well-built printer. It is probably one of the oldest and still best designs as proved by its incredible longevity.

I bought mine two years ago and, still, I feel quite confident that it would compare favorably in many aspects against a 30K€ FDM printer that a client bought last month. Is Stratasys really serious with this beast? May be there are better properties (eg. less warp due to fully enclosed?) But it also features a smaller build volume, a ridiculously limited and exceedingly expensive printing set of material. They also solved warping ABS by printing on... ABS beds (just try to remove it now when you forgot the in-between support!). You bet they bought Makerbot: overpriced "serious business" printers ought to be past, crappy obsolete printers. Too bad they are polluting MKI with greedy business practices though, and not the opposite.

OK, back to our subject. The "UM1" is one of the few printers you can take around you and which will keep printing very reliably without the need for re-calibration. It is also the only one I still blindly recommend... once the user knows that it is not that trivial to 3D print something. The new UM version is probably better in this regard, but it loses some "hackability" that I am fond of...

Still, the Ultimaker printers are big and they sometimes do not suit all my needs. If I was to re-design a clone, there are a few cosmetic but also structural modifications I would make, especially to the original design. Actually, many of my designs are all about improving the printer. Time to summarize what I did and what I would like to do!


Fixing Cura broken linux packages (slicing fails silently)

How to build Cura's slicer "SteamEngine" from scratch

Cura releases for Linux are often broken, probably because the author better implements features than packages (which is a good thing!) and because supporting Windows and MacOS is already painful enough ;)

One of the last issues kept happening due to the linux package made only for 64 bit architectures, which is stated nowhere and not checked during installation. So slicing cannot run when your PC is running a 32 bit linux OS. The easiest fix is to rebuild the slicer, which is a piece of cake compared to 3D printing!

Update (jan, 2014): full instructions on how to build Cura from scratch (see the last chapter).


Friday, January 17, 2014

How to 3D print nylon and trimmer line reliably: do not dry it too much and glue your bed!

How to 3D print Nylon reliably, cleanly and hassle-free.

A well-printed and robust dual-head Nylon mount (check it here).

Nylon is flexible, slippery and incredibly tough when it is printed correctly.

For me, it is a cheap and very useful material to 3D print. It is my best choice whenever PLA is not possible, and the very reason I never use ABS (more about the materials in this post).

But the nice properties of Nylon are the ones that precisely make it difficult to print ! By the way, Nylon also produces toxic fumes when heated, just like ABS, so it better be used in well-ventilated rooms.

I tried many known and unknown techniques to print reliably, and it is time I share my experience because I am happy with what I found.  Read on for more!



Friday, January 3, 2014

Fixes and howto for the DIY Fabscan 3D scanner

The fabscan is cheap... and buggy, but it can be made to work.
In its state, I would recommend it only to tinkerers, or after
a few improvements (easy to make since it is opensource).
For my curiosity, I bought a DIY "Fabscan" to try scanning small objects cheaply.
And it proved to be cheap, in all the possible ways.
In my opinion, the most annoying thing was the totally unusuable FabScan Ubuntu Live CD software.

This post is mostly about how to get it to produce an STL with the Ubuntu Live USB distribution specifically made for the fabscan.








Friday, November 1, 2013

A rant: open or closed, you get what you pay for.

A rant: open or closed, you get what you pay for.


I got "stimulated" again by a feedback on my wooden patterns related to the Python script I posted on thingiverse.

Here is the request (which I must say is fully honest and respectful):

     Very cool thing, but does anybody know how to use this with a makerbot?
     How can I edit the x3g file? Or an other way, how can I convert a gcode to x3g?
     Thanks in advance! -- j.

I have checked Markerbot own site: "Your Replicator 2X can only read files in the .x3g format".

So bad for their customers: they just do not care about the decade-old standard gcode format that all other players support in the field !
A famous strip from Nudel and his repraprip blog regarding Makerbot


Thinking about it for a while, I must say I will not help at all in this respect. Let me say why.

Sunday, September 29, 2013

Help yourself: compatible 3D printer parts that are easier to swap!

Why would I ever re-design a working part of a printer?

It does look robust, but hard to disassemble! (Escher)
Most of customers and users do not tinker with their 3D printer. After all they paid for a robust printer and spent a lot of time setting it up properly. Once done, it stays so (well, at least with the Ultimaker). Sure, it is a desirable feature, especially for the "boxed/walled" frames. But it may get really annoying when you are trying printer part alternatives in the first place, which is the subject of this post.

By the way: there are really two main usages for a 3D printer: the obvious first is to print objects... while the second is to print replacement parts for the printer itself! Sounds weird, eh? "So what are you printing with your amazing printer? - Well, most of my time-consuming designs are printer part replacements!"...

Now back to the question: why shall I sometimes just re-design a part of the printer with no added value beyond the ease of manipulation?

Wednesday, August 14, 2013

Make it yourself: it can be better than what the industry sells you!

I got one interesting abrupt remark related to my hobbed bolt. The idea was that it was both difficult, and may be ridiculous to make one's own crappy part nowadays, while you could buy one, shiny, made on an precise and industrial machine. But who's the chicken and who's the egg? And which is better really? I think the answer is worth a post on its own here and there
The Aeolipile, may be the first steam engine.
It was certainly made "at home" by an early "maker" in Grece.
Since the business angels were not ready (cheap slaves were found everywhere),
we lost almost two thousand years before re-discovering it!

Tuesday, July 2, 2013

Extremely fat extrusion with a 1 mm nozzle

Going "nuts" and 3D printing with a 1.0+ mm nozzle!

A ridiculously big 1.1mm nozzle make it flow like hell !
After some testing with a 0.3 mm nozzle, I really had to try and post my quick and dirty tests with a huge one.

In fact, I had lost my smaller drill bit set made for smaller holes... So I took a brass cap nut, screwed it on a threaded rod, put it under my vertical drill press with a "regular" small drill, and here we go. I measured afterwards it to be something like 1.1 mm. Interesting...

Now for sure it was funny as a friend told me I just had made the first Scoubidou machine! But the first prints still were surprisingly good! Not only can I print very fa(s)t, but it still makes a nice print in the end.

Now, there were a few quirks I should have taken time to fix (see below), but very big nozzles are now part of my consideration when I want to prototype quickly and/or when the printed object needs no special accuracy: refining the ergonomics of a handle, or printing a toy and so on.




Saturday, May 25, 2013

No slipping, no grinding: not always a good thing!

Let your filament slip, your bowden tube pop up... or break something !

If the filament cannot slip nor be ground a bit,
excessive pressure has to "break" something anyway.
Now for sure, and I can prove it: my driving system is very efficient and my bowden stays well clamped...

When I tighten the idler completely to the maximum, the driving bolt grips the filament so well that the weakest point in the feeder mechanism becomes the PTFE bowden tube resistance itself.

As you can see on the pictures, my PTFE bowden tube got stretched and stripped in the pneumatic push-fit connector!

This seriously clogs the nozzle and it becomes a real drawback in the end: check my analysis below.




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, maths and mechatronics. If you have a project and know what "R&D" is, then you already caught my interest ;)