London 3D print show

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Lot of usefull concepts and things around!

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06. Upgrade your projects

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First I need to apologize but I had more and more to do in this period, so I posted just links and the article came later.

The experiences I am having now will be shared here as usual, so just a little patience… today I mean to expand the concept of leaving your projects upgradable, that could be not so easy.

There are a number of mods and hacks around to make your project fit your needs. With a bit of research and open mind you can find a creative way to use these instructions to make your own solution that fits your needs.

I usually search for what I need and mix things up. I would like to give you examples because it will be much easier.

On Arduino side. I use the classic board with removable chip because my target is to produce boards that are integrated and soldered together, I had also some case in which also the height was important and I had to solder the chip directly on board. So how can I have upgrade on this board? The answer is on the documentation that makes you able to rebuild Arduino on breadboard or program ATMEL chip with Arduino board as programmer.

http://arduino.cc/en/Tutorial/ArduinoToBreadboard

Here you have all the information, basically you need a way to link back the right connector and to the chip so you can upload new versions of your sketch simply connecting to your pc the board.

Arduino on Board

Arduino on Board

As you can see in the picture the power is running from the Arduino board to the chip, it is a good practice but can work also with a good power source linked to the board. If you like to have a sure way to avoid interferences you must have a way to cut the board from the current or batteries you use to power it and link this to the Arduino board power line 5V marked.

In this way you can write on the arduino a new updated code.

There is a world out there not just linked to the Arduino in electronic: a lot of functions can be on different boards but most of the time the connection needed are the same form board to board changing just the components on board. A separate board with a connector can be switched to another just keeping the same connector, this could change the input management on the software is running the board or not if you use a universal protocol (PWM, ISP, analog reading or whatever you need) you can just read the value from the right pin of the connector and keeping different boards. This is a modularity that can be used for simple testing processes, but you can also use this to read with different instruments very different inputs around: light, sound, electromagnetic waves… all this can be read with a same scale output on the main board creating in that way a sort of different, all-around sensors.

Do not underestimate the natural connectors a project can have. I have a simple plugin on my 3D printer that change a Raspberry Pi in a web server for printing out my files. This upgrade uses the natural USB connection of the printer and the natural Ethernet connection of the Raspberry Pi that is reachable from my LAN at a certain IP address. This is very useful and fits the files I prepare for the printing with Slic3r.

The approach should be like so, I have a number of projects that are willingly open to have the opportunity to upgrade them. This procedure is in my opinion very useful and important, even if you have to consider a lot of different standards or variables for your project, but when you will need an upgrade you can make a mark II of the project simply changing or updating a part of the project. This will speed up your production line and make your project editable also to other people in simply way.

Make your mistakes, make your things, make your way but please…

Make something!

3D Cosplay, the new adventure

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3D Cosplay, the new adventure

I will delay a bit the new article because these past weeks I have been busy launching the 3D Cosplay project: a new way to build cosplay with 3D printer. Tailoring cosplay on the person that ask them and producing big format pieces with little home printer.

05. Boxed version

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Not everyone tells you about the strategies or numberless solutions to box your project in a nice package that will cover what it has to do in order to make your project secure and usable.

First you must remember that your project has to be still accessible unless you have special needs. I strongly avoid resin coating of parts that I know can need fixing or extra work, extra wiring…

Second the rules and caliper are your best friends in making a box for your project.

Let’s say you have the thing you want to contain somewhere and you have a nice top view of it with all, you first must remember that you are living in a 3D world, you won’t need to create boxes for paper sheets, even if also these are 3D objects with a little height. So first step is to quantify on the top view how tall the components are and then how tall will be the box at least. Next thing you will know with this calculation is the empty room you have that will be crucial to fix things in place or create rooms for extra components that usually we don’t think of.

The advice is to create a box you can handle with your skills. But to start simple let’s say that a person with no skills can find a lot of boxes ready in shops, in his house, within the same project the person is building or in the garbage.

There are a number of plastic container, metal boxes and so on used for food, electricity, lunch boxes that can be modified with little effort and some simple instrument to contain projects electronic or mechanic: a pcb, a clock, a little radio or mp3. Usually you can get rid of some division that could be there or make some holes to keep separated parts of the same project but creating room for the links needed.

Remember also that if you have a control panel or moving parts you need to calculate the room for that: produce a draw or a reference of the project to its maximum extension and always take that in account.

You can draw and build your container with wood or plastic, CNC machines, 3D printer. Notice that is is very useful to have a 3D alias for this process. For an handmade wood or plastic case just use the actual project to be contained and make a box around that. Remember in your box assembly to count all the dimensions of the material you use, add the height and depth of the material: the layer you are using has a space not just a bidimensional shape, that volume has to be taken in account when you build even a simple cube or the cube won’t fit and won’t be cubic at all… If you stick to the handmade case use some of the material to create supports that can be needed to lift the inside mechanism to make it more free of move, notice that lifting the inside will change the quotes of the box at least of the support value. If you have a pcb to box everyone tends to abstract the shape as flat on the soldering side, well this is actually wrong: solder points can be very thick depending on the component they are retaining, measure the room they take and make optimized supports for them. For a music box with a mechanism inside you must count the exact space you need to make the music stop or start when you open or close the box using the switch it has, you need to lift the mechanism until the cover of the box touch the switch in closed position and make sure that the cover can open at least at 90 degrees angle. For a project with batteries remember that they can be hot if you need a lot of power, it is a good idea to give room around to have some fresh air or to open some ventilation hole, another measure would be adding a fan if you have heating problems, but first check where the heat is: too much heat on the batteries can be an error, on some chip or transistor can be normal but consider also a dissipation of the elements, after you close things in a box without ventilation heating problems can only be worst.

Working on a 3D machine like CNC or 3D printer is a little different: it is a good idea to have a CGI alias of your project that can be not so accurate. You can compose a series of boxes that gives an idea of where the project is tall and where is flat. The second step will be to choose the material you want your box and how strong has to be for the usage you need.

Garbage concepts are beautiful and unexpected: think at the old Lego blocks hang around your house, they can be your new box with some superglue to fix parts that are meant to be in place all the time, or think to a beer or soda can that can be a beautiful container for some party decoration or music player. Container are already in your house: use your imagination and shape them for your needs.

Mix the techniques! You can stick completely to a way I explained before but each technique has its limits: combining them you can break that limits. For example 3D print or CNC a transparent material make it less shiny. You can try to polish that with waxes or files or you can leave the printing to hand cut a little panel of transparent material and make a way to glue it or fit it in place in your box. You will have a clear transparent finish on the rough finish of a 3D print or CNC cut that can be a very fancy effect.

Other thing to keep in mind is to make room for ALL. All means all, also the cables of an electronic project for example. Even if most of the people seem to forget cables are the first reason of finishing the space in a project. Choose carefully your extra component but most of all leave some room for that! There has to be an operational space of the extra component. Continuing on the cables they has to be fitted in the box but also you need to fold from open to closed position the box at least in the first packaging action when you close the project in its box for the first time, would be better if you can undo and redo the operation for maintenance.

Last thing I’d like to cover is how to fix things in place with your projects and there are not so many options but some are more complicated to handle.

First it is glue: careful with this because it is one way to not be able to open the project again. If it is not needed for some reason on a box would be better to use removable glue like hot glue that can be scratched away or silicon gel.

Second are screws: if you have a solid base or you provided spaces in your design to put screws in place that will be a good way to take together the box and the inside or part of the boxes closed. You will sure need to provide holes that can be used as a way to secure the object and you can use screws and nuts or just screws that can be placed without nuts if you use wood or tender plastic.

Third is a strange way called mechanical retention: you have a mechanical retention when the box itself without screws or glue has a shape that fixes in place the object inside. The cover of the box and the base need to have staffs, angles, shapes that surround the inside and press on the flat parts or on solid part that raise from the object (e.g. on a PCB it is a good idea to make retention on USB or LAN ports or on an empty pcb part not so much on a chip or a capacitor). This is a modern way to lock in place the project, then the box can be closed with screws, glue, clips or any other way but the inside is not fixed by that, when you will open the box your project will pop out.

One of my next project will be to use an old MP3 player that was headphone integrated in a new box, I will post the photos of the process. I think I will 3D Print the case and I will need to have a 3.5mm jack added to the board because before it was hardware linked to the headphones. It had problems of sound on the old setup and I would like to see if the problem was in the electronic itself or in the speakers.

Make your mistakes, make your things, make your way but please…

Make something!

Coding

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First I am not related to code.org and I am not pushing you to use the site. This is a share  with you because the concept inside are very good, the people in the video have amazing ideas and that is the best answer I can give you to the question “how can you learn yourself to code? Electronics? Arduino?”.
Simply: you don’t have to be a genius… Tomorrow the new post, stay tuned!

04. 3D for 3D printer

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Many people can do 3D, but the 3D has a target. CGI can be used for movies, video games, illustration, design… If you used 3D for different things you will know that every application of the 3D has its rules. The rules are given by the characteristics that we try to do with that files.

3D printing has off course its rules and I am going to list the common errors we can find in the files or how not to make the errors. I will use as reference software the free opensource Blender 3D downloadable here:

http://www.blender.org/

First thing to know, as I told before, is that to be printed a 3D model must be a single shell, empty inside with no holes. There will not be different solid grouped together and intersecting one the other. This will give you some nasty results…

The term for similar objects is that is has to be “manifold”.

To achieve the result it not enough to start from a basic shape and extrude from there all the parts, because even with that approach some errors can be done. Also it is pretty difficult to handle such a process and it is simple to make boolean operation on many different and simpler objects even if in the end you’ll have to solve some errors.

Notice that in the end the STL file will be exported with all triangular faces, so if you need to use tris to correct the mesh instead of quads it is fine. The various software can give problems just if you have some modificator acting on the mesh. Just be sure to apply all before correcting the manifold problems.

Notice also that booleans operations can generate in simple way various shapes. Booleans are logical operations that can change the shape of an object intersecting, adding or subtracting one shape to another. These are very useful if you think about producing the perfect hole for a screw, or sectioning an object in parts.

Typical errors can be found are:

– duplicated vertex

– overlapping faces

– semi-overlapping faces, when 2 different faces starts from one or more common vertex but ends with different one/ones

– overlapping separated sections of the same object

– internal parts resulting as holes in printing that are in fact a close solid internal to another, usually given by boolean operations

– intersecting faces

(Please, see the gallery at the end for more details)

In Blender you use the “Non manifold” command in the select menu that will highlight the wrong vertices. Here I put some pictures of the common errors.

The only modeling an object is not enough since we started the article focusing on a purpose for our 3D. The purpose is to 3D print a thing.

I will have a separate article on how to test your prints or in general a creation that has to solve a problem.

For now focus on what is the immediate target: my 3D stl file has to became an object printed or carved in some material with a 3D printer or a CNC.

First you need to know your target material, how it is made, characteristics, toxicity, weight, resistance and so on. Studying a material is essential to know if the object will resist to the use is intend to.

Then you need to know your machine. I strongly suggest to make tests on the machine, precision tests, resistance tests, extensive use tests, calibration tests and do that often or at least every time you change something. It is critical that you know if your machine gives a problem how you can fix that. Understanding this will give also ideas to optimize and personalize your machine and workflow.

With these 2 analysis in your hands now take a look to you object and find critical part of the thing you want to make. Maybe you can find difficult achieve the precision you need cause of the machine itself. Maybe an object it is not meant to be carved on a CNC but to be 3D printed. Maybe the material you are using is wrong for some reason. Maybe the object has a particular orientation in the model that makes difficult to be properly printed like a really small or nearly 0 surface printed on the first layer, that makes hard sticking the object on the printing bed. Maybe the orientation of the object is such that makes it easier to break when used and simply changing the orientation of the item itself or of the layer printed in the slicing software you can have a stronger piece.

As I told having a purpose in making a 3D model makes things a little harder to control and to choose from.

I have to say that often you will need to think of also the better way to print an object. The better way it is not always a single print: for many reasons you will need some assembly with glue or mounting systems. For example I have done this reproduction of a knife from the game Assassin’s Creed that is identical in the 2 faces. If I print that on a home filament machine I could have some trouble to polish the item when it cames out so I did just one half of the item and obtain the other from a mirror modificator with the 3D software. Glue it together with specific plastic glue and it is beautiful and done.

There could be many reason to cut an item in different pieces and I will cover that in a dedicated design article full of examples.

In 3D printing you can have also another thing to choose, I will return on that also later but for now I will give you ideas: the infill.

You can infill in your perimeters a certain density of plastic. I think this is the reason it is called infill and not simply fill.

You can vary off course the perimeters, bottom and top layers and the infill to achieve different results. First thing to notice is that if you want an even shell all around the shape you can’t rely on having the same number of perimeters and bottom/top layers. A perimeter has the width of the nozzle of your machine (or the width you declared in the slicing software) a layer has the height of the slicing layer you set in your configuration that can be very less than your perimeter.

e.g. If you have a 0.5 mm nozzle and you set 3 perimeters your perimeters has

0.5 x 3 = 1.5 mm

if you are printing some really precise stuff at 0.1mm layer and you put the same number of layers you will end having

0.1mm x 3 = 0.3 mm

You will need 15 top/bottom layer to have an even shell all around of 1.5 mm

For the infill think of how you will have to use the item. It is critical to understand how much strong or light or empty or thin the object has to be. To put an item on yourself I suggest that it has to be light, to have a bottle opener or a slingshot you need strength, to have an artistic piece to expose you need to be precise but can be almost empty with a strong shell.

So infilling rightly your print will avoid problems on your creation and will give you the characteristics you need to have a good item.

If you start thinking from the bottom or “how do I solve this problem” the designs will improve and will come out precisely thought for a specific function. Those are still pretty basic things but starting simple is always a good strategy and as I promised I will cure this blog as I do my projects.

Make your mistakes, make your things, make your way but please…

Make something!

Errors gallery: