Ultimaker FDM 3D Printer

Ultimaker FDM 3D Printer
Manufacturer	Ultimaker
Model	Original+
AKA	{{{aka}}}
Obtained	Purchased through Pledge Drive October 2014
Location	CNC Area
Team	3D Printing
Induction Required	Yes (use request form)
Booking	Yes (use HMS)
Status	Defunct
Tools:   all pages • list • Power Tools • Broken tools     {{}}

The Space has an Ultimaker Original+ printer location in the CNC Area. It is a fused filament fabrication (FFF or FDM) 3D printer. It has an RFID card reader and requires members to show their cards to use, an induction is required before the system will activate. Using this tool will not be charged. It will print reliably at around 80mm per second.

The software used to control the printer is freely downloadable from;-

http://software.ultimaker.com/

There are 3 main steps to using the printer: choose your model; choose your material; and finally slicing a 3D model into "g-code" readable by a printer then and feeding it to the printer. This is typically done via an SD-card for maximum speed, although a computer or laptop can do this when connected to the printer by a USB cable.

Step 1 – Get your model ready to print

The first stage of using a 3D printer is finding a model to print or producing one from scratch. The types of file that are easiest to deal with are .STL or .OBJ. Conversions from other formats to either of these is usually necessary in order to print.

Online Model Repositories

Well known public depositories of models for free usage are;

• http://www.thingiverse.com

• http://www.grabcad.com (needs registration, some models are pay per download);

• http://www.yeggi.com (usually links to above 2);

• https://www.youmagine.com/

• http://www.stlfinder.com (can go ANYWHERE with this one, caution recommended)

For a further more indepth list of depositories;

• http://3dprintingforbeginners.com/3d-model-repositories/

CAD Software

If you want to design models yourself, then three free to use pieces of software are Fusion 360, Blender and OpenSCAD. Fusion 360 offers a surprisingly fully featured parametric CAD package and is well supported by thousands of other makers on YouTube. Blender is GUI based, OpenSCAD is command line based. Using any CAD package requires patience and practice, but gives you absolute freedom to come up with your own designs.

In addition to the packages mentioned here, many others exist and almost any software that can produce STL files is usually suitable for 3D Printing.

Model Checking

Prior to printing you should check any models that you download or produce. The reason for this is that STL models need to be perfect meshes that define a solid, water-tight body. If this is not the case, they won't slice properly. There are several freely available tools that can fix STL files including; Netfabb & Meshmixer.

Its also important to check the dimensions of models you intend to print. You may find that models you download from the internet do not meet the size requirements for your project perfectly. In this case it is possible to scale the STL models in one or more dimension using Autodesk's Cura Software.

Step 2 – Work out your material

The Ultimaker takes 3mm sized filament. Members are encouraged to source their own filament, although for small projects there is a limated amount of PLA available in the space to print with. Some suppliers sell “3mm” filament as “2.85”. This is actually a more accurate measurement of the same material – it extrudes hot at 3mm but shrinks to about 2.85 at room temperature; either will feed on our printer. Technically the smaller 1.75mm filament will also feed on our printer but this has not been tested yet.

Where to buy Filament

Sources of filament are;-

• http://www.ebay.co.uk – although caution is recommended with any particular sale!
• http://www.faberdashery.co.uk
• http://www.shop.3dfilaprint.com/
• http://www.amazon.co.uk
• http://colorfabb.com/ (Dutch)
• http://fillamentum.com/ (Czech)

Exotic Materials

You can also get filament which is PLA with other additives, for instance bronzefill, woodfill (Laywood), brick effect (Laybrick), soft iron for electro magnetic cores, carbon nanotubes, carbon fiber and stainless steel. Caution is recommended when dealing with different filaments with unknown properties – each requires slightly different temperatures and may cause a nozzle to clog.

Measure your Material

It is also highly recommended to MEASURE a new filament to get an average width. Putting this value into the slicing software that converts a 3D model into printer g-code enables the right amount of material to be laid down. If your filament has a different diameter for some reason, the software has to know this!

One great thing is – you can download a model into Cura and it will tell you roughly how long a piece of filament it will need to finish a print. Make sure your reel has enough filament on it!

Temperatures

PLA will print between about 177 for the transparent or translucent varieties, up to about 208 for the harder coloured varieties, especially black or white. Setting a bed temperature of 60 Centigrade or slightly higher will give the plastic a good chance of sticking to the bed. After the first couple of layers the heated bed can be turned off – this helps to reduce curling or warping on smaller prints, as does reducing print speed and printing temperature.

For ABS, a much hotter bed will be required. MINIMUM 105 Centigrade or preferably 110-115. ABS needs a hot surface to stick to.

For other exotic materials it usually states on the box some guideline temperatures. Use these as a starting point but be prepared to experiment.

Step 3 – Print the Part (Prusa I2 Instructions)

These steps have been written for a Prussa I2 but the workflow is extremely similar for all FDM 3D Printers. You should take notes during the Ultimaker induction session and use this only as a reference.

Prepare the Bed

This is THE most important stage. It is fiddly to learn and takes practice to get right.

The surface that models print onto is a square mirror, with a hole cut in each corner. This is clipped onto the aluminium heated bed, and needs to be prepared for the first layer to “stick” to it properly.

If a model is printed straight onto glass – it can be impossible to remove without breaking the mirror.

A coating material has to be added to a clean mirror, to give a surface for the hot extruded material to stick to. When printing with PLA, the best all around material for this is PVA wood glue, smeared thickly enough to be opaque, and then left to dry to a transparent layer. Masking tape is also useful for this and can give very good results.

For ABS, Kapton tape is a better bet. A large roll of this is kept in the Reprap spares box in the Members Room. Again, putting it on the mirror takes a bit of practice to get right.

Once a clean mirror has been coated, it should be clipped back onto the bed, and the heated bed turned on, either via the built in controls on the printer, or via a control program like Pronterface.

Pronterface is again an Open Source 3d program, part of “Printrun”. It is a Python script, and is very useful for manually controlling a printer, to make sure the travel over the bed happens right (no dips or rises), and also that the “home” positions of all the axes is correct. Pronterface can send G-Code to a printer, but does not have the capability to make G-code from a 3D .STL model. Cura or the alternative Slic3r software can do this. Slic3r is not so user friendly as Cura but does make better g-code, in general.

Check the Z Homing Position on a hot bed

The adjuster for this is closest to you, and is a switch mounted vertically on a smooth rod. The switch should be clicked automatically when the nozzle is JUST above the HOT bed. The exact position varies slightly, which is why heating the bed up to begin with is the second most important part of preparation.

Happy that the printer homes and all the heaters work? Good, if your filament isn't already loaded, heat up the nozzle to working temperature, undo the screws on the extruder, and take out the filament that you don't want to use, and feed in the filament that you do want to use. (Video of this to be positioned here in the text at a later date). Then tighten the screws on the extruder, and use Pronterface to “Extrude” until you are sure the printer is squeezing plastic cleanly. It is wise to feed at least 40mm of fresh plastic through a nozzle prior to a print, to make sure that it is feeding and extruding hot plastic properly.

Once you are sure the printer is ready to go, it is time to feed it some G-code. Close Pronterface and get your g-Code onto an SD-card;-

Slicing G-code with Cura

Load your model into Cura. Scale and rotate it to fit the bed.

Choose a sensible “Layer Height”. This is the height each layer of the model is printed at. With a .35mm nozzle, a layer height between 0.175 and 0.28mm is sensible. Less layers = quicker print but weaker layers. So thin is good but slow.

Next, select “Save g-Code” from the Cura Menu. Give it a name, try to put Cura into the title, with a .g or .code suffix, and save the G-Code.

Print the part

Transfer the G-code onto a SD-Card and insert into the printer. From the Menu (press the button), select “Print From SD card”, select your model, and watch it slowly being printed in front of your eyes.

Not happy? Leave a model to print for at least 3 minutes before aborting it (easiest way to abort is just turn the power off on the printer). Some models start rubbish but settle down to print well. Others start well but go badly – it is a good idea to shut down the heated bed after the first couple of layers, also smaller parts print better when printed slowly, as they need time to cool down.

3D Printer Videos

Some videos which explain the basics of 3D printing and getting started

http://www.element14.com/community/groups/3d-printing?ICID=menubar_topics_3dprinting Element 14 videos (required login)