Which filament is the best for your desktop 3d printer?

From engineers, plane- and car manufacturers to architects, artists and other product designers, they all use 3D printing to test if their designs come out the way they were intended. Thanks to the winde range of open-source and affordable desktop 3D printers and cheap 3D printing materials, schools, students, small offices, makers, enterpreneurs and professional designers are now able to set up a studio full of 3D printers to have their students or consumers (workshop participants) experiment on their own. In this article I’m going to discuss the most important facts when choosing the filament for your 3d print. There is a huge amount of companies and webshops offering PLA and ABS filaments for 3D printing, but if you aren’t carefully enough, you can get some really serious issues with bad filaments.

Most desktop 3D printers use the fused deposition modeling (FDM) technology, which means, that they all work with plastic filaments with 3 mm or 1.75 mm diameter. The hot end of the 3D printer heats the filament which melts before being extruded from the nozzle. Most 3D printing plastics have a melting point from 180 to 240 Celsius. After 3000 hrs of 3D printing on my Makerbot Rep2 and several types of RepRap 3D printers, my tip would be: if you want to start 3D  printing, you have frustrations enough (mechanical and electrical issues), spend a few extra bucks to eliminate possible filament issues. I’ve tried several suppliers of 3D printing filaments last year, from the cheapest ones to the premium quality spools as well. The moral of my story is:  you get what you pay for, buy materials from a trusted and verified supplier where you know who makes it, and watch out what you put in your 3D printer. 3D printing is already hard enough without nozzle blockages to deal with.

Unfortunately, the nozzles of the usual desktop 3D printer setups aren’t self-cleaning, so you can have some dust or particles while feeding the filament into your extruder head. Accumulated dust/dirt on the filament, or even actual debris inside the filament, can partially or fully block the narrower output end of your nozzle. High quality filaments come vacuum-packed and sealed for your security, but I’d suggest to check it before you put anything into your 3D printer. I’ve found some really cheap stuff on ebay as well, but the pain of clogged nozzles and wasted failed 3D prints its not worth it.

Some 3D printer extruder constructions might be sensitive to the diameter of the filament, it may be have problems if your roll of filament varies widely in diameter.  I’ve had some bad experiences with the Formfutura supplier, although I’ve ordered several spools from them. With the FlexPLA and the Laywood, I haven’t got any problem, but with their normal PLA spools I have discovered some irregular values after measuring the diameter. I mean, the cross section of the filament should be round with a diameter of 1.75 mm, but mine looked like an ellipse with 2.05 mm along the longer axis. Unfortunately, the hot tube of the extruder of the Replicator 2 has only a 2 mm hole in it, so the filament just got stuck int he hot tube while feeding.

I had to take my 3D printer apart, remove the clogged filament and clean all the parts before re-assembling. Sometimes, the diameter variation could be gradual; in this case, you might have great print jobs for a long time, and then unexpected as the filament gradually gets narrower, you have an extrusion issue.  Or, as the filament gets wider, you start to have an over-extrusion problem. I’ve already read some reports about knots ont he spools, int hat case, those plastic spools weren’t originally manufactured for 3D printing, maybe they are common plastic welding rods sold as 3D printing material. If you have experienced knots or stuff like that, you’d better switch to higher quality filament (like the filament that Gigamax3D sell) that is made specifically for 3D printing. I’ve found that supplier a couple of months ago, and I’ve been really glad because they are from nice quality for an affordable price. I’ve tested them before buying, because they have a store in my country so I could measure the diamter of the sealed spools. They have allowed me to test every spool I wanted, and their filament passed the tests with my micrometer. It was the first time I bought some HIPS spools, and they worked fine as well.

Gigamax-supplied filaments have been tested to conform with all the common desktop 3D printers’ specifications and work best for most applications.I you already have some experiences with desktop 3D printers like RepRap machines, Makerbots, Leapfrog 3D printer or any other FDM 3D printer, you might have discovered as some filaments won’t work fine or can cause serious damage to the extruder head and machine. The quality of your 3D prints depends ont he quality of your 3D printing material as well. That’s why it is important to use high quality filaments for 3D printing. Gigamax offers an array of plastic filament colors. If you visit the Gigamax 3D print webshop  you can see the full range of colors and special materials like glow-in-the-dark PLA or HIPS filaments in bright colors. All Gigamax 3D printing filaments come in a vacuum-packed foil bag with a desiccant pack to keep the ABS, PLA and HIPS spools dry during storage.

They also sell PVA material, which can be really useful if you have a dual extrusion 3D printer like Leapfrog Creatr or a multimaterial RepRap machine like the Tricolor Mendel. 3D printing with FDM technology is really popular because of the simpliness of the process. There is no finishing necessary when 3D printing with extruded PLA, ABS or HIPS filaments. After the FDM extrusion process, the plastic solidifies right away. No chemical reactions, resins, etc. and no further post-processing and/or finishing needed. In case you use a 3D printer with multiple extruder heads with the water-soluble plastic PVA plastic as a support material, you have to dissolve the PVA in water after your print is finished. PVA is an amazing material, unfortunately it only can be used with at least 2 extruders and costs a little bit more than usual 3D printing plastics.

Since I switched to Gigamax3D filaments I haven’t got any issues with filament diameter and clogged nozzles, unless I unloaded the HIPS filament and loaded some Laywood and Laybrick material. I think that some particles may have stayed in the brass nozzle and that’s why it acts like a barrier and the plastic cannot extrude. You know, 3D printing can be sometimes really frustrating, especially if you don’t know the reason for the problem. I’ve had several issues along the months, I’m going to post about typical issues with my Makerbot soon (problems with the Delrin plunger, broken cables, SD card reading errors and wrong plastic pulleys… c u next time;)

How to check your .stl files before 3D printing them

Hi there, today it’s going to be about some general design rules that should always be performed on any .stl file you create before 3D printing. Most of the downloadable .stl files for 3D print offered by several platforms are already checked for 3D printing, and the feedback is quick as well if something is wrong because of the nice community around 3D printing.

© parametric | art

After the 3D printing boom in the last couple of months, the number of the 3D printer owners has rised and a lot of people started to 3D print their downloaded things at home. The system of the RepRap-like FDM 3D printers hasn’t been designed for a plug&play use, if you’re into 3 printing you should know what I am talking about. If you are a natural born hacker, RepRaps are just for you, but if you want a 3D printer for professional production you should buy an expensive FDM printer from the higher class. They use the same technology but the system is closed so it doesn’t need any adjustment or special maintenance.

© parametric | art

If you want to design a 3D model for a visualization render or a video game, you needn’t pay any attention to real world physics. In the practice, the most 3D objects will only contain the meshes that are visible, they don’t need to really connect, there can be a lot of 2D elements in the geometry and there can be some holes and broken meshes or duplicates which can disturb the slicing process while generating the g-code, etc. You can completely ignore the physical world. 
As some of you have already discovered, once you start working with 3D printers this is very different!

I just would like to share the basic design rules of my general design for 3D printing process and the machines I’ve worked with. If you design something in 3D, at the beginning, you probably don’t know which type of machine and material you want to use to realize your object. In general, every single 3D printing technology like FDM, SLS or DLP has got its own pros and cons, so the designs should be optimized for the actual chosen additive manufacturing method and the material for the fabrication. I mostly use my desktop 3D printer which works with fused deposition modeling technology (FDM), actually it is an upgraded/hacked Makerbot Replicator2, which is capable to 3D print with experimental materials as well, like laybrick (sandstone-like stuff) and laywood (wooden filament). I usually print with PLA filaments and sometimes I make 3D prints with wood and sandstone. I already have 3D printed more than 2000 hrs with my machine, and I had to learn the limitations of the FDM process so I could design more complex geometrical forms and parts.

Usually, I make my designs in Rhino with the Grasshopper parametric modeling tool, which is absolutely free. This great plug-in gives you parametric control over your meshes, so I can think about the 3D printing process while designing my sculptures or stuff like that.

If you want to prepare your model for 3D printing, you should know the boundaries of your machine. If not, there are some general guidelines to choose the right and universal maximum size and wall-thickness, based on the build volume and nozzle/beam diameter of the 3D printer. In general, the model should fit into a 15 x 15 x 15 cm cube and mustn’t contain walls with a thickness under 1mm.

If you need support structures for your 3D print, maybe you should add them manually to your model; the automatic generated supports by the several slicer software are a waste of material and if you don’t use some soluble material for 3D printing support structures with a dual extrusion 3D printer, you may have some issues while removing the support structures and get a nice surface finish.

@ parametric | art

Another important thing is the position of the normal vectors of the meshes of your .stl file. All meshes of your model should have their normals pointing in the correct direction. When your model contains inverted normal’s, the 3D printer cannot determine the inside or outside of your mesh or 3D model.  Usual problem is the error of the mesh surface as well, holes, duplicates can make your print wrong.  In Rhino, there are some really nice Mesh Repair tools like Cap Holes of Remove Duplicates, which can make your work easier. Netfabb is an awesome cloud-based tool as well, the free version already allows you to analyze, test and repair your .stl files, split and cut them into parts.

Your 3D printed surfaces must be closed, I’d like like to call this being ‘watertight’. It can sometimes be a pain to identify where this problem occurs in your 3D model, if you can’t find it, there are some really nice algorithms or applications and tools which will highlight the problem area for you. Will It 3D Print is useful site with a funny design, unfortunately, it doesn’t work for me with complex and huge .stl files, with simple geometries it might work. I’ve already put together an algorithm in Grasshopper which analyzes meshes for holes and unifies their normal vectors.

Let me share some really nice apps and tools which I’ve used to create and optimize my 3D models for the 3D printing. At first, you have to create the 3D geometry of your model. I use several professional 3D software’s, but if you don’t want to get into 3D modeling and complex geometries, there are some easy-to-use sculpting solutions which can give you great results without any 3D experience. Of course, you can download .stl files from 3D databases like Thingiverse, GrabCAD, Ponoko, or Nervous System, you also can customize your stuff with some really nice WebGL based 3D modeling tools which run in your browser window.

If you want to create something unique, SculptGL, 123D and Leopoly could be the right choice for you! Both are in-browser 3D modeling environments with 3D print and .stl export function, and Leopoly has got an absolutely awesome controller called Leonar3Do which is a bird-like device to navigate and work in a 3D virtual reality space.

If you already have your model, you have to optimize and check them before 3D printing, Netfabb, the Mesh Repair functions of Rhino, WillIt3DPrint and Meshmixer are great solutions for that, and of course, the new 3D printing features of Blender’s latest release gives you a nice control over these parameters as well.

After your .stl meshes have been tested, you have to slice your model to generate the g-code which defines the tool path for the extruder head of your 3D printer. This article cannot describe the whole world of g-codes that the most desktop 3D printer firmwares use and how they work, but some facts should be cleared. The main target is additive fabrication using FFF/FDM processes. Codes for the 3D printer head movements follow the NIST RS274NGC G-code standard, so RepRap-like firmwares could be used well for CNC milling or stuff like that.

As many different firmwares exist and their developers tend to implement new features without discussing strategies or looking what others did before them, a lot of different sub-flavours for the 3D-Printer specific codes developed over the years. The most common slicing software solutions like Slic3r, MakerWare, ReplicatorG, etc. can save the information in the main format and as a pure g-code as well. If we aren’t sure about the success of our 3D prints, because we try it for the first time, we can test and simulate the 3D printing process with our g-code. There are a couple of g-code visualizers available, some of them already runs on Android as well. CNC Simulators can animate the 3D printers movement and working process as well, so can easily check if our print will work or not. The ReplicatorG and Slic3r offers similar simulating and analyzing functions like Netfabb and WillIt3DPrint.

If everything is ready, and our model has been sliced and fully prepared for 3D printing, we can turn on our magic machine (I mean a desktop 3D printer for example) and prepare it for the work. Make sure your build plate has been leveled correctly because it can cause the first layer not to stick to the plate. You can wash it with acethone but always check the leveling before you print.

© parametric | art

You can use a painters tape if you want to, I personally don’t prefer stuff like that because I print all the time so it would take too many hours to change the tape, I always print with solid raft structures so I can easily remove the prints from the plate without any risk of damage. Make sure you have enough filament on the spool to complete the process, and let’s start heating the extruder! In a couple of hours (or days depending on the size and resolution) your prototype is ready, just like this huge industrial prototype I’ve printed, which took more than 50 hrs to print in 3 separate parts.

© parametric | art

But it looks really cool, I’ve made it with translucent PLA using 70 micron (.07mm) layer height, which is quite good from a desktop 3D printer like my hacked Makerbot. Of course, all the 3D printer manufacturers offer their own software for the machine, and I bet they work pretty good as well, but if you want to push the boundaries of your desktop 3D printer, the open-source software solutions gives you more possibilities for fine tuning and calibration of your machine for special materials or experiments. In my next entry, I’m going to post some results about my latest 3D printing experiments: 3D printing with sandstone and wood – organic materials in the digital fabrication process! Stay tuned 😉

3D printing plastics – PLA vs ABS in practice

Welcome on my blog! Today, we are going to go on with the differences of the most common 3D printing materials, the ABS and PLA plastics. The most desktop 3D printers can work with these materials, last week’s post was about the main characteristics of the two filament types, today it’s going to be about some special aspects of use in practice. I want to discuss some important things about these 2 materials, I mean the shrinkage factor, rigidity, bio-degradability and heat resistance.

Rigidity

A fact is a fact: PLA is a much more rigid material compared to ABS. If you compare ABS and PLA by applying a progressive force, ABS will start to bend and finally will break; while ABS is bending, PLA on the other hand will hold it’s shape (it’s very rigid and doesn’t flex). Actually, this one is the reason for the design fail of the plunger construction of the MakerBot Replicator 2. The guys at MakerBot have set the old plunger construction used in the Replicator1 and other RepRap 3d printers. But those all work with ABS filament, which is . as mentioned above – not as rigid as PLA. After 100 hrs of 3D printing with my new Replicator2 desktop 3D printer, the filament has cut a hole in the plastic cap of the plunger. It’s okay – I thought – and I have tightened the screw on the plunger a little. I got another 100 hrs of 3D printing, but after that, another hole has appeared. There is a much better – a spring loaded – construction for that, you can download the upgraded plunger form Thingiverse and 3D print your own.

PLA is more rigid and its surface is harder as well. When applying more force, after a certain point it will eventually break before bending. You often need more force to break a PLA part than an ABS one especially if you have a thick part.

Something about the shrinkage factor of PLA for 3D printing

Fact: PLA has a much lower shrinkage factor than ABS. Usually it means that it is MUCH easier to use in the most common desktop FDM 3D printers: unlike ABS, PLA deforms definitely less and suffers from very little layer detachment leading to a much higher success rate on your 3D prints. I’ve 3D printed my most beautiful parts all with PLA, ABS isn’t the right choice for fine surface finishes.

With ABS, even a relatively small part will deform when printing if you don’t have a heated bed and/or a heated building environment. With the RepRap machines like the Felix or the Prusa model, it is really hard to get a tempered 3D print environment, because the working area of the 3D printer isn’t closed. (I’ve never managed it to heat it up to 100 Celsius as suggested, my maximum of bed temperature has been 80 Celsius with my RepRap.) With the more expensive desktop 3D printers like the MakerBot Replicator 2X it would be better: the tempered chamber of the 3D printer allows you to control the temperature of your prints immediately.

Are you interested in painting of your 3D printed plastic parts? I have really good news for you: both usual 3D printing materials – PLA and ABS – can be painted and post processed (sanded) if needed. First thing is first… Preparation. There are some Items that you need when prepping the plastics to paint. This first step is really important, because if you missed it, the primer didn’t bond well with the ABS plastic and tended to flake off.

Bio degradability

PLA is a bio degradable material. This means it will resist for very long in indoors use and occasional outdoors use but permanent exposure to the elements will eventually start to degrade it. It is not suitable, for example, for parts that need to stay outdoors 365 days a year; for these applications ABS is preferable.From what we’ve seen over the years we’ve been selling 3D printers there are 3 very specific cases where ABS is preferable over PLA:

Outdoors use

I’ve had a customer a couple of weeks ago who has asked me to 3D print build enclosures for electronics modules that were going to be left outside for many years. In that case ABS was the better choice because it’s not biodegradable, so it is more durable for outdoor use.

Flexible parts

Another customer needed to build supports for DIN rails. The support needed to flex enough to fit into the DIN rail. I have 3D printed the same part in PLA and ABS. PLA, caused by its rigidity, wouldn’t flex so ABS was the right material because of its flexibility. In the last couple of weeks, some flexible PLA materials have appeared on the market as well; I’ve already ordered some spools for testing but I haven’t got any experiences with them yet. I’m looking forward to see the results.

Temperature and heat resistance

Fact: ABS has a higher melting temperature so if you need plastic parts that need to deal with high temperatures (about 100 Celsius or more), than ABS is also preferable over PLA because of its higher melting point.

 

My conclusion: all in all PLA is not a “one size fits all” but it will meet the needs of 95% of the 3D printing enthusiasts and – from experience – it is so much easier to 3D print compared to ABS.

That’s it for today, I hope this posts helps clear out some questions about the right choice of material for 3D printing. In my next post, I’m going to write about some really special, experimental materials which can be 3D printed as well, just think about some wood or sandstone 3D printed things. It sounds awesome, doesn’t it?