Tuesday, March 22, 2016

So You Want A 3D Printer

3D printing is something that caught my interest several years back, the first time I saw a demonstration on a science program.  Back then they were still calling it rapid prototyping, but by any name it is quite impressive.  The ability to push a button and have a useful item appear is very appealing to a lot of us, perhaps owing to the replicator aboard vessels in Star Trek.  It wouldn't be the first time that life imitated art. 

In basic terms 3D printers are simple robots that create exacting designs using liquefied plastic filament extruded thru a moving nozzle.  Printing times vary greatly depending upon size and resolution of detail.  Very large detailed projects can take up to 24 hours or more to print, while less sophisticated items can easily be printed in just a couple hours or so, depending.

As impressive as 3D printing is, it is by no means as simple as pushing a button; that's just a step in the process.  A process that involves many technical and specific steps; with a strong attention to detail.  Success is measured in micro millimeters!

If you're thinking about getting a 3D printer, the first decision is, which one?   Currently there's quite a wide variety of 3D printers available in the consumer marketplace; ranging in price from just a few hundred to several thousand dollars.  Most of the industry leading printers are in the $1200 to $4000 dollar range.  The more budget friendly printers are generally small desktop models, with a small build surface; which is just fine for small projects.  The mid to upper range printers are larger, with correspondingly large build surfaces to accommodate bigger builds. 

The first step is to determine your needs for a 3D printer.  If all you want to make are functional household objects, toys and geometric art; a smaller desktop printer will likely suffice just fine.  However, if your imagination is broader than that, or your needs are more specific in nature, you'll be wanting a more sophisticated platform.  Indeed, even the smaller, cheaper units are capable of doing very fine detailed work; if its not too large an item.

The hardware is only half the equation, so you'll be wanting a unit with state-of-the-art software & firmware as well.  Much will depend upon one's technical background and experience with computer based modalities such as CAD drawing programs and related software.  Some printers software is open source, meaning the user can modify & update it.  Other printers software is proprietary meaning upgrades & modifications can only come thru the manufacturer. 

For those wishing to create their own 3D files for printing there are a number of software programs available which are relatively user friendly: some of the more popular ones are, Blender, MeshMixer and OpenSCAD.  With these or other similar software programs you can create your own files, import files from a scanner, and edit existing files.  For example, you could easily take a file obtained elsewhere, then add to or modify it as you desire for personal use.  What you cannot do is take someone else's file then sell prints on ebay.  Doing such is not only against the law, it is also bad form!

Some research will not only be helpful, it may well spare you both money and aggravation in the long run.  There are many factors to consider before you put your money on the table.  Do you want a 3D printer with single or dual print heads?  Heated or unheated build plate?  Some printers can only use PLA filament, some only ABS filament; and some can do either, as well as some of the newer filaments being developed.

You'll need space for the printer, as well as supplies, spools of filament, etc  Keep in mind also, that 3D printers do make some degree of noise during operation; this of course varies from machine to machine, the point being that none of them are totally silent, so that ambient noise is another factor to consider.  I actually find the sounds of servos working, and the "R2D2" like sounds emitting from my printer almost relaxing.

Once your printer is set up and ready for operation the all important build plate needs to be leveled, and protectedLeveling the build plate is one of the critical steps involved with 3D printing.  If the plate isn't level within the machine, a perfect print will be nearly impossible.  The extruder nozzle tip needs to be roughly .25 millimeters or less from the surface of the build plate for optimal results.  You will want to master this step of the process as bed leveling is required on a frequent basis.  Some users actually re-level their build plate before every print session.

 Printing directly on the build plate is not recommended.  Build plate coverings like blue painters tape, or sheets of  kapton polyimide plastic are required to protect the build plate; and it isn't always easy to get the extruded filament to properly adhere to the surface.  Bad adhesion causes warping and peeling on the edges of what you are trying to print, and a failed or imperfect print is the result. 

To attain the degree of adhesion required; some use a slurry of ABS filament dissolved in a jar of acetone.  Getting the proper amounts of each ingredient is crucial.  Too much ABS filament and it's next to impossible to remove a finished print...not enough, and your print begins skating around the build plate, attached to the moving extruder nozzle. 

When a space age company began using 3D printers they also faced these adhesion problems, and came up with what seems like a great time-saving solution.  They made their own sheets to cover the build plate, that don't require using ABS slurry.   Available from Buildtak.com the high tech polycarbonate sheets are easily installed, easily removed, and provide a nearly perfect surface for 3D printing.

While buildtak does streamline the process while solving the adhesion problem, we find that for optimal results one must be quite exacting and meticulous about the distance between the extruder nozzle and build plate.  If the nozzle is a fraction of a millimeter off, either the filament will not adhere to the build plate, or the finished print will be quite difficult to remove without aggressive measures.

Another after market item you'll need to get consistently excellent results is a filament filter.  Few off the shelf 3D printers actually come with this filter as standard equipment, but they should.  There is an online community of 3D printing people called thingiverse  which has many thousands of 3D print downloads available for free. Just do a search for prints for your specific printer and you'll find a suitable filament filter.  Once printed out, simply roll up some lubricated felt inside the filter and you're good to go. 

The reason the filter is so important is because it removes tiny dust particles, etc from your filament before entering the extruder nozzle.  Without a filament filter; dirt & dust get inside the print head, and you will know this because your printer will suddenly start "air printing" an inch or so above the print in progress, without extruding any filament.

Let's walk thru the process of making a 3D print, to give you an idea of what to expect.  First is file acquisition, whether you create it yourself or download from the web; you need a properly formatted file to print from, it's like a blueprint, and there are literally millions to choose from.  Most 3D printers are stand alone units which means they don't need to be connected to a computer to make a print, files are generally loaded on an SD card, or imported from your computer.

The really nice thing about robots is that once you press the start button you are pretty much a spectator.  You of course want to closely observe the beginning of the printing operation to ensure that you have good adhesion, and a good start.  After the first couple of layers are down you will want to periodically check for signs of warping or peeling at the edges of the print.  In the beginning this won't be much of an issue because your new 3D printer is the coolest tech on the block, and most folks spend lots of time just watching the robot create something out of nothing; it can be mesmerizing.

There is another benefit to watching your 3D printer instead of your TV; you gradually learn how it functions, and how the moving parts slowly knit your object into existence. Every now and then your printer may start doing something irregular during an otherwise normal print.  The most frequent cause is usually a bad file, with internal conflicts invisible to the user, until it tries to print the aberration.  So don't panic and think something is wrong with your printer.  

When you suspect you have a bad, or damaged file it can be fixed quite easily.  Go to a website named netfabb  where you can upload a cronky file, and they will fix it and whip it right back to you nice and fast.

When your print is finished, wait till the cycle has ended and the printer stopped.
On the build plate is your finished print.  Removing the still warm print can be a small adventure in itself depending on a whole range of factors.  When you buy a printer, you might as well also get some specific tools for removing stubborn prints, that way you'll have them at hand the first time you need them.  You'll want to acquire a couple of painting knives from a company called Liquitex;  really they are spatulas with very thin & strong blades made for the arts & crafts community, and they work very good!!  You will need one long bladed, and one short bladed.  Another indispensable print removal tool is the famous "Lil Chizler" which is a simple oval shaped plastic wedge.  To make this small tool work to its best potential you'll want to print out a small knob for a handle, then glue the knob to the center of the lil chizler.  Without this knob, you simply cannot use it to remove stubborn prints, it has to be able to slide underneath, then you just 'walk' it around the edges of the print. 

Once removed from the build plate some post production work may be called for if your print required the use of supports during construction.  Supports are automatically created whenever the printed object has overhanging aspects, or sharp angles.  These supports are designed to be removed easily and they usually do, but some care is needed along with the right tools to ensure that the print remains undamaged.  It can be discouraging to spend four to eight hours, or more on a nice print just to have it scratched or broken during post production.  Supports also tend to leave very small artifacts stuck to the print, like small grains of salt...which also need to be meticulously removed.

Your finished print is generally done at this point; unless of course you desire to add some finishing touches like paint, and/or some type of clear coat finish, such as XTD-3D or compatible product.  Such additional touches make a huge difference, especially on busts, and historic subjects...any print where authenticity is desired.  A cautionary note here about painting your 3D prints; use enamel paint, and not acrylics.  

Don't expect perfect prints right out of the box.  Most of today's consumer 3D printers will likely require some tweaking, tuning and calibrating before they're dialed in just right.  This can be quite frustrating for those who are less acquainted with the processes involved.

3D printing is capable of some astonishing detail.  Most printers (software) have three levels of resolution, low, medium or high definition of resolution.  By way of example, the print of the sphinx above was done on high resolution to bring out the best detail of an exceptionally good file.  To truly get the most from your printer's potential, at some point you'll probably want/need to invest in a digitizer, scanner (@$1200.) for making custom files by scanning the object, which essentially creates the blueprint the printer works from. 

 Adding a small internal fan to your 3D printer will help even more with definition of detail in the finished print, and at some point you will probably want to make that upgrade to your system. 

Periodic lubrication and upkeep every 40 to 50 hours of operation are necessary, and crucial to keep a 3D printer operating optimally.  Beyond that, you will gradually become used to the various sounds/noises your printer makes when in top shape.  When you notice significant changes to these sounds it usually means something needs attention.  After all, we're talking about many moving parts working in perfect unison in 200 degree temperatures for hours at a time.

When a friend and I got into the 3D printing business, we went with one of the industry leaders, Makerbot.  Our first machine was a Makerbot 2X experimental 3d printer with dual extruders and heated build plate.  It was designed with the tinkerer and maker in mind, kind of a sexy little hot rod; and has run more or less flawlessly ever since. 

A few months later we wanted a second machine, and bought the then brand new, just out Makerbot Fifth Generation printer which was touted as a turn key push button printer for the non-expert, less technically oriented user.  Thus began a long and agonizing nightmare with that infernal machine and Makerbot tech support.  To get an idea of what I speak just see the "Makernot" video below.  The Makerbot "Gen-5" is without a doubt the "Plan 9 from Outer Space" of 3D printers.*   The reason the Gen-5 is such a horrid abomination is simple; they began selling units before all the "bugs" were worked out of it; hoping to storm the market before the competition rolled theirs out.  The company was also going thru an upheaval & "housecleaning" where the people who developed the Gen-5 were no longer associated with the program.

 Although you can get some very nice completed prints from it on rare occasions, such is not the norm; far from it.  Worse yet, it has just a single extruder, no heated build plate and prints in PLA filament only.  After months of struggling to get help from Makerbot tech support with zero progress, I called to tell them I was returning the lemon and expected a full refund.  As I suspected, they really didn't want to give my money back to me, so they only squirmed a little when I said I'd accept a brand new 2X printer in a straight trade.  They even included a couple spools of filament.  The lesson here is before you spend thousands on something, go online and see what the reviews, and other users are saying about it!

 My daughter is the IT technician for a major corporation in Alaska.  She knows computers, but had not seen 3D printing actually working until she recently came to visit for a week.  As soon as she saw the setup I could see the gears turning in her mind...after a few minutes of checking things out she says to me:  "OH, the things I could do with one of these!"  I told her I'd leave her my 3D printer in the will, but I don't think she intends to wait that long for a used machine, I think she'll be buying one for herself.  That is why I tell folks that 3D printing is limited only by our imagination. 

When television was first available it was thought only the privileged rich would have one of their own, who else would have the time to sit and watch it?  Same thing with the computer, and ink jet printer; yet now they are practically in every home with electricity, and most of us consider them indispensable.  It's going to be the same way with 3D printing, just you wait and see.  The race is on to see who can produce the easiest, smallest and most affordable 3D printer for the consumer market and whoever gets there first may just be the Henry Ford of this generation.  So, I suggest starting to rearrange the home office to make room for a 3D printer because sooner or later, you are gonna want one.

© 2016 ~ full re-post with permission only 

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