Introduction: How to Use and Optimize a 3D Printer

About: I believe that the purpose of life is to learn how to do our best and not give in to the weaker way.

There are many ways of using a 3d printer. It can be optimized to print more than just trinkets and ornaments.

While some of the following applies specifically to a Makerbot Replicator 2, most of it will be of use with other filament printers.

Intro pic shows a few of the experiments I have done trying to design and print different forms.

Step 1: How It Works

I have been using a MakerBot Replicator 2 filament 3d printer for over a year. It has run over 500 hours and it is printing better than when I first got it. It took a fair amount of adjusting and tweaking to make that happen.

Fused Deposition Modeling (FDM) based 3D Printers use spools of thermoplastic filament. The heated plastic is melted enough to flow and then extruded as thin filaments. They are then precisely moved in patterns and built up layer by layer to make objects.

A fused filament 3d printer is a very delicately balanced machine. If the filament, temperature, leveled bed, speed of extrusion and speed of movement are not balanced together, within fairly narrow parameters, nothing but colored, stringy, plastic turds comes out.

Once these parameters have been tuned and balanced, the results are surprisingly consistent. This makes the 3d printer one of the first truly reliable and useful robots available to the average maker. It is like having a slow but reliable helper in the shop. While you are designing new parts, the robot can be making previously designed parts. And the parts can be almost anything. The main limits are the materials and your imagination.

Contrary to media scoffers and impatient cynics, much more than just trinkets can be created with the currently available low cost 3d printers.

Step 2: What Can Be 3d Printed?

There is a lot of complaining about the limitations of 3d printers. While it is true that the materials and 3d printers themselves are still at an early stage of development, much more than just prototypes and models can be made. Things more useful than googahs and froofoos can be produced.

Step 2 pic shows a 3d printed servo controlled valve for air or water. Details here:

Filament 3D printers can be used to make very useful things such as:

Printed With PLA, ABS, or Nylon

Rulers, compasses, angle finders, squares and other measuring and drawing devices.

Axles, bearings, pulleys, and gears.

Cabinet hinges, brackets, and latches.

Knobs and handles.

Jigs (pic 2) of all kinds:

Hinged boxes, puzzle boxes and electronic cases.

Trays and containers of all kinds.

Toys and puzzles of all kinds.

Measuring cups and spoons for dry materials. When sealed, they can be used for measuring non-food materials.

Prosthetic fingers, hands, and duck feet:

Knife blade and file handles.

Valves, pumps, and artificial muscles.

Casting molds: See here:

Tubes, pipes, and pipe fittings.

Prototypes of things to be sent out to be made of stainless steel, titanium, ceramic, or chocolate.

Funnels, combs, lens caps, hangers.

Birdhouses. See here:

Printed With Ninjaflex Or Other Flexible Filaments

Eyeglass frames, wallets, eyeglass cases, and goggles:

Hats, gloves, shoe inserts, and sandals.

Stencils for painting, lettering, or cutting.

Ink stamps.

Rings, bracelets, and watchbands.

Flashlights, lanterns and lamp shades.

Timing belts, small tires and tank treads.

Hoses and hose adapters.

Hose washers, gaskets, filters and O rings

Rubber feet, door bumpers and door stops.

Flexible printed circuit boards. See here:

And Many Things No One has thought Of Yet

Check out Thingiverse for many useful ideas and downloadable models:

Step 3: Supplies

Access to a 3D printer

Some PLA filament

A free 3d design program like 123D Design. Also helpful is a free program like Netfabb.

Digital Calipers available from:


Step 4: Level the Bed

To get precise prints the first layers have to be laid down very parallel to the printer bed at just the right thickness. Any blips or loose ends on the first layer can be transmitted all the way up the print. This requires the bed be precisely leveled.

There is a very small margin of error for printing precise 3D prints. To close and the extruder will clog, too far, and it will not stick well enough for a clean print.

Your bed has to be very flat and very, very level. Nothing else will do.

Level Your Printer

Your printer should be set on a solid level surface. If the surface is not level, you should shim the corners of your printer until the metal bars that your extruder rides on are level, front and back, left and right. While your print will be good enough if your printer is slightly out of level, very small prints, while hot, will tend to sag and lean if your printer is not very close to level.

Level The Bed
Level the bed according to the instructions that came with your printer.

Level The Bed Again

This process will make your bed parallel to the path of your extruder on the X and Y axis. If your printer is on a level surface, it will also make your bed level.
Print out Calibration.stl in the center of the bed in PLA. Then pull off the print and measure the ends. They should be within .002" of each other in thickness. Keep printing and adjusting the bed until you get an even thickness.

Step 5: Update Your Extruder

Check Your Extruder
To make precise prints or to print with flexible filaments, you need to have the latest spring loaded drive block for your printer. The drive block is what pushes the filament into the hot end which then melts and extrudes the plastic.

Flexible filaments like Ninjaflex are the trickiest to print out and will only work on printers that have the right drive block for the extruder. For an older Replicator 2 you must install Makerbots upgrade kit which includes a spring and a roller bearing. You must also download from Thingiverse the new drive block for the kit and print it out. The newer Replicators come with a spring loaded drive block.

If you have a different 3d printer, you should check out Thingiverse for drive blocks that use a spring and roller bearing that will fit your printer. There should be a very small gap (orange arrow) below the bearing and drive gear and the hole where it goes into the hot end of the extruder. Ninjaflex is like a wet noodle and an excessive gap here will allow it to flex and jam.

Step 6: Getting Filaments to Stick.

If you don't have a heated bed, then getting a printed object to stick well and not warp up can be a challenge.

Test The Bed
After you have leveled the bed, print out boxtest.stl to check how well it sticks. If it sticks too well and is hard to remove you can try lowering the bed slightly. If it is not sticking well, you can try raising the bed slightly. If it is still not sticking well or the edges of the box are warping up, try some of the methods below.

Use A Raft
Printing a raft under the object can make it stick better and reduce or eliminate warped corners.

Blue Painters Tape
If it is not sticking well, blue painters tape can help. Objects with a high tendency to warp will just pull up the tape on the corners. The tape can sometimes stick so well to the print that a solvent must be used to remove it.

Elmers Glue Stick
A thin film of Elmers Glue stick on blue tape or the bed itself can increase the stick of the first layer.

I have had mixed results with it, but hairspray like Aqua Net Extra Super Hold can also be used like Elmers Glue Stick.

Print Some Tabs
If you are printing long objects or ones that tend to warp up, you can add .03" thick tabs to the places that tend to pull up. They can later be cut off. See step 6 pic. You add the tabs in your original design software or a program like 123D Design.

When All Else Fails
Use blue painters tape, Elmers glue stick, a raft AND tabs.

When It Refuses To Stay Flat
If you can, print the object on its edge and you will just have one side that is curved.

Step 7: Avoiding and Fixing a Clogged Extruder

Avoid Clogs
Don't run at higher than recommended temperatures. Filaments often have softeners or other additives that can burn or boil off, leaving carbon or other hard residues that can clog the hot end extruder tube.

After printing, leave the extruder fan running until it turns off. The longer you heat a filament that is not moving, the more likely it is to overheat and leave carbon or hardened bits of material that will eventually clog the extruder.

If a particular type of filament (like woodfil) tends to clog your extruder, do not allow it to cool down after the print. Instead, as soon as possible, unload it and then load some PLA to clean out any residue of the troublesome filament.

Reload The Clogged Extruder

Sometimes softer materials like Ninjaflex will clog the extruder. Unload the Ninjaflex and then reload a stiffer filament like PLA. Often that will clear it up and clean it out.

Strip The Clog
I have not tried it, but some people have had success using Zip Strip Paint stripper. By running it through the extruder tube they say it will dissolve most clogged material.

Torch The Clog
As a final act of desperation, many have reported some success with disassembling the extruder and torching the extruder hot end to burn out any residues in the tube.

Step 8: Vent Your Printer

While most of the common filaments used to 3D print are not poisonous, there is evidence that it is a very good idea to vent the printer. Besides getting rid of the smell of plastic that can fill up a room, the hot fumes given off can contain nanoparticles of filament that will be inhaled. Your body will have to remove these particles and that can put an unnecessary load on your immune system.

Enclose Your Printer
To be able to suck away the fumes you will first have to enclose the sides and front of the printer. You can leave the top open as there should be enough suction to allow for the opening. Any kind of sheet plastic can be bolted or glued onto the sides. I used clear 1/16 sheet polyethylene and printed hinges for the door.

Vent The Printer
You could use a fancy carbon filter system that may or may not catch all the particles. Or, if it is your own room or shop space, you can simply run some pipe with a fan through a wall or window to the outside air.

I used four inch dryer vent and a 12 volt 3 inch muffin fan hot glued together. An incense stick can be used to check that across the top all the smoke will be sucked to the fan.

Step 9: Remount the Filament Spool

One of the problems with most printers is that the filament spools are attached to the back or the side of the printer. This can be very inconvenient when you need to change them or if they jam up while unspooling. In addition, the feed tube adds a fair amount of friction making the stepper motor in the extruder work harder. Eliminate the tube and the print will have more consistent width layers.

A much better way is to attach the spools directly above the printer where the tube friction is eliminated and you can quickly see and loosen any jams.

2 inch PVC pipe can be used to mount filament spools above the 3D printer. I used 2x4" boards attached to existing shelving and a couple of bolts to hold the pipe. If you go to Thingiverse you can find 3D printed versions of spool holders that attach to the printer.

Step 10: What Cannot Be 3D Printed?

Food Safe Containers
These cannot yet be made with a filament 3D printer. Unfortunately, most 3d printed objects are porous with microscopic holes everywhere the extruder changes direction. This leaves an ideal space for dirt and bacteria to settle into and makes them hard to clean well.

Some filaments are however, rated as food safe. So measuring spoons and other items can be made which make contact with dry foods can be made. One use, disposable items can also be made.

Super Strong Plastics
While the currently available plastics are strong enough to be very useful, most of them are porous and not as strong and resilient as cast, extruded, or injection molded industrial plastics. Carbon fiber filaments are in the works but not yet readily available.

Very Precise Mechanisms
While 3D prints are not at this point as precise as a well machined or cast part, they are precise enough to make very intricate mechanisms.

Filament 3d printers cannot at this point print in metal. You can send off your designs to be printed in brass, silver, stainless steel or even titanium. But it is very expensive for all but the smallest of objects.

Conductive Materials
Conductive ABS filament is available but it is barely conductive. It may be useful for anti-static boxes or high voltage uses, but it is not conductive enough to create normal circuit boards. many manufacturers are working on making conductive materials but no filaments so far are available that are conductive enough to be very useful.

Step 10 pic. You can however, print a circuit board and then add your own conductive materials:

Step 11: Tips and Tricks

Making Small Objects
Very small objects can be printed. See here for tips on printing small things:

Watch It Start
Spend the time to watch the extruder as it heats up and is about to start sliding across the print bed to begin the print. Do not allow any blobs or dribbled filament to be dragged across to the print starting area. A clean start will result in clean prints.

Pry It Off
a 1/4 inch woodworking chisel works well to pry off stubborn prints from the print bed. Round the sharp corners to reduce scratches to the bed. This will scratch an acrylic bed, but it does not seem to effect the quality of the prints.

Combining STL models
You can use a program like 123D Design to combine .stl models that you have created or downloaded. You can fuse them together or subtract one from the other. This also allows you to hollow out, cut, or put holes in existing models.

Breakaway Parts
Depending on your print settings, a gap of about .01" will generally give you enough clearance for walls to not stick together. A vertical gap of about .007" will fuse together yet break apart later for easy take apart. This is handy for making molds that need to be taken apart rather than reused.

Using Supports
I generally avoid the use of supports unless they are absolutely necessary. They tend to be time consuming to cut off and usually leave blemishes on the surface of the print. If you print vertical walls or walls that are at a 45 degree or higher angle to the bed, supports are not necessary. The printer can jump horizontal gaps between two walls of up to .3 inches without too much sagging.

Step 12: The Best Filaments and Suppliers

PLA-Polylactic acid is made from renewable resources such as tapioca, sugarcane or corn starch. While it is biodegradable, it is surprisingly robust. It does not dissolve in water and most common solvents will not dissolve it. Pic 2 is a test sample I nailed to the south side of my shop. It has been in the rain, snow and sun for over a year and it did not become brittle or show the UV degradation common to most plastics.

Cheap Filaments
The best filaments like those from Makerbot tend to produce the most trouble free and accurate prints. They do however, tend to be overpriced. Less expensive filaments can produce just as strong and precise a print.

The cheapest filaments will often print just fine. Sometimes the prints will be less precise because the filament is not very uniform in thickness or consistency. I use the cheapest filaments only for a first model test and then print the final object in a medium to high priced filament.

Keep in mind that using other than the manufacturers recommended filaments can void the warranty on your printer.

Here are the most reliable suppliers with reasonable prices I have used so far:

A great selection of all kinds of filaments at a reasonable price with fast shipping. Good source for Ninjaflex.

A good selection of medium priced filaments:


Step 13: Specialty Filaments

This is one of the coolest materials you can print with. It is very flexible and somewhat stretchy. It is very cut resistant and has a Shore hardness close to that of an auto tire. It also has good shape memory, meaning that it can be bent repeatedly and will return to its original shape. It prints as precisely as PLA.

Step 13 pic shows a one piece flexible hinge that was printed flat in Ninjaflex.

This is a flexible material that is somewhere between PLA an Ninjaflex. It is fairly flexible but not stretchy with good shape memory.

Good strength and flex. Will not stick without a hot bed.

There are several filaments that contain a fair amount of wood particles. They can print objects that can be sanded, stained and worked somewhat like wood. They can be tricky to use as they tend to clog up the extruder.

Bronzfil is a filament that has 80 per cent metal particles in it. This allows the printed object to be sanded or buffed to get a bronze metallic look.

Some people have had luck using metal flakes and woodworking glue to paint an object and create the same effect.

Step 14: Limits of Imagination

New Tools New Possibilities.
3D printers make new forms and patterns possible that were unimaginable in the past. Things can be printed that are almost impossible to cast or mill. Step 14 pic is called a gyroid. This is a mathematical form that turns out to be amazingly similar to the microscopic surface of butterfly wings that makes them iridescent. You can buy a model of this at Shapeways:

Succeeding By Failing
To create new things we have to get past our assumptions. Not so easy. We automatically assume things that are just not true. We might assume that a certain glue will not stick to a certain plastic because it does not stick well to plastics. When we bother to try it, we find out that it does stick well. We can come up with all kinds of ideas about why something won't work and then we try it and it does.

A theory may or may not fit the real world but in the end there is no substitute for experiments that can reveal what actually works. In trying things, we may not succeed in our original goal. But, if we are paying attention, we may learn new things that lead to useful possibilities.

Limits Of Imagination
It turns out that one of the chief limitations in the way 3D printers are being used is our limited ideas. Sometimes our tunnel vision looks more like a box. We are conditioned to think in terms of what we have seen and what we have made. We tend to think in terms of the tools we have previously used. Breaking out of our mental ruts is the challenge.

With new tools like 3d printers, there are endless forms unseen and mechanisms unimagined that await release.

Step 15: Other Possibilities

Just Wait And You Will Be Surprised
3D printers are still at a very early stage of development. They are similar to 2d printers when they first came out as dot matrix printers. They will get faster, more precise, and less expensive. It took about ten years for 2d printers to go from dot matrix to photographic quality. It will probably take a similar amount of time for affordable 3D printers to improve a similar amount.

4D Printing
One of the latest interesting ideas is making objects that self-assemble after they are printed. While some things like hinges and other movable parts can be printed as one piece fully assembled, 4D printing attempts to create things that change shape or assemble, after they are printed, when heated or acted upon by other types of energy.

See here:

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