Increasing the Reliability of Your 3D Printer

3D printers are fun when they work but a royal pain in the rear when they don’t. Heated nozzles jam, stepper motors skip a step, a layer delaminates, threaded rods can bind, the part unsticks from the printer bed, the belt tensioner breaks….the list goes on. This gets particularly frustrating when the print gets interrupted in the middle of a multi-hour print or when you just need it to work. So, what should you do about fixing these issues?

1) Buy quality printer filament and store it correctly.

It is unbelievably easy to compare a cheap roll of Ebay filament to a more premium one, simply assume they are the same, and buy the cheaper one. In a good chunk of cases, you will likely be just fine with the Ebay one, but you run the risk of getting inconsistent plastic. This can range from variations of diameter, to oil and grit, to just poor quality plastic. It is often worth the extra $5 or $10 it costs to get a kilogram of a reputable brand and pay shipping. I would highly suggest Gizmodorks’ ABS filament or Hatchbox’ PLA filament.

To store filament right, you’ll want to put it in an airtight container when you aren’t using it, preferably with a dehumidifying packet of silica gel. This could be anything from a large ziplock bag to a tupperware container to a trashbag in a box. Storing your filament also has the benefit of keeping dust off which could accumulate in your nozzle and cause clogging  later on.

2) Invest in a good hotend (the part that melts the filament).

This is incredibly important. I have been in the hobby since the early days and have played with every manor of hotend. A bad setup will jam constantly, burn plastic, and give you all kinds of fuss that you really, really don’t want while a nice one will keep you mostly jam free 99% of the time. Important features to look for are cooling fins which keep the plastic from melting where it shouldn’t, a nozzle that can be unscrewed for cleaning, and a smooth bore through the unit. I have to say, the E3D line of hotends is my favorite. I’ve been rocking the low-price E3D Lite6 for months now and haven’t had a single jam. It is bliss.

3) LUBE!

3D printers are mechanical machines with moving parts. In order for your printer to work well, as with any machine, it requires lubrication. Avoid goopy and oily lubrications such as WD-40, lithium grease, ect. They will accumulate dust and particulates that will gum up your machine. Instead, look for a can of dry PTFE lubricating spray. A light spray on bearings, Z-axis rods, and travel tracks (be it smoothed rod or aluminum) will eliminate most binding problems. If you do this and still get binding problems, see the next section.

4) Get a better z-axis rod.

The majority of 3D printers use a long piece of threaded rod and a nut or two for the z-axis movement. It works and is used by the majority of kit-based printers worldwide. But, you have to keep in mind that threaded rod is meant to be used in construction where it holds things together. I.e., it isn’t designed to move. As such, the manufacturing tolerances on are fairly lax which means burrs, rough spots, bends, and general nastiness for 3D printing. Note that not all threaded rods are bad. If you decide to use one, look for a hardened or stainless steel rod and check it carefully for burrs and bends.

A better upgrade is an ACME screw with an anti-backlash nut. These are actually designed for linear motion which is what we want. They can be a little pricey, but again, we are looking for quality here and not thrift.

5) Get a machined aluminum bed.

When we are first starting out a print, the main thing we are looking for is flatness. If you are using a wood, PCB, or plastic bed, you WILL NOT have a flat surface. This might be from either humidity warping (wood), from heat warping, or simply from the geometries of the bed. A machined aluminum bed will not absorb moisture, will expand uniformly while it heats, and is machined specifically to be flat. You can get these for relatively cheap online. If you can’t find one for your machine, you can always look for a makerspace or a friendly person online to help you cut one out.

Some folks like to use glass. Glass does work and is very flat. My issues with glass is that you will break it at some point. It could be from thermal shock cracking the glass (it likes to be one consistent temp, any hot spots will crack it) or physical shock (from the nozzle pushing down too hard to a sharp contact point when prying prints off). If you do decide to use glass, avoid cheap pane glass like the plague and find a nice piece of borosilicate glass. Borosilicate glass (sometimes called “Pyrex” after the brand) is specifically designed not to crack due to thermal shock.

6) Get a bed heater.

All plastics expand and contract as they heat up and cool down during the 3D printing process. Some of these plastics, such as ABS, will expand and contract more than others. This causes warping in your prints which can sometimes end a 3D print when it peels off the bed. By using a heated bed, you create a warm atmosphere around your printed part while it prints and keeps some of the temperature-related warping to a minimum.

There is some controversy about what kind of heated bed is best. Some folks love the peel-and-stick AC heaters and some love the 12V/24V PCB heaters. Honestly, it doesn’t matter all that much. We are trying to get the bed to around 100C, not boil lava.

You can take this one step further and encase your 3D printer entirely to make a large heated chamber. This is ideal, but it can increase the footprint of your printer significantly for some models. If you want to play around with a heated build chamber but don’t want to break the bank or spend a lot of time, pick up some turkey bags (used to keep turkeys moist while roasting) and fit it over your printer to keep the hot air in and drafts out.

7) Play around with bed surfaces

The bed surface, or printing surface, is what the first layer of your print will stick to. The community first started with glass and plexiglass, moved to kapon tape, then to blue tape, PET, then to glue sticks and now we are at the point where there seems to be a new bed surface every week. Which one do you pick?

Well, it depends on the material you are using and how much work you want to put into replacing it. I’ve tried all of the above and have had varying results. What I’ve experimented and personally love is 3M 8905 Polyester tape. It is thick, inexpensive, designed for high temps, and my prints stick to it like a dream. After my heated bed cools, the prints pop right off with zero prying. I love it.

Second best is blue painters’ tape with a very thin layer of an ABS-acetone slurry. This is a good bed combination which everything sticks to, but it tends to peel off the bed when print warp and its texture causes it to permanently adhere to your print (meaning you have to scrape or sand it off later).

I recommend you try a few and find the pros and cons of each and see what you are willing to deal with. Some are easier than other for various reasons.

8) Take the time to calibrate your printer.

If you machine is out of square, your extruder multiplier is wrong, your heat settings are off, or really anything adjustable is off, you are going to get bad results. Take the time to square your machine to the bed (be it mechanically by tweaking screws and bolts or through software with a bed-leveling/tramming routine). This will prevent your printer from jamming on the first layer. If your extruder multiplier settings are off, you can get jams from too much plastic trying to be forced out or cracks in your print from too little. If your printer is not getting hot enough, you will get jams and/or poor layer adhesion. Too hot, and your plastic will bubble, your print will droop, and warping in imminent.

9) Use a good slicer.

Personally, I love Slic3r. It is easy to use and has an active group of people constantly improving it. Another favorite is Cura (with variations done by a few different companies). There are many, many others and they vary in features. Whatever you pick, check for updates from time to time and don’t be stingy about trying new ones. They all have various strengths and weaknesses which is an article for another day.

10) Keep it clean and taught.

Buy a bottle of acetone to degrease your print surface before every print. Even the smallest amount of oil from your hands can ruin a print. It sucks, but it’s true. Keep your extruder gears clean with a toothbrush to prevent slipping. Wipe off dust and dirt off of any sliding surfaces to prevent scratches and wear. Keep all belts taught with belt tensioners and idlers. Pick up any scraps of old prints to keep them from getting caught. This all seems like obvious bits and bobs to worry about, but it often gets forgotten about and your prints and machine will suffer if you do.

By | 2017-05-16T13:37:49+00:00 August 4th, 2016|3D Printing, How To's|0 Comments

About the Author:

I'm an electrical and controls engineer with experience in C++, C#, Sequencer Programming (ie "Game Loop), a little bit of graphic design, 3D modeling, and bits and bobs of a lot of game design.

Leave A Comment