54 SERVO 10.2013
do see videos, are they all from the manufacturer or from
actual printer purchasers? If you see a lot of videos from
several different users and they are mostly positive, then
that's a big plus. If you see more than a couple of bad
reviews, then that's a very bad sign. If you see a mixture of
both good and bad reviews, it may indicate that the
manufacturer has poor quality control.
Here is the big one to watch out for: It is possible to
print specially designed objects that don't require retraction.
Things like tank treads and stretch bracelets will print
almost perfect on even the worst printer. This is because
the printer does not have to do anything more than extrude
a single thin line of plastic over and over as it prints each
layer. Remember, proper retraction is what really separates
a crappy 3D printer from a good one. Almost all objects
require the use of retraction to get a quality print.
3. Look for metal frame printers only.
Look for a printer that has a steel or aluminum frame.
This can be covered in wood in plastic, but the portion that
supports the linear components should be metal. Stay away
from wood, plastic, or melamine based printers. They lack
the rigidity to give you consistent and accurate prints.
4. Look at the linear motion components.
The linear motion components should all use bearings.
If using steel rods and linear bearings, the rods should be
larger than 8 mm for printers with spans greater than six
inches. Actual linear rails are better than rods and bearings.
Linear rails will add additional cost to the 3D printer but will
make the printer more rigid and accurate. Watch out for
printers that use plastic or wood on the X, Y, or Z carriages.
Look for G2 belts for driving the X and Y axis, and look
for tensioners on those belts. Stay away from ball screws or
ACME screws on the X and Y axis. They are too slow and
problematic when used with 3D printers. Finally, look for an
ACME or ball screw on the Z axis, and watch out for the
standard threaded rod used on some cheap printers.
5. Study the manufacturer's website.
Go through every inch of the manufacturer's website,
in fact. The site should have technical information about the
printer you are researching, and there should be lots of
pictures of the printer in action with links to videos. Look
for a setup and configuration page. A link to an FAQ page
or forums is a real plus. The support page should not just
point you to forums. Contact information should be
available for support via phone or email.
Look for replacement parts listed on the website.
If they don't sell them, how will you fix your printer? Most
— if not all — manufacturers don't offer warranties on their
6. Take a close look at the extruder.
Look for a direct drive extruder. You want a printer
that's as simple as possible. The direct drive extruder should
have some sort of adjustable spring-loaded bearing that
puts pressure on the filament. Look for an extruder that has
easy access to the drive gear so you can clean it from time
to time. Stay away from printers with Bowden cables. If you
can't find any information on the extruder, then contact the
manufacturer via email. If they don't answer, look for a
The printer should have two fans mounted on the
extruder: one is for cooling the filament just above the hot
end and the other is for cooling the extruded filament.
7. Only purchase a printer that has a
You want a printer that comes with a heated bed or —
at the very least — a heated bed option. The bed should be
capable of reaching temperatures of at least 100°C. Some
manufacturers sell their printers as PLA printers so they
don't have to offer heated beds, resulting in a simpler or
cheaper design. The thing is, a heated bed gives you more
options for how you print PLA. PLA will stick to glass when
it's heated to about 70°C, and it will pop off when the
Heated beds require bigger power supplies. The larger
the print bed, the larger the power supply.
8. Take a close look at the controller.
A good controller will allow you to upgrade or
reconfigure your printer. You will be able to add things
like extra cooling fans and heated beds. Some controllers —
like the Rambo — allow you to add a second extruder. Some
closed-source printers have proprietary controllers which
means they are what they are, and you can't make changes
or add upgrades later.
To add a second extruder, you need the following:
• Five stepper drivers
• Three thermistor circuits
• Three MOSFET controls minimum (ramps), or five
(Rambo) if you want to control the speed of the
Currently, the Rambo controller board is the cream-of-the-crop 3D printer controller board.
9. Look into the upgrade options.
Check out what options the manufacturer offers.
Normally, upgrades offered by the manufacturer will be
more refined than upgrades you do yourself.
Ones to look for are:
• Fan upgrades
• Heated bed upgrades
• Dual extruder upgrades
• Power supply upgrades
• Covers or enclosure upgrades
• Software upgrades