Caribou MK3 Rel. 3 User manual

Caribou MK3 Rel. 3
Assembly Manual Version 1.20
11.09.2020

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DISCLAIMER OF LIABILITY: Caribou3d Research & Development specifically DISCLAIMS LIABILITY FOR
INCIDENTAL OR CONSEQUENTIAL DAMAGES and assumes no responsibility or liability for any loss or damage
suffered by any person as a result of the use or misuse of any of the provided information or product. Caribou
Research & Development assumes or undertakes NO LIABILITY for any loss or damage suffered as a result of
the use, misuse or reliance on the information and or product.
USE AT YOUR OWN RISK: Never leave your printer unattended!
© 2020 Caribou3d Research & Development
Authors: Wolfgang Schadow, Ryuichi Shevlin, Henry Schadow, Timon Bald
Photography: Henry Schadow, Wolfgang Schadow, Ryuichi Shevlin (Rel. 2)
Bondtech (Photos in Mosquito sub-section)

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1DISCLAIMER:
This is a kit of components for assembly into a 3D Printer by the end user. Building and using the printer is
potentially very dangerous as it involves electricity and high temperatures.
Building the printer will require physical dexterity and a good understanding of what you are doing. We have
provided fully comprehensive build documentation to enable you to build your Caribou 3d Printer Kit in a safe
manner.
Ultimately, we cannot be responsible for your health and safety while building or operating the printer. With that
in mind be sure you are confident with what you are doing prior to buying or building a 3d printer.
Building and operating involves electricity, so all necessary precautions should be taken and adhered to, the
printer runs on 110V-220V, supplied by a certified power supply.
High temperatures are involved with 3D Printing, the extruder nozzle runs at 190-285°C. The heated bed runs
at up to 110°C and the molten plastic extruded will initially be up to 280°C. Special attention and care should
be taken when handling these parts of the printer during operation.

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Contents
1Disclaimer: .......................................................................................................................................................... 3
2Thanks................................................................................................................................................................. 7
2.1 Sources ....................................................................................................................................................... 7
3General Notice.................................................................................................................................................... 9
4List of tools........................................................................................................................................................10
5Assembly Instructions ......................................................................................................................................11
5.1 xy-Frame....................................................................................................................................................11
5.1.1 Base frame Assembly.......................................................................................................................11
5.1.2 L-Bracket and Feet Installation........................................................................................................20
5.2 y-Axis Assembly.........................................................................................................................................22
5.2.1 y-Rod Installation..............................................................................................................................22
5.2.2 Installation of the Heatbed Carriage ...............................................................................................25
5.2.3 y-Motor Assembly..............................................................................................................................30
5.2.4 xy-Idler (Tensioner) Assembly ..........................................................................................................31
5.2.5 y-Idler and y-Belt Installation............................................................................................................32
5.3 z-Axis Assembly.........................................................................................................................................38
5.4 z-Motors and rods Installation.................................................................................................................43
5.5 x-Axis Assembly.........................................................................................................................................48
5.5.1 x-MotorHolder Assembly ..................................................................................................................49
5.5.2 x-Idler Assembly ................................................................................................................................51
5.5.3 Assembling and Installing the x-Axis ...............................................................................................52
5.6 z-Top Axis Assembly..................................................................................................................................55
5.6.1 Mounting x-Top-extrusion.................................................................................................................56
5.7 Heat Bed Installation................................................................................................................................62
5.8 Einsy Box Assembly ..................................................................................................................................69
5.9 PSU Assembly ...........................................................................................................................................73
5.9.1 Preparation of Meanwell RSP-320..................................................................................................73
5.9.2 Preparation of the 250W PSU .........................................................................................................78
5.9.3 Installation of the PSU......................................................................................................................82
6Extruder Assembly............................................................................................................................................87
6.1 Stock Extruder ..........................................................................................................................................87
6.2 Bondtech Extruder....................................................................................................................................87
6.2.1 Mosquito Hotend ..............................................................................................................................87
6.2.2 E3D Hotend Assembly......................................................................................................................90

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6.2.3 Bondtech Extruder Preparation .......................................................................................................95
6.2.4 Installing the Fans and the PINDA probe..................................................................................... 103
6.2.5 Installation of the Filament Sensor .............................................................................................. 105
6.2.6 Installing the x-Carriage................................................................................................................. 107
6.3 Extruder Installation .............................................................................................................................. 109
6.3.1 Stock Extruder ............................................................................................................................... 109
6.3.1 Bondtech Extruder......................................................................................................................... 109
6.4 x-Belt installation................................................................................................................................... 116
6.5 LCD Assembly ........................................................................................................................................ 121
7Cable routing.................................................................................................................................................. 124
7.1 x-Axis....................................................................................................................................................... 124
7.2 Extruder Cables ..................................................................................................................................... 127
7.3 LCD cable ............................................................................................................................................... 133
8Steelsheet and Heatbed Instructions .......................................................................................................... 138
8.1.1 Preparing the Steelsheet .............................................................................................................. 138
8.1.2 Important! Heatbed Instructions .................................................................................................. 142
9Setup and Calibration ................................................................................................................................... 143
9.1 Flashing Firmware ................................................................................................................................. 144
9.2 Self Test ................................................................................................................................................. 148
9.3 PINDA Adjustment ................................................................................................................................. 151
9.4 Nozzle and Hotend Preparation............................................................................................................ 153
9.5 xyz-Calibration........................................................................................................................................ 157
9.6 Checking the Filament Sensor.............................................................................................................. 159
9.7 Loading Filament................................................................................................................................... 161
9.8 First Layer Calibration ........................................................................................................................... 165
9.9 Final Step: closing the Einsy box .......................................................................................................... 169
APPENDIX
AOverview of Plastic Parts............................................................................................................................... 172
A.1 Frame ..................................................................................................................................................... 172
A.1.1 Einsy ............................................................................................................................................... 172
A.1.2 Frame Components....................................................................................................................... 173
A.1.3 LCD ................................................................................................................................................. 173
A.1.4 PSU (Meanwell, Prusa).................................................................................................................. 174
A.1.5 Spoolholder.................................................................................................................................... 176

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A.2 Tools ....................................................................................................................................................... 177
A.3 x-Axis....................................................................................................................................................... 178
A.1.6 Bondtech specific parts for x-Axis................................................................................................. 179
A.1.7 Default Extruder specific parts for x-Axis ..................................................................................... 180
A.4 y-Axis....................................................................................................................................................... 181
A.5 z-Axis....................................................................................................................................................... 183
A.6 Extruder.................................................................................................................................................. 184
A.1.8 Bondtech Extruder......................................................................................................................... 184
A.1.9 Default Extruder............................................................................................................................. 186
BLength of Nylon filament and Techflex Tubes ............................................................................................. 188
CEINSY Rambo Conectors............................................................................................................................... 189

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2THANKS
There are many people who have contributed on one form or another to the project. We like to
thank everybody who inspired or supported us. Many ideas were discussed in the facebook
groups:
•Caribou Group: https://www.facebook.com/groups/caribou3d
•Caribou Deutsche Gruppe: https://www.facebook.com/groups/caribou3dde
Very special thanks to 3d-Gussner and Bernd Brinkert for their huge support and effort in
providing and testing Caribou firmware.
Thank you, Rebecca and Jason, from LDO Motors and Martin from Bondtech for the quality
manufacturing and relationship.
Thanks to our other supplier: E3d, Microswiss, Slice Engineering, Misumi for delivering high
quality products to us.
2.1 SOURCES
We give references that have influenced the design. Since the majority of plastic parts (even if
much improved and somehow "new and different") have their roots in the initial design by
Prusa Research we like to mention this a first and most influential reference.
•Prusa : http://www.prusa3d.com
Frame
•Prusa i3 MK2-X by davtr https://www.thingiverse.com/thing:1692666
•Haribo Project https://github.com/PrusaMK2Users/3030_Haribo_Edition
y-rodholder:
•they have been inspired by the design of Piotr
Karkovski https://www.thingiverse.com/thing:2830591

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y-bearing holder
•the clamp mechanism is similar to one used on the x-axis. We like to mention that the first clamp
design with insert for the carriage for the bearings holders was done by Vecko
Kojchevski https://www.thingiverse.com/thing:2930007
x-MotorHolder and X-Idler
•inspired by initial clamp design of Arnaud
Rousseau https://www.thingiverse.com/thing:2964026 hole design seen on some screen shoot of
a bear part Bear x-axis can be found here https://www.thingiverse.com/thing:3716110
x-carriage
•earlier carriage design and references therein https://www.thingiverse.com/thing:2770327
z-Top Holder
•hole design seen on some screen shoot of a bear part Bear x-axis can be found
here https://www.thingiverse.com/thing:3716110
z-Motor Holder
•The new motor holder was designed independently but we would like to point out that a
similar design exists by Vecko Kojchevski https://www.thingiverse.com/thing:2974255
Meanwell PSU-holder
•Tobias Reischl https://www.thingiverse.com/thing:3373172
Extruder of Rel. 2 that still can be used instead of the Bondtech extruder
•MK3 Extruder and X Carriage: Vecko Kojchevski https://www.thingiverse.com/thing:2843264
STL for PrusaSlicer as background
•thanks to Patrick Vosshans
Earlier Releases were partly designed by or influenced by:
•Stefan Weber: y-belt tensioner: https://www.thingiverse.com/thing:2666661
•Jon Madden: Prusa MK2/S X-Carriage Adjustable Tensioner
by: https://www.thingiverse.com/thing:2770019
•Vecko Kojchevski: https://www.thingiverse.com/vekoj/designs
•Murathan Araz https://www.thingiverse.com/murathanaraz/designs
•Ocie Ward

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3GENERAL NOTICE
Before you proceed with any of the construction steps, please do the following:
1. Make sure that the required parts (which are listed at the beginning of each chapter) are all
present, correct and not damaged. If that isn't the case, please contact our support
([email protected]m) and we will provide you with a replacement as quickly as possible.
2. Though we remove it for you, check all plastic parts for support material just to be sure.
3. Make sure to have access to all the listed tools. Do not attempt to build without these as the use
of incorrect tools may lead to breakage of parts or a faulty construction. If a tool that we use is
optional, it will be noted at the corresponding step.
4. Orient all self-securing nuts with the thicker end towards the screw.

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4LIST OF TOOLS
Necessary:
-ball-headed hex keys in sizes 2.5mm, 5mm, 6mm
-hex keys in sizes 1.5mm, 2mm
-ratchet with 5mm and 6mm hex bits
-pliers
-calipers (at least 162mm width)
-wrenches in sizes 7mm, 16mm
-phillips (PH1) and slotted (about 4-6mm wide) screwdriver
-scalpel or cutter knife
-scissors
-permanent marker (thin)
-lighter
-right angle ruler
-IPA (Iso-Propyl-Alcohol) 0.2l
-paper towel
-flat surface
Additionally recommended:
-smooth tongue-and-groove pliers
-cutting pliers
-rubber hammer
-5.5mm nut driver
-common sense
-latex gloves

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5ASSEMBLY INSTRUCTIONS
5.1 XY-FRAME
5.1.1 BASE FRAME ASSEMBLY
①L-bracket (4x)
⑥T-Nut (32x)
②Misumi rubber feet (4x)
⑦Extrusion cover (4x)
③M8 x 40mm hex socket screw (4x)
⑧Corner Brackets (4x)
④M6 x 12mm hex socket screw (8x)
⑨x-Axis Extrusion (2x)
⑤M6 x 20mm hex socket screw (4x)
⑩y-Axis Extrusions (2x)
Important: Make sure that the surface that you are working on is perfectly
flat. By using an uneven work surface, you risk building a skewed frame,
which may lead to the printer not being able to be calibrated.
①
②
③
④
⑤
⑥
⑦
⑧
⑨
⑩

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Prepare four
corner brackets in the
following way:
Insert a M6 x 12mm screw to one of the
holes of the bracket.
Screw a T-nut on the M6 x 12mm screw.
Leave it loose.
Top and side view of the bracket.
Do the same for the second hole of the
bracket.
Lay out the extrusions so that the x-
extrusions are (when viewed from above)
horizontal and the y-extrusions vertical.
The X- extrusions should be oriented with
the larger holes towards the outside.
The y-extrusions should
have the larger
side of the hole facing downwards!
Insert two T-nuts into the top facing slot of
the Y-extrusion on both sides.
Insert a corner bracket into both y-
extrusions.
Slot in the front x-extrusion into the two
corner brackets.
You don’t have to fasten the screws at this
point.

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Repeat the last two steps on the back of
the frame.
IMPORTANT: slide in 2x T-nuts in the front
slot of the front extrusions. They will be
used to attach the LCD.
Insert the M8 x 40mm screws
into the
front x-axis.
Tighten the M8 x 40mm screws slightly.

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Now use a right-angle ruler e.g. DIN 875/1
to press the extrusions flat on your build
plate while tightening the
M8 x 40mm
screw.
DON’T tighten too much!
Do the same on the left side.
Repeat the last two steps on the back of
the frame.
Now when the for M8 x 40mm screws are
fastened the frame should lay flat on the
build plate.
After this, the frame should be perfectly
flat and not rock on a flat surface, like a
badly made chair might do.
Now fasten the M6 x 12mm screws of the
corner brackets on y-extrusions.
Don’t fasten the screws on the x-
extrusions.

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Now loosen the 4x M8x40mm screws by
about 2-3mm. Each corner bracket should
now sit flush with the end of the
corresponding Y-extrusion.
Prepare the extrusion covers.
The middle part is too long to fit on the
end of the extrusions due to clearance
issues with the M8x40mm screws. Trim
the middle part of the extrusion end caps
at about the halfway point.
Be careful not to cut them too short, as
they may lose their ability to hold onto the
end of the extrusion. We recommend
using cutting pliers. Trim all four end caps.
After trimming, they should look like this.

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Now install the caps onto the ends of the
two X-extrusions.
The thickness of the cap is 2.8mm, which
we will use to align the x-extrusions and
the corner brackets.
After pushing the caps, the corners of the
frame should look like this.
Reminder: Note that at this point the
M8x40mm screws are loose.
Top view of a corner.

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Using a right-angle ruler to make sure that
the two extrusions in one corner are
aligned and that the extrusions are at a
90°angle in relation to each other.
Now place the angle on the profiles.
.
Now tighten the loose M6x12mm screw in
the corner bracket, fastening the bracket
to the x-extrusion. After repeating this for
the other 3 corners, check thoroughly that
the marked surfaces are indeed correctly
aligned.
While holding the frame in place steadily,
fully tighten the eight M6 x 12mm screws
of the corner bracket with a ratchet.
It is incredibly important that the frame
doesn't twist while tightening the screws.

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The following two steps are OPTIONAL: if you own calipers that are 300m long.
Measure the distance between the two Y-
extrusions at the front. This should be
somewhere around 299.40 – 300.00mm.
Now measure the rear part of the frame.
The difference in length in comparison to
the front should not exceed 0.1mm. The
smaller the difference, the straighter the
frame. Write down both measurements
when you are done.

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Tighten the four M8 x 40mm.
Don’t overtighten them. This may bend
the frame.
Remover one of the end caps on the front
and on the back of the frame
Insert 6x T-nuts in upper slot of the front
extrusion.
Insert 8x -T-nuts in the upper slot of the
rear extrusion.
Now the top of your frame should look like
this.
Insert the two end caps back to the frame