Bulk Man 3D OX CNC User manual

OX CNC
Mechanical Assembly Instructions
Bulk Man 3D
v1.2 2019

OX CNC Assembly Instructions 1 v1.1
© Bulk Man 3D 2019
Contents
About The Ox CNC Kit .............................................................................................................................2
Unpack and Check All Components........................................................................................................2
Tools Required ........................................................................................................................................2
Pre-Assembly Notes................................................................................................................................2
Wheel Assembly......................................................................................................................................3
Y-Axis Plate Assembly .............................................................................................................................4
X-Axis Gantry Assembly –Front Plate.....................................................................................................7
X-Axis Gantry Assembly –Back Plate....................................................................................................10
X-Axis Front and Back Plate Assembly..................................................................................................11
Z-Axis Assembly.....................................................................................................................................14
X-Axis Gantry Assembly ........................................................................................................................19
Ox Base Assembly .................................................................................................................................23
GT3 Timing Belt and Pulley Assembly...................................................................................................26
Finished.................................................................................................................................................30
Post Assembly Notes:............................................................................................................................31
Credits...................................................................................................................................................31

OX CNC Assembly Instructions 2 v1.1
© Bulk Man 3D 2019
About The Ox CNC Kit
The mechanical kit is based on the Open Builds Ox CNC Router designed by Mark Carew and
published on openbuilds.com. There are however a couple of difference between Mark’s design and
this Ox Kit. None of the differences are that great and the Openbuilds YouTube videos available on
putting the Ox together are a great resource and starting point for everyone. Most of the differences
are a result of customer feedback and modifications published on a wide number of internet forums.
Please note that while we have spent a considerable amount of time and effort putting these
instructions together, any errors and omissions excepted (E&OE). If you find an error, please let us
know so we can continually improve this resource.
Unpack and Check All Components
Before starting any build, it is always a great idea to get organised. Start by unpacking your kit and
checking it against the BOM (Bill of Materials) in Appendix 1. If you find any parts missing, please
contact us as soon as possible.
Tools Required
You will also need the following tools:
•3mm Allen Key
•8mm Spanner
•10mm Spanner
•Screw Drivers
•M5 Tap
•Hack Saw (or other means to cut V-Slot)
•Builder‘s Square
Pre-Assembly Notes
1. While these instructions have drawings for the Large Ox, construction of the Small Ox is, in
principle, the same.
2. It is Important to make sure all angles are square. As you progress through your build, use
the Square to make sure everything is aligned before the final tightening of all screws and
nuts.
3. This build requires some of the V-Slot to be tapped with a M5 tap. In general tap to a depth
of 8-10mm. and clean away any swarf and burs.

OX CNC Assembly Instructions 3 v1.1
© Bulk Man 3D 2019
4. When placing any V-Wheels onto the V-Slot, make sure the Eccentric Spacers are adjusted to
their furthest point. Do not force the wheels on as this may damage them creating a little
‘bump’.
5. The Sketchup model is available for download from our website. It is a fantastic resource
and can allow you to move through the design, pull things apart, and measure wherever
required. We strongly recommend downloading the model and becoming familiar with
Sketchup.
Wheel Assembly
Assemble all the Solid V Wheels as per the drawing. It can help to use one of the longer screws to
align everything by threading the parts on one by one.

OX CNC Assembly Instructions 4 v1.1
© Bulk Man 3D 2019
Y-Axis Plate Assembly
The NEMA23 stepper motor is attach as shown. Make sure the 3mm spacers are between the Gantry
Plate and the Stepper. Don’t tighten too much just yet as a little play is needed when tightening the
belts later.

OX CNC Assembly Instructions 5 v1.1
© Bulk Man 3D 2019
Attach the wheels to the gantry. Use Eccentric spacers on the 3 lower wheel and 6.35mm spacer on
the upper 4 wheels. Tighten the top sets but not the bottom as they will need to be adjusted when
put on the V-Slot.

OX CNC Assembly Instructions 6 v1.1
© Bulk Man 3D 2019
Complete both the left and right plates as shown below.

OX CNC Assembly Instructions 7 v1.1
© Bulk Man 3D 2019
X-Axis Gantry Assembly –Front Plate
Attach the spacer blocks with M5 x 10mm screws. If you have 2040 for your Z-axis then use the
nearer set of holes, if you have 2060 then use the otter set.

OX CNC Assembly Instructions 8 v1.1
© Bulk Man 3D 2019
Using M5 x 45mm screws attach the V-Wheels through the Gantry Plate and the spacer blocks. Use 3
x Eccentric spacers on one spacers block and 3 x 6.35mm spacers on the other.

OX CNC Assembly Instructions 9 v1.1
© Bulk Man 3D 2019
Attach the nut block as shown.

OX CNC Assembly Instructions 10 v1.1
© Bulk Man 3D 2019
X-Axis Gantry Assembly –Back Plate
Attach the NEMA23 stepper to the gantry plate with 4 x M5 20mm screws, making sure to place the
3mm spacer in between the gantry plate and the NEMA23.

OX CNC Assembly Instructions 11 v1.1
© Bulk Man 3D 2019
X-Axis Front and Back Plate Assembly
Placing the spacers, shims and wheels as per the drawings below, attach the front and back plates
using the 4 x M5 x 65mm screws. Note two eccentrics are on each lower screw.

OX CNC Assembly Instructions 12 v1.1
© Bulk Man 3D 2019

OX CNC Assembly Instructions 13 v1.1
© Bulk Man 3D 2019

OX CNC Assembly Instructions 14 v1.1
© Bulk Man 3D 2019
Z-Axis Assembly
First make sure you have tapped (M5) all the holes in the Z-Axis V-Slot to a depth of approx. 8mm.
Attach Flexible Coupling to the NEMA23, then using the 40mm Spacers attach the NEMA23 to the
Threaded Rod Plate as shown. Make sure the bearing recess in the plate is facing away from the
NEMA23 (see below).

OX CNC Assembly Instructions 15 v1.1
© Bulk Man 3D 2019
Using 3 x 8mm screws, attach the Threaded Rod assembly to the Z-Axis V-Slot.

OX CNC Assembly Instructions 16 v1.1
© Bulk Man 3D 2019
Mount the X Gantry onto the Z-Axis V-Slot and, turning by hand, screw the Lead Screw into the Nut
Block about ½ way. Attach the bearing and collar and push the Lead Screw into the Flexible Coupling.
Tighten the coupling, make sure the bearing is correctly seated in the Threaded Road Plate recess.
Slide the collar to the bearing and tighten.

OX CNC Assembly Instructions 17 v1.1
© Bulk Man 3D 2019
At the other end, slide on the Lock Collar and bearing. Screw the remaining Threaded Rod Plate into
the V-Slot. Seat the bearing and tighten the collar.

OX CNC Assembly Instructions 18 v1.1
© Bulk Man 3D 2019
The completed X/Z assembly should look like this:
Test the assembly by hand turning the lead screw. Adjust the 3 Eccentric Spacers with a 10mm
spanner to that there is no lateral movement. Tighten all screws and test again by hand turning the
lead screw. If the gantry is to tight then re-adjust the eccentric spacers.

OX CNC Assembly Instructions 19 v1.1
© Bulk Man 3D 2019
X-Axis Gantry Assembly
Before starting the X Axis Gantry, make sure to tap (M5) all the holes on the 2060 and 2040 to 8mm
depth.
Screw the 2060 and 2040 to the Y Plate.