BOM Visible Robot V1.1

This BOM is for a Visible Robot using 12mm x 800mm ‘Y’ shafts; 10mm x 500mm ‘X’ shafts; and 8mm x 280mm ‘Z’ shafts, giving a 350mm x 590mm x 85 – 255mm (13.75” x 23” x 3.35” to 10”) working envelope (X, Y, Z). The ‘Z’ working envelope depends on leveler and end-effector configuration.

See the Visible_Robot_Assembly and Working_Envelope_Choices documents for more detailed information.

The names of the parts are as they called in the 3D-printable .STL files

3D-printed Parts by Major Assembly

Screenshots are not to scale

Base                                          Qty
base_corner_00_top                 1          base_corner_00_top

base_corner_00_bottom          1         base_corner_00_bottom

base_corner_01_top                  1        base_corner_01_top

base_corner_01_bottom           1         base_corner_01_bottom

base_corner_10_top                  1        base_corner_10_top

base_corner_10_bottom           1         base_corner_10_bottom

base_corner_11_top                   1         base_corner_11_top

base_corner_11_bottom            1          base_corner_11_bottom

leveling_dial                                    4          leveling_dial_lg

leveling_dial_long_nut (opt)   4           

leveling_dial_static_v1_1         4          

Base assembly sub-total        16



Gantry                                                     Qty
gantry_shoulder_short_0                1         gantry_shoulder_short_0

gantry_shoulder_short_1                1          gantry_shoulder_short_1

gantry_hip_0                                           1          gantry_hip_0

gantry_hip_1                                           1          gantry_hip_1

gantry_hip_bearing_retainer_0    1          gantry_hip_bearing_retainer_0

gantry_hip_bearing_retainer_1    1          gantry_hip_bearing_retatiner_1

gantry_hip_band_attach                    1          gantry_hip_band_attach

arduino_mega_pcb_bracket_v1_1 1         

arduino_pcb_bracket_clamp           4          arduino_bracket_clamp

megatronics_v3_pcb_bracket (opt. 1)     megatronics_v3_pcb_bracket

megatronics_standoff              (opt. 4)     megatronics_standoff_8mm

Gantry assembly sub-total              12



X-axis                                              Qty
x_carriage_bottom_v1_1           1         

x_carriage_top_v1_1                   1          

x_leadscrew_capture                   1          x_leadscrew_capture

x_uswitch_stop                              1          nema17_centering_ring

X-axis assembly sub-total        4



Y-axis                                                   Qty
y_nema23_motor_mount             1           y_nema23_motor_mount

nema_17_to_23_motor_mount*  1           nema17_to_23_motor_mount

* Use this part with the y_nema23_motor_mount part, above, to mount a NEMA17 motor to drive the ‘Y’ axis. Not needed for X-axis, as the NEMA17 mount is integral to the shoulder.

y_far_end                                                1           y_far_end

y_far_end_nut_seat                        1            y_far_end_nut_seat

y_gantry_drive                                  1            y_gantry_drive

Y-axis sub-assembly sub-total  4    (5, if mounting a NEMA17 motor)



Z-axis                                              Qty
z_carriage_base                          2            z_carriage_base

z_bearing_bar                             3*          z_bearing_bar

z_bearing_sleeve                       6**        z_bearing_sleeve

z_cable_bracket_v1_1***       1           

z_top_motor_mount_v1_1***   1           

z_min_uswitch_bracket               1            z_min_uswitch_bracket

z_max_uswitch_bracket              1            z_max_uswitch_bracket

Z-axis part sub-total                   15

*   Four holes are drilled out for M3 pass-thru, Two drilled to be used as M3 locknuts.
** Two holes drilled out for M3 pass-thru, Four drilled to be used for M3 locknuts.
Reference specifics on drilling pass-thru and locknuts for the assembly in the Post-processing Guide P6, 7.

        *** Used on both Original and Alternate Z-axis forms.


Z-axis – alternate form            Qty

The alternate Z-axis is lower parts-count and stiffer, but requires precision drilling of the bearing seats. This is best accomplished with a drill-press and a fixture or jig.

z_carriage_alt_v1_1                     1      

z_carriage_cap_alt                       1       z_carriage_cap_alt

z_max_uswitch_bracket_alt      1      z_max_uswitch_bracket_alt

z_min_uswitch_bracket_alt_v1_1  1     

Z-axis alternate part sub-total  4



End-effector Platforms
eep_platform*        (beta)            1      end_effector_platform

* This is a stand-in platform meant to allow the fixing of tools to it. It will accept a bottom-mounted motor, or a leadscrew-capture part if the motor is top-mounted. Use this only if you know it will serve your purposes.

eep_cable_bracket                      1       eep_cable_bracket

3_extruder_platform**    (beta)   1       finix_3_extruder_platform

** This is a stand-in platform that will mount three E3D extruders. The boltholes for     attachment to the extruder release mechanism are non-standard. They were derived from a Printrbot gearhead beta direct-drive mechanism. Use this only if you know it will serve your purposes.

3_extruder_platform_cable_bracket 1  3_extruder_cable_bracket

finix_extruder_platform_v1_1       1     

EEP printed part sub-total            1

Total printed parts                       52    (41 with alternate Z-axis form)



Purchased Parts

Base                                                                    Qty
12mm x 800mm hardened, chromed shaft 2    Y-axis
5/16” x 22” (560mm) threaded rod *       4    End-rods
5/16” x 34” (860mm) threaded rod          2    Base stiffening
¼” x 1” hex bolt **                                            4    Leveling
¼” hex nut  **                                                     4    Leveling
.177 cal. (4.5mm) BBs (buy a package)        1    Leveling ass’y bearings
Microswitches                                                     2    End-stops

Base purchased part subtotal                 19

* 8mm can be substituted

** 7mm can be substituted


Gantry                                                        Qty

8mm x 11.5” (~290mm) shaft*                    4    Fixes gantry height
5/16” x 14” (360mm) threaded rod         4    Gantry stiffeners

3/8” x 22” (560mm) threaded rod**         2    Y-axis drive

Gantry purchased part subtotal             10

* 8mm x 13 ½” (340mm) shaft can replace this one to give additional Z-axis height—and workspace volume. Alternatively, 8mm x 9 ½” (250mm) shaft can be used to improve stiffness. These replacements may require gantry hips and shoulders to be printed with slightly different angles at which to hold the stiffening (angled) braces. These also use longer (and shorter) lengths of threaded rod, 16” and 12½” (~410mm and ~320mm), respectively.

**10mm c/b substituted


X-axis                                                                  Qty
10mm x 500mm hardened, chromed shafts    2
LM10UU 10mm linear bearings                    4
Nema23-56 stepper motor *                          1
Nema23-76 stepper motor                             1
Nema17-48 stepper motor                             1
Nema17-60 stepper motor                             1
6.35 x 6.35 rigid coupler **  (Nema23)         1
6.35 x 5mm rigid coupler (Nema17)              1
1/4” – .250 (lead) x 18” (455mm) leadscrew  1    Roton “Hi-lead”
1/4” – .250 anti-backlash leadnut  ***         1
22” (~560mm) x 1/2” (12mm) steel band ^ 1
Microswitches                                                     2
X-axis purchased part subtotal                13

* The mounting features of the gantry_shoulders will take either NEMA17 or NEMA23 steppers.

** The coupler must have a diameter no greater than 5/8” (15mm). NOTE: A flexible coupler may also be used.

*** The boss feature on the x_carriage part is for the Roton leadnut, though others may fit.

^ Banding/strapping can be a good scavenger-hunt challenge. It’s used for strapping large items to pallets. Try appliance stores.


Y-axis                                                                Qty
12mm x 800mm hardened, chromed shafts    2
LM12UU 12mm linear bearings                  4
Nema23-56 stepper motor                           1
Nema23-76 stepper motor                           1
Nema17-48 stepper motor                           1
Nema17-60 stepper motor                           1
6.35 x 6.35 rigid coupler * (Nema23)          1
6.35 x 5mm rigid coupler (w/Nema17)      1
1/4” – .250 (lead) x 30” (760mm) leadscrew 1    Roton “Hi-lead”
1/4” – .250 anti-backlash leadnut                 1
34” (~860mm) x 1/2” (12mm) steel band   2

Y-axis purchased part subtotal                 12

* Flexible couplers can be substituted



Z-axis                                                                    Qty
8mm x 300mm hardened, chromed shafts    3
LM8UU 8mm linear bearings                          6
Nema17-48 stepper motor                             1
Nema17-60 stepper motor                             1
6.35 x 5mm rigid coupler *                             1
¼”-.100 (lead) x 10.75” (275mm) leadscrew  1   aka ¼”-20 (TPI)**
¼”-.100 anti-backlash leadnut                     1
9” (~230mm) x ½” (12mm) steel band **   1

Spring (6mm OD x 40mm len, 1.0mm wire)*** 1
Microswitches                                                      2

Z-axis purchased part subtotal                   16

* Flexible coupler can be used.

** Depends on EEP choice


Z-axis – alternate *                                  Qty  
M6 x 130      or     ¼” – 20 x 5” bolts       3
M6        or    ¼” nuts                                      3

Z-axis alternate purchased part subtotal 6

* Add these items to the list above

** Leadscrews (and screws in general) are measured in TPI (threads-per-inch)–commonly used where the imperial (inch) system is used, and by “lead”–used where the metric system is used. TPI counts the threads per inch of length. “Lead” is the distance along the length of the screw between two threads.

*** Flanged heads & nuts preferred for better pressure distribution



End-effector Platforms
The platform itself is a printed part. Purchased parts will vary depending on choice of EEP, which will vary due to the function intended.



Electronics                                  Qty
Arduino Mega2560                      1
RAMPS1.4                                        1
Printrboard Rev D or later          1
Megatronics V3 Rev. F                1
ATX power supply                           1     Wattage depends on use

Electronics purchased part subtotal   3  (Arduino/RAMPS assumed)

Total purchased parts w/o fasteners 73

Total parts w/o fasteners                       125   (119 w/alt. Z-carriage)



Fasteners        Screws*       Nuts      Washers    Locknuts    Setscrews
Base1,2          M3x20 (8)    5/16” (14) 5/16” (14)  5/16” (12)
M3x12 (8)
M3x10 (8)
Gantry3,4,5    M3x25 (2)    5/16” (8)    5/16” (8)    5/16” (8)    M3 (7)
M3x10 (12)    3/8” (6)        3/8” (6)      3/8” (4)
M3x12 (8)
M3x16 (8)
M3x6   (6)
X-axis1,5,6     M4x16 (4)    // NEMA23 mount
M3x25 (4)
M3x10 (7)
M3x6   (3)
Y-axis              M4x16 (4)    M4    (4)
M3x10 (3)
M3x6      (4)
Z-axis              M3x25 (14)                                    3/16” (6)     M3 (6)                               M3x10 (13)
M3x8 (6) – socket-head
Z-axis (alternate) M6x130 (3)  M6 (3) – flanged
EEP Platform   Depends on platform used

Usage by sub-assembly                Screw usage
Base fastener sub-total       64        M3x6      17
Gantry fastener sub-total    83       M3x10    53
X-axis fastener sub-total    18       M3x12      4
Y-axis fastener sub-total     15       M3x20      8
Z-axis fastener sub-total     45       M3x25    20
Z-axis alternate fasteners      6       M6x130    3 (Z-axis alternate)
M4x16     8

Fastener total                 231    // using original Z-carriage parts
215    // using alternate Z-carriage parts

Total parts w/ fasteners 356    // using original Z-carriage parts
340    // using alternate Z-carriage parts

* I’ve used pan-head screws exclusively except for the M3x8 socket-head screws for fastening the z_bearing_sleeves and z_bearing_bars to the z_carriage_base. The socket-head screws allow for better access with a hex (Allen) wrench.

1 Includes microswitches
2 Includes leveling dial
3 The gantry includes hips, shoulders, their connecting threaded rods, height determining 8mm shafts and plates used as leadscrew capture and stops for the X-axis microswitches.
4 Includes Arduino mount
5 Includes cable band mount
6 Includes motor mounting



Cabling/wiring         Length    Description

Listed below is the wiring with lengths, wire gauges and suggested color codes. The color codes shown pertaining to the motors simply reflect some color codes used by motor manufacturers. There doesn’t seem to be a unifying standard for motor color codes.

The wire lengths for the motors having to be “made-up” will depend on the lengths supplied by the motor vendor. The lengths shown are what’s required to reach from the motor to its termination, including that needed to traverse the flex-banding and still have a little to put in a short loop to resist any stresses.

12VDC Pwr → RAMPS    40” (1m)     4-wire x 16AWG cable (2 wires Bk, 2-wires Y)
PC ↔ VR Comm        6′    (1.8m)    USB Type-A ↔ Type-B cable1

X-axis motor (total)        12” (300mm)    4-wire x 22AWG cable (Bl,R,Gn,Bk) OR (Gn,Gy,Y,R)
Xmax microswitch cable    43” (1.1m)    3-wire x 22AWG (Y, Bk, R)
Xmin microswitch cable    42” (1.1m)    3-wire x 22AWG (Y, Bk, R)

Y-axis motor     (total)        45” (1.1m)    4-wire x 22AWG cable (Bl,R,Gn,Bk) OR (Gn,Gy,Y,R)
Ymax microswitch cable    34” (850mm)    3-wire x 22AWG  (Y, Bk, R)
Ymin microswitch cable    34” (850mm)    3-wire x 22AWG (Y, Bk, R)

Top-mounted Z-axis motor
Z-axis motor     (total)        45” (1.1m)    4-wire x 22AWG cable (Bl,R,Gn,Bk) OR (Gn,Gy,Y,R)
Zmax microswitch cable    45” (1.1m)    3-wire x 22AWG (Y, Bk, R)
Zmin microswitch cable    45” (1.1m)    3-wire x 22AWG (Y, Bk, R)

Bottom-mounted Z-axis motor
Z-axis motor (total)        56” (1.4m)    4-wire x 22AWG cable (Bl,R,Gn,Bk) OR (Gn,Gy,Y,R)
Zmax microswitch cable    45” (1.1m)    3-wire x 22AWG (Y, Bk, R)
Zmin microswitch cable    45” (1.1m)    3-wire x 22AWG (Y, Bk, R)

Bk – Black  Y – Yellow
Bl  – Blue    Gn – Green
R   – Red    Gy – Grey

1 Printrboard uses a USB Type-A to Micro cable. Megatronics V3 uses USB Type-A to Type-B.


Following are some of the suppliers I’ve used. The list should be considered as giving hints. It shouldn’t be taken as authoritative. (The search bar is your friend ;-). I’ve found parts using eBay, Amazon, and AliExpress, as well as going direct to the vendor’s site.

Mechanical parts:
8mm, 10mm and 12mm shafting    – Various from China and USA.
NOTE: Some problems from China, mostly from poor packaging / international shipping.
1/4” leadscrews and anti-backlash leadnuts  –
8mm, 10mm and 12mm linear bearings – Various China and USA – VXB.
6.35mm x 5mm (¼” x 5mm) couplers –     Various    // Used with NEMA17 steppers
6.35mm x 6.35mm (¼” x ¼”) couplers –  // Used with NEMA23 steppers
M3 (3mm) screws and nuts – local hardware store*
5/16” threaded rod, nuts and locknuts –  local hardware store*
3/8” threaded rod, nuts and locknuts –  local hardware store*
1/4” hex bolts and nuts – local hardware store*

* While the local hardware store is both handy and quick, it’s usually considerably cheaper to buy from Internet outlets—especially when you’re buying fasteners in quantity. has a huge inventory of fasteners, as well as a very nice introduction to the various kinds of fasteners—and a printable size chart that comes in handy as a reference in identifying scavenged parts. Alternatively, most cities have fastener wholesalers that sell to small jobbers. They will usually have a counter and sell small quantities. Check the Internet or your phone directory. Denver, CO –Stanley Fasteners.

An alternative to buying small quantities of a large variation of small (M3 or up to about #6 SAE) screws is to buy a larger quantity of longer screws and cut them with a bolt cutter. Wire strippers often feature a bolt cutter for small sizes. (Be sure yours cuts the flavor—metric or inch—that you’re working with).

Electrical parts:
Ribbon cable (40 strand) –  Various
Microswitches – RobotDigg, and others
NEMA17 stepper motors –  Kysan, RobotDigg, Wantai, Minbea
NEMA23 stepper motors –  RobotDigg, Wantai, Stepsyn
ATX power supply – Antec, CoolerMaster, Thermaltake, EVGA
Printrboard –
Arduino Mega 2560 –
RAMPS1.4 – Various – boards from CN came w/o the USB-B mount
Megatronics V3 – ???
Extruders – E3D, Mk8, Ubis

PLA Filament: – has good filament, but limited to 1lb. & .5kg spools, limited colors.

NOTE: for color-matching reasons it’s best to find a good supplier and stick with it. (Colors vary across suppliers).