Voron StealthBurner Entrance Filament Sensor Using MK3S ir sensor pcb

Voron StealthBurner has no filament sensor, let's add one.

In case you have a MK3S's filament sensor retired or spare, we can use it to make a filament sensor for stealthburner.

Voron stealthburner

https://github.com/VoronDesign/Voron-Stealthburner

Voron SB clockwork2 mainbody is modded to added thicker and flat top and added 2 mount holes for the filament sensor.

About the IR Filament sensor:

how it works:

with a short ptfe tube, we don't need a heavy steelball. when filament is inserted, filament push the ptfe tube, the mover part is pushed toward ir sensor.

ir light is blocked by the mover, sensor is triggered (low)

when filament is pulled out/run out, magnet pushes the mover block away, IR sensor is not blocked, not triggered, now it's high.

ptfe tube is smooth and light, it should last long. 

Bonus feature:  

when we use MMU like ERCF or TradRack, SB need a way to lock the ptfe tube, the orignal Clockwork2 mainbody has no such design, using this filament sensor let SB has ECAS connector.

Pro and cons for this filament sensor solution:

PROs:

this filament sensor is small and easy to print, cost is next to zero.

it's simple, easy to make and easy to maintain/trouble shoot, because it's outside of the sb print tool head.

It's a IR sensor so no mechanical micro switch, it should last long long time reliably.

Since the clockwork mainbody now has two mount hole, so future other filament sensor can be easily mounted on.

no heavy steel ball to make print head heavy.

Cons:

need  a MK3S FS IR sensor, it's not very dirt cheap to buy, in case you don't have one.

like most of the SB filament sensor, clockwork main body has to change, so need replace the existing one, need some work.

BOM

• Magnet round M4 2mm  2pcs

• M2.5 screw 6mm  4pcs. 

• M2.5 heat insert 4pcs  ( prefer L3, OD 3.5)

• PTFE tube short piece  ID 2mm OD 4mm

• ECAS tube fitting

• MK3S IR filament sensor : what is this ??   see picture. we don't need all the long short magnet and the steel ball, just the pcb. many other variants are in color RED, as is the PRUSA original one.

 I understand M2.5 is less popular but we are making a small part,  and we want the screws lighter the better as it's on print head.

Print Setting

ABS for clockwork main body as usual, follow Voron print guide,  40% , 4 perimeters

PETG for filament sensor parts, or ABS, 25%+ 3 perimeter+

no support needed.

enable external perimeter first option in slicer for better dimensional accuracy.

Assembly steps

print all parts, 

Push hard to let ECAS fitting into the top part. it should be easy enough for hand press (but hard) into, and difficult to take out.

insert M2.5 X 4 heat insert to all parts: 

1 clockwork main body top, X2  , 

2 base part X2

3 M3 heat inserts for CW2,  for the rest of the SB original design , refer to SB manual

Insert a short ptfe tube to CW2 body entrance, use knife to cut tube a cone shape for easy filament enter.

put magnet M4 2mm into base and mover, repel each other.

cut a short piece of PTFE tube about 6mm (ID 2mm preferred)

put mover part behind ptfe tube. make sure mover is push away from base wall magnet.

use M2.5 6mm , X2 screws to secure top part and base part.

filament sensor is built.

use a filament to insert pullout insert multiple times to make sure it's smooth.

optional, use multimeter and power supply (5V) to test the signal output is correct with and without filament inserted. ( inserted: low ( <0.5V),  no filament: high: about 3.X V )

install fs on clockwork2 mainbody top.

use M2 screw (6mm? 8mm?)  for MK3S IR pcb, use pcb cover to protect the pcb, just in case a screw or screw driver touches pcb, it has a cover so it won't be damaged.

replace the modded clockwork2 main body.

no need to remove the whole sb from voron, just remove front stealthburn part, and remove all screws from the front face of the existing cw2 main body, the old cw2 main body can be removed.

connect wires for the IR pcb , check and double check pin definition before connect to your print head PCB

Config

HappyHare software config file changes:

for reference only, YMMV.

mmu_hardware.cfg

extruder_switch_pin: !SB2040:gpio18 # sensor detects filament just before the extruder entry

for my Mellow SB2040 v3 toolhead can bus pcb, note it need ! at the front.

connect sensor wire to endstop0 make sure using 5V as power and not the 24V.

mmu_parameters.cfg

extruder_homing_endstop: extruder

toolhead_entry_to_extruder: 60

CAD

cad step files are provided.

related

for galileo2 extruder

for HGX extruder