E34M1 for the Creality Sprite Extruder Toolhead

Released V0.2 - first released
Released V0.3 - added belt grabber to front module

WARNING!

Do NOT use CF material to print the PCB spacer, as carbon fibre is conductive and will short the pin on the PCB, damaging the MCU board!

IMPORTANT Notes

Models are made with the exact required dimensions and are meant to be a universal fit regardless of the material you are printing with. Any shrinkage should be dialled in or calibrated in your printer's config or slicer settings. Your printer should print a 3mm hole as 3mm regardless of what material, and a 50mm block as 50mm.

1. Calibration

All printers should be calibrated.

The Calistar calibration makes a big difference: no DIY printer has the perfect step size (e.g., 400) for the AB motor, and it addresses this while also correcting skew. 

Not all extruder rotational_distance/e-steps are the same! Perform the extruder calibration.

2. Excessive Flow

All default settings have excessively high flow (unless you are running an old, worn-out extruder/hotend). Over-extrusion reduces the inner diameter and increases the outer diameter/dimensions. Run the ORCA slicer flow calibration - Archimedean chords + YOLO; it is recommended to start the test at a flow ratio of 0.95 or 0.90. The correct result should be smooth to the touch, with no ridge feel (smooth surface). If none of the results makes a difference to you, the settings are severely extruding, and you should rerun the test with a 0.05/0.10 flow ratio lower.

Introductions

Please read and refer to the E34M1 documentation before proceeding. This remix only contains files required to mount the sprite extruder to the E34M1 module. All other required parts are available on the E34M1 GitHub. You must read the documentation to decide what you want for each module before proceeding. 

The E34M1 consists of 5 Core Modules:
1. Front
2. Top
3. Rear Inlet
4. Bottom Horns
5. ABL Side Mount

This remix provides the Front, Bottom Horns and optional modified ABL Side Mount. In addition to the files in this remix, you are required to obtain the Top and Rear Inlet modules from E34M1 GitHub.

BOM

In addition to the BOM stated in the E34M1 documentation, the following additional materials are required for the Sprite Extruder front modules.

14 x M3 Heat Insert (5mm OD, 4mm Length)

4 x M3 x 8mm SHCS (to secure the CR touch bracket and cr touch to the bracket)
5 x M3 x 10mm SHCS (to secure the Sprite Extruder to the mounting holes)
2 x M3 x 18mm SHCS (to strengthen the Rear Centre Support Strut)
2 x M3 x 20mm SHCS (to secure the motor spacer to the stepper motor)

2 x M2.5 x 8mm SHCS (for securing the PCB Spacer and PCB to the Front module)
2 x M2.5 Washer (For above but optional)

M3 Washer (as required) -  A personal preference that I place a washer on every screw possible

(Optional) PC4-M6 x 1 mm Bowden coupler for reverse bowden setup attached to the PCB spacer

Any other required fasteners should be found on your original Sprite Extruder assembly.

Print Settings

E34M1 follows the ZeroG Print Settings guidelines

Only (GS)PCB_Spacer.stl requires Grid support hence (GS) prefix. 

All other models have been orientated and shall be printed as is without support.

(o)Heat_insert_bracket.stl is a one-time-use tool to help with the heat insert. Do not need to follow the ZeroG Print settings if you want to save some filament. 

Printables 

No.	File	Recommended Materials	Descriptions/ Instructions
1	front_basic_SEP.stl	ABS-CF/ASA-CF/PA-CF/PC-CF Highly recommend CF material, as not only are they stronger and stiffer, but they also have lower density, which helps produce stronger parts with lighter weight. These characteristics yield better input-shaper results than using unfilled ABS.	Refer to the E34M1 documentation if you are unfamiliar with this module. Preparation: Tap all 4 x 2.5mm threaded holes using either a screw tap or simply the screw that you will be using. Install all 14 x M3 heat inserts. Screw in both the M3 x 18mm SHCS into the rear centre holes SLOWLY! DO NOT over-tighten or use power tools. These serve as a structural rebar to support the Sprite Extruder. Note: The 2 ridges serve 2 purposes. First, it serves as a wiring channel for the stepper motor and Heatbreak fan, preventing the wires from dangling out of the front module. Second, it is structural: without it, when forces are applied at the bracket end, the weakest link will break across the large fan hole diameter along the Z-axis.
2	Motor_Spacer.stl	As above	The recess is catered for the Stepper motor wires
3	(GS)PCB_Spacer.stl	ABS/ASA/PA/PC Minimum ABS.  AVOID Carbon-filled material; otherwise, risk of short circuit and fire. PETG/PLA will deform under the heat and pressure. NOTE! This is the only parts that requires support ot print. Use GRID Support with 4 interface layers and 2 walls for easy removal.	Remove the Sprite Extruder fan shroud/CR touch bracket. Replace it with this part (red) so the PCB stays in its original position and the pins are not shorted to the extruder's metal body. This also provides an M6 x 1 mm screw thread for securing a reverse bowden PC4 coupler.
4	SEP_bottom.stl	Material selection depends on the Max Bed Temp the printer can operate at. ABS: Max Bed Temp < 90 °C ASA:  Max Bed Temp < 100 °C PC/PA/PPS/PPA Max Bed Temp > 100 °C	Fan duct. The one and only. Sorry, the Kraken duct doesn't and will not fit due to the dimensions of the heater block.
5	(o)CR_touch_slim_mount.stl	Use CF material similar to the main Front Module above.	(Optional) This bracket relocates the ABL mount to the front, keeping it closer to the body and saving 8mm on the X-axis. Only the CR touch mount is available. For other probe options, please utilise the E34M1 original bracket and mounting location.
6	(o)Heat_insert_bracket.stl	Any material as long as it's not TPU. For one-time use only.  Wall Count: 3 Top and Bottom Layer: 4 Infill Density: 10% Infill Pattern: Lightning	(Optional) This bracket helps to keep the front module upright and parallel. Highly recommended to ensure all 6 heat inserts in the back of the module are upright, thus ensuring the completed E34M1 assembly is squared and rigid. These 6 heat inserts are for structural bolts that play a critical role in squaring and ensuring the rigidity of the printhead.

Assembly

1. Assemble the Front, Top, and Rear Inlet module using only two M3 x 45mm. Do not tighten them first.
   

   

   Prior to mounting the assembly to the Linear Block, it is highly recommended to test-fit the Sprite extruder into the bracket to understand how it should be inserted. Be careful NOT to damage or break any of the wires, especially the thermistor wire, which is very delicate. Refer to step 4 should you wish to test-fit.
    

2. Mount the assembly onto the MGN12H Linear Block. You may tighten them to the final specifications

   

    

3. Route the Part Cooling fan wire out from the top or bottom, as you prefer. Should you wish to route the part cooling fan wire from the top, there is a recess for the thin fan cable to pass through.

   

    

4. Mount the Sprite Extruder toolhead into the front module. This can be challenging; however, it is meant to be mounted from the bottom, about a cm forward, then pushed rearward into place.
    
   Ensure all the wires are securely connected to the PCB. This includes the wire for the part cooling fan and the CR touch wire to the PCB, but leave the CR touch disconnected. I personally prefer to have the part cooling fan connector extended for easy maintenance and fan replacement.
    
   The CR touch wire shall be routed out via the bottom between the fan duct and PCB spacer.
    
   When inserting the Sprite Extruder from the bottom, note that the stepper motor wire and heatbreak fan wire will be hindered by the ridge. Carefully tuck the cable into the "duct".

   

    
   While doing so, the heater connector will also hinder the extruder from moving upwards to align with the rear strut support. Thus, the extruder needs to be positioned as far forward as possible without blocking the heater connector with the protruding feature. You may align the connector such that it is aligned with the void circled in red below.

   

    
   Remember to check the wires for the part cooling fan and CR touch. 
     

5. Mount the ABL bracket as required, either using the original or the (o)CR_touch_slim_mount.stl
    

6. The last step is to install the bottom fan duct. Note there is an additional M3 screw at the bottom rear centre in addition to the 2 long M3 bolts on each side.
   

   

   
    

7. Tightened all 4 long bolts from the rear.

Support

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