LIRECTor for Ender 3 - direct drive printhead

WHY: This is one step further after designing my first all in one printhead - DIRECTor. This one uses the same principles but with some small money is getting much lighter - just getting NEMA17 pancake stepper. If you want to read why all this, look at the previous version, also if you don't want to invest, look there and use it with your stock extruder stepper.

So this is the Lightweight version of DIRECTor = LIRECTor (aka LRCtor)

FEATURES:

• Super lightweight version with pancake stepper and belt gearing (~265g hotend, fans, fan ducts, screws, stepper etc. included).
• Mostly stock hardware (fans, hotend, extruder parts, many screws) with stepper upgrade.
• Very short distance extruder to nozzle (~57mm).
• Compact - extruder stepper is as close as possible to the trolley center to be balanced.
• Enhanced extruder - stronger lever, easy tension adjustment, stepper gearing will reduce extruder artifacts.
• Tuned part cooling fan duct - published design has gone through many versions and updates to optimaly focus the air flow with lower restriction.
• 4020 fan compatible (fan duct in the files - just carefully enlarge holes in the body to fit M3 screws).
• Tested and verified functionality by me - I spent many many hours and filament meters improving, testing and tuning the design step by step but if you have any improvement advices or critics, I'm happy to hear them.

RECOMMENDED PRINT SETTINGS:

• PETG/ABS/ASA/HIPS recommended but test versions with PLA worked no problems for the test period (I tested temperatures up to 255 °C).
• Fan duct for part cooling strongly recommended in ABS/ASA/HIPS or some material with better heat resistance.
• 4 perimeters
• 50% infill
• Supports as shown within the instructions.
• 0,12 or 0,16 mm layer height and high quality (slower) settings - there are some bigger overhangs where smaller layer height helps.

NEEDED HARDWARE for LIRECTor:

• M2 screws from stock radial blower fan - 4pcs
• M3x6 5pcs - stepper motor 4pcs + body screw 1pc
• M3x8 1pc - GT2 pulley
• M3x12 1pc - cable guide
• M3x16 4pcs - hotend cooler fan
• M3x20 1pc - extruder lever hinge
• M3 washer 1pc - extruder lever hinge
• M3 nut 3pcs - GT2 pulley, extruder lever knob, cable guide
• M3x50 threaded rod - extruder lever
• M4x10 1pc - for extruder roller bearing
• M4 washer 1pc - for extruder roller bearing
• M4 lock washer 1pc - for extruder roller bearing
• MR105 2pcs - bearing
• M5 washer 1pc - for GT2 pulley/shaft
• 5x35 mm round shaft
• 6mm GT2 belt 134mm/67T (buy or make)
• 16T pulley for 5mm shaft (buy or print)
• NEMA17 pancake stepper - max 25mm
• Extruder parts (spring, roller bearing, drive gear)
• PTFE tube 49mm long
• Zipties 5pcs
• Stock parts (hotend with screws, blower fans 4010 axial and radial 4010/4020)

When using 16T pulley you get 3:1 ratio, depending on the stepper you may need to change the stepper current or eventually go down to 12T pulley and 64T-65T belt to get 4:1 ratio. I am using cheap 23mm stepper and didn't have to change the current and it runs fine with no overheating or skipping when tuned properly.

PRINTING GUIDE

1. Orient with hotend cooler facing the print surface and other parts as shown in the picture.
2. Print with lower layer height as there are some big overhangs - at least 0.16 and ideally 0.12 on the overhangs, also slower print speed will be better.
3. Set supports for marked faces (in Prusaslicer paint supports - smart tool).
4. Set parameters for different parts as written in the recommended print settings as well as shown in step 1 of printing guide.

INSTALLATION GUIDE

1. Clear the marked holes with adequate size drill bits and cut thread in the extruder lever.
2. Install both MR105 bearings, make sure they are pressed well inside. Insert M3 nut in the big pulley and instal the M3x8 screw.
3. Put the belt on the pulley and slide it in its position where the rim on the pulley is facing the extruder side, then slide M5 washer on the other side. Install the 5mm shaft and tighten the pulley screw.
4. Install the extruder parts (lever, roller, spring, etc), for the M3x50 rod if it's too loose, use drop of superglue in the hole. Fasten the extruder lever tightly but to let the lever move. Also if the lever rubs too much on the body you can help by lubricating the faces or just move it back and forth by hand until it “settles”. Install the extruder drive gear.
5. Install the pancake stepper with pulley.
6. Put the printhead on X gantry and fasten the side screw.
7. Remove the hose fitting from the hotend and put 49mm long PTFE tube inside.
8. Slide the hotend with screws inserted up in the printhead until it touches the top and fasten the screws. The PTFE goes into the hole with some friction but if you can't get it there, carefuly clean the hole with 4mm drill bit but don't make it longer. Also if you need help, loosen the heatbreak and pull it down a bit (I didn't need to)… and don't forget to tighten it later again. To slide the hotend up you have to angle it first because the screws are a bit longer - after you figure it out, it is easy.
9. Install the hotend blower fan with shroud and 4 screws.
10. Route both fan cables through the channel and install the part cooling fan with the duct using stock blower fan screws.
11. Install cable holder on the wheel spacer with M3 nut and screw.
12. Fasten the cables from heatblock and fans with zipties, install short PTFE tube on top of the extruder.
13. Currently the extruder is running opposite direction compared to stock setup, switch two cables in the connector or change the direction in firmware.
14. Optionally install velocity stack for part cooling fan.
15. Now you have to change extruder e-steps (start with multiplying your current amount according to chosen gear ratio) and then do real extruder calibration. For the best results, perform also calibration of hotend PID and extrusion multiplier. Great guide is on the Elli's tuning guide.
16. Ready to print.

If you have anything to share, any idea, critics or just a like, I will be happy to know and I hope you will enjoy the upgrade.

If you really like the design and/or just want to appreciate my work and time spend, you can buy me a coffee.

But I'm just happy if this makes someone else happy.