En­der 3 Pro

The Cre­ality Ender 3 Pro is a pop­ular and af­ford­able FDM (fused de­po­si­tion mod­eling, also called fused fil­a­ment fab­ri­ca­tion, or FFF) 3D printer that has gained a strong fol­lowing among hob­by­ists and makers. Known for its re­li­a­bility, ease of use, and up­grade-ability, the Ender 3 Pro is a great choice for both be­gin­ners and ex­pe­ri­enced users.

My best man gifted my wife and me (mostly me) an Ender 3 Pro for our wed­ding. So far, most of the printing I've done has only served to im­prove the printer... I've made sev­eral up­grades and mod­i­fi­ca­tions to en­hance its per­for­mance and us­ability.

Up­grades

Ex­truder

One thing al­most every Ender owner will end up doing is re­placing the stock, plastic ex­truder mech­a­nism with a more ro­bust alu­minum model (such as this ). A de­sign flaw with the orig­inal often leads to the plastic snap­ping with some con­tin­uous usage— causing under-ex­tru­sion or pre­venting fil­a­ment from trav­eling through the Bowden tube al­to­gether.

This was one of the first up­grades I made to the printer, and it sig­nif­i­cantly im­proved print re­li­a­bility.

Print­able Up­grades

There are many print­able up­grades avail­able for the Ender 3 Pro that can en­hance its per­for­mance and us­ability. Some of the ad­di­tions I've found par­tic­u­larly useful:

• Cable Chains
  Cable chains help manage and pro­tect the print­er's wiring— re­ducing wear and tear, and keeping wires or­ga­nized during op­er­a­tion.

• Fil­a­ment Guides
  A fil­a­ment guide helps en­sure smooth feeding of the fil­a­ment into the ex­truder, re­ducing the risk of jams and tan­gles.

• Spool Holder
  An up­graded spool holder with smooth bear­ings can ac­com­mo­date larger spools and pro­vide better sup­port, re­ducing strain on the fil­a­ment during printing.

• Camera Mount
  A camera mount al­lows for easy in­stal­la­tion of a we­bcam or Rasp­berry Pi camera module, en­abling re­mote mon­i­toring and time-lapse recording of prints.

Con­trol Soft­ware

Klipper Firmware

One of the most sig­nif­i­cant up­grades I've made to my Ender 3 Pro is in­stalling Klipper firmware . Klipper is an open-source firmware that runs on a host com­puter (like a Rasp­berry Pi) and com­mu­ni­cates with the print­er's mi­cro­con­troller (MCU).

This of­fers sev­eral ad­van­tages over tra­di­tional firmware, in­cluding:

• Im­proved print quality and speed
• Ad­vanced fea­tures like pres­sure ad­vance and input shaping
• Easier con­fig­u­ra­tion and up­dates via a web in­ter­face
• Sup­port for mul­tiple MCUs and com­plex printer se­tups

To in­stall Klipper, I fol­lowed the of­fi­cial in­stal­la­tion guide . I used the printer.cfg spe­cific to my model after opening the con­troller en­clo­sure and in­specting the MCU on the print­er's main­board. My model uses the STM32F103 chip with a v4.2.2 con­troller.

You'll need to format a mi­croSD card with the Klipper firmware bi­nary and in­sert it into the print­er's main­board. When you power on the printer, it will flash the new firmware au­to­mat­i­cally. You can then re­move the mi­croSD card and finish the host soft­ware setup on your Rasp­berry Pi.

Cal­i­brate Ho­tend PID

I no­ticed a re­cur­ring verify_heater error that was causing an mcu con­nec­tion error. After some dig­ging, I found that Klipper of­fers sev­eral GCODE scripts for PID cal­i­bra­tion.

To cal­i­brate the ho­tend PID, I ran the fol­lowing com­mand in the ter­minal with my most common fil­a­ment tem­per­a­ture (208°C, for PLA):

Once the cal­i­bra­tion process was com­plete, I then ran SAVE_CONFIG to save the new PID values to the printer.cfg file. This re­solved the verify_heater er­rors for a while, and im­proved tem­per­a­ture sta­bility during prints. The same cal­i­bra­tion process can be run on the heated bed by re­placing extruder with heater_bed and ad­justing the target tem­per­a­ture (60-70°C) ac­cord­ingly.

MCU Con­nec­tion Er­rors

Once in a while, I'd see prints sud­denly halting with an mcu con­nec­tion error in Klipper. Some­times this would happen near the start of a print, other times it would happen hours into a print. This can be awful when you've lost hours of print time and ma­te­rial for nothing.

Why does this happen? How can you fix it?

• Skip using a Wi-Fi en­abled outlet
  I like the con­ve­nience of turning on my printer from the couch, but from my ex­pe­ri­ence these out­lets can be flaky. Plug di­rectly into an outlet, or check that the switch has a good amp-rating that can pro­vide stable power to the printer.
• Use a good USB cable
  I've had a cable-swap sud­denly fix this mcu error issue— then ran­domly gotten it again after a few months. After the first two ca­bles, I ended up switching to a shielded cable with a fer­rite choke. Hon­estly— I think this was the biggest help in re­solving these er­rors.
• Pow­ering other heavy de­vices
  Make sure you're not pow­ering other power-hungry de­vices on the same cir­cuit or power-strip.

Main­sail

I'm using Main­sail as the Klipper web in­ter­face for man­aging the printer. It's vir­tu­ally the same as Fluidd — an­other pop­ular Klipper web in­ter­face.

Main­sail pro­vides a very light­weight web in­ter­face for Klipper that makes printer con­trol and mon­i­toring simple and straight­for­ward. It's also mo­bile-re­spon­sive, so I can check prints and ma­nip­u­late the printer from my smart­phone. It of­fers fea­tures like:

• Real-time tem­per­a­ture mon­i­toring
• Motor con­trol
• Print job man­age­ment
• G-code viewer
• System status and logs
• Camera in­te­gra­tion with the Crowsnest plugin

Oc­to­Print

Oc­to­Print is an­other pop­ular web in­ter­face for 3D printers, and it's what I used be­fore flashing the Klipper firmware. Main­sail is specif­i­cally de­signed for Klipper and of­fers a more stream­lined ex­pe­ri­ence. How­ever, Oc­to­Print will also work with Klipper, and it pro­vides sim­ilar func­tion­ality to Main­sail.

Oc­toPi

One of my fa­vorite ways to run Oc­to­Print is using Oc­toPi , a pre-con­fig­ured Rasp­berry Pi image that in­cludes Oc­to­Print and all nec­es­sary de­pen­den­cies. This makes it easy to set up a ded­i­cated print server for the Ender 3 Pro— let­ting you manage prints re­motely and mon­itor the printer in the browser over Wi-Fi.

Tips and Tricks

Here are a few tips and tricks I've learned while using the Ender 3 Pro:

• Bed Lev­eling
  Reg­u­larly check and ad­just the bed lev­eling to en­sure op­timal print ad­he­sion and quality. I use a piece of paper to gauge the dis­tance be­tween the nozzle and the bed at var­ious points. The paper should just barely slide with slight re­sis­tance.

• Nozzle Cleaning
  Keep the nozzle clean to pre­vent clogs and en­sure con­sis­tent ex­tru­sion. I use a brass wire brush to gently clean the nozzle after prints, and oc­ca­sion­ally per­form a cold pull to re­move any residual fil­a­ment. Stock up on ad­di­tional noz­zles for when you get a clog that can't be easily re­solved.

• Smart Plug
  I use a smart plug to con­trol the power to my Ender 3 Pro re­motely. This al­lows me to turn the printer on and off from my phone and schedule print jobs without needing to be phys­i­cally next to the printer.

• Time­lapse
  If you're using a camera with Main­sail, you can set up time­lapse record­ings of your prints. This is a great way to doc­u­ment your printing process and share your cre­ations with others. Follow in­struc­tions to clone the moon­raker-time­lapse repo and build the plugin. You'll need to add the fol­lowing lines to your moonraker.conf file:

You can also allow the Moon­raker up­date man­ager to handle up­dates for the time­lapse plugin by adding this sec­tion to your moonraker.conf:

Micro SD Backup

If your Klipper host (I'm using a Rasp­berry Pi) fails to finish the boot se­quence— re­vealing the dreaded blinking cursor/​black screen of death in­stead of starting up the Moon­sail/​Fluidd in­ter­face— you might have a cor­rupt SD card. Every Rasp­berry Pi en­thu­siast has faced the awful re­ality of a bad micro SD card. It's a le­git­i­mate problem that can de­stroy your morale and make 3D printing much less fun.

In­stead of re­peat­edly flashing Rasp­berry Pi OS, you can mit­i­gate this risk by pe­ri­od­i­cally backing up the con­tents to an­other storage de­vice. I have a 32GB card in the Pi, so I used an­other 32GB card to create an iden­tical copy using bale­naEtcher . In this way, if the pri­mary card fails, I can quickly swap in the other card and get back to printing.

In­sert the source card into your com­puter, launch bale­naEtcher, and se­lect "Clone Drive" from the main menu. You can tell which is which by plug­ging both in then un­plug­ging one and clocking which dis­ap­peared from the clone menu. You'll need to first format the backup as FAT32 be­fore cloning. Choose the source and target, then start the cloning process. Once com­plete, label the backup card with the date so you know when it was cre­ated.

Rasp­berry Pi USB Power Trick

If you're using a Rasp­berry Pi with Klipper or Oc­to­Print to con­trol your Ender 3, you might no­tice that the USB con­nec­tion can power the En­der's TFT screen— even when the main printer PSU is shut off.

To avoid this, I took a small strip of painter's tape and cov­ered the 5V pin (the right­most pin when looking straight into the male USB plug). This pre­vents back-pow­ering the print­er's screen when the Pi is pow­ered on in­de­pen­dently which could po­ten­tially cause screen damage over time.