Ender 3 Pro Refresh Upgrade

With camping season right around the corner (Dating myself as I started this Article Mid-January)  and a new camper this year, it’s time to dust off the 3d printer and prepare it for service. I picked up my Ender 3 Pro shortly after it was released with the improvements from the Ender 3, but it has been idle most of it life. I have accumulated a few small printing projects over the last few months so between that and having it ready to print quick replacement parts for the camper it’s time

The under itself has spent the last year parked and idol in the corner of my desk in order to get this thing back and online we’re gonna take a look at the current status give a few test prints and identify where we need to start. So the most part my enter is stock any additional parts are very specific such as the glass-heated bed was an upgrade that I purchased and installed the remaining parts are all 3-D printed from the end of itself as improvements the last major upgrade is a 3-D printed direct drive system to enable use a flexible filaments. accomplish this with all printed parts and for the most part worked well there’s also a class bed and a custom hot and shroud other than that the printers stock ender three pro

The direct drive extrusion worked well and held up for the most part but there are some design flaws for starters extruder motor hands further off the body adding additional twisting torque to the gantry.

There has never been a shortage of projects involving the ender three and upgrading it it’s essentially what the printer was designed for via printer on the cheaper side and a graduate success to your custom printer or to whatever your goals are with that in mind I wanted to go into this project with a couple ideas of what I wanted to do one of the big things I wanted to do was remove all possible components from the from the printer frame and into detached unit. The idea here is the printer frame would house all the required components to print only…

• Steppers and Stops, we could eventually remove the end stops on the printer with the right setup and reduce the number of cables in the mix.
• Camera, for now a USB camera will be mounted on the frame for basic monitoring
• Hot End, all the bits here have wires that might need some organizing and extending.
• Print Bed, the heated bed and my glass are not adding any additional challenge are staying put.

As-is MY Ender 3 Pro is a workhorse parts printer for its size.   It is not an great detail printer but it can be one or the other with tuning, which is a great thing for an enthusiast/hobbyist.  I have printed from 28mm figurines (still needing some clean up) all the way up to bed filling garbage cans in mine with only printed upgrades.  Output wise the printer does a great job when tuned to a purpose, for now we are going to remain with a 0.4mm Nozzle on the stock hotend for the remainder of the upgrades.  I predict by the end we will be planning to go for a larger nozzle… 

I think it is time we talk about why I am even at this point, what do I want to change about the printer to begin with?  Concerns about the printer?  These don’t need to be “problems” but can be potential “improvements”!

1. Well the number one issue I have is the noise, steppers and fans are horrible sounding.  I can’t stand being in the room while its printing, such noise that makes it impractical to use with any kind of proximity.  
2. Direct Drive is needs to be solidified.  Printing my own Carriage Base and hot-end cooling to go direct drive greatly improved my printing options, primarily the ability to print flexible filaments.  But it was not without its flaws.  The design had more of the stepper weight off the center of mass and added some additional torque.  Minor visible flexing when making quick movements with the added weight to the X-axis vs conventional Bowden setup.  I was getting “Ghosting” along the X-axis even in lower speeds. Still using the stock belt as well and tension is at its limits
3. With any setup I want to have network capabilities, no more swapping SD cards thank you!  A web interface to manage the printer, I have used Octoprint in the past and have a Raspberry Pi at my disposal.  Ability to have a web camera for monitoring, bonus points for time lapse.
4. Another Axis that was showing fatigue and minor ghosting was the Y-axis. I have a Glass bed on my Ender, so there is additional weight there to keep in mind and like the X-axis the belt is stock but still have room in the stock tensioner.  
5. Z-Axis on the Ender 3 is handled by a single stepper and screw driven.  It connects to the X-Axis on one side and the opposite side rides the frame on rollers.  With the direct drive adding more weight to the carriage, which I plan to keep, the cantilever effect on the X-Axis could be impacted as it gets further from X Home.

There are some other “nice to haves” that I took off the list for now ( including a full enclosure).   But this is the items I want to address before I have the printer reporting for duty within a budget.

Time to start some shopping. Right now I have a small list to decide on: A Rigid direct drive setup, silent cooling fans, Dual-Z, steppers and main board.  The board I go with will drive a lot of the design and planning so let us start there. 

After all my research I decided to go with the Mini v3 paired with my Raspberry Pi 3B+ to run Klipper.  Ordered and will be here in a few weeks, got some time to sort out the remaining bits before it arrives.

I debated what I wanted to do with direct drive to get a better result.  I still want to swap the Y and Extruder steppers but that can wait until we learn more about Klippper and testing the steps.  There are some official Microswiss and Creality Direct Drive Kits that perform the same role as my previously printed parts.  I wanted to keep budget under control some but the Microswiss kit does have an option with a new hot end.   After reviewing all the options and sticking to the plan of retaining the stock hot end,  I have my eyes set on the Creality DD kit that uses four rollers on an all new carriage.  It has an improved profile to keep the center of mass manageable, but on the down side none of my hotend cooling parts will fit and some work may be needed down the road for an optimal fit.  The stock extruder stepper is still going to be used in this case, swapping it for a lighter extruder is still an option down the road.  

Printable upgrades are going to be ideal when it comes to how much control we have over what we get.  If the resources are available it could be “cheap” to prototype with.  I can think of a number of things, if they already exist, that I can just print and install to help most of these items.  Help most, but not solve them all sadly.  Our number 1 issue is noise, and parts I can manufacture won’t help much here directly.  Indirect  More on that later…  Printing a tensioner for the x-axis looks promising.  We should probably still get a new belt, but having a better tension control could be worth having.  For now we can draft up this thing https://www.thingiverse.com/thing:3319649 and when we are replacing the belt we can install it.  I also wanted to up an enclosure for the electronics of the printer that I could add extension cables to the drivers and stops but everything else is in one box.  Having the power supply included in the enclosure what presenting a challenge to print because of the size.  I decided to go with this thing https://www.thingiverse.com/thing:4405355 because it was closest to what I wanted and had a step file I could work with. 

The next smaller printable would include a X-Belt Tension control for the Ender and the new Creality Direct Drive has a new belt is included.  I would guess its the same size, but I know I already had the stock belt tension fully extended and was still seeing slack in the original belt.  This was really just a nice to have that I justified printing out as a fail safe during the upgrade.  On the small scale I also started printing some camera mounts for my Logitech webcam.  I will probably be printing these parts through out the project when I need to do a quick print.  Not needed to be printed in advance at least!

Now that I have a footprint figured out I need to decide on how cooling will work.  Looking at other designs I will likely have the top of the power supply open and cooling a large compartment that is the internal space.  A single fan can probably work but how do we keep the sound down too?  Let’s take into account what fans we have stock:

1. Power Supply Fan – 60mm – 12vdc Fan
2. Controller Fan – 40mm – 24vdc Fan
3. Hot-End Fan – 40mm – 24vdc Fan
4. Part Cooling – 24vdc Blower

In the enclosure  we have access to several of these fans and I see a few solutions worth testing.  Having the Power Supply Fan run 12vdc means it can be easily replaced with a conventional fan, I will use it in my testing but the stock fan is loud and needs to be removed.  If replaced with a silent fan I imagine this might be enough cooling for the enclosure.  The controller fan I would leave unoccupied, unless we want to step it down to 12 vdc and have more fans.  The hot-end fan will need to be improved as well as part cooling I have seen both in a variety of ways but the clean solution is to get different blowers (4010,5010,4020).  Not sure I am ready to decide much on part cooling beyond trying some cheap aftermarket blowers and printable parts, but for the hot-end fan I will be dropping it to 12vdc in the enclosure and using an Noctua A4x10.  This will be quiet and have plenty of cooling capability.    I am going to get a Noctua A4x20 to test against other enclosure fan options I have on hand already.  I have a handful of LM2596’s that I used in a previous project that would be great for the job of stepping the voltage down for the Hot-End Fan and the Pi.

With the Mini v3 ordered I will be able to start printing some of the parts we will need and order what pieces I need.  The printer will be busy with enclosure most of the time but as the parts come out I will move the Ender components around.  My original plan was to pair the printer with a Pi and I have a few older ones I can use, there is no debate here that I am going choose the Pi 3B+ currently collecting dust since its last use previously in an iteration of the Coal Stove.   The overall specs and the integrated wifi on this model is more than up to the task and puts it ahead of anything I have.  I can spend some time talking about the Pi side of things but I don’t really have much to cover until much later.  Not that I wasn’t doing anything, its just not much ground to cover.

Knowing my hardware gave me some options still on how I want to run my web interface and the physical interface between Mainboard and PI.  I anticipate that I will receive the Mainboard with Marlin 2.X, but do I want to use Marlin?  Klipper has come up from time to time working with printers and researching.  Doesn’t seem to impact the decision on physical interface since there are multiple choices.  I went for a simple UART interface from the Pi running Klipper.    Props to BigTreeTech for their firmware being available in Github: https://github.com/bigtreetech/BIGTREETECH-SKR-mini-E3/tree/master/firmware/V3.0 

Getting all of these things going was assumed to take some time but I got the PI steps completed by just following the MainsailOS setup and search for the printer configuration for the Ender 3 (https://github.com/Klipper3d/klipper/blob/master/config/printer-creality-ender3-2018.cfg).  I did configure the wifi before booting and was able to access the Pi with a browser once it picked up DHCP.  Some configuration is available but until I have the board (which is not in the country yet) I can’t do much of value.  I did see the UART wiring for the board, as well as noted it can provide power.  If I went with a Pi Zero then I might consider it an option but I doubt it is rated for more than powering an backlit LCD.  In the final enclosure I will use one of my LM2596’s for stepping the power supply’s 24vdc to 5vdc specifically for the Pi.  For now I am going to provide it external power until I can research and test all the options. 

With a few draft enclosure parts printed I can move the power supply and mount the Pi into its position as well as the power supply fan.  I can already tell that this fan needs to go.  Any 12vdc Fan will work and I will have to crimp some kind of extension from the power supply so I can test fans more easily.  This is the only 12vdc Fan in the entire configuration so we can test with the Noctuas and other fans I have about unless we want to have another voltage regulation device, and we already plan to use two.  Design wise I am going to test operation of the Pi with a single fan connected to the power supply 12vdc in the enclosure.  I already know the stock power supply fan moves sufficient air for the enclosure but the sound is unbearable even with the solid lid I created.  A silent 60mm replacement might be the quick solution here, but the lid for a 120mm Fan is ready to test as well so just got to crimp them up.

The 120mm fan performed great in pulling air out of the enclosure but as noisy as the previous test.  Neither had great airflow over the power supply components with a “dummy” Mainboard installed.    Personally I think it looks a bit off with any large fan on top so I will keep my flat top and exhaust heat from the back panel.  Until we have the board installed the stock power supply fan is sufficient, but I might have to redesign it to move heat with the Noctua A4x20 in addition to something I can connect to the Pi or Mainboard.  

The Mini v3 has arrived and we are ready to set it all up, but before we can install everything I need to strip the stock board, clean up connectors as needed, install a few ferrules for cleaner connection and route the wiring.  For all of this I am following just provided documentation and internet knowledge for clarity,  the install from Ender 3’s is very straight forward but the cable management is a bit of a mess.  We still need to look into extending the cables for steppers and endstops as they are the most limiting at this stage.  Ideally we would be able to know how long we can go and route them cleanly along the frame to one spot.  The hotend wires are not limiting our options yet but if we look at specs on our cables we should look at all of them and determine how far the control box can be from the frame.

For now we are ready to put our prep work to the test, I had configured the pi and can access mainsail already as well as prepared the klipper firmware on another microSD that is already installed in the Mini.  The UART connection that remains is very straight forward and I simply used a block of my good dupont jumpers to bridge the Mini’s TFT header over to the Pi.  On the Pi side I connected the Data leads and ground but not the +5vdc lead.  I want to do some more testing and I am not in a rush to pull the Pi’s external power just yet.  With the Pi on we power on the enclosure and wait for it to boot before continue down the documentation.

We now have the Mini running Klipper and the Pi running Mainsail and the two communicating.  Time to break everything in with the last of my old PLA, oh yea I might not have mentioned that the PLA I have been using is what I had left over and sealed away for about 8 months.  With a final cleaning of the heater block and a fresh nozzle installed we have some very solid prints without any changes to our slicing profiles from our previous running state.  From here I will spend the next weeks putting it through its paces using my old filament and some new spools of PLA, PETG, and TPU.

Before I conclude, there are still some outstanding items to complete.  Internal to the electronics enclosure I need proper mounting stands for the voltage regulation, where needed.  We know we want the Noctua fan on the heat break and have to step 24vdc to 12vdc for that.  I want to explore some options for part cooling with fans I have but could potentially have do this this as well of I go to 12vdc.  Then there is the Pi, coming in at constant 5vdc to  operate.  I will leave it on the power brick until we address the next item….

The wires are a mess…

We have to replace/extend a lot of the cables for the ender to have the electronics out of the way.  Right now it is closely tethered to the frame, but out of the way for the most part.

After I break it all in and have some hours of printing under our belt, I will check back in on where we go from here.