February 22, 2024
Description
This display case tightly fits onto the Taurus cooling duct, version 2 and up. You can find this cooling duct here: https://www.printables.com/model/511962
If you're not already running a Taurus cooling duct that you are happy with, I would not recommend that you proceed with this upgrade. Print and install the duct project first, before attempting this even more ambitious mod.
Warning: This mod will require splicing into the CR touch cable to obtain the needed 5V DC power source for the display (instructions included). Shrink tubing and basic soldering skills are required for the installation, but you should already be familiar with this if you are running a Taurus (similar procedure).
Both the Knomi2 and the FLY-HALO use the same 1.28" round GC9A01 TFT display.
The maximum display resolution for the GC9A01 is 240 x 240 pixels.
It supports up to 65K colors for crisp and crystal-clear display on the screen.
Power Supply: 5V DC
I purchased several from this source:
Amazon.com: BIGTREETECH KNOMI V2.0 Touch Screen Display 1.28 inch UI Multi-Color LCD Perfect for Voron StealthBurner Support EBB SB2240/SB2209 CAN Klipper OTA firmware Upgrade 3D Printer Parts : Industrial & Scientific
You may also see offerings that include a CAN bus PCB and additional adapters/cabling: You don't need all that, this is meant for the Voron printers / Stealthburner. All you need for this is the Knomi V2 itself, the power cable and the external antenna.
Small caveat on the Knomi V2.0 (we're working with BTT to find a way to fix this):
During printing, it will display three acceleration bars, one for each axis.
We learned that the values that are driving these bars are not coming from Klipper. Instead, the sensor that makes this possible is a LIS2DW12 3-axis MEMS accelerometer and mounted on the Knomi PCB itself, sensing how the Knomi moves through 3D space.
If you read this far, you most likely have a bed-slinger style printer, and the print head will only accelerate in the x and z directions while it moves during printing (never in the y direction because that is the axis of the bed). The acceleration bar for the Y axis will therefore never really move and remain mostly at zero. Again, we're looking into this and hopefully there will be a solution soon by getting acceleration values from Klipper instead, yet: A vanity item.
Power Supply: 5V DC
We have a working design to put this display on the Taurus, that I ran myself for a while, but since the V2 came out, we're not including these files. Do yourself a favor and get the V2 instead, which has less issues, is a much nicer display and is also touch enabled.
It could be integrated into this case, but there is next to no demand for it. If you insist, contact me and I will send you the STL's for my basic Knomi V1 case design, or reevaluate and perhaps make an adapter for this case.
Mellow 1.28-inch FLY-HALO
Power Supply: 12V DC
So far, we've seen only 134 sold, so there is not much value into integrating it (although I don't like that fact, it seems to have a more sophisticated and nicer UI design).
It would fit nicely into this case, just needs a different retainer ring designed.
Voltage is also a concern, we don't have 12V without adding a buck converter, which has to go somewhere into this case in addition to the cable adapter it comes with (not enough room for all that). Sorry for now… :-(
Your standard profile will do. Nothing special about this. The parts print without supports, you may get warnings in your slicer about unsupported cantilevers, you can ignore all that - it's due to the cooling vents facing down. It will still print fine.
I like to print mine in the same PETG filament as the Taurus was printed, so that it matches and blends into the overall look.
The Knomi requires a +5V DC power source. It's possible to obtain that from the mother board and run additional wires along with the main flat cable up to the head, which would be a mess and there had to be a better way. Some might think we could buck convert off the +24V at the fans, but that is not going to work (PWM signal, depends on fan speed). After some research, there happens to be a static +5V DC power source on the CR touch probe, that is pretty much always on.
To get our +5V, we'll be splicing into the adapter cable that connects the probe to the extruder PCB. I took the following pictures while working with the Knomi V1, but the wiring is exactly the same.
Where the +5V will coming from is shown in the picture below.
It was my observation that this voltage is always present, as long as the printer is turned on.
Knowing the polarity of the power source at the probe, we can now splice in, like shown below.
Please Note this:
The red wire coming out of the touch probe is actually Ground (on the 1st most right pin).
The black wire coming out of the touch probe is actually +5V DC (on the 2nd most right pin).
You should be able to judge the cable lengths yourself, based on the above picture and your own observations. It came out quite nicely for me.
You don't have to and can do this with what you already have, but I decided to buy extra supplies to make this pluggable and reversible/undo-able:
Replacement cables between the extruder PCB and the touch probe to work on:
Amazon.com: Creality Original CR Touch Cable for Sprite Extruder, 5 PIN Adapter Wire for Ender-3 S1/CR-10 Smart Pro/Ender-3 S1 Pro/Ender-3 S1 Plus, 3D Printer Accessories with Sprite Extruder Installed : Industrial & Scientific
Male and female micro JST connectors to make the display pluggable.
https://www.amazon.com/gp/product/B0B2DCJBRM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
The display device is held in place by a printed retaining ring that is inserted from the back during assembly (included).
This ring locks the device in place so that it doesn't get pushed back into the case while operating it with your finger and the touch interface.
To not allow this to happen was very important in this design, but we found that some users printers are not able to hold the tolerances required to make this successful and lock the display securely in place.
To overcome that problem, we are including three different retaining rings with different characteristics and tolerances:
- Knomi V2 Tight Tolerance Retainer Ring.STL
This ring is as designed with a tight tolerance to fit the rest of the model. It worked for me, but is a bit hard to get back out. If you think that your machine is fully calibrated and true on the x and y axis, print this ring and try it out (1st Choice, recommended, if you have a finely tuned printer in terms of dimensional correctness +- 0.1mm).
- Knomi V2 Normal Tolerance Retainer Ring.STL (Recommended)
This ring might be what works for most, it should snap in with an audible “CLICK” but not allow the display device to move in any direction.
This ring is not recommended, but may be a way to make it work if you can't get either of the two above versions to fit snugly during final assembly. If you end up at this solution, you may want to look at recalibrating your printer and print a new case afterwards, followed by the ring.
- Plug in the external antenna cable as well as power.
- Insert the display into the case and press it down carefully, but firmly until it reaches its final depth inside of the case. There is a little bit of rotational play in the bottom of the case, so make sure it's level by comparing the straight edge at the bottom of the PCB to the rest of the geometry, try to line it up perfectly, otherwise the images displayed later on will not be level.
- Rotate the antenna cable so that it points downwards (not as shown upwards in the above picture).
- Finally, insert the retainer ring with the tolerance of your choice.
The ring has a triangle at the top, this goes into the matching recess at the top of the display case. Insert it at an angle and begin pressing down until you hear several “clicks”, locking it in place.
There are several options, you can install the antenna in several different ways.
- Under the retainer ring
- Over the retainer ring
- On the back side of the duct, between the two fans and even tape it to the side of the right fan.
- At the top of the assembly, sandwiched between the duct, the fans and the case.
This is completely up to you, but we recommend the last option. While doing over the air firmware updates (OTA) using WiFi, we noticed that the last option listed above provides for the best WiFi connectivity and speed. Here's how we did it:
Coil the antenna wire clockwise and feed it through the center of the retaining ring while installing the ring. Make it so that the 3M adhesive surface is pointing up (DO not remove the 3M tape, we don't need this to stick to anything.
Tuck the antenna into the space on top of the duct as best as you can, more on that later.
It's ok to bend it to sort of mold in there, it's flexible and won't break.
To have the additional JST connectors in the harness as shown above really helped me. If you didn't include them in your build, please reconsider. But it can be done without those.
- The first step is to restore the connection between the extruder PCB and the touch probe.
- Reinstall the fans and route the cable spliced from the touch probe in-between the two fans.
- Feed the power cables from the display case through one of the openings on the vertical arm on the Taurus and plug it in.
- I would recommend to let it hang for now and power the printer up to see if the Knomi lights up. If that goes well, proceed to the next step.
- Pull the antenna out a little bit and while holding it, slide the case over the assembly while keeping the antenna a little bit out of the case. You should feel the case rest and snap a little into place while keeping it slightly tilted towards you.
- Holding the case in place, slide the antenna towards you into the case until the antenna is no longer visible. This is the location where we found it looks and performs best.
- Now, press the case onto the duct and down at the same time until it seats properly.
- Finally, insert the two screws and lock the display down into its final position.
While doing that, make sure is leveled, compared to the rest of the assembly.
As of the time of this writing, it is very likely that you received a Knomi V2 device that has old firmware on it and has several issues that have already been fixed in the current version. The latest “firmware.bin” file that you can use to update the Knomi2 is located here, on Github: KNOMI/KNOMI2/Firmware at master · bigtreetech/KNOMI (github.com)
I recommend finding the Knomi IP address on your network and updating the firmware using the provided web interface.
The instructions on how to do all this are here: KNOMI2 - BIGTREETECH documentation (bttwiki.com)
Using the factory firmware as shown above, the Knomi2 will display a red Voron logo animation when in standby. I didn't care for that very much and replaced some images compiled into the firmware to match the Taurus/Ender theme a little bit better.
The “firmware.bin” file that you would need to customize your Knomi2 is included in this release. I will try and keep this custom firmware up to date as new releases come out from BTT, but can not guarantee it.
I would like to thank Brad Brooks for moral support, ideas and testing.
I will NOT answer every question or provide support about doing this, YOU ARE ON YOUR OWN. Refer to BTT for support. There are plenty of resources out there you can refer to, to pull this off, please do your own research and troubleshooting.
The firmware I provided is a clone of the factory firmware, with a few screens changed.
If you have problems with your Knomi2, please reinstall the factory firmware. See if the issue persists and if it does, get with BTT for support and don't ask here, please.
License:
Creative Commons — Attribution — Noncommercial
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Mkloberg
