Yidimu Falcon Pro Display Replacement Hack

After using this printer a couple of months, the RGB screen failed, and I was annoyed to find that the manufacturer considers the display a consumible part, and also that many people already had same issue.. so instead of spending 150€ on a new oficial 10.1" 2K RGB screen (which would most likely fail quickly as well), for 200$ I found a way of installing a 4mm glass backed 8.9" 4K Monochrome screen from ChituSystems**... I lose a small amount of print area, but gain in XY resolution and can print at least 3 times faster.. and is a lot more rigid as well (it is possible that my screen failed from using the plastic scraper to remove failed prints from the resin vat, pressing against the screen🤦‍♂️)

Difference between RGB and Monochrome: RGB are colour screens (first resin printers used them as where cheap and came from tablets), and do not let all the light thru, whilst Monochrome are "black & white" let much more light thru (specially made for resin printers) - you can find more info on Google if you wish to know more ;-)

Or https://www.chitusystems.com/2020/11/03/monochrome-lcd-screen-vs-normal-rgb-lcd-screen-whats-new/

** I used ChituSystems as the original board was also a Chitu board, so I knew that all other connectors would fit, as well as screw holes to supporting panel.. there are many options out there, many makes of display and motherboard, you can find a compatible combo and use that as well, maybe even easier than this if can get a mono display with the ribbon cable coming off the side, so then don't need to move motherboard location 🤷‍♂️

Supplies

You will need the following tools:

• Hex drivers, 2, 2.5 & 5mm
• Phillips 1 driver
• Phillips 2 driver
• 3mm flat head driver
• 2.5mm drill bit
• M3 male thread cutter (+ cutting oil, or any type of oil)
• Tweezers, or long nosed pliers, long plastic stick, to help get in and out distinct connectors
• 96º alcohol, or isopropyl alcohol, and a small (1ml, or 5ml is fine) syringe, to precisely deposit drops of alcohol where the hotglue has been placed to block the connectors in place
• Small file to clean burrs from drilled and tapped holes

Also will need to obtain 3 items:

• the new display https://chitusystems.com/product/pj089y2v5-8-9-mono-lcd-screen-for-elegoo-saturn-with-glass-38402400-monochrome-lcd/
• the new motherboard (the old one only works with 2K screens) https://chitusystems.com/product/chitu-l-m1/ note to get PJ version as this is the glass backed screen above, and only board, the touchscreen is already installed.
• and some right angle connectors, either the plugs (easier, no soldering, but more difficult to locate https://uk.rs-online.com/web/p/pcb-terminal-blocks/7900749, they look straight, but the wires come out of the side, so are right angle) or the sockets (have to remove normal sockets from board and add right angle sockets, I found in my local electronics store https://uk.rs-online.com/web/p/pcb-headers/8971262)

And some cables will need to be lengthened, mainly the motor connector from motherboard to motor driver, this wire does not need to be thick, it only carries a signal, and the LED Lamp Fans cable, from the white terminal connector to the motherboard - the others just about fit without any more modifications.

You will also need to make / get made for you the display adaptor board which I modelled and is attached as STL and .F3D (Fusion360 file parametrized, you can change parameters and the model updates).. I used a CNC to make a wooden part, you can maybe 3D print with a high temp resistant filament (the UV lamps seem to get warm, and the print also gets warm when curing so quick), or CNC out of resin type board, even out of aluminium if you trust my modelling skills enough to pay that much!

And finally some software, from https://chitusystems.com/download/, please download for Chitu L M1, the Firmware contains 2 files, one for the display that is PJ, the other for display Tianma, this second one can be discarded as we have the PJ display

I also leave here a screw graphic, in case you need to know which goes where ;-)

Step 1: Backup Actual Machine Configuration!!

This step I had to go back to, it should be done first, but I also attach here my backup file for reference... it is as simple as running a print.. make a text file with this command:

M8512 "currentconfig.gcode" ; save settings to file

and save it as a .gcode file with what ever name you want...

Run the file on the printer, once done, you will have a new file on the USB drive, called "currentconfig.gcode", open this file in a text editor, and you will see a lot of lines with text starting with Mxxxx, and an explanation of each code in Chinese (!) (my file "old2k_config.rtf") for those who don't speak Chinese, I attach another format of the same file (Machine parameters-Yidimu.gcode)... once installed the new board, you can run this file to restore these settings, or make a copy and change some (see last steps, and UVtools wiki on recommended new and better settings)

Step 2: Prepare Area

The machine is large and heavy, so I used some microfibre cloths under the machine to avoid scratching my table ;-)

Notice that I used different amount of layers to accommodate space below each part when lying the printer down, and separate cloths for Top Plate edge and Body - we will go into removing the top enclosure next step, but all later work will be done in this position... to make things slightly easier, it is better the use one end of the table, and put the side door towards the end of the table, this is easier to get to, although once removed the motherboard there is not much difference

Step 3: Remove Top Enclosure

Remove the small screws all around the inside of the top Enclosure housing - there are 2 screws on either side, and towards the back 2 sets of 4 screws (total 12), then the enclosure just lifts off, there is nothing else attached to it

I forgot to take any photos of this step, but it is so easy, if you have enough ability for the rest of the hack this does not need any more explanation 🤪

Step 4: Remove Bottom Panel With Fans

Remove the small screws all around the edge of the bottom panel, note the orientation of the fans once opening, they should be facing the huge heatsink below the LED lamps... once open and lying on the table, loosen the 2 terminals that connect the red and black wires to the fans - on replacing these wires make sure the red and black correspond with the color on the other side of the terminal block!!

Put aside the bottom panel until closing the machine

Step 5: Disconnect Motherboard Cables

TAKE A PHOTO, and preferably label the cables with the names you will find just below each green socket - always better to have something to remind you in case of doubt, although almost all the cables are also pretty unique and identifiable by other means (following them to where they go to)

The connectors on the motherboard have been hotglued in place, the easiest way to remove hotglue is with alcohol, place a couple of drops on each blob of hotglue, wait a few seconds, and the hotglue should be quite easy to pry out with tweezers of long nosed pliers.. a long thin plastic stick may help get blobs out of hard to reach places that still block the connectors

The 2 ribbon cables (display and touch screen) connectors have to be carefully prised open (see https://www.youtube.com/watch?v=3AH3FCj4jhs for best practice) - note the side of the cable that is "up" (bare conductive wires showing, or plastic backing on the other side), if the touchscreen or display do not respond at all on power up, it is possible that the cable has been put in upside down

Step 6: Remove Current Display Adapter Plate

I forgot to take photos until removed, but is as easy as Enclosure: there are 9 screws around the Display, 2 on each side and back, & 3 on front... once removed all the screws, carefully separate, taking into account the ribbon cable is on the same side as the motherboard, but it will slide out very easily as is already disconnected

Step 7: Opening the Top Plate 1...

Here we must start to take more care, when separating these parts there are wired connections that have to be removed, but we will not remove all, only enough to give us some space to move the Top Plate far enough away to be able to access certain other wires, that once removed will allow complete separation in the next step

First remove the screws around the edge of the Top Plate, then carefully pry aparte the Top Plate from the Body of the machine, sliding away Top Plate on a separate microfibre cloth from the Body helps a lot... once have got a few cms open, stop and go to next step

Step 8: Opening the Top Plate 2...

We will first remove one of the SSR Relay wires, the red one, which will be almost stretched right now but not quite... the other side of the SSR Relay is not necessary to disconnect.. then go to the NEMA motor Driver and disconnect the 4-pin connector (it will have hotglue, again use a little alcohol to remove hotglue first) that goes from the dricer to the Z-motor...

Once disconnected these 2 cables, you will be able to separate the Body and Top Plate some more, until the until LED Lamp section is accessible - do not separate too much, the 2 parts are still connected with the cables of the LED lamp unit, and the red wire that you disconnected before will be almost pulled straight again

Step 9: ... and Separating From Body

Now we have to remove the LED Lamp unit from its housing, but to get to it you have to remove the motherboard first... as all the cables are already disconnected, this is as simple as remove the 4 screws in the corners of the board...

This will reveal the 5mm hex head screws that hold the LED Lamp unit in place, 2 on each side, remove these screws and then also the motherboard supporting plate (or first remove the motherboard plate, does not matter)

CAREFULLY slide back the LED Lamp unit, it is quite heavy and sharp, so use another microfibre cloth - try and avoid touching the LED bulbs, although in theory they are not as susceptible to finger grease as older incandescent or halogen bulbs, possibly not too much of a worry - once it is removed, it will not go far as is still attached to the rest of the machine, but the Top Plate can be pushed away to make space to rest the LED Lamp carefully on the table

Move the Body of the machine away (or move the Top Plate further away) until completed the repositioning of the motherboard support plate, you will be drilling and threading metal, which creates metal shrapnel that can easily short any electrical connection

Step 10: Optional - Solder New Sockets to Motherboard

If you have not managed to get the right angle plugs, then you will have to de-solder the straight up sockets (I first pried apart the plastic housing slightly until could cut away the pins from just below the housing, then could de-solder individual pins rather than 4 at once) and replace with right angle sockets, you should know enough about soldering medium pin sizes to be able to do this without burning the board - one of my sockets melted slightly and moved from position, but not enough to make unusable - it also does not matter what size sockets you use, as long as the first 6 are in place.. the last 2 on the left are not used, but I put new anyway

Step 11: Positioning New Display to Align Motherboard Support Plate

This does not have to be as precise as may look, the new display has a long cable which can accommodate slight horizontal deviation of the motherboard connection to the display, but should be more or less centred...

Orient the support plate so that the offset larger edge is towards the top of the machine... this will give some space below the motherboard to plug in the connectors...

Place the new display in the new adapter and fix with 4 screws to the Top Plate, with the cable on the front side, and take the new motherboard, fixed to its support plate by at least 2 screws, and present on the front side of the LED Lamp unit/ housing - the aim is to line up the display connection on the board with the cable, and at the same time line up the support plate fixing holes (not the motherboard screw posts, the 4 holes further inside) with the top and bottom edges of the housing - make sure when you do this that you have the support plate in the correct orientation with the motherboard fixed to it

Swipe a marker pen along the edges of the support plate, on the actual housing, then remove the motherboard from the support plate and place the plate aligned with the lines just made - centre the plate fixing holes as mentioned above, and then mark these holes - do not worry if they are not completely accurate, next we define better the places we will make holes

Remove the display adapter again and place aside, far from shrapnel

Step 12: Aligning Support Plate Fixing Holes

Now we mark the best we can the places where we will make new screw holes... measure as best as possible the actual screw distance... it is easier to measure from edge to same edge, rather than from centre to centre... translate these measurements to the housing, first mark lightly, and once sure mark stronger - I used a small pair of scissors and the edge of the support plate to get the pairs of markings nice and square... remember to test one last time with support plate, all markings should be centred

Make sure to make markings larger than drill bit, to be able to always see that the drill is centred on markings

Step 13: Drilling Holes

COVER THE LOWER PART OF THE MACHINE! ALSO THE Z MECHANISM CHANNEL

You will be creating a lot of metal shrapnel now, so best to cover up all parts where do not want to risk getting later problems.. use a vacuum cleaner to actively try and pick up bits of metal as they get cut... go slowly for first moments, stopping and checking that the drill bit has not slid away from centre - once started, there should be no problem

Step 14: Threading Holes

WE WILL BE MAKING MORE SHRAPNEL!

When tapping threads, I always use a drop of oil to help cut.. today I only have some bike oil 🤷‍♂️

Try and maintain the tap perpendicular in both X and Y, it is easy to tap at an angle without realizing it (although will not gravely affect the hack if is slightly off)

Once finished, it is time to file away the burrs that remain from the previous operations.

Shown is the shrapnel that remained, even when using a vacuum during the drilling process - do not want that in the Z mech!

Test each hole with a screw now, before mounting and finding out later that some hole does not let a screw enter

And finally check alignment is close enough to allow all screws to enter holes thru the support plate - fix the plate in place, and the new motherboard to its support plate

Step 15: Bringing It Back Together

You can now fix the new display, adapter and mount to the Top Plate - don't forget to remove the plastic on the glass side of the display, but leave the screen side until later... if correctly made, it should be a press fit, although YMMV if you use a harder material than wood.. if it is loose, you will need to obtain 3mm wide double sided tape to stick down the edges of the display to the adapter - any mobile phone repair shop will have some that you could obtain or buy cheaply for the length you need (maybe take the display and adapter to the shop as this stuff is difficult to transport once removed from the roll!)

We now reverse the process of the LED Lamp, so again we will be restricted in how far we can separate the Body and Top Plate, be careful!

Both ribbon cables from Touchscreen and Display have to be carefully folded to fit in the space behind the screen where they now live, first connect the Touchscreen ribbon cable, take note of which way up, and how it is twisted from the touchscreen to the motherboard.. when closing the machine this twist will help the cable stay on one side, with a little help

Connect the Display cable, note how this cable will be folder over towards the bottom on closing the machine

Step 16: Lengthen Cables...

Now you should also lengthen the motherboard to motor driver cable if not done already, the new mother board comes with several connectors ready to grimp to cables and install... the end that goes to the green 4 terminal connector at the motor driver is easy, for the other end I use tweezers (that came with machine) to fold the wire ends (I feel gets better grip on the wire that way) and a long nose pliers to carefully fold and grimp the individual metal tabs on the connector pins, finally slide the pins into the connector body, observing the same order and orientation (so they get trapped properly) as the original connector!

Also good time to lengthen the LED Lamp Fans cable, that goes from the white terminal connector to the motherboard... I did not have any red and black cable, so used the closest I had, orange and grey 🤷‍♂️

Step 17: Connecting More Cables

You should now have the motor cable connected to the motherboard, the fan cable we connect when the machine is better closed..

Can now also connect the Z end stop... this is the tightest cable now, however with carefully routing it should just enter and be very slightly slack

The cables left to connect should be the green plugs on the motherboard, the 4 pin green plug on the motor driver, and the red cable we removed from the SSR Relay... and the USB and ethernet extenders

Step 18: Bringing It Back Together, Even More

Now we bring the Body and Top Plate together even more, until we close the gap - if it does not want to close, maybe the 4 pin connector got trapped at the back 🤦‍♂️

Observe carefully the twist in the Touchscreen ribbon cable, but it should not get pinched, maybe need some help to get in between LED Lamp housing and Body housing - also help guide/fold the Display cable as shown above in step 15

Now can connect the 3 green plugs to the motherboard, the green 4 pin plug from Z-motor to the motor driver, the red cable to the SSR Relay, and the USB and Ethernet extenders to the motherboard

Screw down the Top Plate in place, maybe need a bit of wiggling to get the first screw into place, thereafter should all enter OK

Step 19: And Close the Machine

All cables except the bottom fan assembly should now be connected - present the fan assembly and connect the red and black wires that you disconnected previously..

Lift the bottom panel as if it was on hinges, but when closing, observe that the cables connected to the bottom of the motherboard with the green connectors, have to be bent back on themselves slightly, to allow the closest fan to squeeze by them and finally shut the bottom panel... if you are at all worried about the fan clipping the cables, you will have to find a way of fixing them, however I think that they way they get bent to allow the fan to fit in will oblige the cables to rise above the fan blades, and a thin cable is not easily blown/sucked by airflow anyway

Step 20: Final Mechanical Touches

Now all is closed, then can put the black strips of tape that come with the new display in place - observing the display previously, I noted that the actual display area was about a mm larger than the protective plastic sheet that covers the screen side of the display, so placed the black strips about 2mm away from the edge of the protective sheet...

Finally replace the Enclosure, before removing the protective plastic sheet from the display.

The mechanical part is done, now only remains to configure the new motherboard

Step 21: Software Configuration

Remember the back up config file you made first of all? Now is the time to put that back on the new motherboard..

First take the Firmware file for the PJ version and put the update.LCD and the PJ8.9xxxxxxx.cbd files on the USB drive, in the root, not in any folder... connect to the printer and power on... this will automatically detect and upgrade the FW on the motherboard to the latest available.

Power off and take the USB drive, and put on it the backup config you saved earlier (remove the FW update files, otherwise it will update each time you power on with the USB drive connected), connect, power on, and run this file from the Print menu.. the printer will run it, and quickly beep that it has finished

Your printer is now set up as it was previously!

RECOMMENDED alternative settings, go read the Wiki at UVtools, https://github.com/sn4k3/UVtools/wiki, where you will learn about this amazing helper program for resin printers (https://github.com/sn4k3/UVtools/releases), with Expo calibration, repair of print files, and a load more... very interesting is the authors observations on what parameters should be changed to what values, to help a resin printer have successful prints - above I also left attached the recommended UVtools print settings after having read up on the reasons.. these parameters make for a slightly slower printer than default settings (remember that with mono display will be able to print now 3-4 times faster anyway!), but a lot better print success rate as the author explains the fallacies of print settings and recommends some values that I see totally appropriate

You will now have to change also various parameters in your Slicer, if you are using ChituBox, then you will have to make a new profile, or can just use EPAX E10 4K printer and change the parameters such as Z size... also, I notice that the print comes out inverted on the Y axis, so I changed the Machine Mirror settings from LCD_mirror to DLP_normal (for some reason the printer screen and new resin display show/print at 180º from each other, but at least this way the parts come out correct orientation, otherwise you will have to remember flip in Y - importante for non-symmetrical parts!)... for my Print Settings, with Anycubic normal resin and 0.05mm layer, I am using about 1.4s normal layer time, and 30-40s bottom layer - the attached screen capture is for an old special resin with certain mechanical properties that I had lying around, and with a 0.1mm layer height - it required 5s normal layer which is NOT normal for a monochrome display.

Preferably I would recommend you learn to use UVtools, the Exposition Time Finder, on any and all resins that you use with the printer to find out their ideal expo times.. with such a short expo time using a monochrome, the difference between 1.3 and 1.6s from one resin to another can make a big difference in detail (or lack there of!)

NOTES:

1) once you open up in UVtools any file made correctly in ChituBox, UVtools should then be able make an Expo finder for this machine parameters, otherwise it does not know this machine parameters and will use incorrect resolution settings (see note 2, but this is not from original slicer, which has to be set correctly first), and is also able to reconfigure your Prusa Slicer (or SuperSlicer, a clone of Prusa Slicer) so you can use this slicer instead of ChituBox - this function is in the Help menu, choose EPAX E10 4K printer and change the parameters such as size when you open Prusa/ SuperSlicer - here I also see that by default Prusa / Super Slicer FLIP Y axis (the same as changing Mirror en ChituBox.. finally note that you can ALSO flip the entire print orientation in UVtools (again, many more things you can do with this great opensource software)

2) if you get an error on touchscreen about "Different resolution with projector", then most likely the X and Y resolution values have been put in reversed - for some reason with the 2K screen the X value was less than Y value, so I edited them accordingly, but this display is at a right angle from the previous one, so have to be inverted, X is largest value

3) Unfortunately Yidimu use a NON-dimmable LED Driver (the big silver box with the white label on one side in some photos), otherwise recommendations would say to reduce LED Lamp power to 80% via PWM, but this setup does not have PWM or is dimmable, so we have to use at 100%... this will create a bit more heat in the resin when curing, and may eventually wear out the LED bulbs on the array - look forward to another Instructable about changing these bulbs, as one of mine has already failed, and another is flashing - as the total power of the driver is used by all the WORKING bulbs, each time a bulb fails the rest will have a bit more power sent thru them, and thus will surely fail a little earlier - conceivably there could come a point where there will be a chain reaction of failing bulbs as each failure pushes more power thru the remaining 🤦‍♂️, so it would be a good idea to change the failed bulbs before too many stop working to cause this chain reaction!

Step 22: Enjoy Faster Print Times and Higher Resolution!

If you like this Instructable, it is my first, hope it was clear enough to follow easily, I appreciate any comments if there is something that needs to be cleared up (I will try and edit this later), but I will not be taking any more photos ;-)