12/22/2025 - Began work on the schematic.

Okay so short summary, i have a bit of a time crunch with this project because of the end date of blueprint but i am trying to make it work. I have chosen the STM32F446RETx for its power and not to many pins for soldering. i am going with the TMC2130-TA stepper motor controllers for there excellent performance. I added these stepper drivers and started wiring them up these probably will be the most complex parts because of all the support infrastructure needed. All the caps, sense resistors and i want to add spi bus for configuration Currently working on the mosfets for the heaters and the thermister inputs, also still need to do usbs and power input.

So this is later me an hour before uploading changing this journal so its more detailed because i made my journals in the beginning way to short whoops sorry guys.

Anyways, I choose the STM32F446RETx because when i started this project i thought 64 pins will be sufficient and i wanted it to be easy to place. This is because i am going to hand place and reflow this board. I selected the TMC2130 Stepper drivers because of their excellent performance and features, to name a couple: Silent stepper driver, senserless homing, spi configuration, high power, ext. these where the best ones to fit my criteria so i chose them. I wanted allot of features on my board so i went with 5 stepper drivers instead of the normal 4. At this point i was working on the mosfets to drive the heater and bed, i also wanted to maybe even drive a small spindle from these so i went very overkill with the possibility to use multiple in parallel to get more current. I have 4 and these are driven from the Vin lines so 7v-24v This is about what i have done that day, I mostly looked at datasheets and searched up allot of components, at that moment this was far above my league so i wasn't the fastest.

12/26/2025 - Got further with the schematic.

So just got back from vacation and started working on this late night, cola-induced, no-time, grind of a project again. I got the dc dc converter from texas instuments for the 5v bus also added fan control, dc power input and limit switch inputs. Also thinking about adding an extension place to place a small pcb for different displays and knobs.
Schematicv
For the info i am loosely basing my main board on a combi of the UM2+ main board an the Prusa mini main board for inspiration.

This is me again still an hour before submitting

I choose the texas instruments LM76005QRNPRQ1 because texas instruments is peak and very good, also the have a nice tool i think its called texas instruments power designer to make your schematic for dc/dc converters that will specify everything needed and all the values very handy to have if you are planing to use dc/dc converters that don't have everything integrated.
I started working on fan control, I wanted 4 fans and tach inputs to read the speed. The speed of the fan is controlled by a pwm controlled transistor to change the voltage. The limit switches where pretty easy to design not much to say.

12/28/2025 - Almost completed the schematic

So today we are going further on the late night, cola-induced, no-time, grind of a project that this is, so almost completely finished the schematic except for the thermisters, however @Kai Pereira got me thinking why not just external modular temp sensor measurement converter. This could allow for all types of thermisters of different resistance or type.

also cleaned up the schematic allot!
this has side effects. 11 pages later.
schematic
also started work on the BOM for ordering and the capacitor and resistor sizes.
changed mcu from the stm32f446vet to stm32f407vgt for
A better connectivity
B more pins (needing 50 GPIO is insane)

For display, knob and ext. attachments i have added a expansion port with allot of IO for controlling oleds, knobs, sd cards, ext. without locking the pcb in to one display or any proprietary stuff.

TODO:
component assigning
LCSC BOM
Placing and Routing
thermister board
expansion board

12/29/2025 1 AM - Started on the BOM and finalized Schematic

Schematic

So today is another day that i have done something to this heck of a project. I finalized the Schematic of the pcb, calculated resistor values again and etc.
schematic

Part selection

I was dumb enough to not select parts from LCSC and build on that so i had to find replacements here and there which takes up allot of time. also started the BOM with prices, qty, LCSC numbers and everything. Started to decide which connectors to be used from which type. checked voltage rating on parts of the power circuit.

Time Crunch

I have been realizing that these 8-10 hour days are pretty tiring but the cola-induced late night battle continues. because we never stop no NEVER! I still have allot to do before the 31st January so we are going all in.

TODO

component assigning 50%
LCSC BOM 50%
Placing and Routing 0%
thermister board 0%
expansion board 0%

12/29/2025 7 PM - Continued the painstacking process of part selection and BOM

Part selection

Finally choose all the footprints for all the parts and completed the BOM with all the LCSC numbers and prices.
this was about 3/4 way its insanely time consuming

Also had someone i know check the schematic for error and boy what is it prone to errors at this scale.
for the people that can read Dutch its here bellow for non Dutch speakers the English translation is below that.

Feedback from someone who can actually design PCB's (not me)

Dutch:

Algemeen

• Probeer in component waarden geen punt te gebruiken. Fout vermijdend is dan liever 1k8 dan 1.8k
• Labels met een label-vorm worden met name gebruikt als een signaal van het blad afgaat. Er zijn ook met alleen tekst ook net-labels beschikbaar voor signalen die op de pagina blijven.

Fan
Weerstandskeuze van het tacho signaal. Schakelt nu van 0 naar 2.5V
Ledstroom is 1mA.

USB
Let goed op welke USB-C connector je gaat gebruiken. Er zijn verschillende soorten met verschillende schema symbolen.

MOSFETS
Moeilijk leesbaar door lay-out achtige schema symbolen. Gebruik liever een echt MOSFET symbool en zoek daarbij een passende footprint.
Vaak krijg je van een leverancier gemakzuchtige symbolen aangeleverd. Kies bv de NVMFWS4D5N08 als symbool en pas hettypenummer daarbij aan.
Het schema 'leest' ook makkelijker als de stroom van boven naar beneden op tekening loopt.
Bv van boven naar beneden +5V R68 D19

Power In
Ik zou nog een blusdiode (1N4148) over de spoel van het relais plaatsen
Vbus is nog niet (officieel) verbonden met de USB-C connector

Succes verder!!📯

English:

General

• Try not to use a period in component values. To avoid errors, it is better to use 1k8 than 1.8k
• Labels with a label shape are mainly used when a signal switches pages. Text-only net labels are also available for signals that remain on the page.

Fan
Resistance selection of the tacho signal. Now switches from 0 to 2.5V
LED current is 1mA.

USB
Pay close attention to which USB-C connector you are going to use. There are different types with different schematic symbols.

MOSFETS
Difficult to read due to layout-like diagram symbols. It is better to use a real MOSFET symbol and look for a suitable footprint.
You often receive symbols that are conveniently supplied by a supplier. For example, choose the NVMFWS4D5N08 as the symbol and adjust the type number accordingly.
The diagram is also easier to read if the current flows from top to bottom on the drawing.
Eg from top to bottom +5V R68 D19

Power In
I would place another extinguishing diode (1N4148) across the coil of the relay
Vbus is not yet (officially) connected to the USB-C connector

Good luck!!📯

This has been good feedback for now, still need to complete the BOM and then start placing and routing the PCB.

TODO

Component assigning 100%
LCSC BOM 75%
Placing and routing the PCB 0%
Thermister Board 0%
Expansion Board 0%

12/29/2025 9 PM - Completed the BOM and LCSC order

So finally I completed my Global BOM (except for the price of the PCB itself and the daughter boards.)

this was by farrrrrr the most time consuming. But hard work pays of, plenty of different components to follow the stock that LCSC has. also conveniently the only component i really needed that LCSC didn't have I have at home ;)
I have in total selected 75 components and labeled them and added links and the part numbers. Looked in datasheet after datasheet for specs of different caps and resistors i need for stepper-drivers, stm32f407 and ext. For example I needed really accurate resistors for the 5V DC/DC converter to get a stable and nice 5V so I went for 0.1% instead of 1% like the rest. Also looked at Chinese datasheet one after another to confirm i had the right parts and footprints. The resistor and caps are pretty easy if you find a manufacturer that makes allot and has easy naming scheme. By far the worst were the connectors, I have allot of connectors on my board for all the steppers, limit switches, heaters, ext. This is absolute hell if you do it like my stupid brain did, you need to design around LCSC stock, IF YOU DO NOT DO THIS YOU WILL BE SPENDING HOURS FINDING REPLACEMENTS.
The price is noticeable to say the least.

I must say that this is for 2 Boards and that the stepper drivers are by far the most expansive at €50 total.

###Schematic
I think i am on the 8 revision or something, I really want to make this a good mainboard. So every little mistake i fixed and i make allot of customization possible via the expansion port and thermister ports.

###TODO
Component assigning 100%
LCSC BOM 100%
Placing and routing the PCB 0%
Thermister Board 0%
Expansion Board 0%

12/30/2025 - Started placing components

###Finally began with placing components
After about 40 hours of work in schematic and part selection its has become time to place parts. I am really happy to do this after looking at a schematic and excel for the past 3 days.
So I opened the PCB editor and updated form the schematic and got a reality check on how many parts there really are, looking at 262 parts in a schematic for the last 3 days and it doesn't seem that big anymore until you open the PCB editor and look at how many parts there really are and the shear scale of this project. For your info the biggest PCB before this one that i have made was about 40 components, the hack pad.

first i needed to fix some footprints and symbols so the pins line up.
then I started with laying some stuff out. i looked at the datasheet for the 5V DC/DC converter and copied the layout recommendation to get a feel for spacing and what needs to be where.

This is by far the furthest from the final version, this is just a test and to know the layout from the DC/DC converter.
Then I began on the power input: the connectors, switch, caps, fuses and the relay, yes there is safety integrated;).

when that was about as far as i felt was good for that time I went to the high current section, the MOSFETS. I laid those nicely out with equal spacing so everything looks nice. hihi. ascetics are the priority, i think i want a white or black PCB. those look the best!

These are still proto-layouts and not the final layouts.

Thanks for reading this!!!!

###TODO
Placing 5-10%
Routing 0%
Thermister Board 0%
Expansion Board 0%

12/31/2025 - Placed all the components and started routing the sections.

Placement

First i stated with permanently laying out the stepper motor driver because the are the most complex on the board. This wasn't one go i iterated the stepper motor driver layout until i was happy i think this was about 5 times of redoing the layout and routing. This was difficult because the 3 high amp pins are right next to each other. but got it working. Really learned how to do high amp stuff this PCB.

V1

V2

and last but not least i think V5


then i began work on the power input part of the board, essentially the whole bottom part of the board. and yes i work on safety systems so if something goes wrong you can turn the printer/CNC off with one or two emo buttons or switches. Safety last guys!

then i placed and routed the mosfets.

started a bit on USB because its pretty simple

this is how it looked at this point

already had the 4 mosfets but was still waiting on a review for the stepper motor drivers from someone who is a better designer than me, after a few changes he gave the green flag! YIPPEE! :)
then i duplicated the stepper motor drivers 4 times and changed the references to match the other four stepper drivers on my schematic. then kicad changed it mind and still thought i needed the four stepper drivers even tho i had these already on my pcb. This was really irritating everytime i updated the pcb for pinout fixes ext. i needed to delete the four stepper drivers that it added, after a bit of investigation this is the setting you have to turn on to get kicad to look at the designator and not the id it gives every component.

after this ordeal i was back in the flow state and started on the fans, limit switches and thermisters
J13, J14 and J15 are for power selection of the fan, either 5V from the DC/DC converter or the input voltage supplied by the power supply (credits to AC/DC HIHI i am so funny :D. for getting me trough this 50 or so hours it has been, music has been on full blast (also other artist), i have a sound system the room that the PC is in so its music all the time. anyways here is the picture

and for the limit switches it was pretty easy because of there simple schematic, the thermisters i have external boards for because every different type of thermister needs a different type of system to convert it to a good input for a ADC.

then there was a bit of a reorganization to try and make everything fit on a PCB of 100x175mm
so the stepper drivers where rotated and moved to the other side to be lower, because my idea is to have all the high volts/amps low on the board where the power input is located. placed the fans in between the drivers and mosfets for space efficiency. and below the fans is the 5v DC/DC converter to be close to the input and fuse.

after this it was a point of finalizing, pacing the support infrastructure for the stm

then place place some miscellaneous stuff here and there, and last but not least my favorite the expansion header for all type of shit like front panel IO.
still need to add some 3d models for some renders. But this is where it is at the moment.

My big brain had its 3rd brain cell activate this evening and thought it was MAYBE a good idea to base the pin out of the stm on the board itself and not my round of Russian roulette that i did at the beginning, also fun fact i still haven't figured out how to get stmCUBE to display all the possible pins for a something like a SPI pin or i am just dumb, if anyone knows let me know!!!!

Also had the big brain idea that in a place where 5V is abundant its not that good of a idea to power your LEDs from 3.3V you will have to carry all around to those LEDs so i chanced the resistor values for 5V instead of 3.3V.

Very deep stuff if you want

also if you have resistive loads like heaters and fans place your LEDs BEFORE your mosfet or transistors to prevent excessive voltage in the wrong direction
my caveman brain explanation

fixed a few other mistakes in the schematic after realizing them while laying out the components/routing.
Have a good day i am going sleeping after to many hours today after five days straight of a grind this is.

TODO

Placing 100%
Routing 25%
Thermister Board 0%
Expansion Board 0%

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design that me that looked over my schematic and layout ext.

1/2/2026 - Some small stuff

New Year

I wish everyone a happy new year!
so this wasn't a long day at all mostly family came by so have not put so much hours into this project today, hopefully that will change tomorrow.

Routing

First I routed the big power wires for the mosfets, steppers and fans.

Then it was time to draw the IO for the stepper drivers. So these stepper drivers I use have the capability to be configured via SPI so there are allot of wires per driver 4 per driver (Step, Dir, En, CS) and then 3 for the SPI bus (MOSI, MISO, SCK). I also had to redo the pinout of the stm32 to have a easier pinout with pins based on location not on random choose. this took some time to also find good pins for not only GPIO's but also the SPI's UART's ext.

The process

This is almost never 1 try it almost always takes multiple tries to get it right.
Here is started with the spi lines on the left side of the ic.

then a picture of them all.

then i started on the 20 GPIO lines that needed to be placed.

here redid the pinout of the microcontroller

after that i had them connected to all the driver ic's

then the micro controller itself.

and then changed the signal linesfrom inner layer to an outer layer. credits to @Kai Pereira for this.

routed a bit of the top IO

then also changed the spi lines from inner to outer, this was a puzzel.

extra photo:

Black PCB's look FIRE!

TODO

Placing 100%
Routing 60%
Thermister Board 0%
Expansion Board 0%

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design that me that looked over my schematic and layout ext.

1/3/2026 - Got furter with routing the MCU

NEW MCU YESSSSSSS

So for a performance upgrade i decided to switch to an STM32H743VIT to have more OOMPH in the processor and have possibility for higher step update cycles. I also updated because of the more IO so less restrictions to where the IO is located. But for this something was needed to upgrade.

Complete redo of the MCU

so I added the new MCU to my schematic and had to only change where some pins where located so that was not that much work. Then i decided to completely redo the pinout of the MCU to have nicer wires, and with that comes deleting all traces.
This is where we left of last time.

and this is where i was this morning.

I had placed the decoupling capacitors again because the pinout was just a bit different that is wat is seen above, the usb was on the same pins so that staid the same. then i decided i wanted to clean up the top traces to the extension headers and not have as many vias so redid the pinout. here a few pictures of the progress i think i did like 4 revisions or so.


then changed the pinout of the expansion headers to go from this.

to this

also changed the pinout to go from this


to this, this is to avoid vias and have nicer traces.



then added the boot pin and changed the position of the vias for better accessibility.

to this(for the vias)

also added SWD for debuging (thanks to @Kai Pereira for the tip)


also this is a board from a a few months ago I have come a very far way since then

then i decided to add the four gpio that are inbetween all the expansion port traces to the highway for the other expansion port.
so from this.

to this. way more ascetically pleasing.


then broke out the 4 gpio stuck in the trace highway. and moved it to the other side with I2C as well.

these where the looks so far


then needed to fit some io trough a tight hole

finally added that too to the expansion port.

CRASHOUT

Then the major hour long crashout began on kicad, i had placed 20 traces next to each other for the motor drivers but i realized that the where not correctly spaces as seen by the last line not on the grid. (the cursor is in the bottom right, and is correctly on the grid)

then i did this


deleted all traces yes i did that, i wanted to completely reroute not exactly different but with correct spacing or my autism would kick in.

rerouted the traces so it was correctly on grid, this was far from the fist attempt i think kicad decided to give me wrong spaced traces 4 times after i fist deleted the traces. because he didn't like me.
this was one of the failed attempts

and here i had all 20 spaced correctly. (FINALLY YESSSSS)

Changed pinout

so i wanted nice traces so i changed the pinout, after to many times in the datasheet to see if the pins didn't have any restrictions i started routing.


then did the other 11 at the bottom

time for some tidy up

looking much better.

Then the fan control

i had to also change that pinout

then added the speed sensors of the fans

this is about how far i have come today, two pictures picture of the day progress
from this

to this

yes i am a perfectionist, because if i am giving out 200 bucks for a project i want a good project.

TODO

Placing 100%
Routing 80%
Rework BOM 0%
Thermister Board 0%
Expansion Board 0%

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design that me that looked over my schematic and layout ext.

1/4/2026 1 AM - Finished IO and started with 5V and 3.3V power

Cover Picture

BAND-AID

Finished IO

So after the last bits and bops and some rerouting again of some IO to make place for ADC's that i forgot. This was a big job but forgot to take screenshots of this progress (stupid me)

Here i have placed every single line to the micro controller to make it work, after about an hour of rerouting to accommodate the ADC's this took some time but after that was done i added the fans, mosfets, and the limit switches, this in total was about 3 hours of work.

Crystal

So i heard that you need to add a kind of ground barrier around your crystal so here is my try.

Power

So today i started om some power layout to feed the 5V and 3.3V of the components. this was a bit of a job to add all the via's everywhere for the power that was needed, also redid some planes for better space.

this is where i have ended up, 5V on the bottom for everything, 3.3V on the top for IO and micro controller and VIN to the left for the motor drivers.

Total

Sorry for the short journal today, forgot to take screenshots of the progress :(
this is where i have come today.

TODO

Placing 100%
Routing 85%
Thermister Board 0%
Expansion Board 0%

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design that me that looked over my schematic and layout ext.

1/4/2026 11 PM - Thermister Board

Cover Picture

Also added all the 3D models!

Thermister Board

So started on the first of 2 types of thermister boards, the one for a ultimaker 2+ and i think more ultimakers, but i still have to make the one for NTC's anyways here is the ultimaker thermister

this is the ultimaker 2+ schematic for the two thermisters

still figuring out how this circuit exactly works but its complex for what its doing. I asked someone who knows pcbs better than me if this was strictly necessary and he said "no, this is a circuit for measuring sub C degrees" I don't really need that but the thermisters used in the ultimaker 2+ aren't normal NTC's so for now i copied the schematic so it would work. This is also the whole reason i did this separately on a different board so i i f*cked up i wouldn't have to order a whole new board 40+ EUR. Also did this to have different modules for different types of thermisters that you may see.
anyways here is mine, created my own symbol for this component so it would be correct.

then opened the pcb edditor to route and started placing the components on this board,

Then i placed all the components about to the guidelines of the chip where i could. got this

At this point i tought okay maybe its a good thing to check the space on the main board. well good thing i checked, my thermister board was 13mm wide at the moment and yeah, just look at the picture

looks to me like a pretty 11mm, and i want some clearance so i needed to go down to a 10mm wide board. (10mm outline is gray)

yeah whoops, little oopsie there. Also there is no way that i was going to get these components to fit without doing back and front but i can't do that because i am going to solder this with a hotplate and that doesn't do back and front, only back or front. So it was time to downscale, looked at the datasheet for other possible packages and landed on this. 3x3mm with 0.5mm pitch.

This thing will be very fun to solder :)
At the end i did increase the length between the connectors because 10mm was not enough. as seen in the two pictures.
then added that one and just look at the size difference.

okay so now i rearranged the parts again to design guidelines as much as possible. and ended up with this.

Also added ground pour as recommend by the design guidelines of this chip but i always do ground pour :D
and a cool render, yes i still need to ad the 3d model of the ic.

this ended up successful and I made the first thermister board with dimensions of 18x10mm very tiny.

TODO
Placing 100%
Routing 100%
Thermister Board 50% (still need to do the second one)
Expansion Board 0%
Fixing the BOM 0% (I don't want to do this i hate this)

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design that me that looked over my schematic and layout ext.

1/8/2026 - Second thermister board and expansion board

RENDERSSSSSSS!!!!!!!

So i wanted some nice renders so started learning blender for this project.
This took alllllllllllot of time because i am completely new to blender. But there is one thing supporting me, my NVIDIA 4070TI fighting for its life, render time of 1:45 minutes for 4K render, not to shabby. Imaging doing this on a Inter core I5 integrated graphics that would be painful. Anywhese here are the results of the 2 hour blender grind.
I present:

Expansion board

I started on the expansion board a few days ago and it was not that hard, here is the schematic, its just a simple pinout converter board with 2 resistors for I2C for the display.

The schematic wasn't to hard to make so i started on the placing and routing of the components.
Here i placed the components, and the 2x08 headers are on the backside and have specific spacing requirements according to the mainboard.

Then routed all the components(not to hard after a whole mainboard) and added ground planes


Yes this one will also be included in the renders but haven't got time for that yet and still need to learn blender allot.

Second thermister board

Also started on the second thermister board for the project to complete them, this is a simple one with 2 resistors and a solder bridge selector for the two most common NTC thermisters. The schematic for this one is very simple.

Then i routed this one, not to hard

Very easy.
Then i tried around allot to have different possibilities to join the 2 thermister boards so i only have one pcb and that is cheaper, will be adding the expansion board to.

I decided to use mousebites for this, i really don't know if i am doing this correctly but it should be fine(famous last words)

TODO

Placing 100%
Routing 100%
Thermister Board 100%
Expansion Board 100%
Fixing the BOM 0% (I don't want to do this i hate this but this is the only thing left)
Perfecting renders 30%

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design that me that looked over my schematic and layout ext.

1/11/2026 12 AM - BOM Ughhhhhhhh

More Renders!!!!!!!!

So got further with the blender grind, changed lighting, i think i have 4 or 5 lights, i don't know anymore my brain has been broken by blender. But got some results after 3 hours of changing random stuff that i don't know what it does.

And sometimes you turn some dials to far and then you get stuff like this.

Also me be like

"This looks to me like the control center for a nuclear power plant with all the buttons and options."
Wise words by a stupid man.

BOM

Ughhhhhh my least favorite part of this whole project, the dreaded BOM.

Me at the moment.

So i opened kicad and exported the BOM for the hopefully last time (prob not) and placed it in the half completed bom that i had made to this point

This thing.
Started with checking of everything was correct in the sense of do i have enough? is it the right resistance? is it the right package? ext. this took 2 hours and it was hell.
after this was done i started to look at my LCSC cart and checking if i have everything in my cart and enough.

This is one heck of a irritating job because everything is mixed and inside out so first i gave every part my own number in the order of my own BOM so its easy to see. Then i exported it as an excel document and opened it to check if prices where correct and i had every part and didn't miss something, because if i make a mistake and miss a part i could be 60 euro's deep and that's not fun.

Also i am cooked mentally at least i still have to do the bom for the expansion board and thermister boards. I love life :D
This space is left over for these

but i realllly don't want to do it, but it has to be done. Otherwise i would have to pay for it myself and i am a broke boy and don't have €250 lying around.

TODO

Placing 100%
Routing 100%
Thermister Board 100%
Expansion Board 100%
Fixing the BOM 60% (Still need to add the expansion and thermister boards)
Perfecting renders 70%

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design that me that looked over my schematic and layout ext.

1/11/2026 7 PM - Completed the BOM and LCSC order (2nd try)

Renders

So i am happy enough with the renders for how far i have come and i am still on a kind of time crunch sooooooo.
Perfecting renders 70% -> 100%

Time crunch

So you maybe think i have plenty of time left but nothing is more wrong. I have allot of stuff to do in the next couple of weeks and i want to submit so i can still make changes if its wrong and not wing it and hope for the best. I will give you an short table of what my next weeks look like
12 January School till 16:50 then training immediately after till 21:00
13 January School till 13:00 then i need to work and go to trumpet lesson till 20:00 here i have some time
14 January School till 16:00 and then have to go build up for the music nights on school till 19:00 also have some time
15 January 9:00 - 23:00 music night 1 for the dutch(muziekavonden)
16 January 9:00 - 23:00 music night 2
17 January Volleyball game and then music night till midnight
18 January Concert i can make some time here
19 January school and birthday
and this is prob already to late for a second submit. So i will try to complete the project today

BOM

Still hated this part but got all of the components fixed and correct. After that i made an total and it was painful

whoops, i taught $200 would be enough. Yea absolutely not. I don't have much pictures of this project but there is nothing to see other than a number and letter here and there that's incorrect.
Here are the carts for LCSC an JLCPCB


This is allot of money and i don't have it sooooo MANY THANKS TO AMD AN HACKCLUB IF THIS GETS APPROVED
I am planing on ordering every pcb in black but for the mainboard it would be an up charge and i heard you could get declined for this so i will pay for the black color myself.
For the people who want to see the whole BOM its on my repo.

Cost optimization

So if i want 2 boards i need 6 thermister boards but i am el cheapo so i made a panel and have 12 of each type of thermister board on every panel and its under the 100x100 restriction so its still very cheap

PCB assembly

So long story longer I worked at a company where the did pcb assembly and when i(the only teenager there) was accepted i was told "if you have any projects yourself you can ask and maybe we can do assemble them here" for the dutchies here is the original "Als je een eigen project hebt kunnen we hem misschien hier assembleren"
So i was very excited when i started working there but the went bankrupt. But the started up again so i will ask if i am approved. If so it would be so fun to do my own assembly with expensive pcba machines
I have added the crucial parts for this process, Rails on the sides and fiducials so i can do pcba there if the allow it.
Here you can see the rails on the sides and the V-CUTS for removal, the fiducials are placed on some empty places on the board.

TODO

Placing 100%
Routing 100%
Thermister Board 100%
Expansion Board 100%
Fixing the BOM 100%
Perfecting renders 100% (good enough)
Github repo 20% (the last thing before submiting)

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design that me that looked over my schematic and layout ext.

1/11/2026 9 PM - Blender

Whoops here we go again

Long story longer I was not happy enough with the renders and still wanted to add the sub-boards to the render. So almost completely started over the render grind and got here.

And the old one didn't have the expansion board and thermister board yet, here is the old one

still want to make a video of the modules being inserted into the main board, but that is for a later point in time when i have more time left over.

perfecting renders 100% -> 120%

TODO

Placing 100%
Routing 100%
Thermister Board 100%
Expansion Board 100%
Fixing the BOM 100%
Perfecting renders 100% (good enough)
Github repo 20% (the last thing before submiting)

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design that me that looked over my schematic and layout ext.

1/11/2026 10 PM - Updated github

Render for the front page looks

Changed the spacing a bit so its easier to read the text

My PC is crying after every render i think.

Progress

In this time i learned how to use git and how to link it to a github repo online

This is what you have to work with, it was a hard thing to start so my dad helped a bit with setting up git but after that it was smooth sailing.

So here is the readme:

3D printer / CNC Mainboard

A main board for a 3d printer or CNC with wide possibilities with the use of the expansion board and thermistor boards! This board is based on the STM32H743 for its massive power. And everyone hates loud stepper motors, so it uses the TMC2130 silent stepper drivers, these are not only very quiet but have a lot of other functions!

Reason

So long story longer I have an ultimaker 2+ laying at home doing nothing because of the noisy stepper drivers and recently getting an ultimaker S5 so I wanted to make it quieter and more useful. I was amazed by the Prusa mini being so quiet, so I thought why not build my own mainboard with way more quiet stepper drivers and more functions. The second reason is that I am planning to build a CNC somewhere in the future so I thought it would be a genius idea to build my own 3D printer / CNC mainboard with my own overkill specs and the best stepper drivers. And most of all A LOT of power in amps and compute!

Specs

5x Stepper driver TMC2130

4x Power Mosfets for controlling heated beds, heaters, ext.

4x Fan controller with tacho input

4x Limit switches for homing

3x Thermistor inputs with possibilities for NTC's and PTC's
These possibilities are possible because of the 2 thermistor boards I have designed, and the NTC thermistor board has a solder jumper to select the resistance of you NTC.

2x Safety inputs for disabling cutting power via a relay to the stepper drivers and mosfets

Expansion port for displays, SD cards, ext.

STM32H743VIT6 for big storage and calculation power

Standard 4 pin power connector and 2 pin screw terminal

USB ports, USB-C for programming and external control and USB-A for USB flash drives

Design

This board is designed with a lot of safety features and well thought out design, it has a safety circuit to cut power to the steppers and heaters, good pcb design, followed design recommendation from datasheets, used the right components, and allot more! The pcb has been designed with the right trace width and good trace layout with no sharp bends. Also have good pcb layout.

Schematics

There are 3 schematics for this project:

1. Main board
2. Thermistor modules
3. Expansion module

These are way too long to display here (14 pages) so in the PCB folder there in folder for the board you want to see there is a pdf file of the schematic

PCB

Main board

Thermistor boards

Expansion board

Penalization

I have panelized the thermistor boards for better price per board, the panel still is under the 100x100 limit for the 2 dollar offer on jlcpcb so it’s still very cheap. I needed 6 thermistors for 2 boards and minimum order quantity on jlcpcb is 5, so I made a panel.

Firmware

The firmware provided is Marlin, but I plan to expand this to more firmware’s like Clipper ext. The board is based on the STM32H743 so it's very powerful and can run almost any firmware!

BOM

I have made a BOM for LCSC and a global BOM for all the parts and PCBs these are in the BOM folder
The price of the LCSC BOM for all the parts is about 180 dollars for 2 boards and the JLCPCB order is at the 54 dollar.
This is not the cheapest board but it does have the most functions!

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone I know that is way better in PCB design than me that looked over my schematic and layout ext.

This took about an hour to get finalized but it was extremely rewarding

Interactive BOMs

So i when i was designing this pcb i was looking at the one from prusa for the mini and i saw an interactive BOM and i wanted that to. So after 5 seconds on google i found out its an add-on for KiCad
and its really easy to use so here is the tutorial

Interactive PCB BOMs for dummies

So open KiCad and go to the Library manager

Then click on install under the interactive BOM generator
And then on Apply pending changes.
After its done you can close the window and open the PCB editor
And then click on the logo on the top of the interactive BOM generator to open it, you should get something like this

Here you can change the folder and name to put the BOM and then just click generate.
If you have done it correctly you should get something like this:

Good job you have learned how to create interactive BOMs

Submiting

Yes after adding this journal i will be submitting this project

TODO

Placing 100%
Routing 100%
Thermister Board 100%
Expansion Board 100%
Fixing the BOM 100%
Perfecting renders 120%
Github repo 100% (the last thing before submiting)

Nothing anymore YESSSSSSSS!!!!!!!!!!!!!!!

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design than me that looked over my schematic and layout ext.

1/14/2026 - Updated github after rejection

Front page looks

So there where a few problems with my github.

First i didn't have any pictures of my schematic in my readme. And second i had my BOMs in excel format and not in .csv
So first i added a few important parts of the schematic as pictures in my readme

Second i added .csv files

Blender animation

So i wanted to make an animation that the expansion board an thermistor boards where being inserted so got further with the blender grind, after about 3 hours i got something and i wanted to render the very simple 720p 24fps 4 second 96 frames video AND IT TOOK MORE THAN A HALF HOUR on my big pc with a RTX 4070TI I5-13600k 32GB ram
Render SCORPION MAX V1.png0001-0096
Still not done though want to add some text to the animation and the expansion board.

Perfecting renders 120% -> 150%

Anyways have a good day

TODO

Placing 100%
Routing 100%
Thermister Board 100%
Expansion Board 100%
Fixing the BOM 110%
Perfecting renders 150%
Github repo 110%

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design than me that looked over my schematic and layout ext.

1/29/2026 - SILKSCREEN!!!!

So i didn't want to order yet because my board looked plane so i added some silkscreen art


That is what i have done, still waiting on ordering, LCSC doesn't have a part in stock but will order the pcb's soon.

bye bye!!!
RAWR!

1/30/2026 - Update button broke

So i wanted to set a banner with the new silkscreen art in the blender render so started blender rendering or how its called and got here

This has the new art on the PCB but it doesn't work the set banner image so i am doing it this way, RAWR

2/13/2026 - Recieved the components!

So after a bit of a wait i finally received all the components just before the vacation. My vacation will be fire!
Here is the JLCPCB order

The mainboard stencil

The thermistor board stencil

And of course the PCBs!!!!

And of course the mainboard looks fire!


Then the thermistor boards

LCSC

My lcsc order came in like 2 days later. It was insane i have had some electronic orders but never above like 10 components and here where 82 parts all at once!

I already sorted a bit but here is the order



And of course the stm32H7

Unpacking all the stuff and sorting it took some time but overall my vacation will be booked....

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design than me that looked over my schematic and layout ext.

2/20/2026 - Started soldering the PCB's

So i wanted to start with a simple part of the build. The thermistor boards(yes i know i spelled it wrong on the board itself. English isn't my first language) To say that the thermistor boards are easy is not really true but it is one of the more simple parts, except for the expansion board but those where to easy. So first of all i made a stencil jig to place everything for paste application, i kind of forgot to define a size for the stencil so have a huge a stencil whoops. Then i started setting everything up for the job, getting everything ready took some real long time. I also had to sort thru 84 components for the right resistors, capacitors and ic's for this board, that took some time. You don't realize that problem until you order a ungodly amount of components. Luckily i did a bit of sorting, it was sorted in THT, IC, Resistors and Capacitors. This was already done in the last journal but i want to explain it a bit better here.



Then came the time to do the big stuff. First the stencil jig, i used the wooden plates that they ship on to make my stencil jig.

Then placed the 4 other PCB's around the first to make sure it has no place to go.

Then added the stencil and aligned it with the pads of the PCB.


Then it was time to prepare the setup for spreading the paste and placing the components.

The IBOM generator in KiCad is gold, i think i would have died if i didn't have that interactive BOM.
Then it took some tries but after a bit i got a good spread of solder paste and got to placing components.

Then i placed all the components. The smallest i did before this was 0805 and sop8 so it was kind of scary but after the IC i got more confidence and got it down pretty fast. It wasn't as difficult as it thought it would be.

Then put it on my way to undersized hot plate for reflow

After 2 mins the hot plate was still 20C so i was kind of stressing out, i realized that one of the pins for the power to the top heater didn't make contact anymore. So i just put a piece of solder wick in between but after a bit that failed to so i added a solder ball to the pad on the plate to increase its height and it has worked since.
Then time for the results.

Pretty dang good for a first try.
Then i bend the stencil over the components already on the PCB to apply paste to the other side and placed the components.

Then more reflow.

It all went pretty well i must say. Very happy with the results.

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design than me that looked over my schematic and layout ext.

2/24/2026 - Soldered the main PCB!

8hr

I have solder the main PCB and this was a heck of a ride. I will try to explain in as much detail as possible what i have done and how i have done it. So first of all i had to get prepared, i asked a friend who has a re-flow oven and a hot air gun (didn't think this was necessary but to be safe spoilers it was necessary)

Then i made my stencil setup for the mainboard, placed the 4 other PCB's around the first one so it can't move.

Then got the solder paste from my fridge and let it warm up to room temp, its T5 lead-free 213C solder paste. I got 2 quarter full tubs of this from my old workplace for free because the would trow them out.

Then took one out(very dramatic :)

After that i made a spoon from a plastic box and added way too much to my stencil.

Having way too much solder paste is really nice. I don't have to worry about not enough solder paste in one spot. Then it was time to spread the solder paste, i did that with a as flat as possible PCB i could find, because a card was not wide enough.
This one

After that i spread the paste, and the first time it wasn't completely good so i wiped it all of and tried again, then i finally got a good spread and started placing components. At first the most difficult one, the 5V dc/dc converter IC. That went pretty well i must say.

Then i started to work from the inside out so i wouldn't knock anything off at the outside while placing a component in the center. Then got to the most expensive part of the build, the stepper drivers, took them outside of the tape and placed them.


Then added all the components around the stepper drivers. including sense resistors, decoupling ext.

Then it was the next part, the MCU i was kind of scared for this part because i couldn't really grip it that good with my tweezers because of its size. after that the board looked something like this. (sorry bad image)

Then i did a speed run for the rest because i needed to go somewhere but wanted it in the oven as soon as possible so the paste wouldn't dry out.

Then i put it in the over and after a few minutes after the curve was done i took out the PCB, it looked really amazing! Almost everything re-flowed correctly and i only had solder bridges on one side of the stm32 and the USB connector.


This wasn't that big of a deal, a bit of a soldering iron and a load of flux would fix it.

8hr

Then came the big moment, i took my multi meter and measured between 5V and GND and 3.3V and GND and there where no shorts, so i took my power supply and connected it with the current set very low. I got this(green LEDs are 5V and 3.3V power rails, blue LEDs are mosfets and yellowgreen leds are fan LEDs)

I was very happy! the 5V and 3.3V dc/dc converters worked as the should! I thought the mosfet and fan where turned on because of some random pin defaults(it was not). Then i connected my raspberry pi pico with debug firmware as a SWD debug interface to my laptop to try and get the STM to talk.

After a few hours of debugging i asked gemini why it didn't work and he said to measure the core voltage of the chip. i took my multi meter and got a heart attack the vcap pins where at 0.1V and 0.04V way to low for the STM32H7 to turn on. So i took a look in my schematic and realized Vref wasn't connected to 3.3V so that was the first mistake. I made a solder bridge between these two and lucky the where very close to each other. (left top of the chip)

After that i measured the voltage of the chip core again and got another heart attack, it still didn't rise and was almost zero while i expected 1.2V.

Biggest heart attack ever(No clickbait)

Then i began to doubt my orientation of the chip it had 2 dots on other sides of the chip. First i thought the bottom left was a mold release but after a lot of google and looking at @kai the jolly guy his board i found out the bottom left was the pin 1 marking dot and top right was something else(for the keen guys, yes i had seen the cutout of the corner but in the datasheet it said that corners were not important and not to trust. So now i had the biggest heard attack of my life, so first i wanted to see the damage, i opened kicad and rotated the stm32 180 degrees to see if it would make weird connections.


There where no really weird connections and no GND to 3.3V or smt like that so i said, i will try to rotate it and see if the STM survived.

The rotation

So now the hot air gun came in clutch but it was really scary, if i messed this up and moved my hand a millimeter to much i could forget it and potentially knock of allot of components. So i placed my PCB on my hotplate as a bottom heater set to 180C then i used my heat gun to heat it up at the STM locally after about 2 mins i began to see shiny balls so i grabbed my tweezers and tried to knock the STM out of its place without knocking anything else of the board. This was successful, i still kept the heat on tho to re-flow the pads so the would look good. Then it looked like this.

After that it was time to place it back. I don't have steady enough hands to place it while the solder is melted so i just positioned it on the pad correctly and then started heating it in the hopes it would re-flow correctly.

I set the air speed really low for this so it wouldn't blow it off its place. after about 4 mins it started re-flowing and it was successful!!!!!!

Then did another round of checking if there where any shorts and no there weren't so i added some power again and it didn't explode so i was happy then i measured the core voltage and it was reading 1V not exactly what i was hoping for 1.2V but it was prob just in a lower core voltage config so i thought it was fine. Then i connected the raspberry pi pico again and it showed up in the terminal as a arm cortex M7 !!!!

Then it was just a bit of gemini debugging later to get the STMCUBEIDE to talk to the STM32 and it was working!!!!!!!
I got a blinky sketch to work so i was very happy!
VID20260222165919044
Then i was getting tired of connection problems with the debugger because of the loose pin connection so decided to solder all the THT components. Here are a few pics of the progress.





The red LED shows that the heaters and drivers are getting power, its a safety circuit that can be connected to a e-stop to disable all the high power stuff if something goes wrong and to reset it you have to press a button on the PCB.
This is how far i have come, i still need to learn how to use marlin to upload it and to get everything working.

More updates

If you want more frequent and more up to date updates join my channel #simons-cookbook on slack

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design than me that looked over my schematic and layout ext.

3/25/2026 - Started with firmware hell

So long story short i first tried to get marlin to run on my board ~20H(i will not count this time because it was all vibe-coded and shit) but it did absolutely nothing, then i thought to start with klipper, i had seen how easy the configs where so dove right into the config reference guide and its very detailed! I already had a config for submission but that was just shit and prob wouldn't have worked so i started almost from the ground up with a new config with everything, at first i was a bit confused but after a while i got the hang of it. There were allot of errors at the beginning because of the TMC drivers having their own config section but that was solved pretty quickly.

But then i realized that i would net to set up a sbc so i thought i would do that before i finished to config, it is just a rp5 and nothing special, i choose mainsail and it was really easy to install and get up and running. I was still a bit confused where i would need to config crystals and usb communication but after reading more documentation i soon found out how i had to do it. You would ssh into your sbc and then navigate to the klipper folder. From there it became very simple just type in

and then it would open up this amazing menu

In here is where you can config everything from the communication to the crystal and everything else to boot the micro controller, this is also the point i learned the config is loaded onto the micro controller every time you boot it and it connects to the klipper server on the sbc. After 2 mins i had a config that i thought would work with the usb and a 25MHz crystal. Then it was as easy as exiting the menu and saving it, and then typing in:

Then you would get the .bin file for on the micro controller in a folder. But then i had to learn the whole terminal ssh command stuff again and learned scp still exist so i used that to get the .bin file on my pc to upload it via DFU mode with the stm32cubeprogrammer. And it showed up as a usb device after booting so i was exited! Then i plugged it in the sbc and completed the config file mostly enough so i could get it to boot without errors. I am very pleased with klipper with how real easy it has been. Marlin had been a nightmare i wasted 18+ hours on for nothing. Anyhow it booted but would error out because of out of range temps real quick. This is pretty correct with no thermistors connected.
Then i took apart my old Anet A6 to put this board in


This was the old board

At first i wanted to test the thermistors and get maybe the heating working. So i used my thermistor modules but with 4k7 pullups and connected them to my PCB. After putting the thermistors in other connectors i hooked them up and got crazy temps of 300+ degrees I didn't know what was going on so i got to debugging. I stated measuring the resistor of the thermistors and of the pullups and they were correct. Then i measured the output of the resistor divider and it measured 0.1V which was very weird for a 4.7K pullup and a ~150K thermistor (16C) to gnd then i got a weird feeling i mixed up 3.3V and gnd on my thermistor boards.... And after checking kicad i was correct, i messed up the 3.3V and GND on my boards and instead of a 4.7K pullup i had a 4.7K pulldown.


So first i tried to invert the input pin in the config with the ! prefix but that didn't work so i accepted my fate and started searching for a way to invert it on the thermistor boards after a bit of debugging i found a way, i had to cut 5 traces and make 2 new ones, but it should be possible. After half an hour of concentrating i got 2 of these boards

You cant really see it that well but the idea's is visible.
Then i plugged them in and finally got something working on my board!

Then it was time to get a heater working. I hooked up the nozzle heater and set it to 100C
it went fast, real fast. <20s After 5s i realized the printers is 12V and i was using 24V......
But the heater was working!
20260325-1600-39.8403930
That was it for this journal (i am a bit behind :skulk:)

More updates

If you want more frequent and more up to date updates join my channel #simons-cookbook on slack

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design than me that looked over my schematic and layout ext.

3/28/2026 - Movement

Okay i am writing this for the second time now because the first is gone :cryin: So this may not be the greatest journal i write but i am really done with it to write another 500+ words a second time..
So at first i started with getting further with the config to get the stepper drivers working, this means that i need to config all the connected pins and what the motor driver itself is and how it needs to be treated. So after digging thru the config reference i finally got a motor config i was happy with.

So then i needed to connect a motor to test it, but i didn't want to destroy my printer if something would go wrong so i went and connect a random nema 17 i had laying around to my board. This also had a wiring that was easy to swap wires for if i need another pinout.


Then i powered everything on and connected my board to a power supply and turned everything on. Then pressed the X home button and there was some movement but it sounded really crunchy and just not great at all but it at least did something. So then i did a bit more digging in the config reference and found this

So i enabled it because i new i wanted silent steppers and i thought it would be better if i spent time configuring the silent mode of the stepper drivers that the non-silent mode and then having to also configure the silent mode. So after enabling that all of a sudden the stepper worked great and was really silent and running beautifully! So i was very exited. Then i switched to the X motor on the printer to start configuring the printer itself. At first it was trowing errors that the endstop could not be released but i just needed to invert the endstop pin on the microcontroller

! is for inverting the pin and ^ is for the internal pullup
And then it homed correctly and i had a working X gantry!!!!!! YAYAYAY
Then the rest was just repeat, copy the config, change the pins and try it out.
The Y gantry was no problem and worked great, but i had one problem, the Z axis uses 2 steppers and i didn't know how i needed to config that. So at first i removed one of the leadscrews to only have 1 stepper active

Now that i had 3 axizis i could do a full home
VID20260323232436172
Than the Z axis worked great!!!! So then i dove in the config reference and found a section that explained the use of dual Z motors.

After configuring that second Z motor i got everything working except the extruder. So as you can guess that was next. It wasn't to difficult but at first it had problems extruding correctly, it turned out to be that the tension was too loose and the filament was skipping teeth but that was a hardware problem and not a problem with my own board, so after that everything was working!!!!

More updates

If you want more frequent and more up to date updates join my channel #simons-cookbook on slack

Credits

@Kai Pereira for all my random questions regarding PCB design and blueprint custom project. and for telling me long journals are the best, sorry for the short ones at the beginning. whoops.
Henk, someone i know that is way better in PCB design than me that looked over my schematic and layout ext.