Nitehawk-36 Toolheadboard
Hi, I just received my ldo-nitehawk-36 Toolheadboard. Is there any chance this board will be added in the near future?
If not, is there anything I can do to help?
Sorry if this isn't the right place or such a request.
139 Replies
Here a short summary:
- RP2040 MCU,
- TMC2209 stepper drive
- ADXL345 accelerometer
- "onboard"USB port
- 2 Part Fan Ports
- Hoted Fan Port with Tacho
GITHUB: https://github.com/MotorDynamicsLab/Nitehawk-36?tab=readme-ov-file
Example Configfile https://github.com/MotorDynamicsLab/Nitehawk-36/tree/master/Configs
LDO Documentation: https://docs.ldomotors.com/en/Toolboard/nitehawk-36
GitHub
GitHub - MotorDynamicsLab/Nitehawk-36: A USB toolboard for the Tool...
A USB toolboard for the Toolheads with 36mm Pancake Motors - MotorDynamicsLab/Nitehawk-36
GitHub
Nitehawk-36/Configs at master · MotorDynamicsLab/Nitehawk-36
A USB toolboard for the Toolheads with 36mm Pancake Motors - MotorDynamicsLab/Nitehawk-36
LDO Documentation
Nitehawk-36 Toolboard
Sorry I posted this already in the german channel:
Hi zusammen,
mein LDO NiteHawk36 USB-Toolhead board ist die Tage gekommen. Das wird ja bisher nicht unterstützt.
Jetzt bin ich mal hergegangen und habe mir das "btt-sb-2209-10-rp2040" als Vorbild genommen und dann unter
"~/printer_data/config/RatOS/boards/ldo-nitehawk-36" die folgenden Dateien erstellt:
98-ldo-nhk-2209-12-rp.rules
board-definition.json
compile.sh
firmware.config
toolboard-config.cfg
Bei der toolboard-config.cfg bin ich mir aber nicht ganz sicher. Gibt es da irgend wo eine Info was da alles reinkommt / reinkommen kann?
Was muss ich jetzt noch machen das mir im "Setup Wizard" das Board auch angezeigt wird?
Oder soll ich mir den Ganzen Aufwand sparen, weil das Board in ein paar Tagen eh im Setup-Wizard drin ist? 😇
We're definitely planning to add support for the nitehawk, yes. There's a few minor roadblocks (RP2040 needs a bit of special casing in the configurator), but otherwise it's just a matter of doing it. I believe @MDFPereira plans to submit a PR for it.
It will not be supported in 2.0
You'll need 2.1
Solution
I do… I’m waiting for the thing for testing before submiting the PR
That’s awesome!Tthank you! Btw I am using 2.1
Is there a way I can help?
You can help by testing when it's ready! Besides that, there's always the pesky wiring diagram 😄
I could give it a try!
you can copy paste one of the existing toolboards, the wiring diagrams open for editing in draw.io
Made a Diagram.
Awesome work! We need it to match the general style of the other wire diagrams (font, arrow styling, wire colors, graphics used should be dynamically linked - reusing the existing graphics on os.ratrig.com - and not embedded, and the jumpers should be square).
Thank you!
I'm a frist timer to draw.io, so please baer with me. 😇
1. On os.ratrig.com I 'couldn't find any pictures for:
- Beacon 3d
- Orbiter (I now use the Extruder-Motor picture instead)
- LDO Nitehawk-36
- LDO USB-Adapter Board
So I can't link them dynamically to graphics on os.ratrig.com. Should I leave them embedded?
2. I still need to figure out what font is used and how I can get the correct wire colors.
Right those need to be uploaded first
I still need to figure out what font is used and how I can get the correct wire colors.Open an existing diagram and check the colors there. The font used is Oswald (google fonts)
the nitehawk36.png is a photo i did for myself,
beacon3d is from the beacon website, I changed the color to match it from here: https://cdn.prod.website-files.com/6465fa9b017ab9d60c77979a/6672fbb3d69597ba975eda0c_Main-scheme-Official-CoreXY.jpg
usb-adapterboard is from the docs from LDO
New Version but beacon3d / nitehawk36 / usb-adapterboard need to be updated...
Let me know when the graphics are uploaded. After that I can adapt the draw.io & .webp file.
I'll just upload the files here, or?
Draw.io is a nice program, need to get a bit more familiar with it.
looks good!
Put them here, or fork RatOS-configuration on github, and create boards/ldo-nitehawk36, put it in there and submit a PR
I can fix the images once i get them added to the repo
Thank you, was a pleasure and fun for me.
If you need support for more of this stuff, I‘ll be glad to help. (Toolhead / Boards)
I absolutely hate doing wiring diagrams so that's super awesome to hear! 😄
We're currently missing a diagram for the Orbitool O2, i have already created the diagram but it only contains the board render i did a week or so ago.
Nice, so I'll proceed with Orbitertool 2, it could take until Wednesday though...
I really love doing things like that.
Ah, and I've done the pull request.
First time I've done something like this with github. So please tell me if I've done it rigt.
I have a Nitehawk-36 coming soon, and will be happy to test. If I 'follow' the first post, will I get notified of updates to this thread?
I think so.. But i'll be sure to tag you in here, that'll notify you regardless 🙂
My Eva 3 toolhead's coming along, with mods to support Beacon and a Nitehawk 36. Some wires to crimp tonight; then install onto the machine, probably tomorrow morning.
Then I'm going to be ready to configure Klipper. Already have RatOS 2.1 installed.
As I said before, I'm happy to test the upcoming Nitehawk support, but will have to configure by hand if it's not ready soon. Could I pull it off a dev branch or something?
As I said before, I'm happy to test the upcoming Nitehawk support, but will have to configure by hand if it's not ready soon. Could I pull it off a dev branch or something?
@MDFPereira can you pull the nitehawk board out into it's own PR? (needs a separate branch)
It's ready to merge, but the pull request contains stuff that isn't ready yet (primarily because my lack of time)
Marcio has been in beast mode again and added a whole bunch of new boards 😍
@MDFPereira if it's too much of a hassle i can do it from here it's just gonna invalidate your current PR until you merge upstream changes.
Hey! I can do it, no problem 😉
awesome, thanks man!
Pushing PR. I will wait until merge to push all the others.
PR complete
Hi, if I download the files from the PR, will the board work?
https://discord.com/channels/582187371529764864/1262911038127345745/1263271951586033824
Or is the "special treatment" for RP2040 that what blocks it?
@MDFPereira thanks for the good Work, your drawings are awesome!
you welcome...
Someone told me how to do it 😛 Easy to know who... 😉
👍
Downloading it may work but you need extra work in order to flash and identify the board as per RatOS hardware
Ah, I don't know how to do that.... 🫣
I guess I know, 😇
For me it was my first time with draw.io. So I'm still improving. Though this time it wasn't wasn't good enough, maybe next time 🙂
to make things easier, I just use an existent one and change as per need. New image and redirect the traces
Yes, that was what miklschmidt said what I should do, but, ... first time so, didn't know how it works and had to work out how the workflow for that program is. Now I've got it! Maybe there'll be another chance to help. 😅
How did you make the render for the nitehawk board?
looks awesome
Mikkel does it every single time 😉
he has to upload it to the server for me to use
Oh, hmm,
Maybe he can tell how that works, I can't imagine he draws the whole thing, ... or?!?
i believe he extracted and rendered from the cad file of the board
So, I managed to get my Nitehawk-36 running. There were two issues:
1. The automatic Firmware installation failed because the created firmware file is "klipper.bin" but if it's not "klipper.u2f" it failes.^
--> I tried to modify the "compile.sh" (the cp -f part) but nothing I change seems to matter.
2. The toolboard-config.cfg uses gpios like: "gpio06" but it should be "gpio6".
? (3.) is the filename "ldo-nitehawk-36.rules" right? or should it be "98-ldo-nitehawk-36.rules"
Nevertheless,if I manually copy the klipper.bin to klipper.u2f while the configuration-wizard does the compileingprocess, flashing works like a charm. 🙂
Here is what I modified in the toolboard-config.cfg:
@MDFPereira sounds like there's still some work to do 😄
5 minutes…
Done and pushed.
My bad. When doing mellow sht36 v3, the compiled firmware was .u2f and I changed this too.
The pins, freackin ctrl+v 😛
My fault, of course.
Rules filename also corrected
Should be done now
Thanks @thinksimple for testing
@MDFPereira thank you very much!!
... maybe I do something wrong but the firmware still gets complied as klipper.bin and not as klipper.u2f. (see screenshot)
--> I copied the files from your PR into my ldo-nitehawk-36 directory 🤷♂️
something else that I noticed:
in the file:
board-definition.json
- Maybe there should stand "ldo" instead of "btt"? Don't know for what it but, ...?: "documentationLink": "https://os.ratrig.com/docs/boards/btt/nitehawk-36",
- instructions: the sentence in brackets shouldn't be there?
- instructions: the sentence in brackets shouldn't be there?
That is something really strange…
Since it is a RP2040 it should compile as u2f. But I checked this afternoon and got a bin file.
Will check in 1 hour
Wow, that whas a quick answer! But no hassle!
The link, you are correct, sorry.
I think I will have to wait for Mikkel
as soon as I change from no bootloader to 16KiB bootloader, it compiles as .bin.
and this is a RP2040 board, it should be .u2f
@thinksimple did you use klipper.bin and changed it's name to u2f extension?
and did you download the files after the correction?
yes
I didn't know how to downoad them from your PR, so I made a copy and paste from each file
@MDFPereira and @thinksimple, I'm about ready to configure my nitehawk; where do I get this updated software? ..doesn't seem to be in the RatOS project(s) on GitHub.
I got them from the PR from MDFPereira:
https://github.com/Rat-OS/RatOS-configuration/pull/286/files
but I had to copy and paste the files, 'cause I don't know how to download them from there.... 😅
it is not, yet.
It is a PR and needs to be merged by the boss
that might be the error... With copy paste you remove the permitions from the .sh files
here you go
I'll test it immediately.
for you information
here you goThanks! I still have a bit to go, but should get to it this evening. Will report!
hmm, what am I doing wrong?
so:
1. I deleted the old ldo-nitehawk-36 folder
2. extracted the rar archiev on my windows machine and copied all files to my printer
3. checked the permitions and did a the problem is still there, only a klipper.bin gets created
I checked that. as soon as I change from no bootloader to 16KiB bootloader, it compiles as .bin.
that is why I said we have to wait for Mikkel
i believe it should be a u2f file because it is a RP2040 processor... But it is klipper compiling, not me
There's katapult on that board right?
There's a few errors in the PR, i'll comment there.
when there's a bootloader on the board (in this case katapult) klipper is supposed to compile a .bin. That .bin is what gets handed to the bootloader. .uf2 (not u2f) is for the stock RP2040 bootloader.
So replace all
u2f and uf2 instance with bin
I've made the changes directly in the PR, please give it another spin 🙂Gotcha and saw the commits. Thanks
@MDFPereira make sure you pull you local branch 😄
Anything new learned today…
Will take that into consideration for all the others. But I believe they will not need it
With katapult should be .bin instead of .uf2
Okay, I looked at the zip file you provided but can't make sense of it.
My hardware is ready to go, but my machine was configured for 2.1 and is now (understandibly) getting errors, since I no longer have bltouch, etc. connected to the original ports. So, how can I help test the (nascent) Nitehawk support?
My hardware is ready to go, but my machine was configured for 2.1 and is now (understandibly) getting errors, since I no longer have bltouch, etc. connected to the original ports. So, how can I help test the (nascent) Nitehawk support?
@MDFPereira I just tired to flash the nitehawk but it still fails. Is this as it stand for now the expacted behaviour? Or is there something I do wrong?
Here my output when I trigger flashing all boards from the "Help" button in the configuration Dashboard.
Open configurator and try to flash only the nitehawk. Probably you will need to enter DFU mode for the first flash
@MDFPereira and/or @thinksimple:
Trying to get this going; here's what I've done.
I've copied the RatOS-configuration fork from user 3dprintpt over the contents of my ~/printer_data/config/RatOS directory. I have not modified anything else on my PI, which was installed with the RatOS 2.1 release image.
In the configurator, I now see the NiteHawk36 board. I select it, and attempt to flash via DFU mode, since automatic mode is not available.
I push the described boot button sequence on the the nitehawk and ...nothing. It simply says "waiting for DFU" forever.
I'm confident that the board is wired correctly. After power on (but before entering the boot button sequence), I see three ports under /dev/serial/by-id
usb-Beacon_Beacon_RevD_1949E2BC4E4B333448202020FF0A3C31-if00
usb-Klipper_rp2040_3033393834097360-if00
usb-Klipper_stm32f407xx_btt-skr-pro-12-if00
Note that my beacon is connected via the 'passthrough' port on the Nitehawk.
After pressing the boot button sequence, the 'rp2040' port disappears but the beacon port remains visible. I've also tried unplugging the Beacon. Of course, the beacon usb port no longer appears, but configurator still doesn't get past the 'waiting for DFU' point.
I have not yet flashed anything to the Nitehawk board, but I'm beginning to wonder if perhaps the katapult bootloader is not actually installed on it. The Nitehawk docs say it should be there, but I have no way of knowing for sure.
So, next up, I thought I'd try re-flashing the katapult loader first (via the LDO instructions).
Your thoughts?
...could it be that I need to switch the remainder of my system (configurator maybe) to a development branch as well?
Nitehawk is based on RP2040 it does not have DFU mode, that shouldn't be in the board definition, @MDFPereira remove the dfu section. You can flash it via "unidentified devices" or "sd card" (bad name). For the latter you'll have to use the RP2040 usb otg mode, read the nitehawk manual about what to do with the firmware.
Are you sure this is what the newest nitehawk PR code?
Going…
Do you want me to include instructions for make flash?
No, RatOS runs make flash
That's what the "unidentified devices" button does
Ok
I don't remember if i disabled it though, because people confused their boards too much.
Done…
"SD Card" works via the usb mount mechanism
it's just poorly described (rp2040 wasn't supported back then)
Last time I used configurator it was present
@miklschmidt We should include a section with flash instructions…
Auto flash only works after first “manual” flash (via sd or whatever). Am I right?
I don't remember if i disabled it thoughIt was disabled for me.
we already have four of those, just need one for RP2040
I'm not sure what 'DFU' mode actually is, but the Nitehawk does seem to have three boot modes.
* The two-button reset allows you to mount a drive: this is how you install katapult (which is compiled to a 'uf2' file) * Double clicking the reset button alone enters 'katapult bootloader' mode. In this mode, you can install the klipper firmware, compiled to a 'bin' file * from there a single-click of the reset button boots the klipper firmware. I presumed from earlier comments that this was the approach configurator was taking. It's also possible to comple the klipper firmware to a .uf2 file, and skip the katapult bootloader.
* The two-button reset allows you to mount a drive: this is how you install katapult (which is compiled to a 'uf2' file) * Double clicking the reset button alone enters 'katapult bootloader' mode. In this mode, you can install the klipper firmware, compiled to a 'bin' file * from there a single-click of the reset button boots the klipper firmware. I presumed from earlier comments that this was the approach configurator was taking. It's also possible to comple the klipper firmware to a .uf2 file, and skip the katapult bootloader.
You can flash it automatically via "unidentified devices" because katapult and klipper is already on there.
So.. if I can help more please LMK.
...but I think I'm going to have to hand-install (using the LDO instructions) and go from there. ...just to get my machine running.
...but I think I'm going to have to hand-install (using the LDO instructions) and go from there. ...just to get my machine running.
Compiling via klipper (not katapult) always gives me a .bin
That is 2 modes 😄
I was counting the two-button boot; the 'reset only' boot (katapult) and the application itself.
If booting into usb drive mount mode overwrites katapult then that's a no go
Tomorrow I will assemble mine and test everything. I will correct what is needed
You don't need any of these though
..and maybe I'm mistaken about skipping the bootloader... but the LDO instructions mention using 'make flash' which is what I assumed this was.
sorry if I'm confusing the issue.
No that's a third method (that's what happens if you pick the option in the screenshot above)
Ah, ok.
should I do that? ..or is it equivalent to the LDO method I've already done?
It needs to be done through RatOS to get the correct chipid
OK; giving it a shot. Will report.
Otherwise the board will not be detected correctly
Okay, I get 'Nitehawk 36 detected' ...should I click 'flash again?'
you need the latest files from the PR
excellent you're done
But yes you can flash again to test
I have the latest files, unles you've updated them in the last hour or so.
nope all good
k; I'll flash again to test.
Just small change, removed the DFU part
ah.. that just returns me to the previous menu
...so maybe I'm good.
yeah where you can choose to flash it again, but if you already did that then there's no reason to do it again 😄
Ah.. and the rp2040 no longer appears under flash unidentified board
so, I'm skipping it.
excellent
That means it's working as intended
There' automatic flashing (top left) which is what runs on update
But it's basically the same thing just using the udev mapped path instead of the serial/by-id path
Okay; I'm off to the remainder of the config.
Thanks amillion for your help.
I'm happy to re-test if you update anything... lmk.
thanks!
And thank you guys for doing the hard work
Will let you know tomorrow if something has changed. But giving it is working, I doubt 😛
A small grain compared to what you are doing
@MDFPereira @miklschmidt It Works!!!!
I once again erased the folder and now took the files from here: https://github.com/3dprintpt/RatOS-configuration/tree/development/boards/ldo-nitehawk-36 not from the PR. (I thought the files are the same, ...?)
Thank you so much MDFPereira and miklschmidt!
GitHub
RatOS-configuration/boards/ldo-nitehawk-36 at development · 3dprint...
The RatOS modular klipper configuration. Contribute to 3dprintpt/RatOS-configuration development by creating an account on GitHub.
I'm now getting a klipper shutdown due to a version mismatch, I think:
Klipper reports: SHUTDOWN
MCU Protocol error
This is frequently caused by running an older version of the
firmware on the MCU(s). Fix by recompiling and flashing the
firmware.
Your Klipper version is: v0.12.0-208-g49c0ad63-dirty
MCU(s) which should be updated:
mcu: Current version v0.12.0-208-g49c0ad63
rpi: Current version v0.12.0-208-g49c0ad63
toolboard_t0: Current version v0.12.0-208-g49c0ad63
beacon: Current version Beacon 1.0.0
Up-to-date MCU(s):
<none>
...could the 'dirty' thing be because I've copied the pull-request repo or something?
I did reflash my BTT board; no change.
Sorry... false alarm.
My beacon firmware was out-of-date too; that was apparently the gating item.
Fixed.
Now I'm getting ADC out of range:
MCU 'toolboard_t0' shutdown: ADC out of range
This generally occurs when a heater temperature exceeds
its configured min_temp or max_temp.
Once the underlying issue is corrected, use the
"FIRMWARE_RESTART" command to reset the firmware, reload the
config, and restart the host software.
Printer is shutdown
...
I have a PT1000 RTD.
relevant settings seem correct; doublechecking wiring.
..raw reading at the plug measures about 1.1k, which corresponds to 26C/78F.. so the sensor itself seems OK.
Maybe the pullup resistor has wrong values… will check tomorrow
Yes, that was it.
The nitehawk has a 2.2K resistor; the default is 4.7k
So, should that go in the board definition or something?
I've added to my printer.cfg for now, and am no longer getting klipper shutdown errors.
(figured it out at the same time you did; came here to trumpet my success, only to see you'd already thought of that 🙂
Just checked, I’m missing it on the board definition. Will include tomorrow. Thanks
I thought of that, did not check until your last answer 😉
But on the phone I can’t correct it.. 2:34 in Portugal 😉
good night!
and thanks!
Files corrected with thermistor pullup resistor...
the files are exactly the same. But on my fork it is easier to download 😉
late to the game here.... my NH 36 should be here this evening. 2.1 v2.1.0-RC2-0-g3a587cf6 up and running, just checked the configurator and no nitehawk toolboard avail to select. Reading the thread above, how do I select and se up for the NH board?
You need to download the files in my repo and include the ldo-nitehawk-36 folder in the boards folder for RatOS
Then you will have the NH36 available.
It is not merged yet
tnx @MDFPereira Up and avail as described. All elec parts in hand just need some printed part mods prior to full assy.
@MDFPereira in RatOS.cfg stands the following:
but it should be:
I'm not sure where @miklschmidt is storing this data.
I only have a line to select what driver is used.
"extruder": "LDO-TMC2209"
Maybe I need to include it too...
Also I’m not sure where the low value on run current is coming. Orbiter 2 and it’s cousins should be 0.707.
What extruder are you using?
Ok, sherpa mini is correct.
Be sure to select the correct stepper motor for the extruder… 0.35 seem very low. Only 36sth17-1004ahg uses that
found it...
We need Mikkel to change something on the configurator.
LDO-TMC2209 was created for the Orbitool o2 and Leviathan. It uses 0.110.
The Nitehawk uses 0.100 as you said.
I will speak to Mikkel about this
You’re Awesome!
And that was exactly the one I used… until yesterday where the Motor died. Searching for a possible cause I found the sense resistor problem. But I believe there was something going on with it before. 🤷🏼♂️
No I‘m using the moon’s CSE14HRA1L410A-02 motor. Seems much better regarding heat.
No!!! Mikkel is 😉
Everything is better than 36sth17 regarding everything 😉
files updated...
What does this 'sense resistor' setting do?
My orbiter motor got fried, but it was an older one that should have been operating at .35. Could this sense resistor business be realated as well?
looks like it's related to a reference voltage.
found it in klipper docs, but it's thin on detail:
https://www.klipper3d.org/Config_Reference.html#tmc-stepper-driver-configuration
sense resistor
is one of the factors which determine peak A for the motor.
Together with the Current Scale setting,
I really like this guide on how to tune your steppermotors. Working it through (and the excel spreadsheet) gives a good idea how everything works together.
https://github.com/MakerBogans/docs/wiki/TMC-Driver-Tuning
https://github.com/MakerBogans/docs/wiki/TMC-Driver-Tuning
GitHub
TMC Driver Tuning
Documentation for mods and group buys. Contribute to MakerBogans/docs development by creating an account on GitHub.
There is also a klipper extension for automatic configuration and tuning of TMC driverrs.
https://github.com/think-simple/klipper_tmc_autotune
GitHub
GitHub - think-simple/klipper_tmc_autotune: TMC stepper driver auto...
TMC stepper driver autotuning Klipper python extra - think-simple/klipper_tmc_autotune
sorry, this got off topic.
not getting a response from LDO.... strikes me odd I'm the first one asking about the nitehawk 36 board version documentation. EG: Parts cooling and hot end fans.
wouldn't you want the 3 pin (w/tach) as the parts fan, and the 2 pin fan for the hot end?
They even mechanically placed a 2 pin connector, right next to the HE therm connector, which is right next to the hot end screw terminals. Yet IT, and a duplicate at the far left are labeled as parts fans ?????
I was about to plug my NH 36 in, but figured it would balk, so was preping a HE thermo at least when I noticed the pinning.
@MDFPereira @miklschmidt noticing in the nitehawk repository...the pinouts do indeed match the mfr oem layout and (assuming here) 'kilpperized' verbiage etc ...wondering if docs should reflect it's use for the RatRig based RatOS configs... noting, or defaulting or allowing options to reverse which fan is on which port(s)
from the git
[board_pins ldo-nitehawk-36]
mcu: toolboard
aliases:
x_endstop_pin=gpio13,
e_step_pin=gpio23, e_dir_pin=gpio24, e_enable_pin=gpio25, e_uart_pin=gpio0, e_diag_pin=gpio3, e_heater_pin=gpio9, e_sensor_pin=gpio29,
# accel
adxl345_cs_pin=gpio27, adxl345_miso=gpio19, adxl345_mosi=gpio20, adxl345_clk=gpio18,
# leveling
bltouch_sensor_pin=null, bltouch_control_pin=null,
probe_pin=gpio10,
# fans
fan_part_cooling_pin=gpio6,
fan_toolhead_cooling_pin=gpio5,
# 4 pin fans
4p_fan_toolhead_cooling_tach_pin=gpio16
-OR- is this board, requiring a bit a pin cross connector wiring/plugging to op correctly?
sorry, i don't understand what you mean.
Did you check wiring.drawio.svg? I just checked again and everything is correct unless your fans have different wire order...
I would say that the hotend fan is good with tacho, so you can earlier recognize if the fan doesn't show the expected behavior anymore ... ?!?
I just find it interesting, Nithawks 'stock' fan config. you'd think you'd want the tach on the parts fan to get facilitate % cooling while printing. Yet, I can understand having a tach pin on the HE fan to validate the HE is actually being cooled. BUT.. is Klipper actually regularly even checking something like that?
I had the same question; got my answer here:
https://discord.com/channels/582187371529764864/582187372142395424/1265849728747438161
...but I don't know whether klipper is 'regularly checking'. That's a good question.
It's absolutely useless for part fans. It's very useful for hotend fans as you'll then be able to tell if it's stalled (which causes potentially very bad problems).
yes, it'll run at higher current than requested since the actual sense resistor is lower than the configured one.
won't be a lot though with the 10% difference.
It's very useful for hotend fans as you'll then be able to tell if it's stalled...but the question is: does RatOS/Klipper automatically recognize the rpm pin and implement some kind of warning if the fan is not running? ..or is there some extra config required? So, I take it this is half of a voltage-divider somewhere? Can you point me to something that explains the circuitry in more detail?
No there's no voltage regulation going on at all (it's PWM), the sense resistor is what's used for current sensing, specifying a wrong value results in wrong (in this case lower) readouts and thus the input voltage is applied longer resulting in higher current flowing through the coils.
The TMC driver documentation
as far as tachometers and hotend fans, needs pin, ppr and poll_interval configuration, safety checks can be done via delayed gcode macros
...Okay, but there's nothing implemented by default?
No
As it's very uncommon
in fact the nitehawk and the orbitool are the only toolboards that offer a tachometer option for the hotend
It's kind of insane that it hasn't been the standard from the start.
I just got a nitehawk, but don't have a 3-wire fan for my hotend... Now you're making me rethink that. I've never had a problem, but now that I know the possibility exists, I'm worried 🙂
It's just a question of how much you value safety. For printers with a solid metal connection between the hotend and the rail, it's less of a worry compared to printers where it's mostly plastic.
that said, i've seen melted aluminum in hotends before, but multiple things would have to go wrong (and many safety checks would have to malfunction) for that to happen.
Yeah, that's what I was thinking... don't we have some runaway protection via the RTD anyway?
There's no runaway required
if your fan stops your heatsink will rise to temperatures close to your target print temp
ah, right.
if you're printing PC for example, that can be dicey, some of those like upwards of 350C.
which is right around where cheap aluminum starts melting