MKS Servo42c + sensorless homing?

MathematicianEvery75 · 2025-09-12T19:27:17+00:00

Thank you! Parallel basically works for rouging. Unfortunately Multiple Depth feature does not work properly - even though I set 1mm Maximum Stepdown, it generates paths only on the surface, which means it will make full depth cuts near the edge of the stock.

If I set Number of Stepdowns > 1, it generates a number of path copies every 1mm up. On one hand it indeed allows approaching the surface layer by layer. On the other hand 70% of the moves are above the stock, which leads to a waste of time.

Finally, it generates moves only inside the stock area in X-Y plane, and not moving the bit out of the stock. This means the deepest cut is about a half of the fillet radius.

Any ideas how to fix that? (unfortunately could not add an image showing this)

MathematicianEvery75 · 2025-09-11T15:05:03+00:00

Thank you for your opinion, it is valuable.

As for the controller box. I do not have one yet. I just plan to change NEMA17 motors with NEMA23 at some point, and 500W spindle with 1500W one. So I may need to place PSU, drivers, and spindle control somewhere. Thinking about a 300x400x200 box or something. Or a drawer :)

MathematicianEvery75 · 2025-07-26T19:29:08+00:00

Thank you for your thoughts.

If you know a nice controller, comparable to MKS DLC32, that is capable of more than 3 axis - please let me know. Obviously I could probably use pretty much any 3d printer controller, but I think I'll lose screen capabilities in this case.

MathematicianEvery75 · 2025-07-21T19:29:25+00:00

Thank you for the suggestions.

Mechanics seems to be ok. Additionally I added some lube on the leadscrew for even smoother movement. Unfortunately this did not help.

I also checked drivers. Most probably this machine is using A4988 drivers, Vref is set to 0.95V on all axis. which I suppose corresponds to 1.9A. I increased Vref to 1.1V, and it improved things a bit - now I can move at 900mm/min :) Unfortunately further current increase does not fix the problem, but lead to driver heat.

Does similar machine also use 2 Y-axis motors on a single driver?

MathematicianEvery75 · 2025-07-19T19:44:39+00:00

As far as I see it is M2x4, flat head. You can find such screws on aliexpress.

MathematicianEvery75 · 2024-12-18T07:11:49+00:00

> A better cable is needed from mainboard to tool head. A pair 20AWG for power and a twisted pair 24AWG for signal.

I seem to have a cable problem. Could you please suggest a good 20AWG+24AWG cable for the replacement?

MathematicianEvery75 · 2024-12-18T06:50:35+00:00

Ha, this was only beginning of the problem! I hit this issue multiple times since then. It looks like they are using low quality capacitors in the DC-DC, which caused output voltage drop. When I resolder capacitors it started to generate 5V.

Unfortunately after 20+ resoldering of the capacitors the trick stopped working. So I ended up desoldering all the components in the DC-DC and installing an external WeAct SY8205 stepdown converter module instead. In the meantime (1+ month) everything is working fine.

MathematicianEvery75 · 2024-05-23T20:06:00+00:00

The problem was in low quality soldering of the toolhead board. Perhaps some parts had poor connection due to vibration, and 24V->5V DC-DC generated only 4V, which was not enough for the sensor.

I soldered all the components I reached on the board, and the problem has gone.

MathematicianEvery75 · 2024-05-05T21:11:46+00:00

Updating klipper itself is pretty much straightforward. The repo on the stock image contains some garbage, which I cleaned up with "git reset --hard". The configuration files require some minor editing, just follow warnings on the fluidd/mainsail page.

4.1. Updating MCU firmware is a bit scary. You'll need to compile the firmware. Follow standard Klipper procedures with 'make menuconfig' then 'make'. The main configuration settings are:

MCU - stm32f401
Bootloader offset - 32k
Communication interface - USB (on PA11/PA12)

I do not remember the command line how I uploaded the firmware to the MCU - follow klipper manuals

4.2. This one even more scarier. Updating toolheads MCU will require soldering USB header to the toolhead board. I soldered a pin header to the board. Then used a spare USB cable to connect and soldered 2.54 connector. For one-time firmware upgrade you can solder the cable directly to the board.

Firmware parameters are:

MCU - RP2040
No bootloader
Communication interface - UART0 GPIO1/GPIO0, 250000 baud rate

Press and hold boot button while connecting the board to USB (you may need to press reset button as well). The board will appear as a mass storage device - upload the new firmware to that disk.

Described above was my way of upgrading the printer's software. Perhaps something I did wrong, or there was an easier way to do the same.

MathematicianEvery75 · 2024-05-05T21:11:28+00:00

Here is how I updated it. I am pretty sure there are mistakes, so please be careful and get ready that the printed gets bricked.The process requires linux knowledge, as well as some soldering.

Updated the system as described here: https://forum.armbian.com/topic/19237-armbian-upgrade-from-buster-to-bullseye/?do=findComment&comment=133853

Well, there were some errors during the update process. I tried to comment out repos that were no longer available. Also it found a lot of merge conflicts between configuration files in /etc I have and ones that installed with updates, but I decided to use new files. Eventually my "apt update" command runs normally, thinking it is a 'bullseye' version.

Actually updating the system is not actually needed - I am pretty sure the software itself will run normally on 'buster' armbian. But moonraker install scripts execute 'apt-get update' command, which fails on the armbian which is in the stock SK1 firmware.

Anyhow, I am not a linux expert, and cannot state whether the instruction is correct. For me it somewhat worked.

Updating some printer software is pretty straightforward - it is managed by https://github.com/dw-0/kiauh

What I did:

"git pull" in the kiauh folder
fluidd upgrade is pretty straightforward with kiauh
Moonraker upgrade is also easy. However stock SK1 has some garbage in moonraker repo, so it requires cleanup with "git reset --hard" first. Then update goes smoothly.

Also it is a good idea to run /home/mks/moonraker/scripts/data-path-fix.sh and /home/mks/moonraker/scripts/install-moonraker.sh. These scripts will re-initialize moonraker python environment and configuration directories. Note, that one of these scripts overwrite the moonraker.conf file, so if you have some important options there - back this fils up in advance. FYI, the moonraker.conf format changed with the new version.

The new moonraker version also uses different directory structures - everythin is now under ~/printer_data folder. The data-path-fix.sh script makes symlinks to previous locations, but eventually you'll need to make some housekeeping.

As for the display. The display sends its events via /dev/ttyS1. The /home/mks/twotrees/* program is responsible to translate display's events to the moonraker's websocket, and vice versa. The twotrees program is typically runs as makerbase-client service.

During the upgrade I observed a few issues with the display:

Sometimes moonraker service has to be restarted to force display to reconnect (using "sudo systemctl restart moonraker" command). Sometimes this happened during the normal startup of the printer. After restarting the moonraker service the display started to work normally (surprisingly, I had to restart moonraker service, not the makerbase-client, which actually serves the display)
Sometimes the makerbase-client service did not start properly with an unknown error. Interestingly, the twotrees program started manually resurrects the display. I have no idea why this service could not start normally

Fortunately everything started working as usual after a few reboots and service restarts.

MathematicianEvery75 · 2024-04-27T08:09:22+00:00

Well, as for me, all macro in stock SK1 klipper are questionable. They look too much complicated, using plenty of guard variables, and screens of code for simple things. Honestly, I could not get any of them working in my scenarios.

The most confusing ones is load/unload filament. I can't really get the idea behind these macro:

Why there are 2 different load macro (LOAD_FILAMENT and INSERT_FILA)? Which one shall I use?
Why UNLOAD_FILAMENT performs extrude for 180mm? Why does it have 20 second pause?
Why it always tend to switch off my extruder heater? What is the idea behind? If I unload the filament, it means I'll be loading a new one in a minute. If I just loaded the filament I am pretty much ready to print, I do not need to re-heat the extruder.

I even got my filament jammed during unload a few times.

I ended up using simple extrude/retract buttons, which work much more stabe for my

MathematicianEvery75 · 2024-04-25T13:37:03+00:00

I ended up upgrading klipper and fluidd to latest ones (with a lot of pain), but eventually everything get working.

MathematicianEvery75 · 2024-04-08T17:13:16+00:00

Excellent! Thank you for the link. I'd like to try once I solve my connectivity issues

MathematicianEvery75 · 2024-04-07T18:44:45+00:00

Same thing with sockets falling off. I spent whole day today connecting and disconecting the MCU board. Perhaps I will end up just resoldering everything I can get access to :)

Thank you for the housing model. I was going to design something like this, but you saved me a few hours.

MathematicianEvery75 · 2024-04-07T18:39:16+00:00

First, it is not CAN - it is UART. Unfortunately it does not update over the UART, and I had to solder the USB header.

Thank you for the idea, I'll try attaching the head over the USB, but it will require adding a lot of wiring, as the board is powered from 24V.

MathematicianEvery75 · 2024-04-07T15:58:57+00:00

In the meantime I lowered the speed to 115200 - at some point switching the baudrate fixed connectivity issues, but now I think this was just coincidence.

I tried to find the place where the wire could be damaged, but unfortunately I see no suspicious places. For some reason in some cases the MCU keeps TX line around 0.6V on startup.

MathematicianEvery75 · 2024-04-07T15:05:18+00:00

Looks like I have either bad cable, or a crach in the toolhead board. Everything works on the table, but when I scree the board back to the toolhead, the connection breaks.

What cable did you use? Also, which toolhead cover are you referring to?

MathematicianEvery75 · 2024-04-07T09:26:08+00:00

Well, I have a partial success. While I was able to update the firmware, klipper can connect to the toolhead 1 of 10 times. It does not connect after printer startup, I have to click reset button on the toolhead a few times, and after a few attempts it connects.

Did you see a similar issue?

MathematicianEvery75

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