Troubleshooting a problem with your Smoothieboard

If you have a problem with your Smoothieboard, don't panic.

First of all, make sure you have read the documentation on this website, it is likely the information you are looking for is here, it is a very complete documentation. In particular take a look at:

If you can't find your answer here, you can also ask for help in the community. There are many channels:

Before doing anything else

Including asking for help, please read the “How to troubleshoot” section bellow.

And of course try to find the answer to your question on this page too.

Below is the list of the most common problems and things you can try to solve them :


Here are some of the things you should do when running into trouble, and before asking any kind of help around :

1. Backup your configuration file

Take your SD card out, and save your configuration file to your computer. If you are going to be messing around with the printer, you'd better be safe and make sure if anything happens to your SD card, you will not lose the work you put into your configuration file.

You should really have done this already, it's just good sense.

2. Clean your SD card

Sometimes SD cards get corrupted, and it can cause all sorts of weird and difficult to understand problems.

You should :

  • Format your SD card ( as FAT32 )
  • Paste the most recent firmware file on your SD card
  • Paste your configuration file to the SD card
  • Insert the SD card back into the board and reset it

Then see if your problem still exists or not.

It's probably a good idea to do this even if you don't think it's a SD card related problem, quite often people think it's not and it fixes the issue anyway.

Override doing its job but the user not realizing the full extents of its effects

If you are here because you are editing your configuration file, but none of the changes you make to the file, seem to have any effect on the machine's behavior, it's possible your config-override file is “overriding” ( it's its job ) the “main” config file's settings, and so you are seeing those override settings in action, not the settings you are modifying.

This is a fairly common situation for users who have set everything up, then go back to try to change something in config, only to see no effect, but they do not remember/realize they have a config-override set up, and do not realize the effect it is having.

So if you are modifying config, make sure you think about the override and its effects.

And if at all possible, while debugging issues, simply remove your config override file (save it first of course).

2022/07/17 17:35

3. Incremental wiring

This may not apply to your specific problem, but if it does :

Unplug everything from your board, then plug things back into the board one at a time, resetting the board and testing your problem each time you do.

Start with USB, then the power supply, then do the same for each peripheral in turn until everything is plugged back in. If you do not know what the problem is, it should help you pinpoint it.

4. Prepare your config for asking for help.

Open your configuration file.

Copy it's content.

Now go on the website.

Paste your configuration file's content into the « New paste » box

Click on « Create new paste »

The website will give you a link. You can now give this link to people on IRC or the forums, without having to copy/paste the entire file, and people will be able to see your config and help you.

5. Isolate the problem as much as possible

You want to make sure your remove as many influencing factors when debugging an issue. This makes sure you don't confuse a problem with another, or miss the fact that two problems are actually working together to ruin your life.

For example, let's say your ethernet is not working, then you want to do a few things : 

  • Unplug everything from the board except USB ( which you need for power ) and Ethernet. This makes sure the problem isn't coming from some of the rest of the wiring
  • Use the latest version of the edge firmware ( see ). This makes sure people helping you have the same frame of reference as you
  • Use the latest version of the example config file ( see ), and strictly only modify the lines related to Ethernet, leave all the rest unchanged. This makes sure the rest of your config isn't part of the problem
  • Try at least two different Ethernet cables, this makes sure the problem isn't the cable
  • Try at least two different routers/networks, this makes sure the problem isn't the network

Of course, this is for network problems, adapt depending on your exact case. Use your smarts.

Make sure this is not a hardware problem before asking for help also, is your laser mirror path well aligned? Are all your screws tightened? Is your machine rigid enough for the task? Is your belt tight? Etc.

Finally, make sure you mention all those steps you have taken when asking the community for help, if you don't people will start telling you to do things you have already done.

6. Describe/Take a picture of your setup

Take a picture of your Smoothieboard, a global view of it ( tip : pictures are much sharper and therefore useful, if neither the camera nor the subject are moving. Deposit your camera on a flat surface or fix it in some fasion. If you think pressing the button will make it move, remember you can use a 5-second countdown to take pictures. )

Also take pictures of the connectors, wiring, motors, and overall machine. A picture is worth a thousand words.

When posting on a forum/social media to get help, attach your config ( it's pastebin link ), but also these pictures, as well as a description of your machine/setup ( as detailled as you can be patient for, with special time taken for anything that is not commonly done/unusual ).

If using a mailing list, do not insert the pictures in the body of your email, but rather attach them to the email. This make things easier for volunteers helping you, and not doing so often leads to ridiculously weird email client layouts ( for example if the picture is much larger than the screen ).

7. Before asking the community for help.

If you have an Open-Source board like the Smoothieboard, a board from Panucatt, or one of the many designed by the community and that support the project, ignore this.

If you chose to buy a closed-source derivative board, however, please understand that those are considered to be toxic to the project, and that asking the community for help with those would be similar to asking the community to help with destroying itself.

Please ask for help from the person that sold you that board, before asking the community for help. Providing support for their product is the absolute very least they can do. And of course unsurprisingly they are well known for not doing even that. But please ask them first.

If they don't help you, then feel free to ask the community, but please be aware even then some won't accept to help. If this happens please remember that the community helping you is a service they are giving you, and that when they choose not to, they are only not doing you a favor.

Always make sure you have your board updated to the very latest version of the firmware before you ask for help.

You will likely be asked to provide the result of the version command so make sure to prepare that in advance.

Ideally, use Pronterface when troubleshooting, for various reasons ( one of which is that some hosts hide error messages. Another one is it helps us be better at helping you if everybody we help has the same host ).

1000% make sure you use the very latest example config file ( with your values ported over to it ), and the very latest firmware versions. This can't be repeated enough. This is said here and everywhere many times. If you come in asking for help, and after an hour everyone realizes your firmware is a year old, there is going to be a lot of frustration at you, you probably want to avoid that if you can.

Smoothieboard does not work at all

First off, do any LEDs turn on on the board when plugged in via USB ?

If not, that's very bad, contact your seller.

If LEDs turn on, it then depends on what they do :

There is a series of LEDs on your board, near the center.

They are labelled VBB ( red ), 3.3V ( orange ), and 1 2 3 and 4 ( all green ).

We are still only interrested in the green LEDs.

Different behavior can represent different situations and problems for the board :

Normal pattern

If your LEDs do this :

Then the firmware is running, and the LEDs are displaying correct behavior.

SD card problem

If your LEDs do this :

Then the firmware is running, but the board encountered a problem reading or accessing the SD card, or the configuration file on the SD card.

Try taking the card in and out of the board several times, or try using another SD card ( here is how to set up a new card ).

See bellow for more details.

Firmware crash

If your LEDs do this :

Or this :

Then the firmware is not running. You can try flashing the firmware again.

See below for more details.

Plugged in and 3.3V LED is OFF

This means the microcontroller on your Smoothieboard is not getting any power.

Smoothieboard gets this power from your USB cable (unless you are using the optional voltage regulator or the 5V input): check that Smoothieboard is correctly connected to a USB port or otherwise powered.

If it is, but the 3.3V LED is still not lit up, one other possible reason would be a short on your board.

Unplug the USB cable, and disconnect everything else from your Smoothieboard. Then plug the USB cable back in and check if it starts working again.

If so, there is a short in one of the peripherals. Quite often this is due to incorrectly wired Endstops (shorting 3.3V to GND instead of connecting GND to Signal for example).

If this still does not solve the problem, examine the board for problems with your soldering of components/connectors and any other anomalies you can detect.

If you can still not find anything, contact the community.

The 3.3V LED is ON but LED4 is not ON

LED4 indicates SD card status. If it is not lit up, it means there is a problem with your SD card.

First thing to try is taking the microSD card out of your Smoothieboard and testing it on your computer with a SD card reader.

If it works there, copy the files that are on it elsewhere, format it (as FAT32), copy the files back on it and try again.

If it still does not work in the Smoothieboard after this, take another microSD card, format it (as FAT32), copy the files to it, then try again.

If it still fails, then as you tried two SD cards they are probably both fine. The problem could be with the files on it.

Format a SD card as FAT32, and on that fresh card, copy two files: 

  • firmware.bin , with this exact name, which you can find here
  • config , with this exact name, which you can find here

Then insert the card into your Smoothieboard and try again.

The 3.3V LED is ON but none of the 1 through 4 LEDS is ON

Or LED1 and LED4 are ON, but LED2 and LED3 are not blinking.

This could be caused by a firmware bug, or by a problem with your configuration file.

Try with a fresh configuration file, and if it does not solve the problem contact the community.

If you soldered the smoothieboard then check either the 12 MHz oscillator or the SD card/SD card slot.

  • This could be a bad solder joint with the 12 MHz oscillator (crystal), a bad SD card slot, a bad SD card, and/or a bad config file.

The 3.3V LED is ON, and LEDs 1 and 3 are ON and 3 is not blinking, LEDs 2 and 4 are OFF

This could mean your board has no bootloader, which is very wrong. Contact whomever sold you your Smoothieboard.

The 3.3V LED is ON, and LEDs 1, 2, 3 and 4 are ON and none are blinking

This could mean you have a bootloader but no firmware was ever flashed or found on the SD card. Again, this is very wrong, contact whomever sold you your Smoothieboard.

12 or 24V power is plugged in but the VBB LED is not ON

Unplug power immediately !

Check that your power is not in reverse polarity.

Even if you think you have it correct (read the instructions carefully, the markings on the board can be a bit confusing), try reversing it just in case.

All LEDs are on but LED 2 and 3 are solid

Firmware didn't get flashed, you need to flash it and also make sure you uploaded a valid config.

It smells like something is burning!

Whaaaaa! Unplug everything! Get a fire extinguisher!

Now, try to remember exactly what you were doing with your board, and contact whomever sold it to you.

Mosfets are never turning on

You configured everything right and plugged the heating elements into your mosfet outputs, but no matter what you do, they do not turn on.

Note Smoothieboard does not have a single power input. It has one for the motors, and then the big mosfets have their own inputs, and the small ones have theirs. You need to provide power to each, according to the mosfets you are using. See the documentation on this, it goes into great detail and has diagrams.

Grounding problems

If you don't know about grounding, it's a great idea to read this post :

Changes to configuration are ignored in general

The config changes are not taken into account, files do not appear or do not update on the SD card

If anything like this happens, that could be related to the SD card “messing up”, format the SD card ( as VFAT/FAT32 ), then paste your files back on it.

See SD card.

Sometimes the SD card can get corrupted after which it will do strange things. Always make sure you unmount ( virtually not physically ) your SD card after doing anything on it

For configuration changes which are being made in the config file and are not being applied, check that they are not being overridden in the config-override file in the same folder:

Override doing its job but the user not realizing the full extents of its effects

If you are here because you are editing your configuration file, but none of the changes you make to the file, seem to have any effect on the machine's behavior, it's possible your config-override file is “overriding” ( it's its job ) the “main” config file's settings, and so you are seeing those override settings in action, not the settings you are modifying.

This is a fairly common situation for users who have set everything up, then go back to try to change something in config, only to see no effect, but they do not remember/realize they have a config-override set up, and do not realize the effect it is having.

So if you are modifying config, make sure you think about the override and its effects.

And if at all possible, while debugging issues, simply remove your config override file (save it first of course).

2022/07/17 17:35

Changes to configuration are ignored on a particular line

If a line begins with the # character, it means it is “commented out” and Smoothieboard will ignore it.

You need to remove the # character and Smoothie will now take the line into account.

« No strategy found to handle G32 »

If you try to run bed leveling or calibration, and the board answers something like « No strategy found to handle G32 », please do the following : 

  1. Flash the very latest firmware
  2. Start your configuration fresh from the very latest example configuration file
  3. Enable the calibration strategy by following the exact instructions at zprobe

This error message most of the time means your config and firmware aren't up to date with each other. Upgrading everything solves the issue.

Bed leveling seems to have no effect

If you try to run bed leveling or calibration, and it seems to have no effect at all, please do the following :

  1. Flash the very latest firmware
  2. Start your configuration fresh from the very latest example configuration file
  3. Enable the calibration strategy by following the exact instructions at zprobe

This symptom most of the time means your config and firmware aren't up to date with each other. Upgrading everything solves the issue.

My stepper motor does not turn correctly

If it always turns in the same direction, and/or turns only weakly, and/or makes a strange sound, one very common cause of that is that only 3 of the wires of the motor are connected to the stepper motor driver.

Check your connector and your cables.

If that doesn't help, do the following : 

  • Try this motor on another stepper motor driver
  • Try another motor on this stepper motor driver

My stepper motor does not turn at all and makes a very high-pitched sound

This can happen with Z axis (or any leadscrew driven stepper motor) due to the high steps per millimeter number. You are probably trying to move it too fast. Try asking it to move at a much lower speed ( for example G1 Z100 F100 ).

It's also possible you are trying to home, or to probe too fast. See the corresponding modules for how to modify the default speeds.

If you are using external stepper motor drivers (driven by ENn, Stn and DIRn pins) check polarity, voltage and timings of signals to your driver. Also consider increasing Microseconds_per_step_pulse slightly if the default 1us pulse width is too narrow for your driver or cable lengths.

My stepper motor does not turn at all

And it does not present any resistance/torque when turning it manually :

This means the stepper motor driver is maybe not able to power the stepper motor.

Try wiring a different motor to that driver and try again. If the new motor works on this driver, then the motor is the problem. Otherwise the driver is probably the problem.

If you changed any of the stepper motor driver pins in your configuration, try testing again with a fresh configuration file.

My stepper motor turns in the wrong direction

There are two solutions to this :

You can reverse the order of the wires on the stepper motor connector.

Or you can edit your configuration file. For example, if you have this problem on the beta stepper motor driver, you need to invert the direction pin for that driver : 

beta_dir_pin                                 0.11

Becomes :

beta_dir_pin                                 0.11!

Save, reset and start again.

My stepper motor loses steps

Losing steps means not moving the exact number you asked of your motor. This will result in your machine losing its position and working where it shouldn't, often in the form of small offsets.

There can be several causes to this, here are some things to try: 

  • Make sure you have correctly set the current value for that stepper motor. Too high as well as too low values can cause this problem
  • Make sure there is no mechanical problem in your machine, like misaligned axes, things hitting other things, too much tension in belts, things like that
  • Is your stepper motor driver too hot to touch? Try aiming a big fan at your board (ideally the bottom of it), the stepper motor drivers might be overheating and shutting down for safety reasons. Never put heatsinks on top of your drivers, they are designed to be cooled from the bottom.

My stepper motor changes direction randomly

Your stepper changes rotating direction randomly, however you're sending the same direction command (e.g. X+).

Multiple things can cause this:

  • check ALL your cable connections from board to stepper (possibly with a multimeter, to check if they are not broken)
  • if using external driver:
    • check those cables also
    • check the DIR pin levels with a multimeter. Level (0V/3.3V) should change every time you ask for opposite direction rotation from the board.
    • if using 5V logic level drives (like TB6600), use a level shifter (3.3V ↔ 5V) or change to open-drain in the config

Homing does not work

You ask Smoothieboard to home an axis, and instead of going to the endstop and stopping there, it either does not move at all, or moves a little bit and stops.

What is probably happening here is either Smoothie thinks your endstops are always triggered (even when they are not), or it things they are triggered when they are not and not triggered when they are (inversion).

If it thinks they are always triggered, check your wiring.

If they are inverted, there is either something wrong with your wiring, or your configuration. See the Endstops section for more information on how to fix this

Maybe you have the max_travel settings set too small.

Homing does not stop when hitting the endstops

Several possibilities : 

Maybe the endstops are always read as not triggered, this can for example happen if they are not connected properly. Check your wiring and see the Endstops section for more information on how to fix this.

Or maybe you configured to home to the “max” end of the axis, but your endstop is actually at the “min” end ( or vice-versa ). See the endstop page again for how to reverse the homing direction.

Also sometimes having the sdcard mounted on the host (especially Macs) will cause this, unmount the sdcard and see if it still happens.

My stepper motor driver is burnt

It's possible to burn stepper drivers if a short occurs, or if you manually turn the stepper and it's a high-inductance stepper.

In this case, you have two solutions : either replace the stepper driver, or wire in an external stepper driver.

To replace the stepper driver, you need a hot air soldering station and some flux : 

If you feel this is too difficult for you, or you don't have the right hardware, you can alternatively wire in a $10 external driver like the TB6600 ( easy to find on ebay or aliexpress ).

For instructions on wiring any external driver see the|dedicated page.

I can not connect to my board on Windows

Depending on the version of Windows, you might need to install the Windows Drivers for Smoothieboard

Note on Windows10 the drivers are not needed, and installing them can cause problems.

I get disconnected from my host frequently

This can be caused by several things :

  • Make sure you use as short as possible, good quality, shielded USB cable with ferrite beads on it ( this is a good example of such a cable : )
  • Make sure the Smoothie PSU is plugged into the same outlet as the PC you are connected to, otherwise you can get ground loops.
  • If your printer is unusually large, add ferrite to everything coming from or going to your board ( motors, endstops, thermistors, mosfets, etc )
  • Try using a shorter USB cable
  • Make sure your power supply is clean ( ideally with an oscilloscope )
  • Route wires for motors and mosfets away from signal cables ( endstop, thermistors, USB, etc )
  • Try rebooting the host computer ( especially if the host is a Raspberry Pi )
  • If printing from a Raspberry Pi ( e.g. from OctoPrint / OctoPi ), ensure that the Pi's power supply is capable of supplying the required current at a high enough voltage. The official Raspberry Pi PSU supplies up to 2.5A at 5.1V. Low voltages can cause USB communication issues, as well as SD card corruption and other crashes. With a Pi 3 B or 3 B+ you can monitor under-voltage events by watching for the Pi's red power LED turning off, a “lightning bolt” icon being displayed over HDMI, or you can run dmesg | grep voltage in a terminal/over SSH.

See the USB page

Smoothieboard Mass storage (SD card) is recognized, but not the Serial interface, on Windows

Please take a look at windows-drivers and see next section if that does not work.

How to disable MSD permanently

Install this version or firmware (Remember to rename it firmware.bin)

and add this to your config file

msd_disable  true  # disable msd

The mass storage device will no longer be available, but serial should work.

Smoothieboard Mass storage (SD card) won't mount on my host computer

Even if the smoothieboard seems to work OK, this is almost certainly a problem with the SD card itself. Try using a different SD card. This problem has been reported with some SD cards that shipped with the original kickstarter boards. See this thread for more discussion of the problem. See the SD Card page for information about setting up a new SD card.

Motor won't turn but all lights are correct, motors make no noise at all

Bad USB cable or insufficient power to 5v(Required to give motors enable signal) - Don't underestimate the power of a bad USB cable to waste hours or days of your life.

Pronterface ignores my commands

If sending a command to the board via pronterface and it is being ignored, that is because you need to “escape” it by adding @ before it.

For example do not send Version but send @version.

My machine was executing a file and it stopped

First thing to check : open the Gcode file and verify it's not truncated. This can happen for example due to errors copying the file. It's more common than you would expect.

Second thing, check the Smoothieboard is not in “Alarm” mode. If in Alarm mode, it should turn off it's heaters, but refuse to move. Sending the M999 (or $X or $H) command puts it back into normal mode, but first check your host program for the message Smoothie sent telling it what the problem was, most problems that cause it to go into alarm mode are problems that deserve your attention. It can be hitting a limit switch, or a problem with temperature control for example.

If you are using Simplify3D to stream, try using a different program like Pronterface or Octoprint, or print from SDCard. S3D does not currently support the protocol Smoothie uses for streaming files, and will just stop sending most of the time.

Check if the leds are still flashing, if they are then Smoothie is still running fine, and it was your host that stopped sending the file. If the leds are not flashing then smoothie crashed, there are instructions here to find out what happened.

Am I running out of memory?

Most of memory is allocated during boot, very little is allocated after booting, if you have a very large config file it may run out of memory during boot, in which case it will not boot and the leds will not flash. (delete everything in the config you are not using and try again). To check how much memory you have after boot issue the Mem command, if it says you have over 2,000 bytes free then you are unlikely to run out of memory whilst it is printing.

I burnt one of my mosfets !

Oh no !

Don't panic ! One option is to use a solid state relay instead ( this works well for beds for example ). See

Another option is also to use one of the mosfets you aren't using yet : Smoothie comes with more mosfets than users generally need, so it's likely there is one or even two you aren't using yet, simply switch to one of those.

Even better, if you have the right equipment, you can replace the burnt mosfet yourself, as in this video :

One of my temperature inputs stopped working

It reads inf, or a fixed temperature, despite being correctly connected ?

Check by connecting another thermistor, to make sure it's not a wiring or thermistor problem.

If it still doesn't work, maybe ESD or a short killed your thermistor input. Thankfully, Smoothie comes with spare ones, simply use T2 or T3 instead of T0 or T1, and change the pin in configuration accordingly.

My thermocouple values are weird/inverted

Are you sure you didn't plug the thermocouple backwards ? ( see )

I got a temperature error ( for example runaway ) but don't want my 2 weeks print to be ruined

With a decent host program (like pronterface) it is sometimes possible to recover a print after a HALT in cases where the HALT is not fatal.

What I have done several times when a limit was accidentally hit and entered HALT…

0. Click the pause button in pronterface 1. Exit halt by sending $X (or M999) 2. Raise head by jogging 3. Home XY 4. look at last Z height in pronterface 5. jog head to the last known Z 6. Turn heaters back on wait for temp to be reached 7. click the resume button in Pronterface.

NOTE This will not always work well as several gcodes will have been lost, so if you were on the infill it will probably be ok, if you were on the perimeter then it may be a problem.

Fix the problem first

If you get an error, it means something is wrong. You shouldn't just keep printing as if nothing happened. You need to understand what happened and fix it before continuing, or you are risking your safety.

This “resume” information is provided only assuming you fixed the problem before resuming. Please be safe.

My SD card won't work ( LED4 is off at boot )

If your SD card will not work, configuration is ignored, and LED4 is off at boot ( and boot takes longer than expected ).

The reports of problems like this are rare, but users have reported the following fixes to work : 

  • Clean up the SD card socket with an alcohol/IPA-imbibed piece of paper
  • Clean up the SD card socket with compressed air

My external SD card ( in my panel ) is not working correctly

Ok so here's the thing : external SD cards are extremely bad. They just aren't designed to be talked to over wires, even short ones. You are supposed to talk to them over tracks on a PCB. Wires are antennas and pick up interference. This leads to corrupted data and errors. To talk over wires you need differential signals and/or error correction protocols, and SD cards can't do any of that. If we had a choice we would remove all panels with external sd cards from the planet, they are an infinite source of trouble for users. Works fine for some, they tell everyone how awesome it is to have one, then plenty of others can't ever get it to work reliably.

Because of this, while we did add the code to Smoothie for external SD cards, we can not *officially* support that feature. It's just way too much trouble and user problems flooding all around. If it doesn't work for you, we just can't do much about it, unfortunately.

Try to make the cable as short as possible, add ferrite, and try to trace the cable as far as possible from any source of interference ( like mains cables ).

I'm very upset at something, everyone is mean and nobody listens to me

Now this isn't meant to offend, and it probably doesn't apply to you, but keep reading.

Smoothieware is an Open-Source firmware developed by volunteers on their free time. They are giving it to you for free. It's a favor they are doing you. They are being really really nice to you.

The people in the community who help you, do it in their free time, and could be drinking beers with their friends instead of helping you.

Before you get offended at: 

  • People not answering you fast enough
  • People asking you to read the documentation
  • People not willing to help you right now
  • People not implementing something you want
  • People not not taking your recommendations into account
  • Etc

Please please please remember you are talking to volunteers. You did not pay for the firmware, it's free, and it was done by people who did it to make the world better, with their own free time, and sometimes their own money. All for you, without even knowing who you are.

If you have a problem with your Smoothieboard, the hardware itself, you did pay for that, and you are entitled to your issues being resolved. Contact the seller and they are legally obligated to help you, and they will gladly do so.

But the people in the community are not obligated to do anything, you are not entitled to their help or attention. They are doing you a favor, and if they choose for whatever reason not to do you a favor at any given time, that is not depriving you of anything, that is just « not volunteering to do you a favor ».

To be clear, the Smoothie project is mainly composed of two parts :

  • The Smoothieboard hardware, which you paid for, and are entitled to help/fixes for only from the person who sold it to you, not the community, contributors, or anyone else
  • The Smoothie firmware, which is free, you didn't pay for it, and no-one is obligated to help you with. It so happens that the main Smoothieboard sellers have a policy of helping users with firmware problems even though they are not obligated to ( again : you didn't pay for the firmware, it is free ). But the community and contributors are definitely not obligated to help you with it in any way.

If somebody in the community is not willing to do what you want, remember you didn't pay them, and contact your seller instead.

This is a nice read on the subject:

Again: this probably doesn't apply to you, but if you are upset, please take a moment to consider if maybe this applies. If you are upset and it doesn't, please contact your Smoothieboard seller as soon as possible, the main reason for frustration is users waiting too long to contact their sellers for help.

Very important: if you are upset because your board burned, your seller did something wrong ( please contact them, they really don't want you to be upset ), or anything like that, this does not apply at all. This is only about interacting with the volunteers in the community.

I asked for help for the 15th time today and nobody wants to help me anymore

What is wrong with MKS ?

( this applies to all non-open-source smoothie derivatives: SKR, MKS, AZSMZ and others ).

Was: « Somebody refused to help me because my board is a MKS, what's that all about ? »

Note : This was written at a time when only MKS was doing this, there are now also SKR boards, and even counterfeit Smoothieboards, all/most of this is valid for these too.

Smoothie is a community-built Open-Source project. Many people around the world come together to work and share to make the best possible CNC controller. They put likely more than a century of cumulated work into this, and make a lot of sacrifices so that *you* can have the best controller board and firmware possible, with the best documentation and best support.

MKS ( or azsmz for that matter ) is a company that takes that work, and instead of contributing to it like everybody else, uses it all without respecting the work of the contributors or contributing themselves in the slightest. They don't respect the license of the documentation, they don't release their work as open-source despite it being obviously derived from open-source work. They wouldn't exist without the work of the smoothie community and act as if they had created all this themselves. They also take sales away from open-source companies, and by doing so, severely restrict the means available to push the development of the project forward ( most companies selling open-source smoothie-compatible boards, actually contribute to the firmware in terms of time or money. MKS does not ).

MKS is considered a cancer, a parasite to the Smoothie project.

Because of this, I am sure that you will understand that we are very reticent to help MKS. Helping MKS is like helping destroy the Smoothie project. It makes no sense to work so hard on creating the Smoothie project, and at the same time work on destroying the Smoothie project.

If we help users with a MKS board, we are doing MKS's work in their place, so we are helping MKS. Helping MKS is not acceptable. We understand that you are not MKS, but we still can not help MKS, and by helping you we would be helping MKS.

Because of all this, here is the current policy in the Smoothie project regarding MKS users asking for help : 

Before asking the Smoothie community for help, ask MKS for help. This is not a refusal to help. We only require that you ask MKS for help first. Then if MKS is not able to help you, you can ask the smoothie community, and it is possible that some members will want to help you. Again : our policy is not to refuse to help MKS users, but to require that you ask MKS for help first. If MKS is able to help you, that's great. If they are not able to help you ( which is likely, they are known for being very incompetent ), then you can ask the Smoothie community for help.

Please note that even then, *some* users might refuse to help you. That is their choice, you shouldn't be upset at them, they are only not volunteering to offer you their free time ( to destroy the Smoothie project ).

Please understand that you are talking to volunteers. They are giving you their free time, and they are not required to do so. If they don't want to help you, they are not hurting you, they are just choosing not to give you a gift. If a group of friends is eating cake, and somebody gives you their share of the cake, they are giving you a present. If they do not give you their share, they are not being mean to you, and you are being unreasonable if you are upset at not getting a gift. On this subject please read :

This is from the #smoothieware channel and might be a bit enlightening :

<Spider2077> cummon sense should dictate if you have a MKS not ask for help on smoothie comunities... should call up prusa the knock off PINDA probe is not that acuarete
<Spider2077> i was in shock when i saw there is a page diedicated to explaining why you should not ask for help with a MKS board
<Spider2077> i was babbeling for a few minutes like what the.. jeezzzeeee
<Spider2077> i mean it says smoothie not MKS on the page and channel
<Spider2077> and if you choose to help someone with MKS ok not my problem but personaly i would not dare to ask for help
<Spider2077> just seems wrong, sorry i got worked up
<Spider2077> when i got my smoothie i did a lot of reading and ofcource i ran in to the option to get a MKS and other boards cheaper tempting but then what do i do if i need help knockoffs have no support i mean i thought it was commun sense

A note on hardware

MKS boards have well documented problems : 
  • They use 100Mhz chips when Smoothie is designed to run at 120Mhz ( and very optimized for that speed )
  • They use two layer PCBs when a board this complex should really use a four layer PCB
  • They have poorly traced USB traces resulting in USB connection instabilities ( disconnections )
  • They use DRV8825 stepper drivers which are much more prone to loosing steps than Allegro or Trinamic drivers
  • They are overall very poorly designed ( the first versions were unusable and got fixed by users who mistakenly though the board was Open-Source, MKS themselves has no know-how ).
  • They are not tested before shipping to you, and MKS has been shown to be incredibly dishonnest in handling return/replacement requests ( in one case a year ago the MKS answer was : « please don't ask for a return or my boss will fire me » ).

There is a huge difference in the number of problems for MKS boards compared to normal boards ( meaning MKS boards have much much more problems ), and it's unfair that the Smoothie community would have to deal with MKS' choice to make bad boards.

I'm a contributor to the project and I disagree with someone on something.

Read this it's very insightful.

My board works, now what software do I use with it?

Try one of these:

All software below either knows how to interface with (or how to generate g-code) for Smoothieware.

3D Printing

  • Slic3r - 3D printing slicer
  • Cura - 3D printing slicer and host.
  • Prusa Control - A beginner-friendly interface for the Slic3r engine.
  • Pronterface - 3D printing host. See the guide on the Wiki : Pronterface
  • 3Delta Printer Control - 3D printing host especially suited for delta printers.
  • OctoPrint - Awesome web interface ( Host ) for 3D printer control. On the wiki : Octoprint
  • Simplify3D - Closed source 3D printing slicer and host. On the wiki : Simplify3D
  • Fabrica - Easy to use web control interface ( Host )
  • Smoopi - Host specifically written for Smoothieware, runs on rpi with touch screen or a desktop.


  • bCNC - On the wiki: bCNC Open-Source CNC host with great preview and other operations. Set machine type to smoothie, and add Grbl_mode true to your smoothie config or even better use the firmware-cnc.bin build of smoothieware (Note: You must update to the latest version of Smoothieware to ensure compatibility with bCNC).
  • - Open-Source Simulation & Computer Aided Machining (Free 3-axis CNC Simulator which understands G-Code)
  • CNC.js - Open-Source CNC host with lots of features, running in your browser.
  • - Open-Source CAD software.
  • GCode plug-in for InkScape - CAM, Output GCode from SVG files in Inkscape.
  • PyCAM - Open-Source CAM software.
  • jscut - Open-Source in-browser CAM software.
  • CamBam - Closed-Source, but cheap and feature-full CAM software. Widely used by hobbyists. Video Tutorial
  • Fusion360 - Closed-source CAM with very advanced features, free for hobby/fablab/small business.
  • Fabrica - Easy to use web control interface ( Host )
  • Kiri:Moto by Grid.Space - Free web based toolpath generator with support for FDM, Laser Cutting and CNC Milling.
  • V-carve is compatible if using this post-processor.
  • Smoopi - Host specifically written for Smoothieware, runs on rpi with touch screen or a desktop.
  • FlatCAM - CAM software for working with PCB design milling
  • Tux Plot - A free general use CNC tool for small businesses
  • Candle - Open-Source Gcode sender for CNC mills, designed for GRBL but should work fine with Smoothie in grbl mode
  • Universal G-code Sender - Set machine type to Smoothieware, and add Grbl_mode true to your smoothie config or even better use the firmware-cnc.bin build of smoothieware (Note: You must update to the latest version of Smoothieware to ensure compatibility with UGS).


  • GCode plug-in for InkScape - Laser/CNC CAM : Output GCode from SVG files in Inkscape. Video tutorial.
  • Visicut - Full laser control application ( Host and CAM ), has Smoothieware interface. Video tutorial.
  • LaserWeb - Web-based full laser control application ( Host and CAM ), use to generate GCode but not recommended to use as a streamer of rasters as they do not support streaming the smoothie way.
  • Fabrica - Easy to use control interface ( Host )
  • V-carve is compatible if using this post-processor.
  • Fast streamer - use for streaming raster images from a host to smoothie. Avoids the pauses when using LW to stream. Can handle upwards of 1,000 pixels/sec.
  • Smoopi - Host specifically written for Smoothieware, runs on rpi with touch screen or a desktop.
  • Lightburn - LightBurn is layout, editing, and control software for your laser cutter..
  • LaserGRBL - For laser engraving and cutting, particularly advanced for engraving
  • Polygonia - A tool to easily create repeating patterns for laser cutting : Online tool
  • This plugin for Fusion360 allows you to start your Gcode files from within Fusion360 directly using Universal Gcode Sender ( skipping the step of first saving the file in Fusion360, then opening it in Universal Gcode Sender )


A few words you will see in this documentation that require a bit of explanation :
  • «Host» software is software that is used to “talk” to your Smoothieboard. It allows you to control the machine ( for example “jog” the axes ), to “stream” a G-code job, or to upload it to the SD card, things like that.
  • «Slicing» software is software that is used to take a 3D model file, and based on some settings you input, “slice” it into layers, and generate a G-code file that the Smoothieboard can then execute to print a thing.
  • «CAM» software, or «CAM Package», for Computer Assisted Manufacturing, is software that is used to take a 3D or 3D file, and based on some settings you input, transform it into a list of tool movements ( G-code file ) for a machine that uses a tool to remove material from a workpiece.
2022/07/17 17:36

Here are some ways you can make your board more resistant to failure

Adding diodes to stepper motor drivers

When manually moving a stepper motor ( or the axis it is tasked with moving ), the coils in the stepper motor can generate electricity. If that electricity is too high ( in terms of voltage ), it can damage the fets inside the stepper motor drivers the stepper motor is plugged into, making it so that the drivers can no longer move the motors ( requiring replacing the driver ).

You can fully protect your board against this problem by adding diodes to the stepper motor connector. Instructions to do so acan be found at this link :

This will be a standard feature for the v2-prime and v2-pro Smoothieboard models, but was kept optional on Smoothieboard v1. It is fairly rare that users damage their drivers this way, but some setups are more at risk than other, in which case hardening might be a good idea ( motor models that generate higher voltages, children likely to move the axes by hand often and fast, etc … )

A suprise tool that will help us later :