USB Connection Issues

Hi, I having a lot of problems connecting to the Jackpot board through USB-Micro connection through Octoprint. The connection times out a lot.

If the Jackpot boots up and is accessible over wifi at fluidnc.local and the WebUI loads does that mean a USB connection to a Raspberry Pi running Octoprint won’t work?

Or do both work at the same time?

Either way, getting the Jackpot to work over USB is really flaky. I reboot over and over again and it only sometimes works.

I did see the following error in the Octoprint terminal:
[MSG:ERR: sdmmc_card_init failed code 0x108]

I don’t have a microSD card in the Jackpot, could that be causing problems? Is there any way to disable the Jackpot in WebUI from trying to read a card?

Thank you,

I don’t have any experience trying to use Octoprint on a Jackpot. I know for my Primo with Laser, Lightburn works great over USB. Is there a reason you don’t want to use the FluidNC Webui?

Honestly, I leave my MPCNC unattended in the basement when I am reasonably sure the milling operation is running like I want it to. Octorprint has a plugin called Octotext that can be configured to send a text message to my cellphone when a print job is complete. It works with the Better GRBL Support plugin that Octoprint uses to operate the MPCNC.

I can just let it run and have it text me when done so I can turn off the Makita clone.

Does anyone know how long it takes the Jackpot to fully bootup?

Oh boy. Now you’ve done it.

Wait for iiiiiiiit…



Well, your level of risk acceptance is way higher than mine. Given the amount of power the router has, and having had it touch the collet to the material once, I wouldn’t do that. The room was full of smoke by the time I hit the emergency stop.

I would strongly suggest that this is bad practice, as the router can start a fire in literally seconds.

Besides, I still think that it’s so cool watching the machine work.


It is cool to watch, but on an hour long milling process or more…

I probably should be there watching it the whole time but then that means I am just sitting there instead of working on a Fusion 360 design or whatever.

For example when I surfaced my spoilboard I made sure it moved within the confines of the work area when milling horizontally and checked on it close to its completion in the y direction.

That said, your post makes me want to buy a fire extinguisher.

The router is 600W. If it buries the bit and gets stuck, it will put that energy into the same place and heat up with no idea it is doing anything wrong. A 3D printer nozzle is a lot less power, and it has safety features to not heat up uncontrolled.

We have seen fires in MPCNCs. Luckily, none have taken off enough to destroy a house or harm anyone. There has been at least one in a barn that destroyed the machine and burnt the table to the ground.


I hear what you are saying, I have already ordered a smoke detector to place directly above the MPCNC and a fire extinguisher to be placed nearby just in case.

I never leave the house or anything like that while it is running. I am just on the floor above in my office.

I bring something to do while the machine is working, but no way I’m leaving it unattended.

I had a 5.5W laser start a fire, the first I saw was flames under the workpiece, and even standing there it did some damage before I got it out. No way I’m leaving a 675W router unattended.

That walnut got scorched from having the collet just skim it without slowing from its 1800mm/min speed. Had the machine jammed and it was stationary, there would have been more than a little scorching. That was maybe 15 seconds before I hit the emergency stop, and the room was full of smoke. Like I said, risk acceptance.

If you choose to accept that risk, well, I can’t stop you, but I feel obliged to point put the risk factor in case other people go for it without understanding the risk they are taking. It’s a big one.


It looks like rebooting the Raspberry Pi after the Jackpot is fully loaded and accessible at fluidnc.local can get the Octoprint web address working.

It might not be a Jackpot or fluidnc problem after all. I also ordered a usb adapter that doesn’t allow power from the Pi to power up the ESP32.

Let’s start with this one, as it’s a good idea. You want to have the ESP32 powered only by the jackpot, not by the Pi. If the ESP32 is powered up when the Jackpot is off, then you will have init problems with the TMC2209s, and nothing will work right.

You’ve heard from others, so I’ll just repeat. Please don’t leave your machine unattended. Ever.
500+ watts of burn your house down waiting for Murphy to strike.

Would you leave a small blowtorch unattended for an hour at a time in your basement?

The jackpot isn’t flaky- at least the jackpot in general as a product.
I have one of my Jackpots on a JL1 laser, and use LightBurn to operate it over USB.

It works flawlessly- with the provision as noted above that you have to be sure that the ESP32 is powered up by the jackpot before connecting USB.

You can also compile fluidnc without wifi or bluetooth, I think, if you just wanted USB. FluidNC Installation | Wiki.js

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They just added a new feature that points out any warnings. I think just to add a bit more robustness you might as well just put a microSD in it to stop that notification even if you don’t use it.

The Jackpot is doing it again.

Sometimes I boot it up and it does not show on my router’s connected devices screen.
Sometimes it shows up on the router’s screen but when I load the page fluidnc.local it freezes on a Connecting ESP3D Please Wait.
Sometimes it successfully loads the fluidnc.local web interface but the USB connection to a Raspberry Pi running Octoprint freezes at the sixth stage of the connection process.
And sometimes it everything loads and connects and works.

I must have gone down to the basement 10 times today rebooting the Jackpot to try to get it working. It is driving me insane which is not a difficult thing to do :wink:

Is no one else having these issues?

What version of board is it? Some early models needed a resistor added to reliably boot, I think depending on the esp32 version. I think mine is rc1.2 and it needs the resistor, however with the current esp32 I’m using it doesn’t. Maybe a picture of your jackpot and wiring would help.
I don’t really know, just suggesting an idea.

What are you using octoprint for? You can sign directly into the Jackpot. This is not a common use case.

What board revision and esp are you using, a picture will show us?

What firmware version, the newest one has improved memory handling pretty significantly.

I find Octoprint’s features and plugins useful.

Here is a photo, the lighting is bad in the basement, I hope the details of the board are clear enough.

I just tried putting a spare 2GB partition formatted to Fat32 microSD card in it and it booted ok this time but time will tell if that is the problem.

If its the version of the board that needs a resistor, can you point me to the ESP32 board that works without adding the resistor?

Thank you, sorry, just stressed out,

This is covered above, but one consideration you need to deal with is that any time board power to the jackpot is disconnected, you will need to then physically disconnect the USB cable from the Octoprint server and then only reconnect it after board power is applied.

You can avoid this bit of hassle with a “Data only” USB cable.
If you do not accommodate this and the ESP is powered when the rest of the jackpot is not, you will not have a properly running FluidNC after that until you power down the ESP and do the startup the right way.

Edit: This consideration only applies to FluidNC / Jackpot users that have to use USB (e.g. LightBurn or Octoprint or similar). The normal Jackpot workflow is the controller is wired to machine power and USB is not used- so for the majority use case this consideration does not apply.

You do not need one. You have the newest and most robust.

Maker jim’s suggest seems the most likely. I am not sure why you are using a Pi plugged in as well but I have a feeling the boot timing of them both is off. ESP first then pi.

I highly suggest taking the pi and memory card out and seeing how it does. If there is still an issue update to 3.7.18.