BTT Octopus Pro v1.1 with BTT Pi v1.2.1, Getting 502 Bad Gateway error
Greetings All,
I have a SecKit CoreXY printer that I want to upgrade to use the RatRig ecosystem on a BTT Octopus Pro V1.1 (H723) and a BTT Pi V1.2.1. I'm using 32 GB SanDisk Ultra MicroSD HC1 in both boards. Everything is brand new and never used until now. (Also bought their accelerometer board.)
A friend of mine is running his Voron on the same boards and software, though I'm not sure what version of RatOS he began with.
I downloaded the latest pre-release RatOS-v2.1.0-RC2 from the GitHub page and installed it on the BTT Pi. Followed the instruction and updated both the ratos and ratos-configurator. I then refreshed the update manager panel and ran Update All Components.
I could still connect to the board after that. However, when I attempted to go the configure page I got the 502 Bad Gateway error. Got lost after that and tried things like installing the current Latest version RatOS-v2.0.2 which didn't go well. I'm now going to go back and reinstall the latest pre-release again.
Questions:
* Will the BTT boards I purchased work with the newest release of ratos ?
* How can I resolve the 502 Bad Gateway error if it happens again ?
Thanks for any insights you can provide !
Jay
Update: 04/02/2025
Redid everything with the latest pre-release again. Ran into problems when updating where everything was labeled as "Invalid" but messed around with things and got past them. It appears I now have a fully updated Moonraker install.
Ready to move on to connecting the Pi to my BTT Octopus Pro and then wiring up the printer.
I'm at the 'Printer Selection' option in the v2.4 Setup Wizard.
As I mentioned earlier, I have a SecKit CoreXY printer with about a 300x300x300 envelope. It has four stepper motors. X, Y, Z, Extruder. I'll be using the BTT TMC2209 drivers. Also has a BL Touch probe.
Question: Can someone please recommend which of the existing printers I should select to start with that most closely matches my setup ?
Thanks again.
Jay
29 Replies

All those repos showing "invalid" would worry me. How did you "get past" that and have a "fully updated" Moonraker? What printers have you tried in the configurator?
Hey TheTik, just saw your response. Thanks for that. The only printer I've tried is the Voron 2.4 as this seemed closest to what I have. It's very close but I only have one Z axis stepper motor and apparently the Voron must have three. I'm struggling trying to remove the other two from the setup as I can't find where they're specified.
Regarding the O/S, this was my third attempt to install RatOS. Before attempting it a forth time I decided to just mess around and tried to manually force the 'invalid' to repair themselves. There are two options when you click on one, a soft and a hard repair. I somewhat randomly selected some and attempted the soft repair which didn't work. Then I tried the hard repair. This didn't work on the first one I tried but did on a few others. The next thing I know is whatever I did removed all of the 'invalid' issues and then allowed me to continue updating the rest of them. Been working fine since then.
doing soft or hard recovery breaks a ton of stuff
It's possible my install is corrupted but not that I can tell. Seems like everything is working well. I'm not very experienced with this kind of stuff.
I would recommend doing this procedure, but backup your printer.cfg for any modifications you've already done:
Thanks. I'll try that. Just an FYI, I've seen post that say I should use the Pi password when I log into the SSH. However, I've been using biqu, biqu. Is that significant ?
It would be. A lot of the install scripts assume
pi/raspberry
Thanks. Hadn't tried logging in with that but was able to just now.
Appreciate your help. Do you know where/how I can remove the two extra Z motor definitions ?
drop your debug.zip and I can take a look
You'll have to find the file that is defining them
then find the file that is including that file
Edit a copy of the former, and change the latter to include the edited version instead.
A friend of mine just helped me find the include file where the stepper motors are defined. It's like 3 levels of include down so I'll have to sort that out but I think I got it. Copy what I need out of that file and paste it into my printer.cfg file, and, copy the include pointers in the various read-only files into the printer.cfg file ... I think.
I haven't done the commands you suggested yet and have never messed with the debug file. Should I run the commands and then generate the file ?
I would, as the soft and hard recoveries cause all sorts of issues
Just reread your last comment more closely. Sounds easier than I thought. However, the file that has the Include pointer to where the motors are defined is also a read-only file. Will I be able to edit its include command if it's read-only ?
HMM
You're not supposed to edit any of those files, but you're also doing a custom printer, so make it not read only and edit away!
In which case you should just edit the file that defines those motors
Sweet !!! That would be so much easier !
So the seckit printer I'm upgrading is probably mostly obsolete. Do you think there's any value in exploring taking my learnings and creating a configuration for it ? I have no idea what's involved in doing that but might try if it made sense.
I'll back things up and run those commands later this evening.
Thanks again everyone for your help.
I don't know what would be involved either. I've also got an old voxelab aquila that I want to get up and running with ratos but not sure what all I'll need to do. The mainboard isn't well documented but since I'd klipperized it before I should have what I need, just gotta figure out where to put it.
you must have a CB1 for that to work. I advise you forget that user exists or better yet get rid of it. The only user you should have is
pi
as long as you don't ever plan on upgrading 😉You're correct. CB1 from BTT. I'm probably better off leaving things like that alone as I would most likely do more harm than good in trying the remove it.
Right now I'm just trying to change the file permissions on /config/RatOS/printers/voron-v24/steppers.cfg and have been unsuccessful. Tried it using WinSCP and Putty using the "chmod 775 steppers.cfg" command. It shows the permissions have changed when I list the file but RatOS still won't allow me to upload it.
A little bit of knowledge can be a dangerous thing ... 😉
what do you mean "upload"?
I removed the extra Z axis sections and then tried to save the file using Ctrl-S. Got an error message that the file could not be uploaded. Then changed the permission to chmod 777 and still no joy. Changed the permissions to the voron-v24 directory that the file is stored in the 777 and still no luck.
what are you editing it in?
oh, winscp? not familar enough
I'd edit it from mainsail, or in vim
i gotta start dinner, but I'd investigate editing it actually on the raspi
I'm using Putty to SSH in to the Pi and using raspberry Pi command lines.
I'll have to look into how to do this in Mainsail.
same place you can view the printer.cfg, something like "config files" on the left. My machine is powered down atm or I could guide closer
You probably didn't change the permission of the directory. But if you are going to customize everything I would just copy what you need into your printer.cfg and not use any includes
Oh yeah ... Unless I'm doing something wrong it will not allow me to save my changes.
I did attempt to change the directory permissions for the one the steppers.cfg file is in using chmod 777 and it shows it as changed but still can't save the changes in Mainsail. Maybe I'll try editing them with VIM in the Pi.
OK, making the changes using VIM does appear to have saved them. However, I think this is the wrong file as I still get an error that Klipper fails because it's looking for 'Z1'.
Good Grief ! Making progress though ...
Thank you both for all of your help.
To step back just a bit, everything appears to be good and all of the processes start up as expected.
The problem comes when I attempt to home any axis. I get this error message "Unable to read tmc uart 'stepper_z1' register IFCNT" . I assume this is because the first thing that's supposed to happen when homing is that the Z axis will move in the positive direction (bed goes down) to prevent crashes. However, it's trying to move multiple Z stepper motors when I only have one.
Again, I recommend you make a custom printer.cfg and just copy what you need from the other files and forget about importing a 3z system and trying to modify it to work
I appreciate your recommendations. This is my first time using RatOS so I've never attempted to create a custom printer and not sure what I'd be getting into.
get it close to working, then open the klippy.log file. The first ~5k lines will be the fully assembled config. Toss that into a new printer.cfg and then just have to edit it
Thanks guys. Sounds like a good thing to try tomorrow.