u/FirstInstruction1

Hello everyone
I’m new to sewing and bought a used industrial sewing machine (it’s a cylinder arm) it supposedly was a Juki but I’m pretty sure it’s not so I’m not sure what brand machine I have.

Anyways, I’ve struggled to get the tension to be correct and I’ve tinkered with the tensioning disk and even the bobbin tension but can’t seem to get it to work. Any idea of what I could do to fix this or could this be an issue with the machine itself? Any help is greatly appreciated