Hey y'all, I managed to hack together a printer from scratch and I'm struggling to get it to print well. It's a CoreXY system that's being controlled by a Octopus 1.1. Dual z screws, the works.
I have it moving under it's own power and all. It's able to actually print, but the results are atrocious.
I'm just trying to diagnose what's wrong here.
The bottom/first layer actually looks kinda good. It's just completely shredding subsequent layers.
Have you verified that you can extrude filament with the extruder stationary and a decent height above your bed? While you're at it, you might as well do e-steps.
Yep! It actually extrudes just fine. I'm starting to wonder if maybe my z axis e-steps are just slightly off and it's enough to compound over the course of the print. It seems to hit a certain spot and start grinding itself into the print, which suggests that it might not be moving up enough per layer.
I'd be surprised if it was too cold, but I've heard stranger. This is PETG at 250. I've actually pulled the nozzle and Bowden tube and pushed a very small Allen key through, so it shouldn't be clogged.
Z height is calibrated, and I've calibrated the e-steps for the z axis. I've tried disabling the fade height to see if that was doing something but it didn't seem to make a difference.
I ran through calibrating the extrusion e-steps. It's feeding 100mm when I tell it to do so. I haven't messed with the extrusion multiplier, do you have any information about that?
Because I hate when people ask questions and never go back to update their original post when they solve the issue, I'm gonna post an update here and now.
The fix was actually surprising but simple. I ended up moving the second Z axis lead screw carriage mount a bit further towards the motor. That is, the piece that supports the build plate, where it connects to the leadscrew.
Further diagnostics ended up showing me that it was binding, and one of the problems I had later on was that it was binding but only when going up. So I ended up having prints that got progressively more and more stretched out along the z axis.
Moving it to be further in line and loosening a few mount screws to allow the nut to come back to vertical got me to where I needed to be. Hope this helps!
I realize I'm reviving a super old post here, but I actually did end up figuring out what it was. I posted a little writeup in here if you're at all curious. You were actually kinda close.
Have you done a full calibration? If not, start and work the process. Take your time with it, do each step multiple times. Being a home brew printer it’s going to be very beneficial to get OCD about things. Make sure the frame is square and rigid, the axis are all square to each other, and nothing shifts.