For this CoreXY printer, there’s 2 steppers that jointly control XY motion. The neat use of belts and craftily coordinated control software enables motion in X and Y…
BigTreeTech EBB36 (or EBB42) use CAN Bus, more effort and cost to setup, but you eventually end up with less wires going to the hotend.
CoreXY pic is super helpful, thank you!
I should have followed your lead from the beginning on that one!
so far all I have heard about CAN bus is that once it works it is awesome, but that is a steep long hill to get there and plan on some time. I’m bypassing that obstacle for now…
lol I get that completely. That’s why I’m waiting till @azab2c gets his guide complete. I’m in no rush for it. Just trying to get it to print for now lol
Ok I’m at a loss for what’s going on here. It started off beautiful. When I went to bed last night it was around the 45 and I remember telling my wife I think I’ve finally got it. This look like the best print to ever come off this printer. Then I wake up to this. It looks like it started losing steps on the back z motor you can see the line is straight across the back but angles towards the front making it look like it was level where it should be in the front. Then it lost steps in y only. Not angled across. Print didn’t mo e on the bed. Does anyone have any thoughts on what I need to check. Pulling my hair out with this thing
… Grub screws?
Just checked them yesterday and they were all tight. Originally all installed with blue locktite (except one and that was fixed later) Everything on all of them was still tight yesterday morning but I can check again
Besides the fact that it’s an all-too-common problem here, and the lol factor, it is something that happened to me. Mine looked a bit different, the errors were all on 45° angles (because CoreXY) and it was one loose grub screw.
More seriously, another thing to check is the stepper driver temperarures. The TMC drivers will do weird things if they get hot, because they turn down the current. Looks like the Z didn’t have a problem, but the XY motors are accelerating the print head all the time.
And… G34 is broke again. Soon as I hit G34 I get probing failed. Before it even tries. But G28 and G29 both use the probe and both work fine. I don’t get it…
I was thinking about that and wondering the same thing. It could also be my Z problem. That one motor is holding a lot more weight than the other 2 Z motors. I’m still playing with the sensor for a little bit trying to get that to work. But in the next 30 min it will either work or be turned off again and I will start a print. I will also get my laser temp gun and keep an eye on the driver temp and the motor temps. ooooo I wonder if my Flir is charged…
that looks to me like your extruder was starving and you didn’t get enough filament… did it get caught on something? or was the extruder skipping steps or slipping on the input? nozzle partially blocked? cheap filament? I’ve made way too many things that look like this.
Taking another look at the photos, and I started thinking that the XY error does kind of look like a 45° thing… which would be one of the CoreXY motors, and yeah, one Z motor is dropping a bit more than it should.
What do you have motor current set to, and … you did jumper the SKR to put the steppers into UART mode, right? 
Anyway, get potential mechanicalbissues dealt with first… a motor skipping steps sounds pretty distinct. I can hear it when my printer does this (typically because the print has warped and lifted and the print head has hit it and got stuck) even when the printer is in the other room.
Its brand new Hatchbox PLA that was dried and put in a Dry box with a monitor that shows 10% humidity. It was and still is feeding just fine. I did my best with the pics but the start gaps are only on the back side. its a straight line there. on the other side its leaning like only the back Z motor skipped steps
To me it looks like it only moved in y. It’s hard to get a good pic of it
Ignore the messy wiring, its a work in progress…
One thing I have noticed is they seem to sound idk nosier maybe. I’ll try to get a video of it printing in a little bit and post.
Looks like I might need to put a fan or something on those drivers.
It’s printing again. But only a 2.5mm think square I made up in fusion so I can measure it. Come to think of it idk why I made it so thick. One layer would have been plenty lol
How big are your motors? Are they the 84 oz inch ones or the 56’s that have the removable connector on them?
I had lots of problems at first until one day I was looking at the size of the motors on my hypercube and the lightbulb went off. I ordered some 84’s and it has been rock solid ever since.
@probrwr, are you running V1E/similar 84oz XY Steppers at 1amp or something else? Several month old Snapshot of your Klipper config has 1amp configured.
Think I started with 0.8 but then dropped current after seeing the stepper’s steady state temp (using the V1E temp stickers). Mine are at a measily 0.6 ( my Klipper config ) which probably too low.
@SupraGuy curious what current’s working for you?
What is a safe temp for the drivers? some of them were around 53°C after just 2-3 min of printing. If I bump the current wont that make them even hotter?
I do have 2 40mm noctua fans here that I was going to put in the new LR3 that aren’t needed now that its switched over to jackpot. I could try to come up with some kind of mount for them to blow over the drivers…
I will look to see what my current settings are. probably still at 1 but maybe not as that may have been when I was using the smaller ones.
