Fair enough thank you
I tried a different web based slicer in the past and it just had awful results
Hoping this is a little better and if not I will pick up a cheap windows
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If you’ve got a Pi lying around you could also use that…
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If anyone can spare some thoughts and prayers they’d be welcome, I’m bashing my head against a wall with silly problem after silly problem. I think we’re in decent shape now but fuck me it’s been a good week or two of this
The printer is an Ender 3 body with a mainboard swap, klipper, and a Sprite Pro direct drive and the current weird issue is that after about 4-6 layers the Z axis seems to be lower than it should be so the nozzle is digging into the previous layer and the extruder can’t get anything out. It’s pretty repeatable, I think I’ve ruled out slippage on the lead screw coupler, and I’ve spent quite a lot of time levelling the bed and setting Z offset and swapped to stiffer springs. I’ve now disassembled and reassembled the X gantry and snugged everything down because I think there was some play where the non-driven side wasn’t perfectly in sync with the driven one. Because the nozzle was often dragging on the previous layer I also added a Z hop, but maybe there’s another issue in slicer? This is directly after that hotend swap, so my only other guess is maybe the Z-steps aren’t set correctly (klipper is new to this machine and I’ve gotten very few successful prints out of it, so it’s possible it’s been wrong from the start). If I still can’t get a calibration cube/corner done should I just try measuring Z moves in free space with a calipers? Any suggestions for Z drift/misalignment/whatever much appreciated
FWIW the first couple of layers look (to my eye) good. Not completely squished out and compressed but lines blend together nicely and it’s even across the build plate. I’m not going very fast or high flow at all, 40mm/s and ~4mm3/s until now and the resliced version with Z hop upped the speeds a bit but so far seems to be fine
Octoprint?
I think he meant use it as a desktop with linux to run a slicer, but you could use something like CuraEngine on octoprint too
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As a test, I’d drop the flow to 95% or so and raise the bed to compensate the first layer being thinner. You may have flow a bit high and eventually its getting caught up on itself over the course of the print.
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My first thought was something in your slicer. Like it is thinking your layer heights are different from what they actually are.
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that makes sense thanks I’ll try that next. I did find something else it might be: looks like the single drive z axis isn’t able to keep the x gantry perfectly level with the extra weight of the direct drive. A small bit of upwards pressure from my finger on the cantilevered end seems to help, I’ve tried tightening the eccentric nuts so there’s as much “mating” force (idk if that’s the right term here) as possible but I don’t think it’s right yet
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That was my next suggestion! Excellent thinking. Test those rollers to make sure they’re grabbing without slipping but not much tighter, that’s the sweet spot. Test it when the gantry is low, middle, and high to make sure everything is still square in the frame.
Also, wipe down the tracks on the frame that the rollers run on. If too much of that wheel goop builds up, it can micro slip. Rubbing alcohol works well.
Sounds like you’ve checked out your lead screw motor area pretty well. The instructions always say to not overtighten that one gold piece that the lead screw goes through. I’ve always wondered what that would do.
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Sounds like an accumulating problem, are you sure that your z-travel is set correctly?
This would definitely be worth checking, since it’s so easy. Just home the printer in Z, then command it to go to like Z=100 or whatever, and see if a 100mm tall object will fit under the nozzle.
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The only print I’ve successfully finished was wide and low so the margin of error on my Z measurement makes it fairly useless
But progress: this is the first time I’m printing PLA on an all metal hotend (previously just PETG on metal or PLA on PTFE). So I think my Z stuff is mostly ok now with the tensions set properly, but it looks like I’m getting a lot of heat creep at 210° and just clogging the nozzle from the inside rather than running it into previous layers. I started another print at 200, got much further into it before it started to block, so I paused the print and manually cleared it then the print seems to have resumed fine. I think I did also have some issues with leveling and droop, but it wasn’t the whole problem and I might have been misattributing a layer with a lot of blockage to a skipped layer
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I know some folks with heat creep issues have solved them with a filament oiler - basically a little piece of foam/sponge with a drop of vegetable oil on it, clamped around the filament so that the filament picks up an ever-so-slight oil film on its way to the extruder. The oil not only lubricates directly, but also polymerizes in the hot end and produces a slippery coating like the seasoning on a cast-iron frying pan.
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At long last, the printer has been unfucked. I took the hot end extruder apart and added thermal paste between the cold side of the heat brake and its heatsink and now it’s all g. It’s not even a snug fit so it seems like bad design to not have anything aiding heat transfer there except the grub screw
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Oooof, yeah that would do it!
First test print on an awful slicer
Thinking there may be a slight z wobble issue
Anything else obvious that I should adjust
Given that it’s on an awful slicer, whatever that means - it looks pretty decent!
All I can see is a little bit of banding (Z stiffeners would help probably, also check the tightness of the vertical beam screws)
And the typical under-performing cooling solution
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Printing out some supports for the z gantry also gonna print a fix for the cooling fan
Don’t have a windows laptop atm so did it on the astroprint slicer which is known to do a slightly worse job then cura or other proper slicers (also don’t have my settings failed properly in yet)
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As you might guess from my frequent posts here I’m also fairly inexperienced but:
Looks like a good bit of ringing there to me, where the shape of the arch repeats along what’s supposed to be a flat wall. Lower accelerations or tuning it with something like Klipper input shaping would help
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Was the runaway for the bed or the extruder? Usually I find when that error starts to happen, it’s intermittent. It’s 99% of the time a broken wire for the thermocouple. You should plan to replace. It will likely fail again.
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