Geetech
My favorite ad campaign of all time (I’m also a Shreddies connoisseur).
I have a box in my office - collector’s item (for me).
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Haha. That’s great. I’ve never eaten shreddies. Maybe it’s a Canadian thing? Like having a popular You Tube channel?
My heat sink has four holes, I’d go with a quick drill .
Shreddies are one of those “crossover” cereals here - right between the sugary bad stuff they put near the front of the store at kid’s eye level and the wholesome healthy stuff they put at the back of the store and at grown-up height. There are some things about marketing and merchandising I really wrestle with…
I taped the heatsink for now - I’ll likely drill it when I drill the new Z legs for the MPCNC swap mounts…I’ll have the drill press set for metal work so I’ll kill them all with the same stone. Taping the fan has COMPLETELY changed the printer. Previously when I peeled off aborted prints they would “snap” off. Now they are rubbery when I peel them off. Definite difference.
I had some issues and tweaked the Z end stop a bit and its mighty close but I’m still getting this oddball adhesion thing. You’ll see it in the first video at the very beginning (ignore the rest of everything in that one - I was still tweaking) and at 3:40 in the second one- the “Almost got it here (I think)” version. The fan you hear in the second version is the power supply cooling down. And although it looks breezy at the nozzle (the little thread flitting around hanging off the insulation) there is no air blowing over the print from the heatsink fan or the power supply fan.
Nozzle too close?
https://youtu.be/kL1Zdoe98MQ
That was after taping off the fan. It looked like the nozzle was too close in my opinion so I started monkeying with the Z end stop. Was I right in my assessment of that?
Almost got it here (I think):
https://youtu.be/VSSRmQkZPAg
From yesterday:
See all the “shaggy” bits on the first layer infill yesterday? That seems to be where even now things get a bit bubbly and as the PLA goes down it doesn’t look like it is sticking. But now at least the next pass by “pushes” the previous down (because it can because it’s still rubbery). Check these photos of the latest first layer (and the video above) - you can see the trouble spots are all in the same places as the shaggy bits were. Sorry they are so blurry.
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But, having said all that it looks like the first layer is staying pliable enough that the second layer infill is able to settle it. This one looks pretty good:
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Re: YouTube channel - I’ve been purposely posting these unlisted and without any real descriptors or keywords because I don’t want people finding the videos connected in any way to the MP3DP - could be bad advertising. GREAT advertising for the forum - not great for the machine. These issues have nothing to do with the machine - it’s the builder and tuner that are the culprit.
I have a suspicion that my bed is not completely flat. I’ve often thought when wiping it down that it felt “bumpy” in the middle. When this print is done (or aborted) I’m going to zoom up on the nozzle/bed interface and just transit it left to right in slow motion and see if I can see variance as it crosses over a few of my suspected trouble spots.
It’s looking pretty pro at this point I’d have to say. (I’m gonna regret posting this I bet:)
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The first video was definitely too close. The second was still probably a little too close. The picture with the blobs in it, is too much extrusion, which can be caused by over extruding, too hot, or also just being too close (so it looks like too much plastic, but it’s really not enough space).
I wouldn’t be surprised if some of the other things you’ve tweaked were compensating for the “free cooling fan”. Maybe your filament temperature or your bed temp are a bit too high now, because you were pushing them up to try to get adhesion.
When you’re looking at the skirt, or the perimeters, the second one should lay down basically next to the first one. They should touch, and become one. But ideally, they aren’t just merging into one wider log. It looks to me (from 1500 miles away) that the filament is pretty hot, and it’s extruding too much for the space, so it’s sort of merging the two paths together. Some places are worse than others.
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When that print pops off I’ll have a good look at the bottom and start running a second one with a lower temp setting (need one for the Makita and one for the laser anyway…and one for the foam cutter eventually). When I was fiddling with the Z end stop I was going maybe a third of a turn. Is it THAT fine tuneable? Part of me feels like there’s a bit of +/- variance in the switch alone. Or is it pretty accurate?
I print the same first layer height as the rest, so it’s usually 0.2mm thick. A difference of 10% would be 0.02mm. That would be enough to make it 10% (roughly) wider, and the total surface area on the heat bed could be dramatically different. 0.02mm later is usually nothing, but in the first layer, it’s very important, hence the reason 1/3 turn is enough to change the results. And yeah, I think the micro switches are pretty darn accurate.
But, it can go overboard. As long as it sticks, it really doesn’t matter too much. Elephant feet are easy to clean up. Warping is the real pain.
Oh. My first layer is set to 0.32 (from the old V1 first setup screen shots). Perhaps I’ll dial that down for print #2.
Okay so I made a few too many changes at once but was able to backtrack most of them. A .20 first layer doesn’t seem to be feasible at the moment on my machine. In the process of trying to get it to work I discovered that indeed my bed is not flat. I don’t think it’s warped - there just seems to be some bulging right around the middle - about where the first layer prints start to fall apart. But I think that’s why it was “ok” at .32 but just too close in the middles for .20.
I was “single sheet of paper” good on all edges (corners and middles) but in the middle I was “one sheet of paper” stuck. It’s what I thought I felt when wiping down the PEI. I suspect if I offset the next print as much to the front or back edge I’ll have a flawless first layer.
I’m wondering if maybe a good scrub down with 1,000 grit wet sanding on a good flat sanding block might be enough to get things close enough? Not sure how it happened - that’s the bigger question I guess…I MAY have left the printer preheated and forgot about it for a good eight hours a week or two ago but I have a feeling it was bad before that. I have an order coming up for Ryan so I could always “try again” but I think this one can be fine tuned. Physically for sure, but maybe there are other ways. I think Heffe mentioned mapping the bed somehow? What’s that all about?
I’m sorry I got you worried about 0.2mm. if you’re printing well at 0.3mm, then maybe just enjoy it for a while.
The plate will change shape when you heat and cool it. I can’t imagine flattening it will help. Especially cold.
I made a post with my latest bed leveling table:
You can make and save a table like that without the sensor. I’ve never done it though. You can see from the values how mine is warped. The steps basically move the X,Y to each probe point, then you move the Z down, do your paper test, and save the value there. I wouldn’t make the grid with so many points :). 3x3 is probably pretty good.
I’ve never done it. You’d have to look for a tutorial.
That’s interesting about the bed changing shape. I’ll double check the same spots when it’s cold and let you know how much change I saw. Going to dig through your thread again and see if I can focus in on the bed stuff.
I tried to link to the right specific post. It’s #70442 on the 4th page.
Well that takes the fun out of it doesn’t it…
Thanks!
Don’t bother with all that trouble. Just add a probe, enable the bilinear Z autolevel mode in your firmware and all your first layer problem shall be solved forever.
It’s just a couple hours of your time to make it work provided you have the sensor and it will save you all this hassle once and for all.
I really don’t understand why people still go through the manual adjustments anymore, once you have the autolevel the only thing you might need to tweak from time to time is the Z offset, which takes you litterally 1 second to change in the slicer. I install it on all my machines, it’s a no brainer.
As for bed adhesion, I’ve seen your videos and really can’t conclude with certainty until you actually get the autolevel. It could be overextruding a bit, could be that your Z offset is too far, your bed oily or not sticky enough, something weird with the material, or that your bed flatness is completely far off… Many possibilities, so at least start by ruling off Z offset and flatness first, the rest will be easy after that.
Been busy in here! I missed a lot! But you have been in good hands. I agree 100% with everything Jeff said. Watching the video it looked like the middle of your bed has something under the PEI. Is that a piece of Kapton tape? That could be what is causing the bed to be “higher” in the middle. Not much you can do to remove it without Ruining your PEI so yeah a little sanding might work.
That tape was on there when the bed arrived - I wasn’t sure if it should have been removed or what. Now I’m wondering if it should have been…maybe it’s just shipping tape? It could well be that the pei has reformed itself and there is a bulge from that…
As for the probe - I’m not opposed at all. Always game for some learning. So off to learn I go! (Oh yes, there WILL be a few questions ; )
Incidentally I’ve got a near identical result in that motor Z mount print. Flip them over and you might almost swear the imperfections were modelled into the part - the blemishes are nearly identical on the bottoms. The pieces are still useable so nothing wasted.
And now I have the other two (lower Z) pieces printing side by side which happens to offset things just enough that the middle of the bed is out of the equation. The first infill just completed and - this will likely jinx things here on me - it’s near perfection. I’m going to monitor the first few layers and then maybe rest my eyes on the couch here in my office - so I’m not toddling off to do other things Dui - I’ll be right here by the printer ; )
Kapton is pretty thin, it could be causing the issues, but I doubt it. Usually there’s a hole in the center of the bed with a thermistor glued in with high temp silicone. The tape keeps the silicone from oozing out.
Wait, did you attach the pei directly to the heat bed?
I did…with the 3m sheet adhesive it came with. Bad idea?