I finally decided to install my dual extrusion module yesterday on my A350 and everything went pretty well as far as I could tell. However, I noticed after printing that the first layer is having issues.
I printed a test, but it was small and I didn’t notice much. I need another filament holder for dual extrusion, so I decided to print one last night. This morning I pulled it off the bed and noticed the first/bottom layer was segmented. Like the filament didn’t meld together. I rubbed it with my fingers and the whole layer came off (see photo). I was able to remove the entire first layer. Not sure if I can salvage this print or not.
This extruder is supposed to have auto everything, but it appears that should be taken with a grain of salt. Should/Can I manually adjust the Z-offset? Will this fix this issue? I had no issues with my single extruder. Thanks!
Adjust the live z offset of your right or left or both extruders till your first layer is pretty.
Some forum users agree about a - 0.3mm z offset, so it seems a factory calibration offset or something similar…
Hope this helps!
The one on the left looks more like the infamous (but never addressed by snapmaker) wave/unevenness of the bed, to me. No matter how many level points, it doesn’t (and can’t) account for a bed that just waves up and down between measure point. I’ve seen many references to this, but no-one really has a solution. 
Check out my own bed to see that it just gets worse… this is after their “auto calibration”. Note that the calibration lines just did not print as the heads were hitting the bed, and the area around the test print didn’t stick as there was too much gap, and then the prime tower (and brim) again did not print the first few layers as it was hitting the bed. The bed is just pain warped (to varying degrees) for everyone and Snapmaker, as far as I know, remains resolutely silent on the topic.
Sorry to be the bearer of bad news, but a simple z offset won’t fix it.
There can be warped beds. But the TO just hast a bad z Offset as you can see on his pics. Just to high at whole print. Set the z-offset manually lower until You get a nice surface. There are dozen of Pages with examples how the first layers should appear.
@Doogs75 : don you ever tried a 11x11 calibration in your warped bed? Otherwise you can still use a thicker initial line high.
No - the TO (OP) has a warped bed. Otherwise, why would one side (bottom left of left-had item) be nice, but the top-right of the same be unadhered? It’s not flat. The second print, yes, is just too high (though one of the corners looks to possibly be OK). But… the left hand one is definitely a warped/not flat bed.
<sarcasm> No, I never thought to do a calibration or change the line height </sarcasm>. I get this sort of response to posts all the time - YES I have tried it, NO, it is not the issue. You can clearly see that there’s a warped issue. To be fair, though, I can only see a 6x6 calibration - where is the 11x11? I don’t think it will solve the issue, as I have at least a .5mm warp in places. It may fix adhesion, but it would lead to wobbly parts in return. The print is barely adhering - the brim of the tower is printing at the bottom, but actually engraving the bed at the top. If you can explain/justify how this can just be a line height or Z offset, and it fixes the issue, I’ll send you $100. It’s not - its a warped bed, and if you read a heap of forum entries, it’s quite common, to more or less degree, and pretty much unacknowledged, except by 4 or 5 pretty cluey experts.
Here’s another photo to show that I do know what I’m on about with a warped bed. This is two layers of a raft.
You can see that the edge of the main raft seems OK. The middle is like a bunch of guitar strings - no adhesion to previous layers at all. You can also see that the raft around the prime tower is still transparent - the first layer did not print at all and the second has only left the illusion of print. You can see the wreckage from a previous prime tower which embedded in the bed and can’t be removed (similar to the dual extruder calibration - which seems to ignore the Z height and also embedded in the bed - see Dual Extruder test ignores Z height for more info).
If you look at the OP’s photo, the bottom-left of his left hand print looks OK, and the top-right is not. This isn’t a bed height issue, this is a non-flat bed. Dropping the Z height may hide the issue (I’ve even done that on large non-dimensionally-critical parts - the nice part then doesn’t print the first layer), but it doesn’t fix the issue.
Short story - I know how to detect an uneven bed, and his bed is uneven.
Sorry, but i think also the left side of first picture has a bad Offset. You can clearly See all single lines from the back side which is no proper levelling for me.
@Doogs75: And yes, your bed is warped. Like few here in forum (which is quite normal because most people come just to forum when they have problems…). Thats why I suggested a finer calibration for you. Just use the Forum search for 11x11 calibration.
But sorry, i won’t answer to you anymore. You have a toxic conversation style here last days and just flame around. I am a private user and am not interested in that while trying to help other users with their problems.
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Toxic? For disagreeing with you? Fair enough, everyone’s entitled to their opinion.
Flaming? For saying “yes, I have this problem too”, when there’s very little, or no answers from anyone else? Sorry, but I don’t think letting other users know they’re not alone is flaming. But again, each to their own opinion.
To quote you, “just a bad offset” - if this were so, why the difference in sides? There’s a warp or unevenness as well, at the very least (and no, I don’t expect you to answer, you’ve already told me you won’t. This is for others to make up their own mind on).
But thankyou for the 11x11 suggestion.
Where can you adjust this? By doing a manual offset or is there someway to do it from the console or? Thanks!
Live Z-Offset has to be set on touchscreen while printing. There is no other working way i know.
Sorry for not responding to these, life got in the way.
I am still having issues with my dual extruder. I have attempted to manually calibrate the Z-offset and I can get it to print better, but not great. With my single extruder, I have no issues. I follow the same method with both.
The first layer inconsistency is because I pushed the filament with my finger to get it to detach. It looks semi-solid when you pull if off the bed, but you can see that the plastic never melded together properly. So if you run your finger on it, it will detach and fray like the image. It doesn’t come off like this, I should have been more specific, sorry.
If I auto calibrate, the tests run fine for alignment and look normal, but when I print, it does like the image. If I manually calibrate the same as I do with the single extruder it acts almost like it’s too close to the bed and when I attempt to remove it from the bed it is VERY stuck.
I am going to try and tighten the screws on the bed frame (I have had them come a little loose before) and rerun leveling. I also put in a support ticket, but I have little faith there. Thanks for the suggestions and comments.
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Hello,
Yesterday i install the dual extrusion module, i have same problem for first layer?
Any solutions??
Thank you
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I just had to replace my proximity sensor. I haven’t tried it out yet
Can you be more specific? What exactly are your problems?
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OK, if work with you can you tell me how you replace it and buy it from??
Thank you
The bad first layer may IMHO have to reasons: Underextrusion or Nozzle too high on first layer. Since the upper side of your prints looks like you might even have a bit of overextrusion, my guess is that your nozzle starts too high.
So, make sure that your print is sliced with a skirt or brim, and when that part is layed down, look closely and adjust the Z offset so that the first layer is squished onto the bed just right - look e.g. here: How to Correctly Set a 3D Printer's Z-Offset | Tom's Hardware
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Hello,
what is IMHO ??
i adjust the Z offset muaully and will try again before was Auto adjust
Thank you
IMHO: In my humble opinion 
And just to avoid misunderstandings: I do not mean the calibration procedure - you can do auto there. What I mean is the manual Z offset adjustment via touchscreen while the print is running. If you are on the print progress screen, slide left, select Z-offset, choose 0.05 mm and slighlty adjust until everything runs smoothly.
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Thank you i will try