Bed Leveling/Adhesion Issues for the Dual Extruder

Also make sure you’re not over-tightening the bed screws. They are countersunk screws and the holes are not exactly 0.1mm accurate. I was thinking about the quick swap but mostly for the tool head since I mostly use the 3DP and Laser so no worry about the toolhead touching the bed. Not sure I’d want anything else causing an impact on the already poorly designed bed linear module issue (what I suspect is causing the bed bowing issue). Just so you’re aware, the linear rails screw into the spacers but the bed just sits on the spacer. The spacer has valleys the bed frame sits within so it doesn’t move around. I don’t suspect the rails would interfere with the quick swap but you might need to adjust the height of the spacers before printing.

If that’s true I might be over-tightening, yea. I’m not putting an unreasonable amount of force into the screws but if it’s that sensitive then I still might be overdoing it.

I was thinking about that too, the quick swap for the bed might just introduce another variable and cause more problems. And if I want the quick swap + rails then I’d certainly need to modify the spacers and do some tinkering. We’ll see, I’d like to try to install quick swap on everything but if I have to leave it off the bed, that’s not the worst outcome.

If you ordered the Quick Swap Kit, you do not need to order a new bed frame! See here:

The long-awaited quick swap kit for Snapmaker 2.0 250/350 machines - Snapmaker 2.0 - Snapmaker: where creation happens

I did the same as @Wyphorn and moved the threaded insets from the kickstarter frame to the new frame, and you have your new 3D printing frame. I yet have to see if the improvement is enough to satisfy me (you can see in the thread I linked in that the results are not overwhelming from the pure measurements side, but how this translates into practical issues or not I need to test yet).

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Ah, that’s awesome, glad I won’t have to worry about that. We’ll see how much the level improves once I can my hands on the kit and start experimenting.

@chogardjr that was a great suggestion regarding the metal ruler, the bed is definitely bowed at least a millimeter consistently across the Y axis. X axis isn’t as bad but still has a dip that actually appears to be around the location in my most recent screenshot where the print really started peeling off of the bed.

I’ll try to compensate for this bowing manually my varying my screw tension.

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No luck, I reinstalled the heated bed and this time I didn’t tighten the screws much, just made sure there wasn’t any play or wiggle. The calibration went a bit better and I was able to get more pieces to stick to the bed. However, I think this is really only because I basically just jammed the pieces into the bed more than I usually do (ie, I was able to do a more aggressive z-offset due to the calibration being slightly better). As you can see in the close-ups, the rounded pieces still have some gaps in them but the square pieces towards the top are too close too the bed and squishing extra filament out between lines of filament.

I think I just have a super lumpy bed. I’ll report back when I’m able to do some experiments with the quick release/firmware/linear rails.

Re-reading your initial post: Do I understand correctly that you recently got a new heated bed? If so, I’d contact Snapmaker support and ask for a replacement on warranty - as far as I understand you did not have similar issues with the old bed? I just realized that my old kickstarter print bed (not the frame, the actual heated bed, i.e. the PCB-style thing where it says “do not print on this”) is lumpy - the frame had its own lumpiness, but the bed itself is also far from even, and in places where I cannot do anything by tightening or loosening of screws - it’s areas where there are no screws… That’s the reason why my hopes I had for the new frame seem not to be fully fulfilled: The long-awaited quick swap kit for Snapmaker 2.0 250/350 machines - Snapmaker 2.0 - Snapmaker: where creation happens - still, I yet have to print the test pattern to verify how good/bad it is.

Sent in a Support Ticket on that - Answer was prompt and quick: “I’m afraid we cannot add the ability to engrave ‘G1029A allow on dual extruder’ soon, but I’ve passed your message on to our product team to consider for future releases.”

Sorry, I likely wasn’t articulate - I got a new removable print surface, but the heated bed and frame are the same from kickstarter.

And yea, I got basically the same response when I submitted a ticket.

Also, as much as I’d love to be able to try 11x11 leveling, I’m almost starting to question whether or not it’ll help. Reading Mxbrnr’s post again, it seems like the problem is usually the fact that the bed is simply out of tolerance for what the DX sensors are able to compensate for. If this is true, even something crazy 100x100 leveling isn’t going to help. Maybe that’s also why Snapmaker doesn’t want to prioritize the 11x11 firmware fix? Or I could just be misunderstanding. I’m a bit out of my comfort zone trying to debug this but dang it I’m going to get this machine working

Hmmm - never thought about it this way… what I can say is, that when I did 11x11 with my kickstarter frame and my lumpy heated bed, I was able to print this: Please give us the 11 x 11 bed calibration with heated bed! - #21 by Hauke and this: Maximum Y Position 347mm? - #9 by Hauke

I switched to garolite and forgot about leveling issues, 5x5, quickz-offset and full bed prints is no problem .
if you’d like to try - Printables

If klicky probe looks intimidating, search for other probe mods here, people explored every aspect of it here.

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It’s somewhat intimidating since I need to figure out a solution for the DX myself (my single extruder is fried), but I’m convinced at this point that I’ll need to do a couple mods to get this thing printing reliably. Might as well give it a shot.

So Garolite is so rigid it keeps it flatness even on the lumpy bed? And Do I understand correctly that you’d need a mechanical probe because inductive is not working with garolite? You print directly on it? Do prints easily separate from it?

There is very low variance in surface flatness. So measuring 5x5 will give you very close to reality value of the spot between measuring points. Not like with stock build surface, where between the grid you can have huge crater or a bump from a hot pulled print. Rigidity helps too. Thicker garolite is like glass, but not brittle.
Check out this video about it.

That is correct, but you can use any variance of probe mods available here. Non of them are actually measuring the surface tho. This is the main reason I went with mechanical klicky probe. Check out Fifx mod and proximity sensor mod for alternatives.

Yes, no intermediate adhesives, just wipe with alcohol and PLA, PETG, ASA/ABS - all stick really good to it.

Once you let it cool down a bit, it pops right off - sometimes I get that satisfying click of separated part, but most of the time - it’s 99.9% separated just due to difference in thermal expansion/contraction.

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Yeah, I tried to figure out klicky probe for the dual extruder using only pictures that people generously prvovided. But I need one in hand to finish this. I can’t iterate fast enough in design without one.

@MooseJuice I see your name pop up regarding wiring in @nweolu’s guide. I detached the sensor from my DX and it uses all 3 wires (see pic) instead of the 2 that the guide uses for the single extruder. Is that a problem or should the same 2-wire setup also be plug-n-play for the DX?

My travel schedule is weird, I’m back home again but will be out until Sunday. I’ll design a shroud+casing for the klicky probe then.

It greatly depends on what the sensor or switch you has is.

In his case, it was a mechanical switch, i cant remember offhand, but i think it was NC/COM. If it was NC, it would be like having a wire going into one pin and out the other under normal circumstances, and when triggered, it would be like taking that wire away.

This “wire” would be making contact between GND and I/O.

However, the sensor built into the module is different.

The built in sensor is a NPN proximity sensor, the 3 pins are 24V (voltage) I/O (signal) and GND (24vdc negative). The signal is feeding GND into the I/O similarly, but in a different way.

There can be switches that are dry with 3 wires, it would have a N/O, N/C and COM if it does. In this case, you would wire the same as the other switch, but not use the N/O wire. (dont connect it or you may accidently short the transistor input)

There can also be sensors that are PNP, which would not work on the module.

Edit: Unless you are saying you are taking the sensor from the single extruder and mounting in the dual extruder from something being damaged. in which case, that shouyld be fine. If its a third party switch or sensor it needs to be reviewed to see if its compatable as described above.

Ok, thanks, I think that makes sense. To be more specific, I’m planning on using this switch and wiring based on step 8 from these instructions which came from @nweolu’s guide.

I think the gist of what you’re saying though is that the NPN proximity sensor sends more data than just a binary pressed/not pressed, so it’s got another wire for that. So it’s not unusual that the klicky probe that I’m installing would only need 2 wires.

Download - Panasonic - third wire is just power supply for the probe itself, if I understand it right.