In your case, thats a dry contact switch. So you are good.
The NPN type sensor is effectively a switch that can electronically close the contact to output negative voltage, your doing it mechanically with NC and COM
So yeah, you are good, just skip the N/O output and connect the GND from the board to the COM, and NC to the I/O
Transistor type outputs are significantly faster than mechanical switches, and theres some other benefits to them such as switches have mechanical wear parts, but in our use case, the switch is fine.
There are some downsides to transistor outputs too, mainly being that you need to have power to activate them, they arent going to be able to handle as much current, they are less interchangable and so forth.
The transistor output doesnt necessarily send any more data, although they can. They can be used to signal with pulse width modulation and 0-10v to act as analog type outputs to provide more information than on/off, however, these particular ones do not.
A good ol’ SPDT throw switch is signficantly handier in the real world until you are on the circuit level. I love me some switches.
Thats a nice little mod that person made. I didn’t see the end result I don’t think. At least I don’t remember it.
The mod I have was the photo-eye sensor. It works fine, but the 3d model for the parts on that one are quite good. I like the little magnet to hold it on.
I also have another sensor which I havent used yet, its a barrel mount SICK capacitive sensor. Someone elses mod used a similar one. However this one is normally a lot more money and is actually an M18 body instead of the M12 (which makes it bigger, not always better). I got it as a sample from my electrical engineering vendor. Better off with the smaller cheaper one but ill take what i can get I suppose
My first photo eye sensor got shorted out and I replaced it, but when this one kicks the bucket im going to do that capacitive sensor I think.
Alright, I’m back home and have had a day to tinker with things and had some success!
I’ve installed my quick swap kit (including using the new, improved frame for the heated bed and the old kickstarter frame for the CNC platform) and I immediately noticed leveling improvements. I no longer had the “lumpy” issues like before where one area of the bed produced a good level and others seemed to not adhere properly. So that’s progress!
Unfortunately I still had bits of the print (especially corners) peel away on 20-30% of the parts on my print. For reference, this is what I’m printing:
It got to the point where a piece warped off a pinged around the enclosure so I cancelled the print. Here’s what some of the pieces look like as an example of the really bad corner adhesion.
Watching the print carefully, it looked like the print head just really aggressively went around turns/changed direction and it caused filament to not stick to the bed as often as it should’ve. I changed my slicer to Cura (they have built-in profiles for Snapmaker dual extruder! I had no idea which is why I didn’t try this sooner) and not only did my print time estimate drop from 8 hours to 5 hours, but there are absolutely zero issues with corner adhesion.
I’m hesitant to call this solved just yet because I also thought I had solved things before with the install-bed-while-heated trick, but these are by far the best results I’ve had so far. To recap, all I did was
Install the quick swap kit (the major contributor likely being the new, improved metal bed frame as opposed to the quick swap hardware itself)
Sliced with Cura instead of Luban
Also, I’d like to caution anyone from taking apart the dual extruder head. I disassembled mine while I was tinkering with the probe connector and I barely got it back together. It has an assembly of loosely-attached springs and is surprisingly compact and difficult to put back together if you don’t have experience doing such things.
I’ll keep posting updates here. If I continue experiencing great levels like I have now, I’m willing to call this solved. I don’t actually want to tinker or do any mods if I can get my printer working without them.
After some successful prints for a few days, the leveling issue appears to be back. Spent 3-4 hours (active time, not counting going and doing other things while the bed heats up) yesterday trying to successfully calibrate the machine and couldn’t get it working. It has the same symptoms as my above posts, some areas are squished (too close to the bed) while others won’t adhere.
I’ll be working on the 11x11 firmware update tonight as that’s the easiest thing to do that doesn’t involve a physical modification to the machine.
After trying the 0.2 and 0.8 nozzles all my prints were going bezerk even though I was calibrating hotbed and z-offset before each attempt. Traces on the board suggested the head was actually too low, preventing proper flow of first layer. I eventually found the option to recalibrate the sensors, then recalibrated hot plate as above and z-axis and now all my builds succeed again.
Thanks for the thoughtful reply @tam , I stopped working on this for a while so I didn’t try your suggestions. My unit seems aware of the quick swap kit, I definitely haven’t had the first issue like you’re describing. I’ve also tried sensor recalibration and that seems to sometimes fix things, but just as often it doesn’t.
TL;DR, my experience is that the stock bed just sucks.
Since posting last, I’ve received my single extruder and built the clicky probe mod. It’s very well done, highly recommend if you’re interested. I’ve also bought the a garolite and PEI plate for testing. With the clicky mod installed, I’ve tried printing on the stock, garolite, and PEI beds back-to-back and I tend to run into issues ONLY with the stock build plate. Idk if it’s just extra lumpy or there’s some other issue going on, but I always seem to run into issues where the nozzle is too high off the bed with the stock plate (ie, this is some sort of height or lumpy bed issue as opposed to a bed adhesion issue). YMMV, maybe my stock beds are just bad.
I’d like to work on a mod for the dual extruder next, not sure when I’ll have time to get to it though.
