Received my glass bed and printed a (slightly adjusted) FiFix. Leveling goes easy and prints are now starting perfect! All leveling and resulting adhesion issues are solved 
@stefix sadly cannot read this anymore, but his FiFix work is brilliant!
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Hi,
What changes did you make? Can you share your file?
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While looking at all pictures and other things in all posts above, I kept wondering how this works. Maybe Stefix had a good description on his Thingiverse before he removed that? Only after opening the Fusion 360 files from his āSnapmaker A351ā, I got it that there was a spring inside. But it didnāt make sense why it didnāt fitā¦ Printing it made things clear for me. So a bit of help in understanding why this is so genius!
The parts from a test-print, this is how it looks inside:
What does calibration do
When you start calibration, the toolhead moves downwards until the sensor is triggered by the metal of the standard build plate (see the little red light inside the sensor!). But we donāt have that sheet of metal close enough to trigger the sensor, as there is a glass bed in between now. Without a solution, the head would slam into your glass bedā¦ ouch!
What does the FiFix do
In the black housing (see pictures in my post above), there is an orange block that you can move up (resting position, see second picture) or down (sensing position, see first picture). Based on the guiding slot at the side, upwards-right there is a little notch to rest and lock. Downwards-left, you are turning the foot under the sensor. It is far enough downwards to not trigger the sensor right away.
When you start calibration, the toolhead moves downwards until the foot hits the glass bed. As there is a spring-leg in that block, the foot can keep getting closer to the sensor, until it senses your piece of metal. The toolhead will move back up, and as it is a spring-leg, the foot will make distance as well. This repeats 2 more times at each calibration spot.
When the last spot is measured and the screen asks you to move the Z-axis, move the foot into the upward position, it is now safely away from your print.
Changes Iāve made to the design from Stefix are
- You can screw the FiFix to the side of the toolhead (original version was with sticky tape or with a new side-plate
- Leaving the air vents uncovered
- Smoothed edges (personal taste)
- Screws in the lid do not need nuts anymore
- The foot has a little screw upwards into the spring-leg, not really tight, but allows to better glue it into the spring-leg
- The guiding slot is shorter on the right (it allowed to hit the screw into the X-axis), little notch for locking, and higher; all to make sure the spring-leg/foot does not hit your print and stays locked in upward position. Had to make the whole body a bit higher for that.
What you will need to complete
- 4* M2x5mm screw + 4* M2 nut (for screwing the inner block)
- 4* M2x5mm screw (to fasten the lid)
- 2* M2*10mm screw (to attach to the toolhead)
- 1* M3*7mm screw (for the handle, 7mm is the size to be just outside the body, little longer gives you a firmer grip)
- piece of metal (to glue onto the foot, the sensor will use that for seeing āwhere the glass plate isā)
My print is in black Snapmaker PLA, and orange 3DJake ecoPLA
Have to fine-tune some things in the STLs (so you get enhancements I donāt have). Will upload to Thingiverse with full credits to Stefix. But give me some time for that, Iām collecting all my prints with enhancements to my Snapmaker A350 + enclosure 
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This will be a great mod for us glass users!! The archive of the FiFix files are in the waybackmachine:
https://web.archive.org/web/20201219063917/https://cdn.thingiverse.com/zipfiles/91/00/31/b1/ec/FiFix+-+The+ultimative+Levelingtool+for+Snapmaker+2.0.zip
Can you share your modified files? 
I took a completely different approach and would love some feedback and insights from folks with more experience than me.
I bought some of the thin metal sheets of steel that are supposed to be stuck on the back of a cellphone ( https://www.amazon.com/Plate(8Pack)-Magnetic-Adhesive-Magnet-8X-Rectangular/dp/B07Q5WN41R/ref=sr_1_3?dchild=1&keywords=metal+cell+phone+magnet+plate&qid=1618877701&sr=8-3 ). Then I took them and used the adhesive to stick them to one side of the glass. With the metal side up I leveled the bed - although I did have to slide the glass around a little bit to make sure the induction probe found the metal. After the leveling was done I flipped the glass over and let the magnets hold the glass in place.
Iāve been printing things with no issue on the glass and find myself thinking it was too easy, there has to be a catch. Anyone know what it is?
thanks
It makes assumptions about the flatness and parallelism of the top and bottom planes. If your glass is flat and parallel enough that youāre getting good results, thatās all that matters.
Some float glass actually has poor dimensional tolerance, so that may not be true always.
You can see some of the allowable variances here. For example of just one of the tolerances: 0.3% distortion for bow over the length. For a 300mm long sided square, that could be a bow of almost 1.3mm, which when flipped over would put the center now 2.6mm out.
https://glasstime.guardianglass.com/en/knowledge-center/standards-norms/tolerances-standardised-requirements
We would all hope that glass being sold for 3D print beds would be better than the maximum tolerances.
I wanted an alternative sensor that would work on glass and if possible would fit within the main body of the print head. After some research I found an IR sensor that gets good reviews for accuracy and is small. It is 3.3V or 5V and logic high when triggering so I knew there would be some wiring issues but itās small enough to fit on the right of the nozzle replacing the existing sensor and the right side fan duct. I think the right side fan duct doesnāt work well ( its removed in the new head) and I also use an external front fan. So I redesigned the blower fan box and a combined sensor mount and hotend fan box and a cable to wire it all up. I took 3.3v from the marked pad on the print head circuit board and it connects to the existing sensor connector. The wiring cable also contains a transistor to switch the sensor trigger to pull down the input on the print head board and a couple of resistors, one to make sure the sensor has 3.3v on itās output to initiate the correct operational mode and another for the transistor.
The sensor is a direct replacement for the stock one and I can level on glass using the existing handset process and probe the bed at will.
Accuracy seems way better than the old sensor with or without FiFix type attachment, on 30 G30 probles only 1 varied by 0.01mm.
Nothing here is destructive so it can all be taken out and you can go back to the stock print head though I guess it will invalidate any guarantee!
I can share part design and a wiring diagram with a bit more information if people are interested. This was built for the Snapmaker 2 original print head, not the current one though I think it should work fine in either.
This is the sensor I used:
I bought it from Ooznest in the UK who I have found to be very efficient.
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Iād be interested! Always looking for quicker ways to level other than my .001mm calibrator.
I should also have mentioned that you need to change the firmware as this sensor is in line with the print head and the old one was offset. Its a simple change and was very easy following the Snapmaker instructions on GitHub. As a bonus the current GitHub firmware doesnāt turn the bed heat off when calibrating so you just need to set it to the temperature you want and then do a calibration and the heat stays on.
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Definitely interested in a write up with detailed instructions! Itād be great to finally be able to get a perfect level.
Is this included in the latest official firmware? If its not, it would mean the official firmware is still not built from the Github source code. This would make me angry.
Thank you for your suggestion.
Do you mean that you need the heated bed stay hot when you calibration the machine?
This feature has not been added yet, according to our firmware developer.
We have collected many requests from GitHub repository.
Many commands are added and bugs have been fixed.
https://forum.snapmaker.com/t/new-commands/17494/7
Edwin
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Hi @Edwin
All I know is I can now do a calibration and the bed heat stays on. Itās possible this was always the case but my memory is the process I use now did not keep the bed on.
To calibrate with the bed on I home all axes (this is necessary as a home switches off the bed). Turn the bed on to the required temperature using something USB connected, I use Octoprint (well octopad from my phone actually). Once the bed has been at temperature for as long as you want to wait, start calibration from the handset controller. The heat stays on during and after calibration.
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Thats a good idea!
The air gap is probably causing some heat transfer, but other than that really simple and effective!
I noticed that the calibration routine started at the front edge of the surface before lowering Z, so i think that they have at least some of the github stuff in the official release.
I havent been doing much fiddling with the machine since I was getting so frusterated with things and I am trying to find my way back into it again now.
Holy cow you guys added the pause routine??? I havent been paying attention to anything at allā¦
Its happening guys!
I need to find some intersting models to print and start working againā¦ its been over a month!
I just finished this planetarium, using M600 colour change from gold>red for the calendar ring. Turned out really quite nice!
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Thats great, did you have to find the layer in the gcode and manuallly add the m600 or is th ere an easy way to do with a slicer
I cheated and used a slicer that already supports injecting it (SuperSlicer)
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