Round hygrometer Bambulab AMS slim mod

I prefer to put my hygrometer away from my desiccant boxes.  I find when I put it right by desiccants,  I always gets happy readings from the air around the desiccants, instead of the air from far corner away from desiccants. 

But there is really not that much room inside Bambu AMS to fit a normal cheap round hygrometer - at 16mm, it is too thick to fit on the side of the lid, a spool will bound to hit it as it moves around the roller. 

When I open up the round hygrometer, I found the culprit - the LR44 battery is stacked on top of the boards and screen, increasing the depth of the unit. 

Hence I made this mod - to put the battery on the side of the screen, so I can reduce the thickness to 11mm, which sits a lot more comfortably on the side of AMS lid during print.  Not saying you will never have some fat rolls that would hit it, but you should be able to get through quite some filament without your hygrometer get knock off the lid. 

I also integrate the magnet directly at the face of the hygrometer. When you are making your own cases you don't need another magnet mount. 

===== Print instructions =====

Orient the body face down, and use some minimal support to handle the magnet hole overhang

The back cover will also need some support - There are some overhang faces at the battery door area. Either tree or normal support should do. 

===== Assemble instructions =====

To make this you will need to remove and reuse the LR44 battery terminal from the hygrometer - some soldering skill is required!

1. Open up the casing of the round hygrometer - use a small flat head screw driver to push those detent pins help
2. Remove the guts of hygrometer - note the elastomeric connector on the screen - try not to detach those from screen! I don't how how you can glue it back!
   Also pay attention of the orientation of the screen! if you put it back the wrong way, the screen will only show garbled display. You will need to open it up and reorient the screen to make it work again. 
3. [Solder skill check!] Heat up your solder iron, remove the battery terminal from the hygrometer board
4. Use 2 piece of short wire to connect the battery terminal at the new battery chamber location on the side. 
5. Place the C/F button on the back cover, then clip the hygrometer back cover on, reuse the battery door from the doner hygrometer to secure the battery in place. 
   Finally, the C/F rubber button will likely stick out a lot. Cut it flush so it won't hit the filament rolls during print. 

There are 2 screw holes for m3x5mm screws, but if the clip is enough to secure the case you won't need it. 

Magnet size is 10mmx3mm..  I tried using smaller ones I have ( 6mmx2mm ) and it is not quite enough to keep it in place. Maybe I printed thae case too thick and weigh too much? 

Anyway the 10mmx3mm batteries keep it in place very well.  if battery is too loose, doubleside tape should handle it just fine 

Now throw some more magnets on the out side and embrace the humidity level reality check in your AMS 
( I have yet to make an outside magnet mount.. maybe another day.. )