Ender3 4248 Y motor upgrade

Tested and working.

The ender3 wasn't getting as much love, but that's over, here is a dedicated mod for the ender3 (not the 3pro or 3v2, but 3 "v1") which has a different smaller Y extrusion, a 4020 instead of 4040 found on the 3pro/3v2, and required a tricky setup.

for the ender3pro/3v2, 4040 extrusion I need to rework it, but it is fully functional (you'll find it in the Apollo zip, this is also included in the Apollo zip, under the "Printer mods" folder)

this type of motor: https://amzn.to/3Ss8SzS ( 3 pack ) or https://amzn.to/3Ud9879 ( single pack ) 

this will need more current. Not sure what vref, but if using klipper with UART stepper driver like most after market boards, set the current anywhere between 1amp and 1.4 amp, but do not exceed 1.4amp

that's what I have on my ender3v2 and will be installing on the ender3max Neo I recently acquired ( different motor mount of course on those machine with 4040 Y profile )  

Also have an upcoming Y tensioner mod for ender3 (and a slightly refreshed one for ender3pro/3v2), so belt length might need to be even a bit longer after that, so keep that in mind, maybe leave some spare belt, I'll post that tomorrow or day after, if you want to do both update at once.

this is untested so could have minor issues, but should work.
print in PETG or better, PLA could melt (except the cover should be fine in anything)

you'll need either two M5x16 or M5x30 acting as two of the axles, the "cover" will be different based on that choice.

you will reuse M4 screws from the stock mount, and the metal motor mount, just flipped so that the motor sits lower.
Rest should be relatively intuitive with pictures ( I'll annotate them soon ) , otherwise ask on discord.
mostly M3x8 and heat inserts. For motor m3x8~10mm

M5 will screw into plastic, should be fine, otherwise can make a model but requires 4mm long inserts and 7mm OD (not usable on this as is)
Stepper motor axle: GT2 20T 5mm bore with the set screws
top axle: GT2 20T 5mm bore, bearing with teeth (https://amzn.to/3SmJRWU)
left axle: Two F695-2RS 5mm bore (https://amzn.to/3tTRACv) ( or one GT2 20T 5mm bore without teeth (https://amzn.to/3Sp1YLM) but may need to tweak the model for that one since it's 1mm thicker so let me know if you will use that )

Installation:
This can be done without the motor and metal plate mounted to the printer, but have to be close to the printer to load the belt mid stage

• install heat inserts all around

• pre-attach the GT2 on the motor, set screw closer to the motor, slide it in completely, then away from motor by 0.1mm or so, just enough to not have any friction

• mount block A to the motor+metal plate (inverted, check renders) use M3x8 screws

• M5x30 version
  - install endstop, and endstop wire
  - secure cover
  - pre-load the M5 through the cover and through block B enough to install the bearings, but not stick out any more than that, place the bearing on them.

• M5x16 version
  - load the M5 through the block B enough to install the bearings, but not stick out any more than that, place the bearing on them.
  unlike M3x30 you can install the endstop, and cover later as the very last step

• load the belt have a good chunk loose to make it easy (check render for belt path)

• then place and secure block A to block B with m3x8, secure well

• finally finish securing the M5, don't over tighten them, might even need to be 1/2 turn loose, and check that bearing can rotate, if not loosen a bit more.

• secure motor metal plate to the Y extrusion, with two M4 screws (reuse the original M4 screws that were there)

• on the endstop side there are two more M4 screws under then endstop (reuse the original M4 screws that were there)