Hi, I am trying to replace the extruder with a better quality one than what comes stock with the printer. The issue I’m running into is that the stepper motor shaft does not have a flat side, it’s just round with the gear built on it. I guess this is not the case will all ender 2 pros? When trying to look for a new stepper motor, it seems difficult to know if what I am purchasing is actually for my model printer. Could someone verify for me exactly what I need to get for this printer?
Just to check I understood you correctly:
You want to replace your extruder and you bought an extruder without stepper motor. Now the original stepper motor has a gear press-fitted onto the shaft instead of a flat side. Correct so far?
There are two things you can do:
The first option is easy, but requires a tool.
The second option is also easy: You’ll just need to look for a Nema17 motor, that’s basically it. It should not be a pancake (=flat/small) one, because they are not powerful enough. Low stepping angle (0.9°) is advantageous but not required. You are going to have to tune the extruder steps per mm anyways, since it won’t be exactly like your old extruder, so it hardly matters whether the difference between old and new is small or large.
The third option will yield the best returns. These cheapo single-small-drive-gear extruders without gearing are just bad, especially if you add the loss of control you get if you run a bowden system.
If you can spare a little cash, get something like a TBG S or TBG Lite. They are both equivalent, just have slightly different mounting points.
Compared to the stock extruder, these are a massive improvement.
They use a tiny NEMA 14 motor, which weighs much less than a NEMA 17 that is used by the stock extruder. This does allow using it in Direct Drive configuration without adding a lot of weight to your print head.
To have the same (or actually more) power than the stock extruder, they use a ~11:1 gear reduction. They use dual gear drive, meaning that both gears that contact the filament also push it. And lastly, they use really large filament drive gears, which means that it’s got a much larger contact area on the filament.
With a TBG Lite I can extrude really soft, flexible TPU with about the same quality and speed that I was able to extrude PLA before. The amount of control is incredible.
And btw, when you swap equipment related to the extruder, you need to do an e-step tuning afterwards. Google what that is.