Ender 3: Extruder Stepper Motor - Hand Turn

Question

Should I be able to hand turn the stepper motor for the extruder of an Ender 3?

Trying to figure out why the motor isn’t turning on a new to me, never used, but out-of-warranty Ender 3.

Swapping controller cables I discovered the extruder port on the motherboard is dead, but even if I put it on the X axis and manually move the axis it makes the sound like it should move, but doesn’t actually move at all.

Trying to figure out if it’s seized or something. Doing a resistance test with a multimeter shows a resistance of 4 for either of the two pairs of wires. I am not sure what else to test.

I have a hard time believing I need a new control board and a new stepper motor, but maybe two things are broke.

Thanks for the help!

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EDIT - Got the Extruder Working

After the comments here mentioned that "Yes, it should be able to be moved by hand", curiosity got the better of me and I said, "Well, if its broken, let's see why".

I did the following:

1. I tried to turn the stepper motor by hand again, just to confirm I wasn't crazy from the day before when I tried it. It wouldn't budge.
2. I removed all four screws on the bottom of the stepper motor and attempted to pry things apart. While fiddling with it, I thought I saw the stepper motor turn.
3. Sure enough, I now tried to spin the stepper motor and it moved relatively easily.
4. I put the 4 screws back in place and validated I could still hand turn the motor. I could in fact do so.
5. I hooked the stepper motor back up to the X axis controller and told it to move, and sure enough now it moves and works!
6. Just as a sanity check, I then hooked it up to the extruder controller and it again wouldn't turn.

I'm going to try what @towe recommended to make sure the controller board is in fact fried, but I think I might JUST have a fried board and not a fried motor.

Answer 1

Yes - you should be able to turn the extruder by hand when it is unplugged and therefore not powered.

The V2 comes with a blue plastic knob for this purpose, it may be too small to turn the shaft by hand.

When powered and "steppers enabled" the motors need a lot more force to overcome, but even that can be done by hand or a machine crash.

If you can't turn the extruder at all, its probably toast. That you've tested other ports on the board is excellent problem solving.

Whatever damaged the motor has likely damaged the board too, or vise versa.

You likely need both parts replaced to get this printer working again. Could be expensive - you might want to compare cost of parts with cost of a new printer, remembering there may be other non-functional components still undiscovered.

Plausibly, with a dead extruder, you could slap a laser on this unit and make it a dedicated burner. The creality laser module is around $50 USD.

Answer 2

Criggie's answer is basically correct, but I disagree with the conclusion that it:

Could be expensive - you might want to compare cost of parts with cost of a new printer, remembering there may be other non-functional components still undiscovered.

If you want to turn the Ender 3 into a decent printer, the controller board is one of the components you want to replace anyway, since it comes with either (old models) extremely loud and poorly performing A4988 stepper drivers or (newer models) TMC2208 stepper drivers hard-wired in a mode where they don't work well and malfunction if you enable Linear Advance (which is critical to getting decent prints on a bowden extruder system). Good boardsthat are exact fits for the housing and cable connectors, with TMC2209 steppers that lack the above problems, can be had for $35 or so.

If the motor is dead, that's a pain but not expensive to replace. Equivalent motors are available for $15 or so all over the place, or you could make the upgrade to a light-weight geared direct drive extruder with pancake stepper instead of the large NEMA 17 (which negates pretty much all of the disadvantages of direct drive and gives you a much better printer than you started with).