Z-axis not moving at all

nach00

My Z-axis somehow stopped working. It was working yesterday. My print was sticking only about 98%, so I figured it was either the box fan running in the room, or the bed wasn't level. I was pretty sure the bed wasn't level because I don't think I did a good job leveling it. I moved the unit around today, but when I replaced it and tried to level it, the Z-axis won't move. I've tried checking the connections and they look fine. Tried restarting the unit a few times, no luck. It will home X and Y, but not move the Z. Any ideas?

Samuel Pinches

You could try to swap the extruder (E-axis) stepper driver with the Z-axis stepper driver, and see if that fixes the issue on the Z-axis. If the stepper driver is broken that is not expensive to replace.

nach00

Thanks for the quick response.

Noob question: how do I do that?

Samuel Pinches

1. Unplug the printer
2. Open the case
3. Swap the stepper drivers in the E and Z positions.
  

nach00

oh boy! sounds like fun. dang, I thought was  plug-n-play. ok thank you, i'll have to troubleshoot this tomorrow then. thanks!

nach00

okay cool. I followed your steps and connected everything back together. Now the Z axis moves. Does this mean I should call warranty to get a new stepper driver? Is there another place I can get this stepper driver locally? Also, what do you think might have caused this problem? I don't think that  my unit will work properly with this temporary change, right? 

Samuel Pinches

Great to hear it, the stepper driver is cheap and as you have seen, easy to replace. What you are looking for is an A4988 stepper driver - try ebay, and try searching locally. You can probably find a local 3D printer store will be able to sell you a driver for under $10USD. They are less than $3USD china.

We have not fixed anything yet, we have just transferred the problem from the Z axis motor to the extruder motor, by swapping those drivers.

These drivers can be damaged if a motor cable is unplugged while the printer is on, that is one reason why it is important to have all cables firmly connected.

nach00

any recommendation on brands? Amazon has a ton of them. Mostly 5 packs for $10. Should I just go cheapest of 5 pack? or one for $6, since that's all I'll need (for now)

Samuel Pinches

Cheapest is fine - they should all be using the same chip, and it is a very simple circuit. Nothing wrong with picking the cheapest here. I'd get some spares, as you don't know yet what caused the fault, so it could happen again.

nach00

I finally replaced the stepper driver. Amazon took forever to deliver the item, but now it's installed and I can successfully level the bed, as I have done.

When I  went to start Cura, it asked me to update from 3.3 to 3.4. I did so, and ran into an issue when copying over the JGCreate resource files. I guess the fdmextruder file was updated and the new version didn't like the old file. I went ahead and copied only the A-5  file and added only that printer to my profiles.

When I ran a print, nothing happened. The fans turned on and off and I could feel the bed get hot, but the printer would not move at all. I think the progress percentage even went to 1% at one point , but there was no print.

Well, I decided to uninstall and just use the old  3.3 and it works fine. Just letting you know I think there's an issue with the new Cura.

Samuel Pinches

Good to hear you're up and running - strange about the cura bug, thanks for the warning!

nach00

OK. now my  bowden has stopped working. I read that this unit fails quite often, and that it is very difficult to replace.

It's not pulling filament into the tube to the nozzle. I have to manually push the filament in.

Do I need to have this replaced too? Thanks

Samuel Pinches

... probably

https://jgaurorawiki.com/a5/spare-parts#bowden-coupler

nach00

I forgot to mention that I did not tune the new stepper driver. Will I need to do that?

When you asked me to check the Z by switching the E stepper, I did not change it back. Therefore, the bad driver was still on E, which I replaced with the new one.

Will I need to tune this?

Samuel Pinches

If its working, its working, but I think if you have extrusion problems in the future, it would be one of the first things to check.

nach00

This is my first 3D printer and I sort of knew what I was getting into when I first started. At less than $400, I figured it would be a good learning experience. I figured that I was fairly tech savvy, so it shouldn't be tooooo difficult. LOL
I went to Microcenter the other day to see if they had stepper drivers available, but they didn't. Complaining to the sales guy about how my printer has been down longer than I've been able to use it, made me think that maybe I shoulda spent $2k instead on a Lulzbut with warranty, so I could just swap it out for a new one immediately haha.
Oh well, I guess that's what comes with the price tag.

nach00

Is there anyway to check the status of my bowden? Or, if it's not working, it's broken?

Samuel Pinches

I don't understand... is the extruder motor not pushing hard enough? Because then you should do a stepper driver tune.

nach00

Maybe. I'll try tuning it now.
This is weird.
On my Z-axis, I'm getting a read of .69V. I know it is supposed to be between .7V and .85. But when I do a smidge of a turn, thinking it will increase to .7 or a little more,  it drops straight to 0V. And if I turn past that a little more, it jumps back up, past .85V to 1.0v. 

What another bad stepper?

nach00

Yup, guess so. Maybe I messed the first replacement somehow when I was tuning it. But I changed it out again and the new one can reach .72V fine. Testing now.

edit: X, Y, Z working now. about to check extruder

edit2: would you know why the fan on the hot end is making a really weird and loud noise? Like a rotary engine gone bad or something. I've tried to tighten/loosen the fan housing but it doesn't help. Only way to get rid of the noise is to quickly stick and remove something into the fan blades while its running, then the noise goes away and it sounds normal.

edit3: ok so yes, i'm not sure why my extruder stepper was not working after changing my z axis extruder, but I did have to tune my Z-axis stepper driver. Lost another stepper driver in the process. Maybe it got mixed up when I was swapping them during testing, but I think that's why it wasn't working: because the voltage differences.  

It's just starting the first print layer now, so I'll report again soon

seafian

Hi nach00,
the cold end cooling fan on the heater block can be really annoying. Mine started to scream after a few hours of operation on my A5 I now have since 10 days. Removing the fan cover, taking the fan off, peeling off the sticker on the side adjacent to the rotor and putting a drop of oil on the axle made it silent again after mounting the whole stuff back

Maybe that helps in your case too

... and keep up tweaking your unit - the more you do the better you will know it and it's always good to have some spares 

Rgds Andreas