Strange Ender 3 V2 Issue

[borgesp]

Thanks for the links.

[Larry]

@borgesp

No worries. Here is another tidbit that I think explains why this occurs after the printer has been sitting idle as well. When the print first stops you can’t manually rotate the z screw, the stepper motor is still in control. After a time I can rotate the z screw - implying that that the stepper has been disabled or is no longer in control. This may have been know to everyone else but it was a learning for me. In any event this whole thing is definitely (I think!) a mechanical issue.

yes stepper motors dis-engage after prints are done. Takes a min or 2

[Ender5r]

Perhaps someone with more engineering knowledge can help: how can I measure a lead screw to find out its pitch. Do I simply measure its current location, rotate it 1 full turn, then measure the location again?

[Larry]

@Ender5r

Perhaps someone with more engineering knowledge can help: how can I measure a lead screw to find out its pitch. Do I simply measure its current location, rotate it 1 full turn, then measure the location again?

Maybe this video will help

//youtu.be/4bgMbHLJEJY

[Ender5r]

Funny, I was just looking at that 1. Haven’t listened to it yet though.

[borgesp]

I watched the same vid earlier today. Here’s another one.

Lead Screws - Printer Upgrade - Chris's Basement

Not sure why Larry’s link looks better (I’m new at this forum stuff). Let me know if this doesn’t work.

[Gramps]

@Larry

@borgesp don’t buy the BL touch it is nothing but one problem right after another with it.

I agree with @Larry I started with a Bltouch on my v2 and spent more than the difference in cost of the EZABL trying to get it working. To get full functionality with the EZABL on the v2 you should also replace the LCD with a Creality 12864 off the Ender 3 Pro. No more flashing the LCD just flash the printer and your done. Plus you get a lot more features. Less than $20

[Larry]

@Gramps

I agree with @Larry I started with a Bltouch on my v2 and spent more than the difference in cost of the EZABL trying to get it working. To get full functionality with the EZABL on the v2 you should also replace the LCD with a Creality 12864 off the Ender 3 Pro. No more flashing the LCD just flash the printer and your done. Plus you get a lot more features. Less than $20

Yea i agree with the LCD changeout to i did that. Big thing is you can use baby stepping which makes all the difference in the world

[ATTACH=JSON]{“data-align”:“none”,“data-size”:“medium”,“data-attachmentid”:9603}[/ATTACH]

[borgesp]

You guys are giving me lots to think about! So I missed the part of Larry’s earlier post where he said he replaced the BLtouch - I actually ordered one before getting the advice on the EZABL. Oh
well, I don’t have it yet, I could always sent it back.

I’d kind of looked into these earlier and see some pros and cons with each.

I should have the anti-backlash nut early next week. Don’t expect it will solve the issue but I like to troubleshoot via elimination and one step at a time.

I need to learn how to include quotes of previous posts - can see it helps keep track of things.

[Ender5r]

At the bottom of each post there is a box with “Quote Comment Flag Like”.

[roon4660]

I just learned something.

[borgesp]

Installed the anti-backlash nut today and as expected it did not eliminate the noise. I can still feel the z rod couple rotate slightly when the stepper is disabled and then it klunks next time it moves like it’s “taking up slack”. Hard to believe as it’s very tightly secured. I may try a different coupler (did I mention I was stubborn?) before I install ABL.

@Ender5r

Good observation. It would be really interesting if you can corelate the gantry move with the klunk. BTW, how many steps/mm is your Z axis? I ask because, when Creality was shipping Ender 5s with 400 step/mm Z screws, people would complain that the print bed would drop on its own once the stepper was disabled. They changed to an 800 step/mm screw, which is what’s on my Ender 5 Pro, & the problem went away.

A little confusion on this issue. As far as can tell my printer is 200 steps per revolution. The Transmission Ratio z is set to 400 which must refer to the length of the rod? Of course there is nothing in their documentation on what many of the menu items represent so this is a guess. But the stepper motor is a 42-34 and the specs on that clearly state it is 200 steps/revolution. As far as I know the Ender 5 uses same model stepper motor.

My current workaround is to home the printer (I can se the nozzle is slightly high at this point), I raise the the gantry and re-home and now the nozzle is where it is supposed to be. Start print.

[Ender5r]

It’s not the stepper motor you need to look at (it is part of the formula, but not really needed at this point). You need to look at the LCD menu. Find the menu item where you can set steps/mm. In there, find the Z value. I’m betting it’s 400.

[borgesp]

The LCD menu does say 400 but I don’t how you can take a a stepper motor that is 200 steps/rev and turn it into 400 by a setting. It is what it is. I think.

[Ender5r]

I’m afraid it’s not. You see, part of it depends on how many threads there are on the lead screw & its diameter… If you have 1 thread of 2mm pitch, 1 turn of the screw will move the nut 2mm. If you have 2 threads, it will move 4mm. A 4 threaded screw will move the nut 8mm. So, you can see it’s not a simple ratio.

Have look at this video from Rick’s Basement: [U]Lead Screws - Printer Upgrade - Chris's Basement - YouTube

[borgesp]

I think this is the same one I linked to earlier. In any event my z screw has 2mm pitch, 4 threads so it lifts 8mm per revolution.

[ATTACH=JSON]{“data-align”:“none”,“data-size”:“medium”,“data-attachmentid”:9636}[/ATTACH]

Pretty sure this picture describes my situation. The menu item says Transmission Ratio Z, no units. I don’t know what it represents but I don’t think its steps/revolution and I don’ think the units can be step/mm.

[Ender5r]

The 400 is almost certainly steps/mm. Isn’t that the menu item you looked under?

[borgesp]

Like I said the menu isn’t very clear [ATTACH=JSON]{“data-align”:“none”,“data-size”:“medium”,“data-attachmentid”:9639}[/ATTACH]
But if I have .04mm/step which is what the math says, I do not know what the 400 represents.

[Ender5r]

I’ve never seen it worded that way, but it must mean 400 steps/mm. It’s really the only thing that makes sense AFAICS. Also, the values make sense as steps/mm.

[borgesp]

One revolution = 200 steps. In one revolution the travel is 8mm. 200/8 = 25 steps/mm. The 400 means something but I still don’t think the units are steps/mm.
From the video there are .04mm/step. To convert to steps/mm –> 1/.04 =25 steps/mm, another way of calculating it.