z-banding/print surface quality

Dirtsen
Posts: 6
Joined: Wed Dec 19, 2018 9:52 pm

z-banding/print surface quality

Postby Dirtsen » Wed Dec 19, 2018 10:27 pm

Hello fellow Raise3D-Users!
I am having a hard time with my Raise3D N2. I can't seem to get rid of this issue:
48377186_2553973187962698_2486149490101190656_n.jpg


at first it looked to me like z-banding. A recurring pattern that kinda matches the pitch of the leadscrew... but looking closely... I'm not so sure.

I am using a Raise3D N2 Dual with bondtech extruder upgrade
I use Simplify 3D and Cura

Material used: PLA
printed with
30mm/s outer perimeter
40mm/s inner perimeter
50mm/s infill

I own a couple of printers and had issues with z-banding before and was always able to solve the issue myself. But im at a loss here. First of all the things I tried so far:

- Rule out Filament Quality issues: I tried different brands of Filament and measured diameters. This is not the issue,
- swapped nozzles (0.4 and 0.6)
- tried each extruder
- printed with heated bed turned off or on doesn't make a difference
- printed with parts fan off or on doesn't make a difference
- PID tuned the hotend
- cleaned extruder Housing
- checked spring tension of extruder
- tried different extrusion multipliers from 0.95 to 1.0
- Checked voltages on stepper drivers (0.5v on the extruders, as should be after the bondtech upgrade)
- checked on the screws of the ballscrew-bearings. They are all loose as they should be.
- Heated bed is level.
tried different printing temperatures and speeds

Some things I noticed when i took the top black plastic housing off to get a good look:
- the belts are a not as tight as i would usually have them on my other machines
- the x and y motors have a flexible coupler. In my understanding, this could introduce problems.

My thoughts on the matter:
- I haven't ruled out z-banding entirely but I'm not sure either. The decoupled ballscrews in conjunction with the z-linear-rods should eliminate this.
- is my x or y-axis rod bent? Can it cause this kind of print surface?

I'm somewhat experienced but I'm out of my depth here. Any input on this? Something else I could try to diagnose the issue?

tulipua
Posts: 15
Joined: Mon Mar 05, 2018 12:06 pm

Re: z-banding/print surface quality

Postby tulipua » Mon Dec 24, 2018 10:55 am

Same problem...N2 Plus
No ideas...
Attachments
48390225_377318073033913_6704063273219653632_n.jpg

tulipua
Posts: 15
Joined: Mon Mar 05, 2018 12:06 pm

Re: z-banding/print surface quality

Postby tulipua » Thu Dec 27, 2018 9:27 am

Hi! Check the Z and E drivers try to change but be attentive and follow the instructions!
In my case drivers or motion board (will order new all)

zemlin
Posts: 413
Joined: Sat Oct 21, 2017 2:02 pm

Re: z-banding/print surface quality

Postby zemlin » Thu Dec 27, 2018 1:00 pm

Do you have any z-hop at retraction? That combined with the loose ball nuts *can* introduce some inconsistency on the Z height as the ball nuts can rotate freely and don't always return to the same spot when they reverse directions. You can test this by eliminating any z-hop at retraction. Then the ball screws only turn in one direction. If that resolves the issue, I have a fix.
viewtopic.php?f=5&t=9804

tulipua
Posts: 15
Joined: Mon Mar 05, 2018 12:06 pm

Re: z-banding/print surface quality

Postby tulipua » Fri Dec 28, 2018 8:30 am

I turn off retraction for a clean test

Dirtsen
Posts: 6
Joined: Wed Dec 19, 2018 9:52 pm

Re: z-banding/print surface quality

Postby Dirtsen » Fri Dec 28, 2018 12:46 pm

I don't have Z-hop enabled. That should not be an issue. I do hear a loud "clack" sound sometimes when the printer starts printing and moves the bed up or down. I can't really make out the source of the sound.
I did notice that one of my x-rods is a little bent. I ordered a replacement and will see if that fixes it. I doubt that the issue is with the Stepper drivers.
Another suspicion I have is, that the temperature of the hotend is not as stable as the thermistor "thinks"...

Dirtsen
Posts: 6
Joined: Wed Dec 19, 2018 9:52 pm

Re: z-banding/print surface quality

Postby Dirtsen » Fri Dec 28, 2018 4:46 pm

I don't know what the hell is wrong with this Forum... my replies do not show up...

Once again: I don't have Z-Hop on retractions enabled. So that should not be an issue.

Z-Axis: I can hear a loud "clack" at the beginning of the print when the bed starts to move. I've checked if the ball nuts have moved but they always stay in place.

X-Axis: During intensive inspection of the machine, I have noticed that there is a very slight bent in one of the X-rods. I have ordered a replacement and will check if the problem persists.

Extruder temp: Something I am still going to check on is how well the temperature is being kept on point. I suspect that there could be temperature drops every now and then that do not register with the machine as they should. I have a temperature sensitive material, that stays matte when printed under 200 degrees and becomes shiny when printed above that temperature. i've noticed, that I have prints with streaks of matte and shiny surface quality.

zemlin
Posts: 413
Joined: Sat Oct 21, 2017 2:02 pm

Re: z-banding/print surface quality

Postby zemlin » Fri Dec 28, 2018 9:13 pm

Dirtsen wrote:I do hear a loud "clack" sound sometimes when the printer starts printing and moves the bed up or down. I can't really make out the source of the sound.
Keep your eye on the ball nuts when the print bed starts moving. I think you'll see the ball nuts rotate a few degrees and that clack is the ball-nuts/screws/holes contacting at the end of the rotation limit.

tulipua
Posts: 15
Joined: Mon Mar 05, 2018 12:06 pm

Re: z-banding/print surface quality

Postby tulipua » Fri Dec 28, 2018 11:22 pm

I heard "clack" Z too but after lubrication motor has gone and Zemlin is right about ball nuts

Dirtsen
Posts: 6
Joined: Wed Dec 19, 2018 9:52 pm

Re: z-banding/print surface quality

Postby Dirtsen » Sun Dec 30, 2018 12:54 am

lubricating the motor? I will have a look at the ball screws... again.

Dirtsen
Posts: 6
Joined: Wed Dec 19, 2018 9:52 pm

Re: z-banding/print surface quality

Postby Dirtsen » Wed Jan 16, 2019 10:12 am

Nope, this did not fix it. the ball nuts stay in place and do not move. I am currently replacing the linear rods.

User avatar
Noren
Posts: 434
Joined: Sat Nov 26, 2016 12:54 am
Location: Borås, Sweden
Contact:

Re: z-banding/print surface quality

Postby Noren » Thu Jan 17, 2019 11:57 am

Check your motor couplers.
Skärmavbild 2019-01-17 kl. 12.56.16.png

Dirtsen
Posts: 6
Joined: Wed Dec 19, 2018 9:52 pm

Re: z-banding/print surface quality

Postby Dirtsen » Sat Jan 19, 2019 5:14 pm

Alright, I've had some time the last couple of days. I took the top of the printer and checked if the rods were straight. The Y axis rods were not... so i thought. I took them out and replaced them. When I was putting the new rods in, and getting the belts back on i noticed that the rods would bend when some pressure was put on the X-axis belts. The belt tension was okay but that got me thinking... the Y axis rods have a long standoff part before the pulleys. Long story short: I designed a small part that would help move the pulleys closer to the bearing, releasing some of the strain the rods were under. And now the problem is contained. This seems like a designflaw to me or am I wrong here? Anyways, my "banding" which turned out was a wobbling Y axis rod is now okay.

User avatar
Noren
Posts: 434
Joined: Sat Nov 26, 2016 12:54 am
Location: Borås, Sweden
Contact:

Re: z-banding/print surface quality

Postby Noren » Sun Jan 20, 2019 3:55 pm

Please share some images of your mod. Interesting.


Return to “N Series”

Who is online

Users browsing this forum: No registered users and 2 guests