Wavy Prints at higher parts

[hugepanic]

Hi,

recently I have the problem that my prints are pretty wavy at the edges at higher positions.

It looks like they start perfectly straight at the print bed, and get worse with every millimeter I print.
The first 60mm (2 1/2") look pretty good, and after that it gets worse.
At about 29cm (10") the edges of the part are offset in x and y direction by about 1-2mm, resulting in wavy edges and walls.

The Z-level looks good.
I have now tried 3 different materials, all have the same problem (2x ABS, 1x PLA).


I have done lot´s of prints in the past at these heights, and never had a problem.

I have allready checked the drive belt and the roller/shuttle parts.
Belt seems to have enought teeth, the roller/shuttle parts don´t have any play.

The printer is now about 1year old. I have changed the hotend to a e3d V6 in the past.
With the V6 hotend, I did good prints at these height levels.

I have also changed the mattercontrol software version to the old version I have had much good prints with (1.4x).


Does anyone have an Idea what causes this problem?

How can i diagnose the complete system to find the error?

Thank you

[Xenocrates]

How thin is that part? Have you tried adding some angled supports to it? I've seen similar issues on poorly supported features which flexed while they were printing. It may be that your part is not cooled enough, or is bending for another reason as the hotend goes by, which would cause the waves.

[hugepanic]

Hi,

I am pretty sure that heat or support is not the problem.

The brown test print from the foto is a triangle/prisma printed with spriral vase option. The part is 1layer thick --> 0.4mm

The other prints i have had this problem are normal parts, with about 7-10% infill. I have printed many of these, and never had a problem.
Right now I am printing thin aricraft wings, the problem is very visible at the trailing edge, but all other faces are affected too.

What makes me think it is not a heat problem:
Why does it print the first 6cm perfect?
I have printed with my enclosure,and without the enclosure. No change in the problem.

Right now I am printing the same prisma again, to see if the problem is repeatable.

I also have checked the G-code. The code is the same from layer 2 to layer 1500. So it is not software related....

[dsiegfried]

Are you running with a heated bed? Having the heated bed on caused my parts to have z-ribbing. See my post under Troubleshooting for details.

[hugepanic]

Hi,

yes I am using a heated bed. At ABS i am printing with 105°C bed temperature.
I am using the heat bed to heat my print chamber to reduce cracks.

I have had perfectly good prints in the past with the same setup, so i don`t think it is something like that....


As an update:
Yesterday I was pretty happy, since i found at "higher levels", the hot-end has some play. It seemed that the bowden and wires created a moment that resulted in a loose hotend.
So I have printed a better hot-end clamping device with no play, at every bowden position.

2 test prints later, I had to learn that this was not the problem. I still have about the same wavy prints.....


EDIT:
I just came up with a new idea.
I have added a poti at the hot-end fan. I found that the fan is so strong, that i get negative effects on my prints. So maybe the fan is too weak, and the top side of the hotend gets so hot that it melts the hot-end clamp very lightly. So it just makes it less stiff..... This just happens after some ours of printing, so this might be the reason to only happen at "higher levels2....
This is something that you can not diagnose very well..... right now, I do a new test print with full hot-end fan...

[hugepanic]

Hi,

I have finally found the solution.


In the end it was one for the slider-shuttles that run the profiles up and down.

I have had checked these many times, and they never had any play.

The one was pretty loose, i could move it around about 2-5mm.

Today I assume that it was somehow clamped, and did not show the play under most circumstances. I don't know the excact mechincs behind it.

I have tightended the and adjusted the bearings, and the print quality was perfect.

(In fact, the quality is now even better, since I have readjusted and improved many places in order to find the error)


Best regards

[Xenocrates]

Well crud. I didn't even think of the cheapskates. That used to be a go-to check for everyone. I've been spoiled for too long with the self-adjusting cheapskates I suppose. Between that and my previous experience with somewhat similar wobble, I suppose I ran you down a bit of a rabbit hole.