seam printing with clear colorfabb xt

[pascal32]

Hi there. I've been trying to print a cylinder with colorfabb xt petg. Initial prints were pretty rough. I was able to get the quality better, however I had to use an extra restart distance of -.35 and a coast of .10. Using wipe just spread the issue all over. this is causing what I suspect is under extrusion after the layer change. with the settings as is, the seam is indented on both sides. The side where the extrusion happens around the layer change isn't as nice as the other side. with a clear material I expect to see the seam, just isn't expecting this much.

does anyone have a profile for me to try or suggestions?

printer is a qidi tech I with a .4mm MK10 nozzle.

245 degrees with a 60 degree bed along with a -.2 on the Z is getting pretty good adhesion.

attached the profile

Thanks!

[pascal32]

one more picture

[Leeway]

I hope they help you figure it out. I am making something fairly similar, but with a circular base lofting to an oval top. I am also using clear Pet G. Different brand. Almost identical settings for the temps. I like how S3D will do the vase modes. Pretty much seamless. I would like to see them give an option for choosing more than one extrusion thickness for that or choose which direction the perimeter shells are printed in. If we could do either, then the seam would virtually disappear. It comes from the head travel changing direction on the inner and outer shells.
I did make it a suggestion for the future.
I look forward to seeing if there is a work around.

[dkightley]

I would like to see them give an option for choosing more than one extrusion thickness for that

Stop and think what you're asking for! Vase mode is where filament is extruded continuously in a spiral around the outside of a vase like shape. If you want two extrusion widths, where is the second filament going to come from? Stop the first extrusion to do the second? Okay....but you've just destroyed the one continuous spiral!

[Leeway]

I understand what the vase mode is for and how it works, but it could have a stopping point in the layer to repeat inner layers identically. Then resume the corkscrew for another round.

I should have just stuck with changing the shell extrude direction.
That would be much easier to implement. There is very little seam on the inside of my parts. The seam is mainly on the outside where that shell extrudes in the same direction, but because it's outside instead of inside, it physically moves the other way.

These parts are exactly dimensioned to have 3 extruded beads for the .8 mm nozzle at .4 mm layer height that make up a layer. Very strong parts this way.

I will mention that we have several cnc machines and all of the Cam packages used for those have selections for the direction of travel.
So I think it would be an excellent feature. Not just for me, but for guys that may want a stronger thin wall vase with a hardly noticeable seam.

[pascal32]

suggestion on how to tune this a bit so i can get the seam cleaned up without sacrificing the other areas? Vase mode won't work for the end product which is a small container. on a side note it does print nicely in vase mode, the issue is stopping and layer changing.

thanks!

[Leeway]

Mine come out the best when I print two. Align them equal distance from the center point in the bed. Then use that point for the start points. My seams are bulged just a little bit outward at the seam on the outside. Only slightly on the inside. Pretty smooth there and easy to clean up the seam on the outside with a fine belt sander. It would be better without the seam of course, but it does function.
Looks like you may need to try to give a higher extrude percentage. Not much. One or Two percent increments. That may fill your seam better.

[wirlybird]

Start reducing the negative restart. -.35 is a lot.

[Leeway]

The second reply here may also provide a solution to the noticeable seam.

viewtopic.php?f=8&t=6883&p=29855#p29855

[pascal32]

those are some good suggestions, I'll give them a try. the printing two - I should be able to too a pillar or shield for the same effect.

thanks!