First layer not filling up completely

[Jos360]

I just got finished building the Rostock Max v2 last week and it has been almost non-stop printing. Addictive stuff!
I encountered a couple problems which all got fixed with help from this board. But I do have a question for which I can't seem to find an answer.

When printing surfaces (first layer) on the bed, it doesn't always seem to fill up completely. It does on small surfaces (max 10mm width) but on the larger ones, every now and then it seems to choose it's own pah.

I have attached an example picture. This is ABS on 228 degrees nozzle and 85 degrees bed temp. Printed on kapton tape sprayed in with 3dlac. I seem to get good adhesion on the bed judging from other prints (difficult but not impossible to remove from the bed all around the print).

First layer thickness .2mm, layer speed 15mm/s. Object to be printed is 200x24,5mm surface.

You can see that after a certain amount of layers it "wanders" to the side and doesn't fill the void anymore.
Any thoughts?

[Mac The Knife]

After a week of printing? Now would be a good time to give all of the mechanicals once over. Readjust belt tensions and cheap skates rollers.

[Polygonhell]

My first guess womb be some mechanical issue most likely on the tower that is in line with the arrow you drew.

[Jos360]

Thanks, I retensioned the belts and cheapskates but it didn't fix the problem. The strange thing is that layer 3 which is exactly the same layer prints perfectly. The problem only seems to happen on the first layer.

But after about the 80th layer on this print it started separating from the table in that corner that didn't fill up so I think I have to find the problem in adhesion after all, or maybe a concave in the bed.

[KAS]

Check the squareness of the towers again and re-calibrate everything after your adjustments to the belts/skates. Two of my end stop switches were loose after the first week and that caused some crazy issues. Basically tighten everything down again, but definitely re-calibrate the entire process.

You can also change the orientation of your print to rule out various axis issues, but that's just a short term fix.

[Jos360]

Thanks,
I noticed after a couple days that my prints started to deteriorate in quality and it was indeed the endstops being loose and being pushed up, so orientation of all 3 towers was off. I recalibrated that and fixed the stops in place and that hasn't been a problem since.

I will try and start from the beginning of the build manual regarding calibration. Maybe I forgot a step.

[Jos360]

I realigned the towers and found that, as suggested, the X tower (the one behind the yellow arrow in my first post) wasn't adjusted correctly. I recalibrated the endstops, belt tensions and cheapskate bearings again and now the first layer prints perfect.

For some reason the 2 missing lines were filled in at the end of the first layer, probably a mistake in the g-code. The angle on the pic is different but it's the same part. The left side in the pic is the same area that was faulty before.

[Jimustanguitar]

For some reason the 2 missing lines were filled in at the end of the first layer, probably a mistake in the g-code.

It's definitely in the GCode, yep. Different slicers will handle how different sections are connected differently. I've noticed that Cura tends to parse large sections into chunks like this. I bet it would be different if you tried a different slicer.

[Jos360]

I did indeed use Cura, I am printing a wing design from Catia and slic3r or kisslicer are making all kinds of weird mistakes from the STL, while Cura is the only one I found so far that handles it correctly, it's a 9hr print and last time at about 60% it started skipping layers because the Gcode had a couple of almost empty layers in it, which ofcourse caused the part to seperate and curl...
I hope this one will be better.