First Layer - Transparent area and perimeter problems

[Sam-Nicolai Johnston @sam-n-johnstongmail-com]

Hello,

I am having problems with many of my prints (on fine setting):

1. In a certain section of the PEI bed, on the first layer, a complete section is almost transparent/translucent. This is pretty much corrected on the second layer. You can see in the middle of the second image I included that the perimeter is almost invisible. A big chunk of the print was like this on the first layer. I feel like this is a nozzle height problem (should I decrease or increase the height of the nozzle?), but the rest of the print is fine, so maybe it’s a leveling problem?
2. As you can see from the third image, there is warping on the front of the model as well. This is worsened by the fact that one of the perimeter around the model wasn’t printed at all. So the warped easily there. How can I fix this? Should I do a custom profile to use the 0.8mm nozzle on the first layer? Or print in normal resolution?
3. Warping! Hahaha, lots of it. In the old AM, I could control the internal ambient temp and it would lower the warping a bit, but now I cannot control it in the new AM and it is set at a low ~30°C. Since it’s pretty cold here, the walls are really cold and I think affected my print on the right side of the images. I tried adding insulator but it was too late. Can I change the ambient temperature for the Robox? Should I increase the bed temp? Is doing that possible?

Thanks a lot

Sam

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[kevin @kevin]

I think your Pei bed is little bit warped and not even, and some heating bed has a problem with even heating. Some parts are not heated compare to other parts. You can search related topic about this in this community.

[click @click My Robox is a Green Kickstarter Limited Edition]

@sam-n-johnstongmail-com
“In a certain section of the PEI bed, on the first layer, a complete section is almost transparent/translucent. “

Try to heat the bed and then press it down. I think I managed on several occasions to push in back in. My theory is that PEI is warping upwards on heat because it cannot easily slide under the clips. Pushing it in while hot (after a small test print for instance) helped sometimes…

“As you can see from the third image, there is warping on the front of the model as well. “

Yes, that’s what materials we’re using do. What is the fill you used? Is it possible you to lower infill %? Maybe thinner walls? I am just giving you ideas - not advice as I am with similar problem, too. Here are some more: http://www.makerbot.com/blog/2011/06/23/12-ways-to-fight-warping-and-curling/

“In the old AM, I could control the internal ambient temp and it would lower the warping a bit, but now I cannot control it in the new AM and it is set at a low ~30°C.”

You definitively can do that in new AM too. You might need to create new material (using exactly the same as one on the reel), change ambient temperature and write it back to reel. I’ve just done that yesterday increasing Black ABS’s temperature to 55º.

Is that white PLA you’re printing with? It is worth, maybe, trying some other PLAs, too… I have bad feeling that this particular is really bad warping wise. In next few months I’ll source more PLA (I’ve got more than enough ABS now) and give it a go. Some other people (different printers, too) had more success with PLA than I warping wise - so I suspect it is the material…

• This reply was modified 4 days, 5 hours ago by  click.

[click @click My Robox is a Green Kickstarter Limited Edition]

PS I’ve just seen your print’s third image (again) - definitively try to lower fill to 10% or even less. It doesn’t matter if it ‘sags’ inside - less fill - less stress it should have.

As I said - you can play with wall thickness, too - again it should lower the warpage…

[gid @gid My Robox is a Green Kickstarter Beta]

When I was concerned about bed warpage, I came up with a useful test. Model a cuboid about the size of the Robox bed and just a millimetre or so thick. Print it, but abort the print just when it finishes the first layer. I found a number of “transparent” spots that, for me, were solved by flipping the bed.

I should do this again, come to think of it. It might be worth hacking a bit of GCode to do this so we can compare the results… it’s easy to edit by looking for the end of the layer and the Z-axis move instruction and deleting all the stuff after that until the footer.

Tom Gidden -- Bristol, UK -- New Roboxer? Check out the wiki, and add yourself to the map! http://roboxing.com/user_locations

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