Good questions! I definitely don't autolevel. Here is the engineering idea behind autoleveling:
If bottom layer is .3mm then the nozzle should be .3mm from the glass. Auto level such that z=0 is touching the glass.
The problem with that concept is that parts are dimensionally perfect and usually stick "okay" but "okay" means certain part shapes will always pop off the glass and most part shapes will pop off too early maybe 10% of the time. 10% is too much.
kapton tape
Only works with heat. I used it many years ago with my first home built heated bed. It worked fine with no treatment with PLA but since then I've heard it's best to clean it with alcohol also. Just like blue tape. I never personally tried it with ABs.
brim versus raft
Brim makes parts stick like hell. Raft allows flexure if parts are shrinking. They are totally different ways to approach the problem. Brim is keeping any air from getting under the corner of a part and also it spreads the forces around a curved edge instead of having all the force on a point if your parts has corners. Raft is purposely sparse and allows some flexure of the raft itself such that the part can shrink and flex slightly but still stay stuck to the glass. Raft causes very ugly bottom surfaces so it's not recommended unless you are printing something really difficult like PEEK with an all metal hot end at 360C. (360, not 260!)
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gr5 2,295
I love glass. I'd stick with glass. I used to use kapton before glass. ABS is a bit trickier than PLA but you will eventually be an expert if you keep it up. You fixed 2 of the issues - you raised the build plate temp (but you should go to 100C) and you added some glue. But probably too much glue. The 3rd issue is the most commonly ignored - you need the head closer to the glass. For now simply turn the 3 screws about 1/3 turn CCW to move the glass .166mm closer to the nozzle and try again. But there are subtleties to these 3 tricks (heat/squish/glue) and it can help to spend the whole 15 minutes watching this video:
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valcrow 145
ABS is kinda rough. I would recommend using Ultimaker ABS (it doesn't warp and sticks onto glass) You need a small layer of glue not to help it stick, but to help it UN-STICK so it doesn't chip your glass plate upon removal of your part.
Most other ABS I've tested have similar results as you describe. It works up till a certain point and then warps away if the part is of any decent size. Only a full enclosure will help with this type of ABS or you'll have to resort to kapton + abs slurry and that's kinda messy and not fun. Make sure your fans are off.
Ultimaker ABS for some reason sticks really well and doesn't warp that much in an open environment. Probably some voodoo magic in it.
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Karel1986 1
Thank you @gr5 very informational video on different techniques.
I see now I definitely put on to much glue on the glass plate.
Regarding the leveling. I auto level before a new ABS print and I've tried manual leveling (with instructions of Ultimaker).
Does the auto level function in UM3 gets the nozzle close enough to the buildplate in your opinion for the first layer?
I will try 100C build plate today and see what happens.
PS: can you use Kapton tape right away after applying?
PS2: so a brim is good enough in comparison to a raft?
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