Bottom layer lines less visible

[pad 0]

I am new with 3d printing, just got my um2 for 2 weeks.

I have tried a few settings but lines on the bottom layer are always very visible :

- 0.3 and 0.2 layer thickness

- fan off, fan on

- 75°C, 65°C bed temp

- 230°C, 210°C, 205°C hotend temp

I saw the topic about backslash and it is not.

Any hints to make the bottom layer as smooth and better looking as top layer ?

 

[owen 19]

Hi pad

You may need to adjust the nozzle closer to the bed for the start

A picture would be helpful too

 

[IRobertI 517]

Like owen says, check your bed leveling. It's critical to getting perfect first layers. I also find that using thinner first layers make them look even better (0.1-0.2 instead of the default 0.3).

 

[pad 0]

Sometimes I get a glossy bottom : it is smooth and I can't feel the lines.

I have also thought about the distance between the hotend and the bed. I am doing the bed leveling with a papersheet like described in the manual.

 

[mnis 11]

In addition to the exact alignment of the bed, is there anything more to say:

- This is also very much dependent on the material used.

- Then adhesive aid is required for direct printing on glass, which leave absolutely no visible residue.

- Prints the first layer with 20-25mm/S

- 210/60 degrees plus ahesive aid directly to glass should work just fine.

- After all of the first layers were printed stepwise temperatures can be lowered.

- With a good ahesive aid PLA sticks even at 45 degrees bed temperature.

- Without ahesive aid there is below 75 degrees bed temperature separations and distortions of the objects.

- Also print a lot of users on cold Plexiglas, which should also allow smooth surfaces.

Here are two examples for printed directly on glass objects with adhesive-aid.

Markus

[gr5 2,094]

Just move the glass a little closer to the nozzle. Or alternatively you can increase flow on the first layer - maybe 150%. If you increase too much the pressure will build up too much and the stepper will skip. Same problem if you move the glass to close to the nozzle.

Also don't do .1mm bottom layer thickness as that is too difficult to get perfect. .2mm bottom layer is a great compromise.

 

[SandervG 1,519]

How about heating up the bed a little bit more.

Would that help blending the first layer?

I wouldn't recommend it with a print that has some low/early overhangs, but this seems to be like

a pretty straight forward model.