How do I do this best?

[basteluwe 1]

Hi guys,

I have asked before (another topic) for advice on how to get a better bottom surface. After some thinking, I'm not sure I'm on the right path all together. What I want to do is print a small box for some electronics like this one:

I thought the box would have to be placed face-down with the writing towards the buildplate.That would be the side to look at later, so I want it to be as perfect as possible. A Testprint yesterday with only 3mm thickness gave that result:

Quite terrible to look at! The letters actually are not so bad, it's the area around that spoiles the view.

So how would you advise that thing to be printed?

Have a nice week,

Uwe

[owen 19]

It looks like you need to print closer to the build plate. Then experiment with a thinner than usual first layer plus increase the extrusion rate for the first layer. Also make sure your text is deep enough. I have had reasonable results recently with 0.1 mm first layer, 110 % flow for first layer (but 100 % may go ok too), 0.7 mm deep text using glue stick and printing with abs through a 0.25 mm nozzle. Hope this helps. Good luck.

Owen

[tinkergnome 883]

So how would you advise that thing to be printed?

What about the "Blecheimer method"?

[basteluwe 1]

It looks like you need to print closer to the build plate.  Then experiment with a thinner than usual first layer plus increase the extrusion rate for the first layer. Also make sure your text is deep enough. I have had reasonable results recently with 0.1 mm first layer, 110 % flow for first layer (but 100 % may go ok too),  0.7 mm deep text using glue stick and printing with abs through a 0.25 mm nozzle. Hope this helps. Good luck.

Owen

 

Thanks Owen!

Printing closer to the plate seems logic, but how to set that up? I know how to calibrate the plate by a piece of paper. But how to measure, if I want to get even closer?

I will definately try to increase the flow, that seems very promissing. I didn't know, I can do that for just one layer!? As for the nozzle, I only have the standard (0.4 mm), using PLA at the moment.

Regards.

Uwe

[basteluwe 1]

Question:

how to change material flow ONLY for the initial layer?

I checked Cura and only found a general setting for flow.

Am I overlooking something?

Regards Uwe

[geert_2 509]

If your material is transparent or translucent, you could design the text as hollow characters *inside* the model, at 0.3 to 0.5mm below the surface facing the glass table. This is good for prototyping and 3D-printing, but not for mass production injection moulding of course (unless you would want expensive overmoulding with multiple moulds, like often done on tooth brushes these days).

See a photo how this looks with 3.5mm high x 2.0mm wide characters:

https://ultimaker.com/en/community/35918-printing-small-letters

[owen 19]

 

It looks like you need to print closer to the build plate.  Then experiment with a thinner than usual first layer plus increase the extrusion rate for the first layer. Also make sure your text is deep enough. I have had reasonable results recently with 0.1 mm first layer, 110 % flow for first layer (but 100 % may go ok too),  0.7 mm deep text using glue stick and printing with abs through a 0.25 mm nozzle. Hope this helps. Good luck.

Owen

 

Thanks Owen!

Printing closer to the plate seems logic, but how to set that up? I know how to calibrate the plate by a piece of paper. But how to measure, if I want to get even closer?

I will definately try to increase the flow, that seems very promissing. I didn't know, I can do that for just one layer!? As for the nozzle, I only have the standard (0.4 mm), using PLA at the moment.

Regards.

Uwe

 

To get closer to the the build plate, after you do the standard level tighten each of the 3 bed levelling screws by the same amount. 1/8 to 1/4 of a turn anti clockwise when looking from the top.

Sorry I see Cura doesn't allow to increase flow on the first layer (I used Simplify3D). You could add a line of gcode at the start of the first layer to increase flow but I would try without that first. Getting closer to the build plate should have the same effect.

0.4mm nozzle should be OK. You seem to have fairly big text.

Edited February 7, 2017 by Guest

[basteluwe 1]

If your material is transparent or translucent, you could design the text as hollow characters *inside* the model, at 0.3 to 0.5mm below the surface facing the glass table. This is good for prototyping and 3D-printing, but not for mass production injection moulding of course (unless you would want expensive overmoulding with multiple moulds, like often done on tooth brushes these days).

 

Thanks for trying to help, but my problem is not the letters!

It's the visible lines on the surface. Those I need to get rid of.

Regards, Uwe

[basteluwe 1]

To get closer to the the build plate, after you do the standard level tighten each of the 3 bed levelling screws by the same amount. 1/8 to 1/4 of a turn anti clockwise when looking from the top.

 

I have done a short test print with flow increased to 110% but with same bed-leveling like before. Result was a little better but not good enough. Now I will do a new trial with reduced distance. We'll see.

Regards, Uwe

[geert_2 509]

 

If your material is transparent or translucent, you could design the text as hollow characters *inside* the model, at 0.3 to 0.5mm below the surface facing the glass table. This is good for prototyping and 3D-printing, but not for mass production injection moulding of course (unless you would want expensive overmoulding with multiple moulds, like often done on tooth brushes these days).

 

Thanks for trying to help, but my problem is not the letters!

It's the visible lines on the surface. Those I need to get rid of.

Regards, Uwe

 

Yes, I had understood that.  

You can not get totally rid of these lines, but hollow characters inside a transparant model do reduce the ugly effect. Instead of the weird outline-patterns that you have now, you would get nice straight diagonal lines, which are hardly visible. The fact that the whole model also gets a sort of frosted glass look, or a carbon or textile look when using a transparant or translucent material, even masks them more.

And as mentioned before by others, your nozzle needs to sit close to the build plate, so the first layer is squeezed hard. Printing slow also helps, then the filament has more time to melt and to flow into the corners.

Even in high pressure injection moulding you see these "weld lines" where flows meet each other. It won't get better than that, unless you chemically smooth, or sand and paint the model.

Edited February 9, 2017 by Guest

[basteluwe 1]

Yes, I had understood that.  

You can not get totally rid of these lines...

And as mentioned before by others, your nozzle needs to sit close to the build plate, so the first layer is squeezed hard. Printing slow also helps, then the filament has more time to melt and to flow into the corners.

... It won't get better than that, unless you chemically smooth, or sand and paint the model.

 

Hi Geert,

Thanks very much for making me understand!

I have now reached an acceptable result and I didn't even have to get the plate closer to the nozzle. What I changed was, reduce the first layer to 100 (stupid me I started with 300). I also reduced print speed for first layer down to 20 mm/s and lastly I increased the flow to 110%.

I think I can live with that result now.

Once again thanks for helping!

Uwe