Settings for PLA prints

[meskan 0]

what are the best settings to use to get the smoothest surface finish?  

[gr5 2,172]

It depends what area you want to improve but my first advice is to use PLA which looks better and is stronger.  In those photos those parts look 100% operfect - I can't see any defects.  I think the photo is a bit underexposed.  Note that shiny black filament shows up defects more than any other color.  Flat black shows very little defects.  If you must use shiny filament try a light color (but not white which is harder to print regardless of material).

 

General advice for improving quality is to print at half speed.  But it depends on your particular issue.

[meskan 0]

Yes I meant PLA..... I couldnt change it after posting.  The pics are what I want to achieve.  I can't have any lines or they have to be very small.  Currently I spray prints with body filler spray paint and sand off smooth. 

I don't know what an ideal layer size or print speed is?  Does PLA give the best finish or another material?  Im doing a print now on .1mm @ 45 print speed.  I'll post how that turns out.

[meskan 0]

 

Here's one set which is about 5" long

[gr5 2,172]

6 hours ago, meskan said:

Yes I meant PLA.....

I fixed the title for you.

[gr5 2,172]

3d printing gives you lines.  Are you saying you don't like the lines?  You can drop from 0.1mm layers to 0.06 layers but you'll still see the lines - they'll just be thinner.  why are lines so bad?  Some people like the look of the lines.  It shows a little bit about the process.  Like most people don't mind the grain in wood and in fact think it improves the look of wood items.  Some people hate the grain of course.

 

So you want those thin layer lines to go away?

 

Well you could do acetone wash.  It will shrink the part a bit but there is a process.  YOu can't use ordinary PLA you have to use certain brands of filament.  

 

You should practice on many small parts first but this guy (cloakfiend) is the expert with PLA smoothing - watch some of his newer videos - there's many many pages to go through.  I'd maybe read the first page of posts and then skip to the end and go backwards as over the years he improves on his techniques.

https://ultimaker.com/en/community/10412-acetone-finishing-on-pla

 

Or you could look into using polyfill and the polysmoother.

 

Or you could do ABS and acetone vapor (but ABS is much more difficult to print - I recommend you stick with PLA or polyfill).

 

Finally you can use "rough" filaments that make the lines pretty much invisible but the surface is rougher.  It's pretty amazing, really.  Let's see - ngen LUX comes to mind - amazing stuff - but you might not like the look - sparkly.  CF filled filaments also tend to hide the layer lines.

 

[meskan 0]

12 hours ago, gr5 said:

3d printing gives you lines.  Are you saying you don't like the lines?  You can drop from 0.1mm layers to 0.06 layers but you'll still see the lines - they'll just be thinner.  why are lines so bad?  Some people like the look of the lines.  It shows a little bit about the process.  Like most people don't mind the grain in wood and in fact think it improves the look of wood items.  Some people hate the grain of course.

 

So you want those thin layer lines to go away?

 

Well you could do acetone wash.  It will shrink the part a bit but there is a process.  YOu can't use ordinary PLA you have to use certain brands of filament.  

 

You should practice on many small parts first but this guy (cloakfiend) is the expert with PLA smoothing - watch some of his newer videos - there's many many pages to go through.  I'd maybe read the first page of posts and then skip to the end and go backwards as over the years he improves on his techniques.

https://ultimaker.com/en/community/10412-acetone-finishing-on-pla

 

Or you could look into using polyfill and the polysmoother.

 

Or you could do ABS and acetone vapor (but ABS is much more difficult to print - I recommend you stick with PLA or polyfill).

 

Finally you can use "rough" filaments that make the lines pretty much invisible but the surface is rougher.  It's pretty amazing, really.  Let's see - ngen LUX comes to mind - amazing stuff - but you might not like the look - sparkly.  CF filled filaments also tend to hide the layer lines.

 

We are a foundry and all our patterns have been cnc milled and sanded smooth so that the castings are also smooth.  The lines will show up on the casting and OEM companies will not approve them aesthetically.  The body filler spray works well, but of course extra time added.  Im printing the attached now at 1mm @ 45 speed and the lines are not good.  

I will look at the things you mentioned,  Thx

[gr5 2,172]

Yeah sanding and body filler spray and bondo - that's a good solution but a LOT of work.  I'm told you want to "wet sand" (make sure sand paper is wet) to keep things cool as PLA gets soft at 52C so you need to keep the sandpaper and plastic cool for best results.

 

Acetone smoothing works quite well but you have to read a lot of that thread I linked to.  You can't just use any PLA - you have to use certain brands.  Basically I believe it needs to be "cheap" pla with fewer additives and the color can make a difference as well.  Some people paint on acetone with a brush for more control.  If you leave it in acetone too long the layers can separate making it quite ugly.  I think you want thicker walls for this reason also.  You can contact @cloakfiend directly - he's very helpful.  He has youtube videos showing his process also.  All in that thread/topic I linked to above.

 

ABS acetone smoothing is much simpler and more consistent (but printing ABS is harder).  You use acetone vapors.  Typically you fill a paint can or other sealed container with just 1/4 inch of acetone and you put a metal tray above - such as a wire rack - or build something out of the lid of a tin can.  Then put the part above in the vapors only.  Then seal it up for 10 to 60 minutes.  There's lots of youtube videos on this.  PLA smoothing is more rare and needs a complete dunk into the acetone.

 

polyfill is an interesting process as well as I mentioned.

[cloakfiend 995]

Regarding pla smoothing with acetone. Im not sure about the pla being cheap or not. But it needs specific additives in it which enables it to smooth and more importantly you need to print higher rez, i usually go for 0.06. I know you may think print times may be too long but I can guarantee you that you make up time in post and you dont need filler. That picture frame thing above would be easier to slap filler and sand, unlike other complex geometry. You also need to be able to sand without leaving marks as well, again sanding acetoned pla is easier than sanding filler in my opinion. I use various colourfabb pla/pha colours for my pla, but apparently that thomas sandler guy on you tube makes some transparent green pla that smooths as well and is much cheaper. Any questions just ask, but as gr5 said. Dont over do it. As your model will split. A single heavy brush on should be fine but you need to take extra care if thecmodel is flat or has thin areas. If its flat like the frame then put a few books on it over night as it dries or even a few days depending if the acetone has ecaporated or not. Have a play and remember to use nitrile gloves...a few of them! Good luck whatever your method.