Matt finish for better post processing?  

RE: Matt finish for better post processing?

That is a huge project. with 1x1 lego and 8000 pieces it will be a square of around 90x90 pieces or 70x70 cm.

Just trying to picture that and thinking how that would look from what distance. Would the surface finish really be that important? I would think you will look at it from a distance anyway.

Getting that many pieces look the same with different colors will be very hard. You idea of sanding that all together sounds like a good idea to me. But be careful with sanding as it is very easy to overheat PLA that way. 

Just thinking out loud here. Lets see what others thing.

But would love to see the finished project.

RE: Matt finish for better post processing?

Yes, pretty big at around 70x75 😀

I had wondered whether to reduce the number of bricks and colours but I don't think it'd look good.  I think it might be quite challenging and if it works out I'll definitely share a photo.

Looking at what I'm testing now I'm tending to think that 0.2 height with concentric top layer won't need any post processing.  I'm used to printing small things which are examined closely but with this one as long as the bricks aren't terrible I think it'll be OK.  I'll print a larger number of bricks and decide from there as well as exploring the matt option too.

RE: Matt finish for better post processing?

Prusa Slicer has the variable layer height option that could be useful for this as you will only see the tops of the bricks. That could speed things up.

RE: Matt finish for better post processing?

If I'm understanding correctly, you want to print a large piece that looks like it was made from lego bricks. Only the tops will be visible. If this is the case, why not just print thin tops and save a LOT of filament? Have you considered just printing panels of brick tops at the maximum size that will fit on your printer bed, then just painting the tops? If you use a thick paint, they should all look somewhat like the original plastic (ABS IIRC) and have a uniform finish.

RE: Matt finish for better post processing?

Thanks, different layer height is a good idea, I've made the bricks a low height but it would still save a fair chunk of time.

Individual bricks of 1x1 size (8mm square with 1 round top) in different colours which are snapped onto a board in a single layer to form a picture.  I could print smooth tiles but it won't look the same without the lego shape.

I was hoping to avoid painting as that will be very time consuming, if I did that then I could make a board with tall dots and space around them to make spraying easier.

RE: Matt finish for better post processing?

I was hoping to avoid painting as that will be very time consuming, if I did that then I could make a board with tall dots and space around them to make spraying easier.

More time consuming than printing in different colors? For the time and money you're going to spend I'd find a lego store and just buy what I need. Have the whole project done in a weekend.

RE: Matt finish for better post processing?

Posted by: @lize

[...] Individual bricks of 1x1 size (8mm square with 1 round top) in different colours which are snapped onto a board in a single layer to form a picture.  I could print smooth tiles but it won't look the same without the lego shape.

Sounds like you want to do something like Lego pixel art but on a larger scale. If most of the background is one color, you can print larger plates in that color, then just do the individual colored "pixel" pieces in other colors. I'd be inclined to cheat and print larger pieces in the needed patterns and fit them together rather than build it from that many 1x1 blocks. In the example below, print the green sections as 2 large parts. Unless, of course, this is just something you enjoy doing like a jigsaw puzzle.

RE: Matt finish for better post processing?

I understand what you're saying. I'm not in the habit of printing things for the sake of it and will opt to buy something if its cheaper/readily available but I thought it'd be a fun project and be satisfying.

Lego store bricks = over £500 + base boards

Rolls of PLA in colours I don't have would be about £150 or less if I bought smaller rolls of the shorter volume colours and still quite lot of left over for other things.

Think I'll give it a go and report back.

RE: Matt finish for better post processing?

@bobstro

Yes, I wondered about printing larger parts but then thought you might see theres no gaps.  I'll have a try at that as well and see what I think, it'll take some time to sort out the colours for various sizes.  Would be even more like a jigsaw, just a bit quicker on assembly.

Did you print those, they look very smooth or are they bought ones?

RE: Matt finish for better post processing?

Posted by: @lize

[...] Did you print those, they look very smooth or are they bought ones?

Oh, sorry for the confusion. That's just an example of "Lego Pixel Art" I found on the Internet. I wanted to make sure that's the sort of thing you wanted to print.

You could try printing larger parts with groves between the Lego parts, then dip just the bottom-most layers in a thinned wash of dark paint to enhance the appearance of separate pieces.

RE: Matt finish for better post processing?

Perhaps printing with a Hilbert Curve and a single perimeter will give you the look you want? without having to post process.