3D print LEGO element

[Jaco van der Molen]

Hi folks,

I realize this might be considered heresy among true LEGO purists, but has anyone experimented with 3D printing LEGO elements, using an LDraw part file
(Or Stud.io part file for that matter)

For a very special project for a friend, I want to make a Technic, Axle and Pin Connector Angled #7 - 168.75 degrees in green.

So far, this part only comes in Reddish Orange from 5 sets.

Could someone provide me with a file format for a 3D printer?

Help or tips are much appreciated.

Jaco

P.S. Hoping some future botanical sets might ever use this part in green for plant stems... ;-)

[Jeff Jones]

ldview has a option to export as stl

[Rene Rechthaler]

Do you need the part printed or do you just need help with the files?
Our digital files are sometimes too perfect for printing, and the part has to be redone digitally with the correct tolerances...
(i have a 3D printer and green filament, and i've done some Lego prints too...)

[Jaco van der Molen]

Do you need the part printed or do you just need help with the files?
Our digital files are sometimes too perfect for printing, and the part has to be redone digitally with the correct tolerances...
(i have a 3D printer and green filament, and i've done some Lego prints too...)

For now I would be interested in the file for this part. I have someone to print who has the right color filament too. Perhaps a few other parts if this is a success.
Tnx!

[Jose Alfonso]

Do you need the part printed or do you just need help with the files?
Our digital files are sometimes too perfect for printing, and the part has to be redone digitally with the correct tolerances...
(i have a 3D printer and green filament, and i've done some Lego prints too...)

Also the DAT file is not always a closed volume so the same will happen with the STL exported from LDView. Sometimes the slicer software will automatically fix that. Also the printer must be well calibrated to get a printed block that fits perfectly with the official ones (or just modify the STL to compensate any problem).

[Orion Pobursky]

I have printed a few parts. Some notes:
- I used LDView export.
- Printing a part that small in actual size on a FDM printer is going to be tricky with the standard 0.4mm nozzle. If you are using a Bambu printer (which I recommend), I'd try out their 0.2mm nozzle.
- As Rene pointed out, meshes from LDraw export aren't necessarily closed and may have internal surfaces. Most slicers will try to fix this but you may have to play with the settings.
- Fit is going to be very tight. Tight to the point where if you put an axle into the hole you may end up destroying the printed part to remove it. I'd recommend playing with the scaling to dail in the clutch power.

[Chris Böhnke]

I have never tried this myself, but maybe pre-adjusting a few details of the LDraw file (still in .dat format) will help with this?

Whilst there is a whole lot of tolerances in play we have little knowledge of, we know that a few functional details are omitted in digital models:

*Lego themselves give Technic pin holes often as "Ø4.9" implying a 4.9 mm hole. LDraw's standard at 12LDU translates to just 4.8mm, creating a tighter fit
*Bricks and similar elements are assumed as multiples of 8mm/20 LDU, ignoring the 0.1mm play around each brick. I am not sure, but I think studless Technic beams have even more play.

Maybe making a copy of the hole primitive, adjust the diameter, then inline the "fake primitive" for the export gives a better result in printing?

EDIT:
Ok, will likely not do much, if the nozzle has a resolution of 0.2mm...

[Rene Rechthaler]

Also, the original part has the "reduced" axlehole with the thin tooth...
that may be hard to print/fragile, maybe recreate the part with the standard axlehole instead.
What filament/material and method is your contact using?
maybe you have to manually add some support.

[Jose Alfonso]

Ok, will likely not do much, if the nozzle has a resolution of 0.2mm...

The diameter of the nozzle affects to the resolution of small and fine features, not to the dimensions of the printed object. With 0.2 mm the corners and tips are less rounded than using 0.4 mm or wider. Smaller diameters also mean longer printing time.

[Jeff Jones]

i wonder if anyone tried to 3d print ldd mesh

[Johann Eisner]

Hello Jaco
If you are considering printing the part, you could also paint it, which might be less work. Because there will be a color difference either way.

[Jaco van der Molen]

Hello Jaco
If you are considering printing the part, you could also paint it, which might be less work. Because there will be a color difference either way.

We thought of that. Even printing in white and have it spraypainted.
But I think we found a very near color green filament.
The printed part is rather good. Strong clutch power.
Axles and pins are hard to remove.
But that is not necessary, because once the model is build, it wont ever need to be taken apart.

The model will look like this:
   

Custom brick-build hood