Anyone with experience printing custom Lego bricks?

I’m thinking about buying a Form 1+ to print custom and original Tente bricks. Tente is an spanish toy similar to Lego but with different interlocking system and nowadays is out of production. Any experience with Lego will be valid for Tente. :wink: I have found only one topic related with Lego: the minifig comparison. In another web a Form 1 was used a year ago resulting interlocking problems, but the author didn’t try other dimensions. The second case is from six months ago about a Form 1+ printing successfully a Lego gear. So my doubts are:

  1. Interlocking: Maybe after testing several dimensions and with a specific printer resolution I’ll find the best interlocking?
  2. Orientation: what is the best orientation to minimize the number of supports (less resin wasted and less sanding).
  3. Max number of pieces by print: other SLA printers allow to use all the volume of the printer, but with the Form 1+ seems that only a layer of pieces can be printed. I’ve tried the trick of putting a brick over another in the STL before importing it with PreForm. The auto generated supports for the above brick are wider than of the lower one, save the supports with the base on the lower brick (similar to the used for the overhang parts). I don’t know if this is the best way (seems to waste more resin on the supports) or it’s better to make several prints with only one layer of bricks.
  4. Old computer: I know that PreForm requires an OpenGL 2.x computer for the 3D manipulation, but I would want to make the orientation and support generation on a recent computer, then save the FORM file and open it with and old computer (without OpenGL 2 support) connected to the printer. Is it possible? The printer and the old computer would be in the workplace, and the recent computer in another cleaner room.

Thanks in advance for your answers. :smile:

The Form1 is probably not a good printer for this purpose. Due to unreliable calibration methods the dimensional precision leaves a lot to be desired and unless you got really lucky and got one of the machines which happened to come out of their calibration process spot on you would likely not get to a point where you would have reliable shape and interlocking.

I only know the fit using the materials Detailed Plastic and Strong&Flexible from Shapeways. With S&F, the bricks jumps when the stud of one brick is a little bigger than the hole of the other. Detailed doesn’t jump, but the fit is weaker. I haven’t tried Frosted Detail material. So it will be OK if bricks printed with Form 1+ doesn’t jump and have a stronger fit.

I’ve built an extensive series of giant lego minifigs on thingiverse using FDM printers.

Reproducing something like an individual Lego block on any 3d Printer is going to be difficult. It comes down to tolerance and allowance. Lego are some of the best made injection molded parts out there. The tolerances they hold during manufacturing are mindblowing. You may have better luck using a SLS (selective laser sintering) style machine through Shapeways or creating a mold and Resin Casting the parts.

I’ve found the issue is often not your ability to print the block, but you ability to accurately measure the block you’re trying to reproduce. When making these blocks, errors of a fraction of a mm can be the difference between success and failure. Lego’s allowable variation on their molds is 2 micrometers. Thats hard to even reliably measure without special tools.


I agree for the most part. Except I’m pretty sure a very well calibrated and aligned high resolution FDM or SLA printer should be able to produce reliable enough results so that with trial and error editing the model and checking the results you should be able to get something pretty good.

However I haven’t tried. I’ll have to try on my FDM and see how I do. I know there is no way my Form1 will do it.

As I said, SLS (Strong & Flexible Plastic/nylon, ± 0.15 mm accuracy) produces jumpy lockings. Detailed plastic (photopolymer, ± 0.1 mm accuracy) is less rigid and maybe a little compressible, so a little larger stud fit in a little smaller hole. About resin casting, I think the bricks tend to break after some use, but I’m not sure, and it seems to me a more dirty and toxic process than using the Form 1+.

I know the requirements for Lego casts, that also means they cannot use many times their casts as some clone toys could do to reduce costs. With Tente is the same, but maybe it’s less restrictive because of its different locking system. As Lego bricks, the basic unit is 8 mm wide, but the diameter of the stud is 6 mm and the wall width is 1 mm. In the original ABS bricks, you can see that the walls bend a little to admit a little bigger stud and the gaps between the bricks aren’t uniform, so having thinner walls helps, except when using S&F material from Shapeways. The next image shows a Tente 2x3 brick:

I don’t need to build simple bricks, but other pieces that also have studs, so I need to know that making with Form 1+ won’t result on jumping pieces. :grimacing:

Sometime ago I saw Lego bricks made with FDM that fitted very well (the user said so), but the finish with FDM is very “wiry” and I’m not sure what happen with the locking after using the acetone trick to smooth the walls. I’m not very convinced of using FDM printers for this task. I could be wrong but FDM remembers me to an old matrix printer whereas SLA would be an inkjet printer.

That’s an understandable reaction to most FDM printers. However my machine prints well supported objects with a layer height of 40microns and line thickness of 25microns quite well with no visible striation and most of the “wiry” look is not visible at that resolution.

@RocusHalbasch which FDM do you have?

@Jose_Alfonso_Solera, Because the part is so small and needs high tolerances, I would most definitely just pay up at for the prime-grey material/machine. It is actually very cheap for parts this size and the texture and accuracy is beyond your wildest dreams if you have been using

Here is the face of the electronic enclosure that has ALL of it’s history with me and 3D printers. This is a part in the photo. The square programming pins in the middle are 500 micron each. (Zoom into the gaps around them!) The print was perfect. The black slot is to plug in a MicroSD card into. The mating connector that plugs into this whole rectangle is standard and off-the-shelf. It has the seal and even has a natural space where the programming pins fit into.
This is to give you an idea what Prime Grey is and can do.

A slightly customized and very lovingly built and tuned MendelMax 3, which I built myself from a kit.

@RocusHalbasch I expect your results with your FDM printer. At least they are cheaper printers and have more available colours and materials than SLA ones.
@JoshK Sometime ago I saw the materials and prices of i.materialise and they seemed more expensive than Shapeways. I’ll check it again. The web says that Prime Gray “has a medium mechanical resistance”, so I’m not sure if this means the piece will break after a few uses, or just means the thinner parts with this material are a little fragile.

Both Form1+ and PrimeGrey resins are brittle. The Form1+ a bit more. The Form1+ resins do warp, Prime Grey never warps.
I ran a fast quote, a twisted rook that is 21x13x13mm is $6.89… Is that Lego block sized?

My target pieces has a maximum bounding box of 32x32x24 mm (1:300 airplanes) and a minimum of 8x8x10 mm. For example, how about these two examples:

  • 15 pieces of 1.38 cm3 (airplane).
  • 25 pieces of 0.22 cm3 (small navy anti-aircraft).

They are not the same models, but similar to the next image (20 CIWS + 8 Harrier):

The Harriers doesn’t fit with another piece and they are hollowed in the bottom, and the CIWSs fit on one stud.

The next image shows these customs parts with original ones after being painted by another person (no sanding):

There’s bulk pricing too, I don’t know the details. Maybe just upload them and let it show the cost.

@Jose_Alfonso_Solera, since you already have the files maybe you can have one sample printed on the Form1+ and one sample printed at materialise and compare. That should tell you everything you need to know. I would even recommend breaking them to learn their strength.


  • 20 Harriers: 76.60 € in White Detail at Shapeways, 80.40 € in Prime Gray at i.materialise.
  • 25 anti-aircraft: 20.35 € in Frosted Detail at Shapeways (White Detail gets bad prints due to long thin tubes), 70.75 € in Prime Gray at i.materialise.
    VAT and shipping not included in the prices. So with the airplanes i.materialise is competitive (similar price and better finish), but not with the smaller pieces. :confused: I think the reason is the allowed use of sprues at Shapeways.

Interesting, thanks.
However you end up printing them I would recommend checking out silicone molds and 5 minute mix/cure urethane plastics. I do it all the time because it is far faster, easier, and cheaper than printing. Have a look at to see what can be done.

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Many years ago a member of the Tente community made some silicone molds and also posted a tutorial, but nobody has continued that work (an later that person changed to Lego after a flame war :worried: ). I think some experience is needed for the design of the molds for special figures, and some of the substances involved in the process are toxic… As a curiosity, in the community of another discontinued game for construction of castles (bricks are 50% larger) molding is more popular and recently someone is trying a Prusa i3 for ornamental elements (archs, windows, etc.).

I’m a “digital” person that prefers to pay a little more money instead of wasting time and getting headaches tinkering with a printer kit, so in case a FDM has enough quality for my pieces, I would choose an Ultimaker 2, Zortrax M200 or similar instead of a cheaper and equivalent kit, it’s just a personal choice and I can afford it.