Draft:

Here I want to show you my 3D printed parts for customized frames with LEGO. It is not about sense of using LEGO or even start a discussion. I want to show you about the possibility to design. This was mine.

General:

LEGO is quite popular in Europe. But somehow I could not understand, why there are only very few frames of quadcopters made out of LEGO bricks.The reason seemed to be, that there were no special parts for motor mounts. There are some tilt mechanisms for tricopters published on the web, but non of them seem to be popular for a complete LEGO tricopter frame.

The advantages for a LEGO frame for me were:

- Availability of spare parts (like bicks for booms etc.) all around the world

- modular for a wide range of constructions like quadcopters, tris, hexas

- zip-tie "glue" will break and fullfill a demolition zone keeping the more expansive parts safe

- quite stiff constructions possible

- even kids are able to design frames

disadvantages

- no motor mounts or special parts available on the go

- 3D printed parts should be accurate

- weight

My first attempt:

LEGO offers a lot of possibilites of trying out construction - for kids and adults aswell. The company itself offers thousands of different bricks. They offer designing tools aswell. One is called LEGO digital designer (LDD). The download is here or here.

This is a screenshot how you change and edit things in the LDD. You only need a short periode of time to get into the control.

LDD offers you the possibility to see every brick created by the danish company ever.You are able to design your own model. After completing the computer aided constriction you are able to list all needed parts in a XML-Format including a preview of every brick and the number needed. There are special services where you can order all needed bricks online of several collectors, who are selling bricks (used and new ones) for a living. Shops are located all around the world. And there are several tutorials how to order the bricks of your construction in the web.

And even better - the possibility to output an instruction manual (step by step guide) like it is used for the kits available of LEGO. Then you can share your multicopter thoughts with others.

In the output of the building manual you get detailed steps. Here are some examples:

For me this was not enough, because the major parts were missing - motor mounts and tilt mechanism.

Second attempt:

After trying to design a frame on my computer with LDD, it did not feel like constructing LEGO in my childhood. I needed the parts physically. The 3D print technology had to be used for creating the missing parts.

I tried to construct the parts in high detail, working with several tools for crash simulation in my profession during time off. Several lunch breaks later - after research and designing - the following data was 3D printed and were used for the second construction loop. The first parts broke while attaching the bearings into the holes of the tilt mechanism. The bearings were used to get the best performance out of the tiny mounts for the tilt mechanism. They worked out pretty well.

The actual data is using a wider diameter for attaching the bearings. With this state of constructing it will work out well. A "bearing free" version will come along during the next days. Keep in touch with the thingiverse project page.

Here is the link for thingiverse 3D LEGO multicopter mounts.

This is the example of the tilt mechanism already mounted on a LEGO tail boom. It is quite stiff. The picture below is showing the first version of the mechanism using a 3D printed brick as a base plate for the tilt.

The picture below is showing the tilt mechanism "version 2". It uses original bricks with one hole as the base for the mechanism. I did not choose the plastic connectors due to possible high friction in the connected parts. Therefore I made an adaptor for a 3mm shaft. In the machanism itself there are the mentioned bearing responsible for a precise tilt control.

This is the motor mount on the fixed end of the tricopter (or quads etc.)

Here you can see the inserted needle bearings already inserted in the tilt mechanism.

The project is not finished yet.

Ufortunately there is not enough time at this moment to complete my first tricopter frame and to actually test it. But for being part of the community I want to share and see how it is working for you.

Hope to give you