Interlocking Brick Design

Hello people.

I came across a good idea for recycled plastic products: Interlocking brick.

So I thought I would kick this off, I have uploaded an initial design but it needs some work and ideas. I think first we should discuss the function of such a brick, maybe a list of must haves. Once we have some good feed back I can start to modify the design.

It should be:
– Simple interlocking design
– The mould needs to be easily constructed and reusable over many times
– Injection mould friendly (consistent wall thickness etc)
– Works with a precious plastic machine (injector)

The idea is to come up with a simple and easy to make design that works really well.

I have uploaded the CAD files to Grabcad but I will try to attach here.

*edit – cant upload STEP files here :confused:


Hmm it indeed would be nice if we could attach .STEP or .stp files here in the forum, or any other CAD files for that matter, so that it’s more easy to share idea’s

What about copying the Duplo lego bricks?
Making copies for personal use is never illegal, as long as you don’t sell them.

Everyone may build patented idea’s just the same. And then we could create new blocks (Technic Duplo?) Or other form and shapes. Then publish those new bricks under a GPL or Creative Commons license, so that LEGO is free to produce those bricks. (as long as they respect our terms and conditions)

If we can make a DIY friendly version of the brick that would be cool right?

It’s not about destroying their business, it’s more about taking it into another use case. (extending the life of the Lego Plastic)

Though the Lego Gods may have different thoughts on that?

Uhm… turns out I was wrong… have a look at this.

Expired patent of the day: Lego

now i wonder if CAD files are already available for all those bricks?

I was also thinking about real life building blocks instead of toys.
The posted design looks like it’s meant to work for construction. If so, what should be the mix used to produce such blocks ? using only plastic without a filler like sand looks very resource consuming.
This kind of applications can be useful to recycle some contaminated plastics, thermosets such as tyres, and plastic mixes (#7 other).

Nice article.We provide interlocking bricks, paving blocks, pavement for house as well as commercial for more info contact us at

Trial and error i guess… start with a birdhouse scale up to a dog house?. i think brics always will have a use and from there look how people use them. Upgrade the design to those use cases etc.

I assume that you are talking about toy blocks similar to lego. I think it would be a great idea to create.

But would it be something that could be feasible on a larger scale to make bricks for building of housing? or would this become too heavy or not be structurally sound?

any more ideas?