Everson Siqueira believes there are serious patent issues with the Brick Layers concept.
I had a long chat with Siqueira, who is a 3D print YouTuber that runs the channel Geek Detour. Siqueira has been investigating the Brick Layers controversy.
Here’s the catch-up: it has been determined — years ago, it turns out — that slightly alternating the z-height of parallel extrusions will greatly increase the strength of a part. Normally extrusions are aligned at the layer level, and this introduces a weak point where breaks often occur. A Brick Layers style extrusion eliminates that weak point.
This is terrific, so let’s all use it? Nope, not possible at the moment due to a number of factors.
Siqueira — and the rest of us — would like to have a “Brick Layers” option in the major open-source 3D print slicers, but no such thing exists yet.
However, it’s getting close. Roman Tenger integrated a script into OrcaSlicer that provides Brick Layers capability.
When I wrote that story, I discovered there were some patent issues surrounding this method. Evidently, it was patented in 1995 by Stratasys (US5653925), and that patent expired in 2015, right on schedule. But then it seems that the method has been re-patented by Addman in 2020 (US11331848) — or at least an application for a European patent, which is still pending.
We learned that Addman, a hardware company, had contracted with Create it REAL, a software company, to develop the method in their slicer for use with Addman hardware.
Clearly, there was some confusion here, and it wasn’t clear what the outcome of the Addman patent would be.
Siqueira explained that he had done deeper investigation into this question: why had the Addman patent been allowed given that the Brick Layers method had been previously patented and then expired — leaving that method literally in public domain status?
Why hadn’t the patent examiners noticed that a method was being re-patented? This is from the original 1995 Stratasys patent:
And this is from Addman’s 2020 patent:
Seems a bit similar, doesn’t it? How could patent examiners have missed this?
In Siqueira’s investigative video, he discovered something almost unbelievable. A mistake seems to have been made.
The Addman patent said that they have looked at prior inventions and adjusted their method to improve performance:
“The prior art has somewhat recognized and addressed the bead configuration issue in order to improve its properties. For example, U.S. Pat . No. 5,659,925 teaches a process for adjusting the deposition rate of the beads to provide a predetermined porosity greater than zero in prototype modeling.”
That references the original 1995 expired Stratasys patent. But wait — they put the wrong patent number in the document!!!
The Addman patent references US5659925, which is a 1996 patent for a “Door closer holding mechanism”. In fact, the Stratasys 1995 patent is US5653925. They put a “9” instead of a “3” in their document.
This no doubt directed patent inspectors to look at the door closing patent rather than the actual Stratasys method, which is essentially the same as that described by Addman. Could this have been why the Addman patent is going forward?
Siqueira discovered several other discrepancies in the Addman patent, suggesting that there could have been errors in submission and evaluation of the patent.
My hope is that this method that was clearly described in 1995 and now expired, becomes truly available for the 3D print community.
I encourage you to watch and support Siqueira’s video, and hopefully this situation will be resolved soon.
Via YouTube
