All 3D models can be purchased from this link: cults3d.com/en/3d-model/tool/...
This masonry grooving cutter from Lidl is a pretty good tool for its price. I would definitely recommend replacing the cutting wheels with better quality ones. It will be less fiddly when cutting into concrete.
There is one design flaw though, in my opinion. The grinding dust has an obstruction in its path, which is the mounting post. The cross-section of the pipe just behind the cutting wheels is reduced by this, and there is worse dust extraction, even if you use a powerful vacuum cleaner.
I modified this slotted cutter, drilled out the collet on both halves of the housing, and designed a connecting mounting and sealing sleeve that just needs to be tightened down with pull-tape.
For the mounting hole in the cutter blade housing, I designed a friction cap. The suction is more efficient and concentrated on the bottom surface where the cutting occurs.