Sorry to say but it doesn't seem to be worth it.
Motors -- too small, too low power
Simple gantry design ... just buy a 3d printer and dodge a cheap pnp head on it.
OpenPNP ... not even developed by Opulo...
EMC ... don't even dream about that.
eg.
https://www.m3.tuc.gr/EQUIPMENT/DMU50eco/Sinumerik%20810d/Planning%20Guide%20Edition.pdfAnd all those printed parts DIY ... I mean you can print them straight away right now.
Extruded Aluminum is cheap and you can get it everywhere.
There's not even a drag-chain just some dodgy hanging part.
1700$ ok the guy is an enthusiast who should be supported but that's too much.
If I would like to go that way I'd rather buy a chinese machine maybe used, and update their controller to support openpnp if the chinese
software is not sufficient.
A PNP is not difficult to design and build --- it's all about the feeders.
Want 50 feeders? ... setup-time per feeder 3-5 minutes ... 2:30 - ~4:00 setup time for the feeders.
It's quite some work to design reliable feeders.
How about humidity can the machine stand different humidity levels?
- You also need to organize the smd components
- You will have to organize your PCB projects (and revisions)
- possibly stock monitoring / component counter
- you will need a stencil printer
- you will need a reflow oven
certainly it can all be done cheaply but if you want to do it efficiently it will be more expensive.