I live in Hanoi, Vietnam. I just came across the Openflexture project and i want to make one myself but not much parts are here, including the “super-rare” lenses like the acromatic and the condenser ones which are impossible to find and I have no access to aliexpress so please help me.
There is some discussion of the condenser lens and alternatives in other threads, including Suitable condenser lens "beam angle".
The f=50mm achromatic lens is usually a bit easier to find, although it can be relatively expensive. It is more of a standard part for scientific experiments, so you would be looking for scientific optics suppliers.
If you build the ‘low-cost’ optics module it does not need the achromatic tube lens, which means there are fewer parts to find. The field if view and resolutikn are similar to a 20× lens on a conventional microscope. This can be a really good place to start. To move over to the high-resolution optics later you just need to print the optics module and assemble it with the tube lens and objective. Everything else can be re-used, including the camera.
I was able to find some good condenser lenses but acromatic lenses seems to be very tricky due to the fact that most lab equipments are not easily found even in the capital, Hanoi and the most modern city, HCM city.
Cool! If you have access to a resin printer, including transparent resin, it might be nice to try to print one! Ralf Bauer has some papers on this; look at the paper below.