Darling Square has "The Exchange"[1] which has Solder stations, 3D printers and a laser cutter but I'm unsure how to book time with them. Might be worth giving the library a call.

[1]: https://www.cityofsydney.nsw.gov.au/talks-courses-workshops/...

eg: https://www.cityofsydney.nsw.gov.au/library-information-serv...