I made my own "screwshield" (see picture).
Now I want to connect a couple of motors (230 V, 12 V)......
I did a test with a lamp (see other picture) with a simple optocoupler and a triac (circuit: yep, see the picture).
That works, but wil it work with a motor, without damaging the motor(s) and/or other electronics (it will run for a longer time; not just a few seconds/minutes).
What kind of motor? Synchronous motors are very inductive and might cause problems but 'universal' motors (the noisy ones) can usually be controlled with a triac if there is a suitable snubber circuit. Someone else will have more experience with this.
It is a "normal" motor (or as you say, "a noisy one").
What is a "snubber circuit" ?