Does anybody know how to record scratches on a beat?

Sort of unrelated with this forum but i'm just curious if anybody here ever puts scratches from a vinyl turntable on top of a beat, what do you guys do to add it on?

A bunch of these guys do. Try asking in Production Techniques if you're looking for help in doing so.

beat machine -> one channel of dj mixer
turntable -> other channel
mixer output -> recorder

or you can just go
turntable -> dj mixer
mixer -> recorder

and play back the song while you record just the scratches.

edit: yea stay out of off topic

Sample a blank space from a record and put it to a track.

Thanks guys, sorry i'm just new to this forum lol, I wasn't sure where or where to not post, think I know now thanks.