Some tape are run from pancakes on the sprinters but half were recorded real time from a master to banks of ten specialised recorders (again units you've never seen before, nothing like consumer units). You'd be surprised how many commercial vhs tapes on the shelves at the time were duplicated from a VHS master not a one inch etc.
This machine won't chew the tape and the commercial machines I used to use at a video duplication center (authorised) would have serial control to run through other units like oscilloscopes to monitor signal noise quality off the tape and any drop below set level would automatically pause the machine so tensioners could be adjusted and the issue investigated. First you need a playback machine that is well maintained, no perishing rubber guides and belts inside and regularly serviced inside to remove oxides etc. They use the types of machine you 've never seen, if they use consumer vhs machines just walk away.
Its far more than pressing play and record on two machines. But if you want to do it right pay for the service.
If you want a crappy conversion, do it yourself. My server!! easy enough to spin up a windows 7 VM, pass the usb box through to it and let her rip The alert for me was hearing the tape hit the end, and start rewinding to do the next one, and the great thing was, it didn't tie up my main computer, I used a spare machine that had plenty of grunt.
Thanks to a weekend in there, I was able to get a pile of them done, and by tuesday I was ready to hand back the VCR and loan the portable SSD to him to copy off the footage. I got through the tapes in about a week, but I'd start one in the morning, then when I got home do another 2 or 3 (if I was staying up late) before bed. The software waited for the end of tape by looking for a completely black screen - if it saw 5 minutes of this, it would chop that off the video, and then stop recording and close the file. I forget the software's name but it was truly set and forget. I took his VCR (nice 6 head stereo one) back to my place along with 21 tapes, and set up the PC to do them. Sorry this is an old thread but its an interesting thread - I did a similar thing for a friend (his computer was too weak, and I had a TBC and capture box from my days of doing it in the 00's).