An electric prime mover makes a lot of sense, and works well but its important to factor in the losses. The win is the lineshaft rpm is rather low so you can step down with pulleys etc. Opening with a 5-10hp motor is reasonable, particularly if you intend to end up with substantial machines on the lineshaft- if its only ever going to be a drill press and smallish lathe or lineshaft hacksaw etc then maybe less.
Well there's part of the challenge. Factories of any size that relied on lineshafts might have begun with coal-fired steam as prime-mover. The first change may have been to convert the steam boiler to oil-fired. This had a parallel that lasted - for mobility reasons - into my own youth, late 1940's, early 1950's. Perhaps later-yet, elsewhere in America?
Steam driven road-rollers. steam driven "traction" engines that came by at harvest time to flat-belt power the cider mill G'Dad used to turn the output of 5,000 cider-apple trees into something cheaper and easier to get to market at a reasonable return - gallon glass jugs of cider - than the apples themselves.
Cider apples are not all that "pretty" nor necessarily varieties one would want for munching or making pies, after all.
The need there?
A power cord to a roller working a backwoods country lane is impractical. Our little valley didn't HAVE utility-mains electricity even to residences anyway. Diesel, new, still cost more than steam, old, that was not as hard to repair. Even if it needed MORE labour to KEEP in repair, the steam-era skills were still widely available in a town (Weston, Lewis County, West Virginia) that was blessed with the B&O railroad maintenance roundhouse .. where, as with most "subsistence" farmers (or orchardmen), of that era and prior, G'Dad had a "town job" - to wit as the foreman of said steam-railroad roundhouse.
So the small-town lineshaft shops switched to a single, large, electric motor, once a power utility arrived FOR a town. Some had even BEEN the town's source of power for "street lamps", then publc buildings or residences and such off the surplus or evening output of their steam plant.
Either the motor "type" was soft-startable (DC, repulsion-induction) ELSE fed through a big old cone clutch the "operating Engineer" could slip for a soft-start of all the rotating mass of shafts, pulleys, and at least "some" of the belts as well.
If "no one has yet done this" applied, I could see some virtue in your project for educational & historical purposes. But many HAVE DONE it. Some "static", some actually working.
That - and photos, even videos - serves the "societal" need.
Beyond that? It isn't just needless extra work.
It is a LIVING and
ongoing engraved invitation to a potential NIGHTMARE as to safety hazards no longer taken in stride by a general society that had fewer options in their day.
Not to mention an inherently more fatalistic attitude toward risk and responsibility than we have - or Lawsters tolerate, NOWADAYS.
You'd love to show the kids how it used to be? But yah dare NOT even run their klewless "wonder what happens if.. blood and screams follow..) PARENTS though the place whilst shaft is in motion?
There's a "third party" or societal expectation w/r to safety hazards yah just cannot expect to unwind.
Probably should not even TRY to do - if you expect any sort of "comfort" left in you ass-ettes toward enjoying a solvent retirement.
"Chickening out, am I?" Betcherazz, I am! "Owls are fowls" as well.
And yah don't see a lot of them ending their lives early in the local rotisserie chicken display for $4.99 a bird, do yah?
Life get tedious? Suicidal Owl at least gets to make a head-on gun-run at a BMW's grille ...and go out in style rather than as warmed-over leftovers!
A flat belt horizontal can soak up a lot of horsepower so if you're inclined to eventually get something interesting along those lines then starting on the powerful end will be helpful.
The tiny Burke #4 - "born" (or copied..) around 1903 as a plain-bearing flat-belt design .. can use as much as 2HP worth of "input". A "proper" flat-belt drive horizontal 10 HP or so.
But few do. 2 or 3 HP is plenty for most. "Native" electrified used more. And worked faster.
Even the lightweight 5205 lb Avoir USMT "Quartet" wants 5 HP for its horizontal spindle motor, another 3/4 HP for the knee's traverse gearbox, and a third HP or so for the juice pump.
Use of the #9 B&S vertical is sub -2 HP, seperate motor, much the same as an average BirdPort or clone - and still the 3/4 HP knee power motor and the juice pump.
All this "stuff" is nicely electrically interlocked and such. No fine way you would be able to operate all that off line shafting in the same floorspace footprint and remain remotely situationally aware.
You'd have to have separate horizontal and Vertical mills - which I actually recommend, and HIGHLY so.
The combo is a nasty pain in the arse if I actually had serious or frequent work for it. I have
neither, so it suits MY limited-space needs just fine.
Your shop, your life, your time, your money, but....
Kitting it out with vintage. "rescued" line-shaft CONVERSIONS?
Now .. .
that could work.
They were lower-powered, HCS tooled before HSS tooled, worked waaaay slower. They were highly prized and better cared-for by the craftsmen of the era who loved them over the previous choices of blacksmith's hammer, chisel, saw, and file. Subsequent owners were more often infrequent users. Think not so much "factory" as repair, side-needs to fab, garage, farm, or hobby, no longer run a whole shift - not necessarily even once a week.
The tease from the "older guys" when I started under the tutelage of a genuine master, War One Germany vintage?
"Herr Pelz must have flagged you as a fast learner. We only got to use a MACHINE
once a day in our apprenticeships!"
So even when quite old? Those turn of the century to crash of '29 machines tend to have less abusive damage and WEAR than...
.. 1930's onward "modern" machine tools run into the very ground on war work, then run UNDER the ground by cheap-arse marginal firms until they were beat beyond reasonable work-around for way wear.
The actual line shaft, OTOH?
Get you some old photos blown up and sepia-tone printed.
Hang 'em on the wall,,, instead of hanging the REAL lineshaft from the overhead.
In the fullness of time, the Executor of your estate will bless you for that wise compromise.
And probably, later, rather than sooner, what with the "gotchas" all that belting can surprise a body with. Or damage it.
CNC career, enclosed cabinets, modern safety interlocks is damned-poor preparation for "life, back in the day"... an era of machinery that took no prisoners.
Some among us who grew up in the midst of it? Sixth senses. Eyes in the SIDES of yer head as well as the back. Attentive hearing. Skin sensitive to the slight draft off a moving belt you were too close to.
A whole package of that 'awareness' is not put into place overnight. Yah had to sorta "grow it", one scare at a time.