I'd skim youtube vids for home made knife sharpeners...

I'm sure that advice will make Mr Onion cry...

https://youtu.be/xYA-zVxS6hw?si=YK1Pt0UvpgEnnKE9" rel="nofollow - https://youtu.be/xYA-zVxS6hw?si=YK1Pt0UvpgEnnKE9

I can't offer any direct experience of late either but I've never used a belt sander for a knife except very coarse work finished with a second operation. Prior to swapping to a replaceable insert type knife many years ago, I used a disc sander for rough form just after hardening the steel blade, then followed with a hollow grinder. Prior to that I always finished with a porcelain stick and this would instill an edge you could shave with as it was sharp as a straight razor. 

Good quality hollow grinders will do the same with different wheels once the holding jig is positioned properly. Look for one with a sliding table as they are very accurate, simple to use, and quite fast. Use coolant to protect the heat treatment of the steel blade.

Hugh... are you looking for a SHARPENER, or a BELT GRINDER?

When making, or doing a heavy repair on a knife, one uses a grinder, frequently a belt grinder, to establish the curve of the edge, then set the bevel of the blade, then the sharp angle, and then once those angles are cut, the sharpening is done with a stone or diamond hone.

If you REALLY want an edge, once it's been honed, one finishes it with a strop...

My belt grinder is a Hammond F-2... don't have picture of it handy, but it's like this one:

I don't know...but I think most people don't sharpen OFTEN enough.

When I was a butcher's helper(OK...grunt...) he'd cut,cut,cut,cut,sharpen....repeat as needed. He only needed 30-40 seconds to sharpen every few minutes,usually as I was hauling something on or off the table. Said I took longer to get the meat than for him to resharpen his knives.

It doesn't take long to address a blade, as long as it doesn't have deep nicks.  There's circumstances that having a finely-honed blade ISN'T what one wants.  When meatcutting, the blade will actually be more effective with a fine grinding pattern, as it acts like micro-serration during a pulling or pushing action.  When cutting smoothd leather, a finely-honed edge does better with that polished sharp... but one HAS to remove the burr that forms from a stone.

I'm not a fine woodworker, but I carefully hone my chisels, so that I don't have to make lots of lousy cuts (and I make lousy cuts)...  the oiled stone with an angle jig... but when I'm sharpening carbide teeth on my lathe tools, it's a diamond hone, either on the Di-Acro toolcutter, or the plastic plates that come in a set of three from Horror-Fright.

Dave has great insight as always.

I use many different methods to sharpen things. A file does a lot of it! The one that blows peoples minds is utility knife blades. Three passes on each side and done. Much faster to sharpen than change blades. Of course, they don't last forever, change as needed. Take the last three passes into the cutting edge to remove the burr.

Lawnmower blades are another file project. This is a little more work but blades last a loooong time. Keep a sharp set in the shop ready to go on, sharpen the dull ones on a rain day.

Use Arkansas stones on my kitchen/hunting/fillet knives. A steel in between honing.

Brush hog blades get the 6" grinder, I really hate that thing!

I like to sharpen drill bits on a belt sander but don't currently have one so have to use the bench grinder.

Should mention, a steel is effective because the edge is not really dull, just 'rolled'. All the steel does is beat it back in line.

Yeah, there's LOTS of things that'll sharpen a knife blade.  Here's an odd, but very effective one if you need to touch up your daily pocketknife...

Roll down your car window most of the way.  Leave an inch or two sticking out.  Run your knife blade across it as if it was a narrow stone... MOST windows' edges are radiused and slightly rough due to how the glass shape is manufactured, and that edge will do a pretty good job of restoring a dulled pocketknife... and it's built into the car!  ;-)