Grinding wheel balancing fixture - video

Grinding wheel balancing fixture. By Mr. Modify. 4:03 video:

https://www.youtube.com/watch?v=eCDeCCrCqTE

If anyone wants to make one of these may I suggest large wood-chipper blades which can be had for a reasonable price. Wood planer blades work as well.
The knife edges are very accurately ground.
Fine resolution bubble levels can also be obtained from manufacturers such as L.S. Starrett if you would like to add some refinement.

Both posts have good details, using otherwise too large parallels is clever, not to mention already heat treated and ground.
I too, prefer a bit more responsive bubble level. That would allow 3 leveling 'feet', while just two are operated to correct the adjustments [figuratively pitch & yaw].
But any leveler I've used [or seen] had an arbor shaped axle, not loose per the video. It's clearly sufficient, demonstrating lots of settling time. I believe any decent size drill blank or reamer shank offers all the straightness and little rolling resistance to be a logical choice.
Planer blades! How come I don't know any woodworkers?

[edit 21 Aug]
The arbor question kept recurring. All I can figure is those were larger wheels; a bushing could be right size but imperfect perpendicularity to wheel edge. That 'nodding' would be tough to balance out of plane, let alone wheel itself.
Still interested regarding the plain shaft, certain that largest slip fit diameter is satisfactory.

Bullseye level offered by mwmkravchenko is quite nice at 1° range in .002 increments.

https://www.aliexpress.com/item/4000...72be2e0ee4p0OQ

No connection. Just a reasonable price for a accurate bubble level. I use a cash credit card for any payment. As in a credit card that you put the cash onto. Done that after someone helped themselves to three grand of mine once. Never had a hiccup with anything from Aliexpress after doing some checking and digging before I purchase.