South Bend 9a (undermount) Belt walks off under load

[Dave Paine]

These are some pictures from my SB Heavy 10.

The gearbox was removed in this picture. The mounting foot also has slots. This was taken before I cut the old and worn out belt and removed the headstock.



Underneath the headstock. The slot is much larger than you may think.



The headstock replaced and a new flat belt glued. The joint is shown in this picture. This is the same belt from Al Bino which Basement Shop Guy shows in his video.

 

[NortonDommi]

I stand corrected. I've never seen one of the lathes in question, In my defense it was nearly midnight and I'd been up since 3:30!
Looks like a joined belt is a must then unless you are Penn or Teller.
To return to the problem, I have gone back and re-read dansawyer's original post.

If when running in forward and back gears engaged I firmly, but not straining, put a load on the spindle the belt walks off the counter shaft toward the tail stock. When in reverse the belt runs off the spindle pulley toward the left, away from the tail stock.

dansawyer If I am interpreting this correctly is the belt running around the spindle AND the countershaft?