The Talking Machine Forum — For All Antique Phonographs & Recordings

[quote="Andersun"]

I believe you will have troubles with any mandrel option other than an original Class M mandrel ( as George Paul described ...... brass, lipped mandrel like the one currently on eBay) unless you swap the Class M endgate with a Triumph Model A endgate.

Update:
I was able to fit a Home Model A mandrel on my Class M with the Class M endgate and the thread pitch seems the same. As you can see my belt is loose because of the Home mandrel's smaller pulley. This mandrel can be adjusted to align the belt properly if you put the Home pulley on backwards. A Triumph pulley will also fit on the Home mandrel. The speed will have to be adjusted for the smaller pulley if that's what you decide to use.

Before blaming the mandrel or pulley, Is the tension screw, all the way to the left or right, you also might want to reverse the smooth and rough side of the belt, I had trouble with belt material from Antique Phonograph Supply company staying on the pulley (of any phonograph, home, Triumph ect. And used the Ron Sitko kind, and problem solved. New Sitko belting seems to be wavy and stiff at first, but after running awhile behaves very nicely, I could never get the "precision" belting to work, so went back to Sitko belting. (It seems to belting you have is the "precision" belting.