Toyo 45A: Rear Extension Slipping

[John Rodriguez]

I've got a problem with my 45A where no matter how hard I tighten the extension knobs, the back moves forward way to easily when extended, to the point where I have to pay really close attention when composing and removing the dark cloth to make sure the back doesn't move.

Is this common in older 45As? Is there an easy remedy?

[Gem Singer]

John,

The tightening knobs have probably worn the surface smooth where they contact the extension rails.

Extend the back to its maximum. Lightly rough up the surface of the extension rails with fine sand paper (the kind that's designed for sanding metal).

Making a rougher surface for the locks to grab onto should solve the problem.

[Rod Klukas]

You could also order new knobs and shaft. That way you don't mar the finish on the metal rails.
If you need the part numbers let me know.
Rod