The Dynohub keeper is a rare tool but there is a way to manage without one.
The Sturmey Archer dynohub keeper is a difficult thing to find these days. Sturmey Archer haven’t made them for a long time now. Those that do exist are usually tucked away safely in a dealer’s or enthusuast’s workshop.
Separating the armature from the magnet is not very often necessary. On the occasion that it would be useful to separate them what do you do when the keeper is not available?
We could go to an engineering workshop and have one made, but this would probably be too expensive if all we have is one job to complete.
The answer is simple. We use an old spare armature as a keeper. Even a damaged one will work. Simply push the existing armature out using and replacing it with the old armature that you are using as the keeper.