Would this work, providing your solenoid housing is non- Ferris?
I can imagine it providing more pull-in strength, or push, whatever.
(might not have the same holding power)

 

hi Hamlet,
That type of solenoid is readily available, some versions are latching plungers that require a winding current reversal to release.
E
https://www.google.com/search?q=sol...17sraAhXBK8AKHbD-AlUQsAQIpgE&biw=1417&bih=890

 

The magnet on the latching type solenoids is just for retaining, you want the plunger to be soft iron etc, non-magnetised.
Max.

 

I see there's another thread on this subject, don't know how I missed it:

https://forum.allaboutcircuits.com/...rod-magnet-instead-of-an-iron-plunger.147776/

Not sure it applies to my application, which is more like a reciprocating linear motor than solenoid or relay.

I have no idea how to define my terms any dearer than thus: solenoid has soft iron core, my reciprocating
linear motor has a permanent magnet core/plunger/mover.

 

Not sure it applies to my application, which is more like a reciprocating linear motor than solenoid or relay.

If it's what I think it is they use a nonmagnetic material in the middle of two iron/steel end pieces. That's how the ones I've seen plans for are done. Here are some done another way - http://physics.kenyon.edu/EarlyAppa...ure_Engine/Reciprocating_Armature_Engine.html