what do you think of this idea?

i'm thinking of trying this out when possible for improving punching power

attaching a small shot put ball to a rope which would be suspended from a beam and throwing jabs and crosses with it, a lighter one for the jabs though
(shot puts come in different weights)
this is similar to using a medicine ball but i think better because a shot put is a more appropiate size which fits into the hand easily
the idea of suspending it from a rope is so that you are not bearing kilos of weight on your shoulders thus tensing them up before throwing the punch, which contradicts the focus of being loose and relaxed
personally i don't see how you can get more specific than this

 

no your not supposed to hit it it starts in your hand and you launch it forward the same way as when you throw a punch (like with the medicine ball)

 

good question i was thinking about that myself
i've experimented launching a dumbell (2.5kg) onto the grass and realised there was a bit too much effort coming from the arms and shoulders, and not enough resistance on the torso twist or legs
so maybe a slightly lower weight ball (4 pounds), with a weighted vest would be better, also this could be done standing on a very slight incline for the purpose of improving power in the leg extension
i don't like the idea of holding dumbells for speed/power because you have to hold onto them and decelerate the punches
as for tubing i'm a bit dubious about that idea because a punch is ballistic and constant tension reduces this ballistic action
the initial inertia of the movement is what is important, especially in the legs and torso - the arms/shoulders should not be exerting much tension at all when throwing punches