TromboneChat

I was researching extra things to put on my hagmann valve (valve caps, tone rings, etc). When I found out there is a new redesign of the hagmann valve that took place in November 2016.

What exactly changed in the redesign? Are some problems fixed/created as a result? Does it play any differently? What are your general thoughts on this redesign?

Pictures can be found in this link

http://www.rathtrombones.com/accessories/heavy-valve-cap/

Thanks and enjoy your day.

~Jack

Interesting. Looks like maybe they changed the design to have less surface area on the outside edge, which can make less friction? You'd really need to talk to someone whose taken both apart. Maybe ask Rath directly?

Hagmann valve has a spring which pulls the rotor towards the inside spindle. I don't understand what that undercut accomplishes,  as there is no pressure on that outside edge. That cap is only a loose pressure fit; basically just a dust cover. It does not function as a bearing surface.

It looks like Hamgann (this was Hagmann, not Rath that made the change) have reduced the sidewall height of the rotor, which may or may not improve the action. It does reduce surface area on the outside face of the rotor. Brad is correct about the cover, it is not a bearing, simply a cover to keep dirt ot and oil in.

M

It looks like Hamgann (this was Hagmann, not Rath that made the change) have reduced the sidewall height of the rotor, which may or may not improve the action. It does reduce surface area on the outside face of the rotor. Brad is correct about the cover, it is not a bearing, simply a cover to keep dirt ot and oil in.

M