Just caught this, and off to Ottawa in the morning.
I don't know what all this talk of bearing wear is about. The longest running rig I've been able to inspect is going on 4.5 years old now and I don't see any sign of thrust bearing wear beyond the break-in dimple that forms during the first 30 hours of operation.
We never left Delrin for the thrust surface. In our experiments, we got a slightly more incisive sound with metal thrust plates (as if we needed it), but our trials with stainless and brass gave us the "willies" in terms of the possibility of risk of galling. Once we observed this with one sample, we were unwilling to take the long term risk when the Delrin served us so well.
Also, keep in mind that the thrust plate is replaceable as well as having two sides available for use. It can be flipped over.
In response to Doug's question, apart from minor geometry changes (wider top support flange and expanded central oil reservoir), it's essentially the same bearing that Chris, I, and the other three constituents of the "Teres-5" collectively designed in January of 2000. I assume that Chris is still implementing a replaceable thrust plate too.
Those of you coming to the Front Range on the 13th and 14th would have had the opportunity to hear a Schröder clad Platine-Verdier, but I just learned that it's owner put it up for sale.
Cheers,
Thom @ Galibier
