Engelbert Schmid, in our opinion, makes the best horns in the world, bar none. They sound great, are marvellously even and in-tune, and are built like jewelry. But even the best horns aren’t perfect.
In years past Schmid horns had a problem with stop arms breaking (usually at the most inopportune time). This was never an issue for most owners but it happened often enough to be a concern. The problem was in the design of the stop arm. The arms broke at the point where the shaft meets the body. The sharp corner provided a natural breaking point and focused all the stress in the stop arm at one point. ( Fig. 1)
Fig. 1
Fig. 2
Schmid corrected this problem by redesigning the arm so the shaft had a fillet at the point where it joins the body of the arm. (Fig. 2) This little bit of extra metal absorbs the stress from the shaft and distributes it over a much wider area. The result is a much stronger and less failure prone part.
Here at Osmun we’re pants and suspenders guys. We figured we could make this part even stronger by replacing the original plated brass screws with 8mm long stainless steel screws. (Fig. 3)
Fig. 3
These screws extend the full length of the stop arm shaft (the screws are shown 1mm extended to alow for the thickness of the string) and replace an empty threaded hole with a solid stainless shaft that is very unlikely to break, ever. We also have 5mm screws available. They’re not the total solution the 8mm screw are but they can be installed without re-tapping the stop arms. Since we instituted this practice we’ve had no broken stop arm problems.
Schmid stop arms and screws are available at in the Parts section at osmun.com.
Posted by Bob Osmun 
