Amati-Kraslice A51 natural trumpet/bugle mouthpiece 3D rendering

Model of an Amati-Kraslice A51 tenor trombone-shank natural trumpet/bugle mouthpiece, intended to be very close to the original design.

The cup profile is somewhat like the Vincent Bach 1-1/4C, 1 [no letter], or Schilke 20 mouthpieces, with nearly a tenor trombone shank instead of the trumpet shank seen on these other models.

This is in the A19 signal horn/natural trumpet mouthpiece series, standard issue for the ABG-291. Amati-Kraslice states the A19 series pieces are for "bugles and fanfare trumpets", and can be used on other F/E-flat/alto-voice natural trumpets with this shank size. The general design has been in production since the 1950s or 1960s.
The catalog claims the shank opening outer diameter is 10.2 mm, but Vennture measured it at 10.348 mm / 0.4074".
Supposedly this is the small-shank version of the A60, which has a larger shank with outer opening diameter of 10.7 mm.

It also is a decent match with the Amati-Kraslice ABG-221 cavalry-style bugle, pitched in F. This bugle is coincidentally the inspiration model for the "Ceremonial Bugle".

The Amati ABG-221 does not have perfect intonation, but the A51 slots relatively solidly for "Taps", though the tone could stand to be mellower. For a trumpet player, the A51 makes it relatively easy to clearly articulate fast bugle calls on the ABG-221, giving an almost "heroic", orchestral French horn tone to some calls.

Note that the ABG-221 receiver opening has a diameter measuring 12.07~12.11mm / 0.476~0.477" (shank fit & caliper measurements in photos). The Materialise prints ordered are shown fitted with the ABG-221 for reference.

The cup and shank combination might also be useful as a transition piece for doubling on trombone, especially if the shank is modified. Al Cass, Chasons, Lausmann, and others have made these sorts of mouthpieces to assist brass musicians crossing over to/from trumpet and trombone. In this way, the A51 could perhaps help trumpet, mellophone, French horn, or alto/tenor horn players to double on trombone or small-shank euphonium. For the design as-is, note that the shank might bottom out depending on the receiver design; fit is not guaranteed, and your mileage may vary.

If you haven't encountered the "Ceremonial Bugle" before, it is a bugle-shaped metal device, with an electronic speaker insert used to simulate bugle calls, mainly "Taps" at military funerals. When the speaker insert is removed, they can be played normally, but they come with a shallow-cup, ill-fitting mouthpiece. This setup usually does not sound good.

For appearance's sake, small-shank tenor trombone mouthpieces can be used as a visual replacement, but this A51 design should be proportionally more appropriate. While the "Ceremonial Bugle" is not assembled to the level of quality expected from Conn, King, or Amati-Kraslice, this Amati A51 should be at least on-par with the Ceremonial Bugle's included mouthpiece.

Warning: any "Ceremonial Bugle" played live (without the speaker insert) should have its joints and tuning slide checked for leaks, as it is not expected to be constructed with the standards of a normal brass instrument. I write this from experience with these objects, especially compared to the rather nice natural trumpets, signal horns, and bugles produced by Amati-Kraslice in Czechia.

Note that the shank opening outer diameter of 0.4074" / 10.348 mm is smaller than the 0.4220" VennCAD default standard for small-shank, tenor trombone mouthpieces.

No dimensions have been adjusted or modified for printing or cutting. This model is intended for experimentation.

Printed in August 2024 by Materialise NV of Belgium, using their Gray Resin. From the specification page, it has accuracy of ±0.2% (with a lower limit of ±0.2mm) and 0.3mm clearance.

No sanding or post-processing upon delivery.

For print verification, the STL has overall length 87.26 mm / 3.436", and [greatest] outer diameter of 27.90 mm / 1.099".
Note that the shank opening is somewhat thin and fragile with resin prints.

As before, note that the shank opening outer diameter of 0.4074" / 10.348 mm is smaller than the 0.4220" VennCAD default standard for small-shank, tenor trombone mouthpieces. The Amati-Kraslice ABG-221 receiver opening has a diameter measuring 12.07~12.11mm / 0.476~0.477" (caliper measurements in photos).