First B flat trumpet prototype :

Audio recorded from a French ONPL Trumpetist

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Made with OpenScad :


Prototype made ​​from acoustic studies of a Bessel bell and dimensions from a professional valve trumpet.
First impressions of the sound are very positive. The sound is very centred according to several professional musicians who have tried it.
The highs are a little more difficult with a standard mouth (Bach 1/2C), but that is not the case if a mouthpiece more suitable to the instrument is found.
This is likely due to the design which is more like a big bore, shape offering less resistance than a normal trumpet, and various adjustments made due to defects in the printer setting.
After several trials, it appears that the trumpet is quite playable and does not present any significant wholesale defaults.

Points to change for the next prototype :

  • Correct the printer settings that were missing (already done!)
  • Tuning slide
  • Review leadpipe
  • Reduce thickness
  • study more precisely cut pieces
  • Review the joints between parts

When printing this first prototype I had not yet finished my printer settings, which caused the trumpet to be porous. At the beginning it was unplayable.
To fix it, I had to waterproof the inside with a saturated acetone solution.
This procedure will normally not be necessary, although it allowed me in addition to correct some rough spots.
I will make a page to detail this procedure because it may perhaps serve in some cases.
Each printed piece was few inches long and they had to be welded together using acetone.