PrintBone practice mute for Trumpet, (Bass) Trombone and Flugelhorn - customizable!

The PrintBone practice mute: A practice mute for your trombone, bass trombone, flugelhorn or trumpet that is compact, plays with little resistance, is light and sounds well. The partials are in tune and it is quite silent.

I let a few people test it, their comments:

'This one plays well in all registers. The one I actually bought in a store does not.'
'This feels more like playing without a mute than my own practice mute'
'This is actually in tune! I like the compact sound it produces'

In fact, a local teacher recommends these to his students and uses the version for trumpet himself.

There's a review in German of the trumpet version, in which it is favorably compared with three commercially available mutes - including measurements of how much it attenuates the sound Four versions are available:

• The small bore variant fits just about any trombone, at least from 7.5 inch bells up to 9.5-10 inch bass trombones. It doesn't raise the pitch much, if at all, on smaller belled trombones, and raises the pitch about half a tone on bass trombones
• the large bore variant fits large belled horns like the Bach 42, Conn 8H and the PrintBone without raising the pitch too much. It also fits flugel horns. It's a bit more compact model and sounds a bit bigger (not louder) than the small bore variant.
• The bass trombone version fits bass trombones and mutes it considerably while preserving a nice bass trombone sound. It is a bit louder than the other two options, but it should be enough for most situations. Fits a Conn 112H and a Jupiter JSL-740R very well, a Bach 50B good enough. Not yet tested in other trombones
• The trumpet version is for trumpets All three variants sound well and play in tune in all registers.

You can open this in the customizer to change almost any dimension and the bell flares, meaning you can design this to be any practice mute for any brass instrument you want.

It prints airtight enough without supports in PLA on my Prusa I3 MK2 in 2-6 hours, depending on the quality you want. Tested to work in ABS, PLA, NGEN and PETG. NGEN and PETG seem to sound best.

Print Settings

Printer:

Original Prusa i3 MK2

Resolution: 

0.1-0.3mm

Infill:

20%

Notes: 

Pick any layer height you like. Supports not needed. Either set number of perimeters high enough to not require infill, or set infill to 20-35% - infill will only be used in a very small volume of the mute.. Set line width to 0.45 and check 'detect thin edges' in slic3r. it should print with three full wall lines all around with a 0.4 nozzle, or two lines with a 0.6 nozzle.

Post-Printing

Glue a strip of cork, foam or rubber to the mute so it stays in the bell. The cork should form a relatively airtight seal, so all the air passes through the mute and not between the mute and the bell.

To make a template for the cork, you can use  a piece of paper, wrap it around the mute, cut to the right shape. Or, a suggestion from a maker: use masking tape, adhere to the mute,  cut it to the right shape, peel it off and make a template out of it for the cork, foam or rubber.

A printable template (with a regular printer or a 3d-printer) would be even nicer. Go ahead and modify the openSCAD files if you want to let it generate one :)