First print at 0.05mm - bore gauge!


Measuring the inside of wind instruments accurately is really tough. Most calipers don’t reach, and most bore gauges don’t cover the necessary range. I had no luck finding anything that would work for sale.

My solution was to print my own! Each rod, and at the smaller sizes, sphere, has a hole for a 3mm by 3mm cylindrical magnet. These were modeled with the very end surface of the magnet at the widest point (the measuring plane), so when marking my depth stick all I have to do is start at 3mm.


The depth stick is a 3mm steel rod, which goes through a hole in a small sheet of plastic to mark flush with the end of the instrument. Then, a series of depths and diameters can be generated to reconstruct the bore profile. Accuracy, especially at the narrowest points, is critical, and so the increments become more numerous the smaller the measurement.

Now I’m all set to accurately and precisely measure any bagpipe, flute, oboe, or recorder I might come across! Thanks to the low hardness of the Color resin, I don’t have to worry about scratching anything.


This is going to really help when I measure my Flemish medieval bagpipe to test out some different materials. SLS nylon has been a great material for bagpipes and other wind instruments, and I’m excited to try out some of the more rigid versions.

The only downside with nylon is that you can’t get a mirror finish except by cutting it. A satin finish is good enough for bagpipes and flutes, but a mirror finish is really preferable for wind instruments, so I’m also looking at other materials such as engineering resins which have a higher polish.


What size hole, how deep and what level of accuracy do you need? There might well be an off-the-shelf that will work for your application.


To within 0.1 of a millimeter between 3 and 5, to 0.2 between 5 and 7, and 0.5 for larger diameters.

Some of these bagpipes can be a few feet long with difficult to access geometry.

Believe me, before making like 50 models, I was willing to spend anywhere below $600 for something that would just do it for me (if I could get it in a reasonable amount of time). There just wasn’t anything out there, and fellow researchers / makers always made their own.




Sounds like DIY is state of the art for bagpipes then and +/- 0.1 mm is not an especially tight tolerance compared to what I was thinking (+/- 0.005 mm). Good luck with it!


0.1mm is the increment, not the tolerance. These are within 0.01 for tolerance; not really necessary to go beyond that because they will never be perfectly positioned.