Drone Bore Explanation and How to...

[B McCarthy]

Over the years I've perused countless threads about drone bore sizes and measurements.

My question, which most likely has been addressed somewhere, involves the actual measurement techniques and locations for these measurements.

I was wondering if a description including drawing or photos is available where the less inclined (specifically me) can start.

My reasson for asking is that if so many here are discussing and measuring bore sizes, etc is everyone doing it in a standardized manner?

Just thought I'd ask since I've been pondering this for some time.

Brian

[Iain Sherwood]

Getting longjoint and bass-mid bores is easy enough using a vernier caliper; it's the drone top bores that can be difficult. With today's standard sized metal fittings you'd need to run cylinders of varying size up the drone top from the bottom until you got the right fit, then measure the correct one with the caliper.

Some older pipes have large bushings, others smaller; some have bushings the same size as the bores, so it can be easy or difficult, depending on the age and maker.

[bob864]

A bore gauge is a nifty tool.

[Iain Sherwood]

Yes, but you really need a telescoping bore gauge and it's hard to find one small enough.

[jsragman77]

You can get into the top bores by bending a long paper clip into a modified shepherd's crook. You have to widen the middle portions of each side of the crook so the sharp end won't scrape the bore.

Mark

[Bill Urquhart]

I came up with a good alternative for measuring the top bores. Roll a piece of computer paper around a pencil, being careful to roll evenly and not crinkle. Let the pencil slide out, and holding the roll so it doens't unravel, insert it all the way into the drone top. Let go. It unravels exactly to the inside diameter of the pipe. Adjust the paper to make sure it unravelled evenly by sliding it back and forth a bit inside the drone. Then just measure the ends of the paper tube that stick out past the bush or tuning chamber. Just in case you have a drone where the bush is smaller than the top bore, just measure the end sticking out of the tuning chamber.

[countrypiper]

I came up with a good alternative for measuring the top bores. Roll a piece of computer paper around a pencil, being careful to roll evenly and not crinkle. Let the pencil slide out, and holding the roll so it doens't unravel, insert it all the way into the drone top. Let go. It unravels exactly to the inside diameter of the pipe. Adjust the paper to make sure it unravelled evenly by sliding it back and forth a bit inside the drone. Then just measure the ends of the paper tube that stick out past the bush or tuning chamber. Just in case you have a drone where the bush is smaller than the top bore, just measure the end sticking out of the tuning chamber.

Or mark it with a pencil and use the unravelled length as the circumference - and then calculate the diameter using Circ/Pi=Diam where Pi is about 3.14 - this is useful if you have a ruler and a calculator - rather than a micrometer.

[Troy Jesse]

So now with this cheap and relatively easy method, everyone get to measuring!!!!

[David Corbett]

not being a real scientific type, much less acoustics expert, wonder if total "volume" (capacity not db) of the drone -vs- length / bore would be an accurate measurement, certainly easier to measure. tape up one end of the drone or drone section. fill with water, and then measure the water.

Just a curious thought that came to mind.

[countrypiper]

not being a real scientific type, much less acoustics expert, wonder if total "volume" (capacity not db) of the drone -vs- length / bore would be an accurate measurement, certainly easier to measure. tape up one end of the drone or drone section. fill with water, and then measure the water.

Just a curious thought that came to mind.

With Delrin pipes - this might be OK - but I'm not too sure that giving ABW pipes good soaking is such a good idea.