Making Tubular Chimes
(I don't have any plans to update this but it seems to be a popular page so I'll leave it up as a reference - 12/31/11)
This page is a chronicle of my quest to make a set of tubular chimes. If you don't know chimes are an incredibly expensive percussion instrument costing around $5,000 for a set. Me being a cheap SOB decided to make my own.
1. Research and Tube Length
The first step was to determine the material I wanted to use. The easiest to obtain was Cast Iron pipe like the kind they make pipe clamps out of.
It only costs $18 per 10 feet at Home Depot so it isn't that expensive. Anyways now that I have a material I need a formula to calculate the length based on the frequency.
After a lot of research I came up with 2 frequencies.
F=1.133 π K V / L2
V= Speed of sound in the material
K= Radius of Gyration in a hollow Cylinder (more on this later)
K=SQRT( Ri2 + Ro2 ) /2
Ri, Ro = the inner and outer radii of the cylinder respectively
and the other formula
F1/F2 = (L2/L1)2
F1= First Frequency
F2= Second Frequency
L1= First Length
L2= Second Length
Anyways after a whole bunch of math I rewrote the first and the second one in terms of Length.
L = SQRT(1.133 π KV/F)
L2 = ( (L1)(SQRT(F1))(SQRT(F2)) )/F2
Also during this time I bought a 3 foot piece of pipe and tuned it to A5 (880Hz). Using measurements I made during this processes I was able to obtain reference #'s to verify all of this.
Then I input all of this into an Excel Worksheet. Don't worry if this appears to be a bunch of gibberish I will explain it at some point.
|3.91895775||k1||3.89540235||AVG K||3.918957753||Ref. Note||881.7808774||Total Feet||95.74405681|
|491000||k2||3.89429623||Ref. Length||87.868125||Total Cost||172.3393023|
|Note||Freq.||K||Act. Length||Length1||Length 2||AVG.||Nodal Pt. 1||Diff||Feet||Cost|
The important part to note is the lengths that I obtained with the 2 formulas. With this info I just need to buy the pipe, sandblast the coating off it, and cut it to the rough length. Then with the help of an electronic tuner I have to just fine tune them. Unfortunately the estimated cost to produce one set of chimes appears to be around $600. So this will all have to wait till I have more cash. Right now I'm thinking that I will sell them for around $1,000 - $1,500. If you're interested let me know.
**I'll probably never get around to this but there's some good info so I'll leave it (2010)
To the authors of these 2 pages: Your sites made this project possible