Tone chamber and pin wrapping

[Raibeart]

It's not "poor work"; wood is a natural material and moves with time. I'll confirm what Calum says -- it's very common. The fix as he says to to ream the chamber cylindrical. Doing so removes only a tiny amount of wood, and you add a tiny amount of hemp to compensate. It won't change the sound of the pipes.

[Calum]

Once you machine a piece of wood, it will continue to move for around 100-150 years. Sooner or later, a maker has to release an instrument into the wild and the fact is most of them will move. My instrument, new in 2009, has two tenors that seem to still be dead round, but the bass middle joint has moved a little. It doesn't need reamed yet and doesn't seem to have changed that I can tell in the last 5-6 years, so may never do.

There's no need to reline - the amount to be taken off is measured in thousandths of an inch and will have no effect on sound at all. You'd have to take much more out to line it.

[pancelticpiper]

The midsection has a swelling that causes it to fall when the pin reaches proper tuning height.

On the advice of a pretty savvy pipe mechanic, I wrapped further down the pin...

Ah, I see.

Bagpipes need to function in a different manner than plumbing, and you can't fix an un-true tone chamber through hemping strategies.

What you have going on is what I call the "Coke bottle" tone chamber.

The chamber was reamed true when the pipes were made, but over time the chamber has expanded where not bound by the ferrule.

So like a Coke bottle the chamber is wide inside but tapers to a narrower "neck" under the ferrule.

I've had pipes where this exists on the bass and tenors top sections, but due to me tuning those three high on the pins it doesn't matter.

Where it does come into play is on the lower bass chamber, which on my pipes tunes rather low.

I need to have the lower bass chamber have strictly parallel sides so that it can tune anywhere and stay at the same tightness on the bottom pin hemp.

The mystery is how 100 year old pipes can have perfectly parallel tone chambers and new pipes can have Coke bottle ones. Seems that new pipes can develop this issue rather quickly.

I used to send my pipes off to a maker, but he told me

"You know, I don't put the joint on the lathe to do that, I just do it by hand. It's easy, why don't you buy a reamer and do it yourself?"

So I did, and I've corrected the chambers on my various pipes myself ever since.

Removing an amazingly small amount of wood transforms a nearly useless joint into smooth perfection.

Here's the type of tool, they're not expensive: Adjustable Hand Reamers - Grainger Industrial Supply

The trick is to go very slowly, making tiny adjustments in the reamer as you progress. Be gentle, don't try to force things. You develop a feel for the wood of the specific joint you're working on, where the wood is softer and where the harder areas are.

No it doesn't harm or change how the pipes sound one bit, because you're removing wood from the area that's not involved in the sound, being past where the hemp seals.

Another issue tone chambers sometimes have is being out-of-round. These tend to leak no matter how you try to hemp them, because the hemp is round and the chamber is oval.

The same hand reamer fixes that problem too, however in this case you are slightly increasing the ID of the tone chamber. I've not been able to detect any difference in sound or stability when I've corrected out-of-round tone chambers on my pipes.

[Lochie]

Awesome advice panceltic!
The tool would be cheaper than shipping off the drone section to a maker.
Is there a specific one you prefer?
The link brought me to a page with several reamers, and I'm a bit challenged when it comes to tool specs...

[pancelticpiper]

I'm a bit challenged when it comes to tool specs...

Nearly all the tone chambers I've done have used one of these two sizes (all sizes in inches)

19/32 min to 21/32 max (bores from .59 to .656)

21/32 min to 23/32 max (bores .656 to .718)

A couple sets have needed the next bigger size

23/32 min to 25/32 max (bores over .718 which aren't common)

Now that's just for tone chambers of ordinary fullisize Great Highland pipes; stocks need much bigger reamers, and smallpipes need much smaller reamers.

[Rick Pratt]

Lots of info here...thanks.


I am a retired woodworker (boat builder) and this solution appeals to me.

But i think i need to have the ID read before ordering.


Rick

[Raibeart]

Digital calipers can be had for <$10

[Wulls]

De gustibus non est disputandum as they say, What is the "best sound" is a matter of opinion. What can be measured and graphed is the presence of higher harmonics.

With the vintage and new pipes I've owned (YMMV) having the bass top high on the pin and the bass bottom around halfway down the pin creates a tone with more higher harmonics present, a tone which has been described as ringing, bright, nasal, buzzy, and so forth.

Having the bass top around 1/3 to 1/2 down the pin and the bass bottom higher on its pin creates a tone with less higher harmonics present, a tone which has been described as dull, dark, round, tubby, etc. These tonal changes can be quickly demonstrated on most bass drones just by moving the positions of the various joints.





Here all four pins are more or less matching.

This is very true.......
As an experiment lift your bass top a few mm above the hemp, tune them with the bass bottom as normal and play them a while.
Then pull the bass top down to two fingers above the mount and retune on the bottom.
If you can't hear the difference take the entire set of pipes apart, wrap them in bubble wrap, and put them on Ebay......

[Jim Fogelman]

Check out Ringo’s article on hemping pipes. I’ve done mine like this for about 8 years now and have been very happy with how my drones sound and behave.

https://www.thebagpipeplace.com/consulting/cm-6-moisture-control/supercharge-your-bagpipe-drones/

[LloydB]

Nearly all the tone chambers I've done have used one of these two sizes (all sizes in inches)

19/32 min to 21/32 max (bores from .59 to .656)
B]21/32 min to 23/32 max[/B] (bores .656 to .718)

A couple sets have needed the next bigger size
B]23/32 min to 25/32 max[/B] (bores over .718 which aren't common)

Now that's just for tone chambers of ordinary full size Great Highland pipes;
stocks need much bigger reamers, and smallpipes need much smaller reamers.

My 'collection', of adjustable reamers, totals 5 or 6 different sizes... for GHB
and smaller pipes. Decent used reamers show up on eBay from time to time.
Here's an earlier thread:

https://forums.bobdunsire.com/forum/great-highland-bagpipe/technique-instrument/107908-