I have noething better to do than go through old post…
this ones from 2003
http://chiffboard.mati.ca/viewtopic.php?p=138038&highlight=#138038
I’ve not, but thanks for recalling this thread.
I have a lathe arriving next week and intend to make some C drones over the next month or so.
Dimensions for a B chanter are useful to have around (assuming they are good).
Am I mistaken here but is there a way to put these figures into Excel so that it plots you a graph of the bore?
David
Just goes to show what a mine of useful information this forum is. All you have to do is keep digging. 
It also has D plans a little further down… 
I had spotted those but if I ever attempt a D chanter I’d try copying my own first.
The idea being if I swop the reed from my existing chanter I should get an idea of how good my work was.
David
If I knew those plans were good , I would have a custom reamer made… But I can’t drop $500 on a reamer and not be sure…
If they are the dimentions Childress uses for his pipes, you can consider them good. I’ve had the chance to play two sets made by him (one half set and one 3/4 set). They played and sounded very well (in fact they sounded particularly well when their respective owners played them).
mabye B.C. will post a reply, if these plans are still in use and good to use… I’ve no doubt they are 
I believe that Bruce Childress wouldn’t post these plans if they weren’t good… the man is a master pipemaker and has a great reputation to uphold, it is unlikely he would ‘shoot himself in the foot’ as it were.
Managed to get the graphs to plot:
Not sure it’s any more help than the numbers but it looks more interesting.
I’ve changed the inches to mm.
It does makes the short parallel section more obvious at the throat on both chanters.
It also looks like the taper reduces on both chanters about half way along.
Is this what chanter bores tend to do?
David
I saved those measurements, for future attempts at my own pipe-making, but how much use are they without the outer profile measurements? Wouldn’t chimney hieght affect tunning?
Mike
Exactly, and that may be why we see scallops in some chanters and not in others.
BC does give the outer profile measurements:
For both D and B pitch chanters, the outside is a straight taper from the Thumb D hole at .65" to the ghost D hole at .85". There may be variations on the outside diameter, though.
He mentions some variations. What we don’t know is are these deliberate or just results of the making process.
At least we have a reasonable starting point.
Thanks BC
David
Wide-bore (aka concert pitch) chanters tend to go the other way, i.e. the taper usually “concave”. In other words, the rate of taper is steeper near the bell, and less steep in the ‘top hand’. Of course that doesn’t mean that there’s anything wrong with BC’s variant.
Narrow-bore and/or “flat” chanters tend to have a ‘convex’ taper, such as what you see in the plots.
Noticeably missing is the actual throat diameter, that is, the minimum diameter on these chanters. If we take BC literally where he indicates throats of 0.219" for the D and 0.171" for the B chanter, then his throats are unusually large (5.56 mm and 4.34 mm respectively). More usual values would be between 5.2 to 5.4 mm for D and between 3.7 and 4.1 for narrow bore chanters.
The bell diameters look pretty normal to me.
Bill
[edited the’typical’ values I suggested for wide bore CP and narrow bore chanters]
Thanks Bill,
Talking about the D bore.
If the bell diameter is “normal” but the flare is concave as opposed to the more usual convex. That would mean that the bore is wider than usual in the mid section of the chanter. And possibly the upper section too if the throat sizes are correct.
What are the implications of this?
Would holes sizes have to vary from the usual to compensate?
Would it have a more flat chanter timbre?
I’ve heard too wide a throat gives a gurgling Hard D.
David
Err, “concave” is normal for (wide-bore) D chanters.
That would mean that the bore is wider than usual in the mid section of the chanter. And possibly the upper section too if the throat sizes are correct.
What are the implications of this?
Would holes sizes have to vary from the usual to compensate?
Would it have a more flat chanter timbre?
I’ve heard too wide a throat gives a gurgling Hard D.David
This is all pretty general (regarding where the bore would be wider/narrower). I can’t say for certain what the general implications of convex versus concave are, given the same approximate rate of taper and throat size. It’s probably safe to assume that the two might want somewhat different reed/staple geometries.
“Everthing affects everything else” in this business, so by extension there’s probably a set of counter-adjustments for any change that will in theory compensate.
I seriously doubt that changing the profile from ‘concave’ to ‘convex’ would yield a more “flat-chanter-like” timbre; the flat chanter timbre seems to be tied not only to the details of the bore perturbations, but the shallow rate of taper, small bore, and small reed. On the other hand, I haven’t done the experiments to disprove the hypothesis, and “flat-chanter-like tone” is a pretty subjective thing…
A gurgling bottom D is one symptom of an over-wide throat, but it can be caused (and cured!) by other things as well. For instance I’ve seen it cured by increasing the reed volume above the staple.
regards
Bill
Hiya Bill! Extending the two nearest reed seat line co-ordinates ( D.234, Z13.65 & D.219, Z13.51) and intersecting them with the two nearest bore line co-ordinates (D.234, Z12.08 & D.219, Z12.73)…the throat intersection is at D.204, Z13.372. I really hope this is what Bruce had in mind cuz I’ve already turned the dang reamer blank. LOL 
Yes, that sounds a lot more typical, i.e. .204 = 5.18mm, actually about a thousandth narrower than usual. You’ll have to ask Bruce I guess
John Mulhern wrote:
Hiya Bill! Extending the two nearest reed seat line co-ordinates ( D.234, Z13.65 & D.219, Z13.51) and intersecting them with the two nearest bore line co-ordinates (D.234, Z12.08 & D.219, Z12.73)…the throat intersection is at D.204, Z13.372. I really hope this is what Bruce had in mind…
http://bagpipereamers.4t.com/ >Yes, that sounds a lot more typical, i.e. .204 = 5.18mm, actually about a thousandth narrower than usual. You’ll have to ask Bruce I guess
This is correct. There is no cylindrical area anywhere in the bore. What you see on the graphs is simply due to not having any measuring rods that match the throat diameter precisely. As for the variations in the bore, concave vs. convex. That is accidental. My first attempts at reamers was to shoot for a perfect conic section. Subsequent tweeks of the reamer, based on what my ear was telling me, resulted in the variations you see. I cannot explain them. The ear is the final arbiter.
All this is why I cut my reamers out of 1/4 tool steel, and I don’t harden them. Yes, they loose thier edge quicker. Yes, you have to take great care to avoid “chatter”. But, you also have the ability to alter the reamer at will. My reamers look crude-as-hell, but I wouldn’t part with any of them. Complete creative control is worth the previous mentioned problems. If you have someone tool and harden a reamer for you for $500, you are stuck with it, for better or worse.
Is it possible you can give us an example of what you mean.Say you have a particular probelm with a certain note what might you do with the reamer to cure it ?
RORY