Here are good starting sizes for U-Pipe drone reeds made of cane:
Key of D
Key of C
|Tenor ||3/16" diameter ||2" length|
|Baritone ||7/32" diameter ||3" length|
|Bass ||9/32" diameter ||4" length|
|Tenor ||3/16" diameter ||2 1/4" length|
|Baritone||7/32" diameter ||3 1/4" length|
|Bass ||9/32" diameter ||4 1/4" length|
Here are the sizes of reed seats for drones I make in D and C:
Tenor drone reed seat: 15/64" diameter, 1/4" depth
(tenor drone reed seat: 3/16" diameter, 3/16" depth before 2011)
Baritone drone reed seat: 1/4" diameter, 1/4" depth
Bass drone reed seat: 9/32" diameter, 9/32" depth
Making Cane Reeds
Select a piece of cane which is near the diameter you need. Cut it to length. Use the existing drone reed as a guide. Reed length and diameter can be quite variable - the drone slider will compensate for many differences. For good starting points for drone reed sizes, see the specifications list, above.
Ensure that one end of the cane tube is airtight. Test this by sucking on the open end. If one end is blocked by a node, cover it with a layer of beeswax to seal it for good.
Tie on the bridle. Wrap two turns of beeswaxed Nyltex or other strng cord around the tube, near the closed end of the reed. This is the bridle. Tie tightly and securely. Push this thread down the reed to about 3/8" from the open end. Most cane tubes have slightly smaller diameter near the node. Pushing the bridle from the node end to the open end makes it tighter, a good thing.
Use a sharp razor blade and cut into the reed about 1/4" from the closed end. Cut at about a 70 degree angle from the axis of the reed. Cut no more than one third way through the tube.
With the blade in the cut, rock it back and side to side to start a split down the tube. Lift the tongue up with your fingers or with a knife inserted in the split. Do not cut the cane to produce the tongue. Do it by splitting only. Split it down to the bridle.
Most of the time there is a piece of fluff in the bore of the tube. If so, blow it out or fish it out with a knife or paperclip.
The drone reed seats are cylindrical. I use windings of Teflon tape (plumber's tape) around the open end of the reed to enlarge the cane to the diameter of the reed seat. I use enough to make a tight fit. The reed should not wobble in its seat. If the reed is removed more than once it will probably loosen the seal to the extent that more Teflon tape should be applied. If the reed is larger than the seat, trim the bark off at the open end.
Most pipe makers use a tapered or conical reed seat. I ascribe to the theory that a tapered fit is merely waiting to loosen up. If you have tapered reed seats, wrap waxed thread around the end of the reed as necessary for a tight fit.
Adjusting Cane Reeds
Note: If a drone reed which once worked well has now gone bad, it is very likely that it will take but a minor adjustment to restore it. Big changes will likely overshoot the mark, making it even more out of whack.
The goal is an absolutely stable and pleasant-sounding note at the bag pressures you use. Most reeds which reach this goal will sound a double tone when started. With low pressure the reed plays one tone, then as more pressure is applied the reed pops into another more stable tone at the pitch and volume you desire.
If the reed claps shut under pressure, try springing the tongue open. Lift the free end of the tongue a distance about equal to 1 or 2 times the diameter of the reed cane & let it snap back. Do this a couple times, then give the reed a try. If this is not helpful move the bridle back towards the open end of the reed, making the tongue longer. Another option is to put a hair under the tongue. Hair from your head is fine for this. Lift up the tongue and pull the hair by the two ends back towards the bridle.
If the tongue is too open it will not close and vibrate or it will take too much pressure to vibrate. Roll the cane between your palms to press the tongue back towards the tube. Another option is to move the bridle towards the closed end of the reed, shortening and closing the tongue. If the reed plays too hard you can also scrape the tongue with a knife, making it thinner and weaker.
If the reed is unstable a lump of beeswax stuck to the tongue near the free end will sometimes help. Start with a bit about the size of a grain of rice. Add more if it seems helpful. Weighting the tongue in this way will also flatten the note. It will possibly make the reed stronger and keep it from clapping shut.
The slightest change in the position of the bridle makes a big difference in the way the reed plays. That is why the bridle should be a tight fit. It it becomes the least loose, replace it. The reed should fit snugly in the reed seat without wobbling.
The best test for a drone reed is with it in the drone and the drone in your set, bellows blown. I will sometimes test drone reeds by putting them in the drone and then mouth blowing through them. Blow for no more than two seconds at a time and do so infrequently. Moisture ruins drone reeds as well as chanter reeds.