Bag size - different air requirements?

On the ‘pictures of your pipes’ topic, anima commented about the bag that came with the drones he recently received.
“it’s bigger and I find myself working less to keep things going now.”

Jeff, your chanter will use the same amount of air regardless which size bag you use. What do you experience different that makes it easier?

Anyone else have a similar experience where the bag size was changed where the bellows and chanter remained the same?

your chanter will use the same amount of air regardless which size bag you use. What do you experience different that makes it easier?

Tony…my B set came with a small bag and small bellows. I played them for 2-3 weeks then decided to hook them up to larger bag and bellows. What a difference! I’m sure it can be explained in terms of physics, but imagine starting out with a bag the size of a softball, then stepping up to a football, basketball, and regular size bag. Then going to an oversize bag. The differnce wouldn’t be in the amount air to the reed, the difference would be on how much easier it is on the shoulders because of the size of the reservoir, and I’m guessing that with a larger bag, you’d move the elbow less times. I’m pretty sure that’s what happened to me. Take a beach ball…you might squeeze once (and a very small distance) for a tune played twice through!

The key word from Jeff is that he is “working” less. Tis true.

Edit Note: of course a small bellows would be as hard to play with a larger bag, it’s the bag elbow that would feel the relief..if a piper is using the right rythms.

[ This Message was edited by: Lorenzo on 2003-02-14 19:49 ]

Tony, I think Lorenzo got it right. The bag is is physically bigger and when inflated, fits better under my arm, and requires less active pressure from me, ie. I’m not having to squeeze as hard.

Jeff

OK, so where does one buy large or extra large bags then?

Bags are as important as any other part of the system, so should one be concerned about makers? Warranties? What’s the market like here - or is there one at all really?

B~

Hi Bri…It was years ago, and I think it was Denis Brooks, and he was trying to emphasize the virtues of larger bags. He pumped his bag all the way up, shut off the drones, took the bellows off (set them on the ground) and played a reel all the way through once (w/repeats) with just the chanter. I was amazed needless to say. And he still had air to spare!

There was discussion on the U-LIST recently how Jerry O’Sullivan had a special set of huge bellows made for himself.

OK, I’m all ears with the bag size topic…

Lorenzo, thanks for the input. I appreciate your contributions and want to say thanks for the knowledge you share.

The condition is to use the SAME bellows and chanter in these tests. This way, the only change is the bag.

My Mackenzie practice set and Mackenzie full set use small bags. My Childress half set and Childress full set use MacHarg bags that are also small… same thing with the Wooff half set. These bags are all really close in size.

The O’Grady bag is larger than the others but the bellows doesn’t appear as efficient as the others so I can’t give an honest (accurate) comparison to the other sets.
I don’t want to chop up any of the fittings to switch these for tests. But, I should be able to add my Mackenzie bellows to the O’Grady without much work.

I played for an hour today on Childress full set (that arrived yesterday) and though my bag arm (and shoulder) is aching, my bellows arm feels no pain. I’m more comfortable with this set than the others. Childress did some drone reed modifications for me that I really like. I’m not sure exactly… they are quieter than the standard drones. I need to physically compare them to my half set to be sure. I think the reed tubing diameter is smaller. This may play a part in lowering the amout of air needed to drive the drones.

Brian, I’d contact Joe Kennedy for a quote on a custom sized bag. The US dollar to Canadian makes it a good value.

If I found a chanter/reed combination that knocked me out, I’d surely attach it to the best bag I could find, and attach the best bellows to that bag…and leave it. You would need no others. Without the best bag/bellows combination it’s difficult to know a reed or chanter’s true potential.

Once you settle on your favorite drones/regs combo, and have them attached to your favorite bag, you can still adjust the winding on several different chanters to fit the same reed cap, usually.

You may have to untie/retie certain stocks to your favorite bag…to get set up, but that’s easy. Wrap them with PTFE tape before retying. I hate stocks that are glued, or gummed up. I can actually (just barely) twist the mainstocks in both my bags for the best alignment on my lap. And they don’t leak.

Once you get set up with the best combination, you may find that trying lots of different reeds is more interesting than trying lots of different pipes. But it’s important, initially, to try lots of different equipment…how else would you know?

I’ve made lots of bags and bellows and have experimented in all shapes and sizes and have found that the smaller ones are far better.Its more to do with ergonomics I think than the amount of the resevoir of air.Take Highland Pipes for example,common sense would say that a bigger air resevoir would be best so as to save on your breath but it aint so!the most important thing is to have a bag that is comfortable under the arm and sits well under the body ,rate of air transfer ( bellows/bag )is controlled by the synchronisation of both so the size of the bag is even less important.
I too had a recent problem with a new set and I am getting sore bag armitis…I think the reason is twofold..Stiffer reeds(definately on the regulators)..a tendancy to drift into playing with the bellows more than using the bag a possibility,(it doesnt have to be very much either I’ve noticed )I do not have this problem with my other sets so it may well just be a New Set Thing.
Just one other thing ,consider the weight factor in having ginormous bag and extra large bellows+ no doubt a larger case also would be needed.
Slan go foill
Liam

..

I haven’t played on the O’Grady bag in long time… and I do recall having to tuck it higher into my armpit (against advice) to get better leverage.

Another observation that might have a pressure difference: O’Grady is using leather (Canadian hide) that is thicker than the others. It holds it’s shape better when deflated, weighs more and is less ‘shifty’ when playing.

OK, so question number two:

What happens if you don’t change the diameter of the bag (inflated) under the arm, but you DO change the length? For example, my Penny Chanter bag is a continuous curve along the bottom edge, almost crecent shaped. But most of the u.p. bags I’ve seen looked much more rectangular in their shape ie; more volume towards the rear of the bag as the corners haven’t been trimmed away. Any advantage there as far as the ‘resevoir’ theory goes?

B~

I was able to use the O’Grady bag with the Mackenzie bellows and chanter this morning.
Here are my findings:
The size difference is not that much. They are probably within 10% of each other, certainly less than I imagined. The stiffer bag was slightly easier to deal with when pumping up, but the wider neck of the Mackenzie bag allows for more chanter movement, both played about the same with regard to pressure.
pictures:

larger pictures:
http://www.angar.net/pipes/bags1.jpg
http://www.angar.net/pipes/bags2.jpg
Physical dimensions:
Total length (top seam to bag stock)
O’Grady 27.75"
Mackenzie 28.75"
Total height (top fold to bottom stitching)
O’Grady 11"
Mackenzie 10"

The bags look close in the above pictures but take on a completely different appearance when the neck curves are aligned.

large image:
http://www.angar.net/pipes/bags3.jpg

I would like to try something significantly larger just to see the difference. Lorenzo & Jeff can you take pictures of the bags you have?

Brian, I tend to think a long narrow bag would put air where you can’t use it. When you squeeze near the center, the ends would pop up like an inflatable raft.

I think Uilliam is correct saying “Its more to do with ergonomics” not so much the bag size but the design.

tony, what are the inside measrmentsa(top to bottom,inside seem). i just made a new naugha bag and made it 13 in. wide,lying flat. my old bag was somewhat smaller (11.5") and i really like this new size. the main diff. is that i made it more square and have the stocks in the correct place . i made my neck 30"+1"for chanter stock and cut back to 28+1"
i think its all of where everything is located on the bag, having played one that was incorrectly set up.i did my first from pictures.
tansy ps thanks for all the pictures! i printed out the one with a bunch of your pipes on it and leave it lying around for me lady to see,it makes my little halfset and three chanters look deceivingly innocent to those unaware of a severe piping abuse problem. stay with the same woods and metals,they look more the same to those who don’t play.

Tansy,
Measuring bag height from the fold to the stitching is 11" on the O’Grady and 10" on the Mackenzie.

Years ago, I worked for an upholstery firm that made sofabeds. The square cushions often puckered in the corners. To cure this, they ended up trimming the last 3-4" at a slight angle.
Are you gluing the seams?

thanks,i guess that 13"is very large, i found the measurements somewhere on the computor. yes i am gluing the seams and i have some slight puckering on the lower back edge which i plan to trim out on the next one as you suggested. i found an auto upolstry place and they had a remnant area ,everythig 5 bucks a yard,so i have enogh for 2 more bags and some bellows.i told this huge friendly red headed redneck that worked there that the material was for the bagpipes and he sold me 2.5 yards for $5!quite able to experment with these prices. the length of the neck seems very important,my old bag was way too short at the neck but worked ok until i plugged in the B chanter-3" longer ,then everything needed correcting.i like the naugha bag a lot so far. plastic goes against my grain but it seems hard to get away from these days,guitar strings,fipples,money,safe —

My smaller egg-shaped bag, that came with the B set, squares up to be about 10x14 in. minus the arm extension. This has the brass buttons on the seam all the way along–you’ve probably seen them. You can find pics of them on just about any GHP web site…same basic shape and size.

My larger square bag is about 11x16 in. minus the arm extention, and looks about like Tony’s larger bag.

There’s no magic in taking the work out of piping, or making piping easy…just easier. And don’t believe everything you hear (after all, this is the internet!)

Saturday night, I looked closely at Paddy Keenan’s vinyl bag and noticed that if anything, the square shape was a little longer, and maybe a little wider. Hard to tell with that 1" flat seam all the way around. He told me the vinyl was doubled to give it the thicker feel of leather. His bellows were medium size, double leather (thick feeling), and he pumped the bellows about 2 1/2 strokes in 5 seconds on average, but variable…and playing about 6 reed most of the time. I watched carefully from the front row (about 12 ft from him) and never noticed his bag deflate at all, no in and out “lung” action.

I’ll offer a few more “Keenan” observations in the Concert thread, and a new one called “Ergonomics” and how Keenan uses his whole body.

Brian…I don’t know exactly where to buy an extra large bag, or who makes the best ones…probably Michael MacHarg -“the wee piper.”

I need some advise on seaming the bag. I was thinking of gluing the seam and then riveting afterwards. What type of sealant would your recommend and what type of rivets. I have read enough about cutting and tying in the stocks and think I can handle that with out a problem.
I have a big enough piece of leather I may make a bellow if the bag works out.

Bag sizes & ratio’s

A good size for a bag is one that holds between 4-5 litres of air, this should be able to be filled with about a 4 to 1 ratio, 4 pumps of the bellows should just about fill the bag, always keep the bag full when playing.

A bigger bag will take more pumps filling it but once full will work at the same rate as a smaller one will, IE the reed/s will use the same amount of air whatever size bag is fitted.

Like Uilliam I prefer the smaller bag, 28-1/2" X 10", a bigger deeper bag has a slight dissadvantage in that when playing with others, if you let it go down, they will be waiting for you longer as you fill her up again.

The most important thing is that it fits under your arm comfortably, sometimes the deeper bag tends to push downwards and away from you when its full, this stops you getting your arm around it properly, when playing you should not need to keep re-positioning the bag, you should be able to play and forget its there kind of thing, a persnal fitting is sometimes needed for the shorter or vertically challenged person.

The way it is positioned against your arm is also important, if you are squeezing it off center say near the front part of the bag where the neck starts, then the overall travel of your arm will be limited to 2 to 3" of the travel from the side of your body.

If your arm it centered nearer the middle of the main sausage the travel is increased by a couple more inches giving better control, the nearer your arm lies to your body the less leverage you will have.

Also, bellows that are not efficient are a bain, if the bag takes much more than a 4 to 1 ratio to fill it, you can soon get tired fingers, because the faster you pump the more your hands and fingers are constantly changing position on the chanter causing stresses on unclimatised tendons especially for beginners who’s body is not used to being moved in a new/strange way, a poor set of bellows is like a leaking bag.


Davy.