DIY sackbut crook

[earlymodern]

Hello all!
I have one of the rather large-bore tenor sackbuts by Tomes. I am learning to play in A at 465 with the historical 4 positions. I would like to also play in A while at 440 which means that I need a crook to lengthen my trombone by a half-step either between the slide and bell section or the mouthpiece and slide.

Has anyone out there made there own crook? I suppose I would need to take some measurements, order the appropriate tubing, and cut and bend it?

Any advice on this matter would be marvelous.

For those interested, here is a great paper on the trombone in A:
https://pdfs.semanticscholar.org/0d18/7 ... 5f2d49.pdf

[LeTromboniste]

Hello all!
I have one of the rather large-bore tenor sackbuts by Tomes. I am learning to play in A at 465 with the historical 4 positions. I would like to also play in A while at 440 which means that I need a crook to lengthen my trombone by a half-step either between the slide and bell section or the mouthpiece and slide.

Has anyone out there made there own crook? I suppose I would need to take some measurements, order the appropriate tubing, and cut and bend it?

Any advice on this matter would be marvelous.

For those interested, here is a great paper on the trombone in A:
https://pdfs.semanticscholar.org/0d18/7 ... 5f2d49.pdf

Nice! I personally also prefer staying in A even at 440 whenever possible or practical and especially when it comes to solo or virtuosic chamber music. I'm happy to see others are enthusiastic about doing that!

My instrument has a tuning slide so I have a set of extensions for A at 440, I can measure them tomorrow and let you know the cumulative extra length. Of course it's a different instrument with a different bore and bell taper so you won't need exactly the same length but it should at least give you an idea of where to start. You can measure it yourself as well, by measuring the physical distance between your 1st and 2nd (modern and equal tempered) positions and multiplying that by 2.

You will need to expect running into some trouble though, as a half step crook is always problematic. It requires a very tight loop which tends to make the instrument rather stuffy especially if it's inserted between the mouthpiece and receiver. If your Tomes is one of the models with a very long slide tenon and a slide receiver that doubles as tuning mechanism with a wingnut, then it's also problematic to put it between slide and bell as it forces you to put the bell all the way out and you end up with a bell in 1st or 2nd position. In any case a half step crook is probably too short to be built in a way that would keep the bell in the same place even if you had a short tenon and receiver. One historical solution for half-step crooks was to have an alternative slide bow that loops onto itself, that way it doesn't mess with the slide\bell assembly. Of course that is impossible with a modern soldered slide.

In any case, expect the tuning to be somewhat different with a crook/extension (it tends to make the middle and high As sharp and the C# flatter than it already is).

[brassmedic]

Do you know how to bend brass tubing? It's actually quite difficult to do. Not a DIY procedure.

[brassmedic]

My measurements on a Meinl A=415 tuning slide was that it added about 2", so your crook would need to add 4" total. But theoretically it would be 6" total to put a Bb instrument into A.

[earlymodern]

Thank you Maximilien and Brad for the help!
Very interesting about the overtone tuning issues introduced. I also was wondering how much of an issue low Bb falling off the slide would be (althought the lack of leadpipe makes things quite flexible). I like the idea of swappable slide crooks! I hadn't heard about that.

Yes, I figured the bell would end up in a weird place but thought I'd not mind too much.
Thanks!

Do you know how to bend brass tubing? It's actually quite difficult to do. Not a DIY procedure.

Darn, I thought that might be the case.
And besides that I would need to make the ends tapered because this instrument is friction-fit.
Could you point me towards a resource on manipulating brass tubing? I will probably need to commission this piece from a professional but at this point I am very curious about how thing things are done.
Thanks!

[brassmedic]

It might be more practical to find 2 small radius crooks, like valve slide crooks, for example, that are the right bore size, and connect them with ferrules to form a loop, and then connect two straight pieces on both ends. Doesn't that sackbut have a sliding connector that's not tapered?

[earlymodern]

It might be more practical to find 2 small radius crooks, like valve slide crooks, for example, that are the right bore size, and connect them with ferrules to form a loop, and then connect two straight pieces on both ends. Doesn't that sackbut have a sliding connector that's not tapered?

That sounds great. I just read about tube bending and was indeed overwhelmed.
The bell section does terminate in a straight sliding tube which acts as a tuning side. But that has a tapered end which fits to the slide tenon. I was imaging a crook in between them but I suppose an alternate version of the sliding tube could be made (preferably with a loop so the bell is not crazy-far back).

1A856528-6D37-488D-9589-B7FCD064518A.jpeg

[brassmedic]

Oh, I see. Yeah, ideally you want a loop with a tapered tenon on each side. If you did it right, you could have the bell position remain the same. I wonder if any stock trombone receiver pieces would fit that taper. To put a taper on a tube, you have to anneal it and then either draw it through an expanding ring over a tapered mandrel, or pull it by hand through a draw plate.

[LeTromboniste]

Thank you Maximilien and Brad for the help!
Very interesting about the overtone tuning issues introduced. I also was wondering how much of an issue low Bb falling off the slide would be (althought the lack of leadpipe makes things quite flexible). I like the idea of swappable slide crooks! I hadn't heard about that.

Yes, I figured the bell would end up in a weird place but thought I'd not mind too much.
Thanks!

Do you know how to bend brass tubing? It's actually quite difficult to do. Not a DIY procedure.

Darn, I thought that might be the case.
And besides that I would need to make the ends tapered because this instrument is friction-fit.
Could you point me towards a resource on manipulating brass tubing? I will probably need to commission this piece from a professional but at this point I am very curious about how thing things are done.
Thanks!

You could just ask Brad here to make one for you!

As for low Bb being really far out, yes it does push that note further but keep in mind it's a really high note in meantone tuning so you might still have it on the slide. On my instrument I still have a meantone Bb at 440 but I probably wouldn't have an equal-tempered Bb and I most definitely don't have an A#. If your slide is shorter, that might be problematic.

The effect on the tuning is noticeable but not too problematic, just takes some getting used to. The same tendencies are there when using a G crook, but then they are more pronounced.

[LeTromboniste]

I think your idea of having an alternate version of the intermediary straight tube made with a loop is your best bet in keeping the slide in the same place and also to achieve the best stability. Adding an extra crook where you already have an intermediary tube might make it structurally very unstable

[LeTromboniste]

(practicing Bovicelli I see! It's also my quarantine practice material)

[brassmedic]

I think your idea of having an alternate version of the intermediary straight tube made with a loop is your best bet in keeping the slide in the same place and also to achieve the best stability. Adding an extra crook where you already have an intermediary tube might make it structurally very unstable

Good idea. Now that I think about it, there isn't any need to have a second tenon joint there.

[earlymodern]

(practicing Bovicelli I see! It's also my quarantine practice material)

Yeah! Was just working on this in my [video] lesson.

[earlymodern]

I think your idea of having an alternate version of the intermediary straight tube made with a loop is your best bet in keeping the slide in the same place and also to achieve the best stability. Adding an extra crook where you already have an intermediary tube might make it structurally very unstable

Good idea. Now that I think about it, there isn't any need to have a second tenon joint there.

Yes, I think that could be quite elegant.
The more I learn about this the more I think that I am in no way qualified to build such a thing. I will PM you, Brad to see if you are interested in giving a quote. Thank you so much for the help in brainstorming on this!

[LeTromboniste]

(practicing Bovicelli I see! It's also my quarantine practice material)

Yeah! Was just working on this in my [video] lesson.

On trombone or cornett?

[earlymodern]

Yeah! Was just working on this in my [video] lesson.

On trombone or cornett?

Trombone! I’m taking lessons from Liza Malamut now. She is a fantastic teacher. At least private coaching is still possible during this time.