• FAQ  • Search  • Memberlist  • Usergroups   • Register   • Profile  • Log in to check your private messages  • Log in 

Leadpipe Venturi Catalog


Goto page Previous  1, 2, 3, 4  Next
 
Post new topic   Reply to topic    trumpetherald.com Forum Index -> Horns
View previous topic :: View next topic  
Author Message
highscreamer
Regular Member


Joined: 28 Jun 2013
Posts: 13
Location: The Woodlands, Texas

PostPosted: Sat Mar 20, 2021 7:21 am    Post subject: Reply with quote

This is a good thread and the numbers submitted match up very well with my measurements. It is also interesting to note that most leadpipes that I have measured from manufacturers are right at 8-5/8" long.

Two important things about leadpipes that come to mind (beyond the venturi measurement) are: 1) the taper shape and 2) the measurement of the end of the leadpipe. Here is a chart with a variety of leadpipes measured down the tube. The '64 Benge MLP follows a traditional Schilke-style linear taper, but with a large venturi opening, this Blackburn leadpipe starts small but has a very fast and early taper, the 8335LA starts big and is fairly linear and the Bach 25 ('74 Bach #37) is fairly small and slow. Also note the leadpipe exit. I was surprised to see how many leadpipes, that I had measured, exit at .451" - .456"

_________________
Lou Gagliardi
HighScream Brass - highscream.com

HighScream Brass Brio and Dolce Models
Yamaha YTR-8335 LA Bb
1994 Bach Stradivarius 43 Sterling Silver / 25-O
Courtois 154R Flugelhorn
GR Mouthpieces: WB-Classic, WB-Studio-M
Back to top
View user's profile Send private message Visit poster's website
James Becker
Heavyweight Member


Joined: 02 Sep 2005
Posts: 2827
Location: Littleton, MA

PostPosted: Fri Mar 26, 2021 5:24 am    Post subject: Reply with quote

Thank you Lou for sharing the graphic of leadpipe tapers. I've always thought it important to include what occurs after the venturi. Much like the mouthpieces throat (bore size) only tells part of the story, the backbore shape and volume, shank engagement (gap) helps to complete the story.

Here are a couple more venturi sizes to add to the conversation.

"Barn era" Getzen Super Deluxe Copper Temp bell and copper leadpipe, venturi .333", receiver gap with Bach 3C mouthpiece at .373"

Bach 190 .401" bore Eb replacement leadpipe venturi .316", receiver gap with Bach 3C mouthpiece .178"

I hope this is helpful.
_________________
James Becker
Brass Repair Specialist Since 1977
Osmun Music Inc.
77 Powdermill Road Rt.62
Acton, MA 01720
www.osmun.com

Our workshop is as close as your nearest UPS store https://www.ups.com/dropoff?loc=en_US
Back to top
View user's profile Send private message Send e-mail Visit poster's website AIM Address
lipshurt
Heavyweight Member


Joined: 24 Feb 2008
Posts: 2641
Location: vista ca

PostPosted: Sun Mar 28, 2021 9:03 am    Post subject: Reply with quote

If you had the 80J with a bigger venturi it would basically (i think) be a B700 Large bore. The B700 has the lighter bracing and a whopping 358 (mine anyway) venturi. It plays great, especially soft dynamics. The sound is very dark, and with a shallow mouthpiece the sound is very bright. It's bigger than i can handle. But the pitch and response really are good. I would think the big venturi might make it hard to play soft, but no.
_________________
Mouthpiece Maker
vintage Trumpet design enthusiast
www.meeuwsenmouthpieces.com
www.youtube.com/lipshurt
Back to top
View user's profile Send private message Visit poster's website
yourbrass
Heavyweight Member


Joined: 12 Jun 2011
Posts: 3619
Location: Pacifica, CA, USA

PostPosted: Sun Mar 28, 2021 12:27 pm    Post subject: Reply with quote

Most Benge pipes are about 9 1/8" long. That's the other length that's popular in trumpet design. Bach, Calicchio and others are the shorter length mentioned; 8 5/8" - 8 3/4".
_________________
"Strive for tone." -John Coppola
Edwards X-13
ACB MV3C /ACB A1/26 backbore
https://yourbrass.com/
Back to top
View user's profile Send private message Visit poster's website
agroovin48
Regular Member


Joined: 07 Feb 2014
Posts: 94
Location: Goodyear, Arizona

PostPosted: Sun Mar 28, 2021 12:42 pm    Post subject: Reply with quote

This is by far the most intriguing lead pipe discussion that I have seen. I am particularly impressed by the graph showing the internal changes in the lead pipes. This is something that I never knew existed since I have never really studied the mechanics of lead pipes. I always naively thought that the lead pipe started out at the the receiver and then had some unique formula for a direct taper to the tuning slide.

Will someone with insight explain how these internal changes are made in the lead pipes and is there some sort of a formula that manufactures use to establish the changes for resistance and note production?

Just how is a lead pipe formed?
_________________
agroovin48

Alan Cahill

1933 Conn Victor 80A Cornet
King Legend 2070
Adams A1V2
Back to top
View user's profile Send private message
Bethmike
Veteran Member


Joined: 21 Jan 2020
Posts: 192
Location: NW of ORD

PostPosted: Sun Mar 28, 2021 3:51 pm    Post subject: Leadpipe Venturi Catalog Reply with quote

Same for me, I have found this subject really intriguing. I think it interests the mechanical engineer in me as much as the trumpet player.

I would also really like to learn how the rate of expansion of the diameter of the leadpipe impacts playing characteristics. And maybe it is different for different players based on the airstream they create / use.
_________________
Bach190ML43
Kanstul 1001
Bach NY7
Yamaha 631 Flugel
Back to top
View user's profile Send private message
yourbrass
Heavyweight Member


Joined: 12 Jun 2011
Posts: 3619
Location: Pacifica, CA, USA

PostPosted: Sun Mar 28, 2021 6:08 pm    Post subject: Reply with quote

There is much of the magic, or failure in the taper.
_________________
"Strive for tone." -John Coppola
Edwards X-13
ACB MV3C /ACB A1/26 backbore
https://yourbrass.com/
Back to top
View user's profile Send private message Visit poster's website
Divitt Trumpets
Heavyweight Member


Joined: 11 Aug 2015
Posts: 519
Location: Toronto

PostPosted: Mon Mar 29, 2021 4:50 am    Post subject: Reply with quote

agroovin48 wrote:

Will someone with insight explain how these internal changes are made in the lead pipes and is there some sort of a formula that manufactures use to establish the changes for resistance and note production?

Just how is a lead pipe formed?


Some people use math to determine the taper(s) they want. Some don't. Some use straight tapers and some use a series of different tapers over the length.
The thing about the math is that the rest of the horn has to be taken in to consideration because the bell taper will affect the balance as well.
The leadpipe I use on most of my models is one I machined freehand on my lathe with no math. It happened to work out great, but I have made many leadpipe shapes that weren't nearly as good.
A new bell shape I'm experimenting with doesn't work well with my regular leadpipe so I'm trying others to see if I can get the blow where I want it.

Over time and with many trials and errors, the builder gets to know the effects of changes in taper in certain spots. Measuring as many other pipes as possible also helps see the shapes that tend to work best.

To make a leadpipe you can start out with a tube or a sheet of brass. The sheet is formed and brazed and then drawn/burnished to size. The tube is drawn to size.
_________________
www.divitt-trumpets.com
www.facebook.com/divitt.trumpets
www.instagram.com/divitttrumpets
Back to top
View user's profile Send private message Visit poster's website
highscreamer
Regular Member


Joined: 28 Jun 2013
Posts: 13
Location: The Woodlands, Texas

PostPosted: Mon Apr 12, 2021 2:47 pm    Post subject: Reply with quote

Like Ewan Divitt says, they are either drawn on a mandrel with a drawing bench or made from sheet metal. I do the latter in brass, copper and bronze, though I hammer and roll on a generic tapered mandrel until straight and smooth. The precision of the final taper dimensions are a direct result of precision cuts on the sheet metal. Simple geometry (2*pi*r) produces the right diameter at the desired points down the tube.

Lately I have been experimenting with smaller venturi, with faster early tapers. (See the Blackburn 19 leadpipe example in the chart above)

As Ewan points out, the bell taper and leadpipe taper are co-dependent in both sound and blow. Rarely does a huge venturi and fast taper work well with an early bell flair. (Unless you are Arturo)

I am early in my observations, but learning fast.
_________________
Lou Gagliardi
HighScream Brass - highscream.com

HighScream Brass Brio and Dolce Models
Yamaha YTR-8335 LA Bb
1994 Bach Stradivarius 43 Sterling Silver / 25-O
Courtois 154R Flugelhorn
GR Mouthpieces: WB-Classic, WB-Studio-M
Back to top
View user's profile Send private message Visit poster's website
agroovin48
Regular Member


Joined: 07 Feb 2014
Posts: 94
Location: Goodyear, Arizona

PostPosted: Mon Apr 12, 2021 7:09 pm    Post subject: Reply with quote

High Screamer, will you post a simple diagram of what you are talking about so those of us who have limited mental capacity can see what you mean? Do you machine a mandrel to specs or cut a piece of sheet metal to specs and roll it around a mandrel? I still can not visualize it.
_________________
agroovin48

Alan Cahill

1933 Conn Victor 80A Cornet
King Legend 2070
Adams A1V2
Back to top
View user's profile Send private message
highscreamer
Regular Member


Joined: 28 Jun 2013
Posts: 13
Location: The Woodlands, Texas

PostPosted: Tue Apr 13, 2021 2:24 pm    Post subject: Reply with quote

Quote:
High Screamer, will you post a simple diagram of what you are talking about so those of us who have limited mental capacity can see what you mean? Do you machine a mandrel to specs or cut a piece of sheet metal to specs and roll it around a mandrel? I still can not visualize it.


Here are some photos of a leadpipe from sheet brass:
1) cut to shape, 2) anneal, 3) shape on mandrel, 4) wrap with annealed wire to close joint, 5) brazed, 6) remove annealed wire, 7) file, hammer & roll smooth














_________________
Lou Gagliardi
HighScream Brass - highscream.com

HighScream Brass Brio and Dolce Models
Yamaha YTR-8335 LA Bb
1994 Bach Stradivarius 43 Sterling Silver / 25-O
Courtois 154R Flugelhorn
GR Mouthpieces: WB-Classic, WB-Studio-M
Back to top
View user's profile Send private message Visit poster's website
LittleRusty
Heavyweight Member


Joined: 11 Aug 2004
Posts: 12647
Location: Gardena, Ca

PostPosted: Tue Apr 13, 2021 2:30 pm    Post subject: Reply with quote

Very nice Lou. Well done.
Back to top
View user's profile Send private message Send e-mail
JayKosta
Heavyweight Member


Joined: 24 Dec 2018
Posts: 3276
Location: Endwell NY USA

PostPosted: Tue Apr 13, 2021 2:38 pm    Post subject: Reply with quote

My understanding is that that mandrel is slightly smaller than the finished size and shape of the leadpipe ID. The mandrel serves as an undersized 'internal anvil' for the precisely sized and shaped sheet of brass to be formed around, and held during soldering of the seam. Then the mandrel provides the firm internal support for the final 'rounding' of the leadpipe by use of the small hammer seen in pictures 4, 5, and 6.
The taper of the leadpipe is determined by the precise cutting of the flat sheet brass. I don't think the mandrel is forced into the leadpipe to cause any internal 'stretching' or 'forming'.
_________________
Most Important Note ? - the next one !
KNOW (see) what the next note is BEFORE you have to play it.
PLAY the next note 'on time' and 'in rhythm'.
Oh ya, watch the conductor - they set what is 'on time'.
Back to top
View user's profile Send private message
agroovin48
Regular Member


Joined: 07 Feb 2014
Posts: 94
Location: Goodyear, Arizona

PostPosted: Tue Apr 13, 2021 2:41 pm    Post subject: Reply with quote

Thank you for the visual. That is what I needed. I can see that the mandrel is machined with the taper transition points and then wrapped with the sheet stock and shaped then brazed. Good lesson!
_________________
agroovin48

Alan Cahill

1933 Conn Victor 80A Cornet
King Legend 2070
Adams A1V2
Back to top
View user's profile Send private message
highscreamer
Regular Member


Joined: 28 Jun 2013
Posts: 13
Location: The Woodlands, Texas

PostPosted: Tue Apr 13, 2021 6:34 pm    Post subject: Reply with quote

Quote:
The mandrel serves as an undersized 'internal anvil'


Jay you've got it. The mandrel is typically used for rolling out leadpipe dents. I got it from Allied or Votaw. When I am hammering or rolling on it, I work all the way on the small end of it so the pipe is loose and, as you say, it acts like an anvil while planishing or rolling.

Thanks Alan and Rusty.

In keeping with the OP, I will post more charts of some other leadpipes. I have others, including a Bach #7 from a Mt Vernon and a French Besson that I plan to measure. I'll share the charts.
_________________
Lou Gagliardi
HighScream Brass - highscream.com

HighScream Brass Brio and Dolce Models
Yamaha YTR-8335 LA Bb
1994 Bach Stradivarius 43 Sterling Silver / 25-O
Courtois 154R Flugelhorn
GR Mouthpieces: WB-Classic, WB-Studio-M
Back to top
View user's profile Send private message Visit poster's website
Divitt Trumpets
Heavyweight Member


Joined: 11 Aug 2015
Posts: 519
Location: Toronto

PostPosted: Tue Apr 13, 2021 6:54 pm    Post subject: Reply with quote

JayKosta wrote:
My understanding is that that mandrel is slightly smaller than the finished size and shape of the leadpipe ID. The mandrel serves as an undersized 'internal anvil' for the precisely sized and shaped sheet of brass to be formed around, and held during soldering of the seam. Then the mandrel provides the firm internal support for the final 'rounding' of the leadpipe by use of the small hammer seen in pictures 4, 5, and 6.
The taper of the leadpipe is determined by the precise cutting of the flat sheet brass. I don't think the mandrel is forced into the leadpipe to cause any internal 'stretching' or 'forming'.


The size and shape of the mandrel determines the leadpipe inner dimensions.
Plainishing the seam of a brazed tube will widen the diameter of the tube. The type of seam (butt, scarf, toothed) will also change the methods used to get the seam smooth.
I personally don't believe you can make an accurate(repeatable) pipe without an accurate mandrel.
When I make my bell tubes, I hammer the seam smooth on an undersized mandrel and then burnish the entire tube down to the final bell mandrel to eliminate any stretching from hammering and make it easier to spin at later stages.

You would never braze a tube with the mandrel inside it for a few reasons.
The first being that it is a huge heatsink and will make doing a good seam way more difficult.
The second is that the mandrel will be damaged by the flux and heat and will rust and potentially warp depending on the type of steel used.

I have done seamed pipes in the past, but these days all of my pipes are drawn on a draw bench.
_________________
www.divitt-trumpets.com
www.facebook.com/divitt.trumpets
www.instagram.com/divitttrumpets
Back to top
View user's profile Send private message Visit poster's website
LittleRusty
Heavyweight Member


Joined: 11 Aug 2004
Posts: 12647
Location: Gardena, Ca

PostPosted: Tue Apr 13, 2021 7:10 pm    Post subject: Reply with quote


Link


This is an interesting YouTube video of Ewan Divitt making a trumpet leadpipe.

Can’t say I am a fan of the background music, although I am a fan of new students learning music.
Back to top
View user's profile Send private message Send e-mail
Divitt Trumpets
Heavyweight Member


Joined: 11 Aug 2015
Posts: 519
Location: Toronto

PostPosted: Wed Apr 14, 2021 3:08 am    Post subject: Reply with quote

That video is from many years ago. I've refined my process considerably since then, but the overall idea is there.
_________________
www.divitt-trumpets.com
www.facebook.com/divitt.trumpets
www.instagram.com/divitttrumpets
Back to top
View user's profile Send private message Visit poster's website
Dronzoni
New Member


Joined: 26 May 2021
Posts: 2
Location: Salt Lake City

PostPosted: Tue Mar 01, 2022 12:56 pm    Post subject: Reply with quote

James Becker wrote:
Thank you Lou for sharing the graphic of leadpipe tapers. I've always thought it important to include what occurs after the venturi. Much like the mouthpieces throat (bore size) only tells part of the story, the backbore shape and volume, shank engagement (gap) helps to complete the story.

Here are a couple more venturi sizes to add to the conversation.

"Barn era" Getzen Super Deluxe Copper Temp bell and copper leadpipe, venturi .333", receiver gap with Bach 3C mouthpiece at .373"

Bach 190 .401" bore Eb replacement leadpipe venturi .316", receiver gap with Bach 3C mouthpiece .178"

I hope this is helpful.


What do you mean by Barn era? I have a Copra-Temp as well from the 50s, and its gap is .406" with a Bach 1 1/2C (and .5" with a Monette). Also, there's practically no venturi. I don't have the means to measure the venturi, but there's hardly any visible difference between the inner diameter of the venturi compared to where it sits in the mouthpiece receiver.
Back to top
View user's profile Send private message Send e-mail
Goby
Heavyweight Member


Joined: 11 Jun 2017
Posts: 641

PostPosted: Mon Jul 17, 2023 7:47 pm    Post subject: Reply with quote

Wanted to bump this thread and see if anyone has any more measurements to add. Does anyone know the exit bore of the Selmer 80J leadpipe?
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    trumpetherald.com Forum Index -> Horns All times are GMT - 8 Hours
Goto page Previous  1, 2, 3, 4  Next
Page 3 of 4

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group