whitworth drawings

[gary michie]

Hi I have whitworth drawings found  in the   Artilleryman- Vol.16,No.4- Fall1995- page 5   that I can't read. Does any one have a copy of that page? I need the thread measurements and the diameter measurments of the breach in that area.

[KABAR2]

If someone has these I would like a set too please  

[Cpt Ed]

AOP in Port Huron, MI  (Don Lutz)

list as:

No. 23 CSA Civil War 12 pdr. Breech Loading WHITWORTH rifled cannon Drawings.

The one on page 5 of the ARTILLERYMAN magazine, has been reduced down from a larger format and you can't really read the dimensions. The drawings and article were provided by William W. Fetterly who lists his address in Gig Harbor Washington with telephone number.

However this is vintage from 1995.

[cannonmn]

The drawings and article were provided by William W. Fetterly who lists his address in Gig Harbor Washington with telephone number.

I'm quite sure I heard Wm. W. Fetterly passed away in about 2000.  I've spoken to his son once, I think, perhaps he's carrying on the tradition.  Wm. was a machinist at Coors brewery, and a very talented machinist at that.

[Double D]

I have the AOP drawing and they leave a lot to be desired. In the text description in mentions the thread is "double threaded" double leade?, and comes of in 2 1/2 or 3 turns.

I don't know if htis will help any, but here is the breech detail from the AOP drawing.



Click on this URL to get a full size drawing

http://www.fototime.com/CD61B2B473D71FD/standard.jpg

[Cpt Ed]

I have a set of AOP plans but was unable to provide any images because our master cannon builder Dominick in Pennsylvania has my copy for a special project he is working on for me.
 
Here is a poor reproduction image of the one Drawn by William Fetterly in 10/10/91. This is page 1 of 7.
Perhaps if you track down his son, even after the 14 years he might still have the original.
The magazine on page 7 gives you his address and phone number back in 1995.

[Double D]

That plan is a heck of a lot better than the AOP drawing!!!

[GGaskill]

That plan is a heck of a lot better than the AOP drawing!!!

I would say.  I couldn't figure out what the other drawing was trying to show.  Might have had a chance with some pix.

[gary michie]

Hi;
I have the AOP drawing #23 too and the drawing that Cpt Ed shows is what I am talking about. As you can see... nice pic. but you can't read the small print. I see that it is a dual theard 180 deg. from each other and showing 6 theard in about 4-1/8"  of travel..... divded by 2=1-3/8 per inch. Off  the top of my head that is as far as I can get.    Any help?

[GGaskill]

For reference, "Lead" is the distance advanced parallel to the axis when the screw is turned one revolution. For a single thread, lead is equal to the pitch; for a double thread, lead is twice the pitch.

The drawing says "(Double thread, pitch 11/16", lead 1-11/32")".  Unfortunately, I cannot read the thread height dimension or the minor diameter dimension in the jpg (it is better to save line drawings as gif's since the lines don't get fuzzed.) 

Even more unfortunately, the stated pitch and lead are incompatible for a double start thread.  If the pitch is correct, the lead should be 1 3/8" (1 12/32".)  In any event, a non-standard pitch which would be hard to cut without special gearing.  Otherwise it looks like a standard square thread except for the way it ends against the shoulder.

[Ex 49'er]

I have a set of AOP plans but was unable to provide any images because our master cannon builder Dominick in Pennsylvania has my copy for a special project he is working on for me.
 

Can you give us a hint about what Dominick the Master Cannon Builder in  Pennsylvania, is working on for you? Something that goes Bang?

[BoomLover]

If Dominick is working on a "special project", I think it would go without saying that it will go "Bang!" Almost no doubt about it! And, with the plans he is working with, I'll bet it has threads, too. At the Lone Pine Shoot, there were several Whitworth's, 30mm and 40mm. They were some very nicely made guns, too. BoomLover

[Cpt Ed]

I have a set of AOP plans but was unable to provide any images because our master cannon builder Dominick in Pennsylvania has my copy for a special project he is working on for me.
 

Can you give us a hint about what Dominick the Master Cannon Builder in  Pennsylvania, is working on for you? Something that goes Bang?

IT WILL NOT GO BANG, IT WILL GO BOOM!!!

[gary michie]

Hi:
As GGaskill put it, 1-11/32 is a problem, What is that in sllymeters?  My old Mazak will do millmeters and I do have the "change gears". I can slow it down to .0005 per rev.maybe I can speed it up to 1-3/8 or 34mm that's 1.438" per.

 Dominick can you give any input ? I'm surprised to see a acme still of thread allthough  I've seen it in two different sorces. I would think that Whitworth would have used his thread with the chanfer on the one side it seems to me that it would be stronger, but I'll be happy to go with the drawing .

[GGaskill]

By definition, the relationship between inches and millimeters is:

1 inch = 25.4 millimeters

I think I would ignore the 1 11/32" note and go with 1 3/8" (11/16 x 2).  Making the parts match is what really matters and the stated numbers can't work.

[dominick]

I'm going to Gettysburg tomorrow to look at a Whitworth close up.  If I can measure anything for you, please let me know by early tomorrow morning.  I doubt very much if I can open the breech on one.  The cannons [I think there are two??] are outside displays and probably have the breech welded shut.  As for the breech threading operation, I never cut threads on a lathe before so I can't help you there.  There are others here on the forum who are better qualified to help you with that.      

[GGaskill]

Cpt Ed sent me a scan of his drawings and I have made a new CAD drawing of the threads only based on the readable dimensions on the drawing.  The thread is actually a style of Acme thread, not square.  There appear to be a couple of errors on the original drawing in addition to the illegible dimensions.  The 4.687" length at the bottom is scaled from the print as the length on the drawing can't be read.  Also, the height of the thread was scaled from the drawing for the same reason.  So we are assuming the drawing was done closely to scale originally.  The flanks of the thread are 1/32" wide so the angle works out to be about 5.7°.

[guardsgunner]

GGaskill
   could this be be just a Modified SQ. Thread which I think has a 5 degree angle ?  I'll have to look it up.

dominick
   Gettysburg was pretty good about allowing me to measure the Ellsworth in the Mesuem. There is a 12 Whitworth inside, Dont know if it will open. They wanted me to be there early ,before the crowds.

I have never cut a double like that before. I think that I would be making seeveral practice runs. Dont even think that I can over 1/in on my lathe, or the one at work either.

[GGaskill]

could this be be just a Modified SQ. Thread which I think has a 5 degree angle?

Square threads are square; parallel sides perpendicular to the minor diameter.  I think these are really predecessors of Acme threads, before there was a standard.  You could make anything you want (stub Acme comes to mind) unless you a trying for an exact copy.

If the thread actually ends with a radius as the drawing shows, these threads must have been milled with an end mill with the thread angle ground on it.  Probably easier to get this coarse pitch on a mill with a geared rotary head than a lathe, although I don't know how the inside thread would have been cut.

[Victor3]

   could this be be just a Modified SQ. Thread which I think has a 5 degree angle ?  I'll have to look it up.

 It's possible. The modified square form was (IIRC) designed to be easier to cut than a true square, where it was difficult to keep the tool from breaking. I seem to remember that the tool required a 10 deg included angle, so 5 on a side would be correct.

 Speaking of difficult threads, when I worked for a company that made medical implants, we often had to cut reverse angle buttress threads (internal and external). Most common had a 45 on one flank and a -5 on the other.

[guardsgunner]

 
Unless your makig the perfect mesuem copy; I wouldn't worry about minor change in the thread isn't going to hurt. So whats an extra turn of the breech.
  Also might remind you that the reason Whitworth went back to muzzleloaders in 1864 was leakage causing the breech to seize.  A acme may cut down on that a little.  I think that occured here (in the states) while using bag charges.
  It would be a project just trying to make the round base cartridges while having hex sides.

  A Whitworth is still in my future, but a more powder conserving 3 pdr version is in mind. 

[Cpt Ed]

SOME WHITWORTH BREECH THREADS.

Private collection in Florida.



Reproduction private collection.

[KABAR2]

Do you have more photo's of the original in Fla. ?

The second gun is a great little gun belonging to one of the members here.

[Cpt Ed]

Do you have more photo's of the original in Fla. ?

This is all that I have taken at a local reenactment, here in Mount Dora, Florida three years ago.

[Max Caliber]

Here is a good picture of the threads.  These pictures were taken in the old Gettysburg NMP museum.  I didn't see these guns in the new museum but could have overlooked them in the mass of slack jawed tourist.

[dominick]

Well, I went to Gettysburg Yesterday.  The barrel with the open breech is not there as Max Caliber stated.  The Ellsworth is still on display.  The photo host I use is temporarily down and as soon as it is running, I will post the detailed photos.  Here's a link to a video I took.

 http://www.youtube.com/watch?v=nJaWthKC-oM

[gary michie]

Hi:
First of all thank you for ALL of the info.and pics.   You guys are a great bunch.

I have a Question for "Cannonmn".

I think you posted a group of pics. of "The working of a Whitworth" they were Yellow and hand written. The picture Dahlgren G095 shows that the hinge is thearded on;   A mistake of the writer; or another whitworth?

The AOP# 23 shows a carriage with asmith adjustment, is there another barrel configument too?

[cannonmn]

The pic Gary wanted is in this post; the same info was probably posted here, but it was easier for me to relocate on NSSA:

http://www.n-ssa.org/phpbb/viewtopic.php?t=10880

[dan610324]

YES BUT THOSE !D!OTS STILL DONT ACCEPT ME ON THEIR SITE
THATS AFTER MANY ATTEMPTS TO HELP ME FROM A LOT OF DIFFERENT VERY KIND PEOPLE

I think its best I stop there before I get banned from this forum

[cannonmn]

Dan, here are the non-NSSA links which are the "guts" of what I posted over there:

http://s17.photobucket.com/albums/b62/cannonmn/miscforumsetc/forums27/?action=view&current=2a68de69.pbw

http://i17.photobucket.com/albums/b62/cannonmn/miscforumsetc/forums27/WhitworthinWNY002.jpg

http://www.go2gbo.com/forums/index.php/topic,127064.0.html

http://i17.photobucket.com/albums/b62/cannonmn/miscforumsetc/forums27/DahlgrenG095.jpg