Author Topic: seacoast  (Read 1570 times)

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Offline rampa room artillery

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seacoast
« on: September 09, 2009, 12:25:30 PM »
hey seacoast boys,
  how about the 7in brooke rifle??  any good pics and info yet?? i cant wait to see your handy work, it always amazes me.

rick bryan
 3rd va co B
    NSSA

Offline cannonmn

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Re: seacoast
« Reply #1 on: September 09, 2009, 01:44:47 PM »
I'd like to see how they will replicate the rough finish on those, the originals weren't lathe turned.  Sandblast with really big nozzle and gravel?

One of my Navy Yard videos shows many Brooke rifles, 6.4 and 7 inch.

Offline Double D

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Re: seacoast
« Reply #2 on: September 09, 2009, 02:07:02 PM »
The Seacoast guys are sticklers for accuracy in their museum quality working models.  All pits, cavities and casting lines will be exactly 1/6 scale...without fail!   :)

Offline Cannoneer

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Re: seacoast
« Reply #3 on: September 09, 2009, 05:32:02 PM »
I'm anticipating the diplomatic manner in which T&M are going to inform Double D, and Cannonmn that they're both slightly mistaken in their assumptions about Seacoastartillery's intended goals in the finish that they are attempting to achieve on their historic coastal artillery pieces.
RIP John. While on vacation July 4th 2013 in northern Wisconsin, he was ATVing with family and pulled ahead of everyone and took off at break-neck speed without a helmet. He lost control.....hit a tree....and the tree won.  He died instantly.

The one thing that you can almost always rely on research leading to, is more research.

Offline KABAR2

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Re: seacoast
« Reply #4 on: September 09, 2009, 05:36:16 PM »
Well the reply should come soon they are reading this post.......  ;D
Mr president I do not cling to either my gun or my Bible.... my gun is holstered on my side so I may carry my Bible and quote from it!

Sed tamen sal petrae LURO VOPO CAN UTRIET sulphuris; et sic facies tonituum et coruscationem si scias artficium

Offline Double D

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Re: seacoast
« Reply #5 on: September 09, 2009, 05:41:31 PM »
Well the reply should come soon they are reading this post.......  ;D

Well it must good,  I have refreshed three times now and nothing!  :)

Offline seacoastartillery

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Re: seacoast
« Reply #6 on: September 09, 2009, 06:31:21 PM »
    Rampa room artillery,  Don't know how we missed this one.  Jointing more white oak is making me jumpy, especially when the motor pulley's key fell out of the keyway and the resulting screech was enough to make me jump back several feet!!  What most people have a hard time understanding is reconciling the factory-new look of ordinance and what we kindly call an "aged" or "weathered" appearance of a model. We DO NOT make models.  We make exact recreations of arsenal or foundry-new artillery.  Our website goes into the differences between an 'exact recreation' and a model or replica.  Basically, models can be made out of wood, plaster, aluminum or any other material as long as the "look" is correct for a particular moment in time.  After four trips to Fort Moultrie in Charleston, South Carolina we know for a fact that most of the reinforcing bands were machined on the 7" Treble-Banded Brooke Rifle that we are building.  Ours will be as well.  We have already showed all the tube photos that we have time to do; we have yet to show everything together and there are no Platform photos yet.  We are building that now and the entire Company Brooke Rifle (Second prototype) will be ready by Christmastime.  Photos are planned to be show after that, with maybe a few of the woodwork before that time.

     Information??  How about something that most manufacturers would fight to keep SECRET.  As you guys know by now, our price point is quite high at $15,000, so the vast majority of our customers would never even think of firing their seacoast gun.  They are collectors and they want to protect their investment; that isn't hard to understand.  So why even make them functional at all?  Despite a lot of hand wringing by our lawyers, Mike and I decided to make each and every one as functional as the original were, only a little smaller!
    The SECRET is that we failed on the first attempt to make an accurate tube for the Brooke on the First Prototype.  We carefully cut that rifling as accurately as we could and raced out to the high plains range and very carefully loaded and shot round after carefully-made round.  The first five shot group at 100 yards was as big as, no bigger than, a basketball!!  Why shoot more than five with those disappointing results?  But we did, and another basketball group proved 'something' was wrong.  We went back to the shop and triple checked everything like bolt dia., length, cavity depth, skirt thickness, etc. and the powder charge weight as well.  All checked out O.K., so the rifling was checked next, and there was the problem.  A math error had defeated us by causing the rifling form to be off by .011" on the origin of the hook in the hook/slant form of rifling, which caused an irregularity in the intersection of the hook where it intersects the land.  Also called triangular or sawtooth rifling,  Brooke's rifling form was a little different from that of the Blakely seacoast gun rifling, but not too much.

     The second proto had a slight error in it as well when the indexing collar slipped during manufacture, but this tube proved that the new Swedish Steel cutter with the corrected form was good.  Even with the mfg. error, this tube will do 3" to 5" for five shots at 100 yards.  The second proto tube, version 'B', using a new 7 set screw collar instead of 4, has done 1.5" at 100 yards and will do less than 2.5" every time.  In early December we will be starting on tube production for a batch of four that we hope to complete by the end of March.

That's the latest, Rick.  Thanks for asking!

Mike and Tracy    
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Victor3

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Re: seacoast
« Reply #7 on: September 10, 2009, 12:41:25 AM »
"....we failed on the first attempt to make an accurate tube for the Brooke on the First Prototype."

 You could turn it into a rifled liner for Gary's Parrott. Wouldn't want it to go to waste, and it would produce better accuracy than golf balls ;D

"It is a capital mistake to theorize before one has data. Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts."

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Offline RocklockI

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Re: seacoast
« Reply #8 on: September 10, 2009, 04:07:55 AM »
that project is pretty far down on the list .....mike will  kill you/or me  dead , if ANYTHING gets between them and those cannons .

i' m busy too . Thanks for reminding them though ! ;D

i was wondering if you could upset or ...obsturate (sp) a golfball to grab the rifling , spin and improved accuracy .
"I've seen too much not to stay in touch , With a world full of love and luck, I got a big suspicion 'bout ammunition I never forget to duck" J.B.

Offline GGaskill

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Re: seacoast
« Reply #9 on: September 10, 2009, 04:17:55 AM »
While the golf ball probably distorts a little at the beginning of the powder burn, I doubt it stays out of shape long enough for rifling to spin it.  But you might be able to attach a sabot that could engage the rifling while attached to the golf ball and get spin from that.  Also, if the sabot stayed attached, it would act like a tail and give aerodynamic drag which would inhibit random spin.  But it would have to be something like styrofoam because the ball is so low mass.
GG
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Offline Victor3

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Re: seacoast
« Reply #10 on: September 11, 2009, 12:18:06 AM »
that project is pretty far down on the list .....mike will  kill you/or me  dead , if ANYTHING gets between them and those cannons .

i' m busy too . Thanks for reminding them though ! ;D

i was wondering if you could upset or ...obsturate (sp) a golfball to grab the rifling , spin and improved accuracy .

 I didn't know it was even on the list  ;D

 Gary, just pocket a bunch of them fancy steel bolts when they're not looking and forget about golf balls  ;)
"It is a capital mistake to theorize before one has data. Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts."

Sherlock Holmes

Offline seacoastartillery

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Re: seacoast
« Reply #11 on: September 11, 2009, 06:21:33 AM »
 
Victor3 quote:  "Gary, just pocket a bunch of them fancy steel bolts when they're not looking and forget about golf balls."


     Hey, Smoke in your eyes, nose and throat, guy; don't give Gary any more ideas!!!  He has far, far too many of his own!  Besides he has a big project that he is working on so he won't be on the range anytime soon.  I am allowed to tell you only that he is working on a cannon or rather a series of cannons, and from his drawings, they look grand.  He has about five hundred times the artistic talent of either Mike or I, but I will defer to him on any details.

     One loose end that we have neglected to clean up is the answer to our question, "How do do drill a really straight hole in multiple pieces of wood at various angles to each other?"  Most people responding wanted to use fixtures, which is a standard industrial practice, but they are a hassle to build and can cost money too.  A separate thread later this evening will explain how to do this repeatedly, again and again, ACCURATELY without pesky fixtures.

Oh, we just figured out how to shoot golf balls accurately, in theory.  Now where is the time-expander, so we will have time to make the special tube that will facilitate this,..........Seacoast first.  The theory only works if you can make a muzzleloading, breech loader.  Think about what one of those would look like.  Details later.

Regards,

Tracy and Mike

Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline KABAR2

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Re: seacoast
« Reply #12 on: September 11, 2009, 06:57:02 AM »
"A muzzle loading breech loader"................

So by forcing a patched golf ball down a rifled tube to insure proper spin you than load the charge behind it

by breach loading? 
Mr president I do not cling to either my gun or my Bible.... my gun is holstered on my side so I may carry my Bible and quote from it!

Sed tamen sal petrae LURO VOPO CAN UTRIET sulphuris; et sic facies tonituum et coruscationem si scias artficium

Offline cannonmn

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Re: seacoast
« Reply #13 on: September 11, 2009, 07:11:56 AM »
Quote
i was wondering if you could upset or ...obsturate (sp) a golfball to grab the rifling , spin and improved accuracy .

For your bindere, dundat files:

My son and I went out to shoot the Hotchkiss 1.65" b/l mountain gun, many years ago.  The express purpose of going out was to test my great discovery that standard golf balls just exactly fit the bore of the Hotckiss so as to let the rifling grab them when they exited the chamber.

We fired about ten rounds like that with, let's say, 2 or 3 oz. of BP, musta been FG?

The balls could be seen to go roughly straight out for say 40-50 yards, then hook to left very sharply, say somewhere 50-80 degree change of course, quite amazing. 

The problem is that the little dimples in the ball were made to do certain things with little spin or slow random spin.  When they get a lot of spin in only one direction, plus some canted grooves cut in the outside, they behave as described.  Trust me, bindere, dundat, but if you want to reprove it, be my guest and please report back.  PS I recommend you don't shoot where there's anything you don't want to hit, off to the side of the range (not knowing if you will use a RH or LH twist rifling.)

Offline cannonmn

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Re: seacoast
« Reply #14 on: September 11, 2009, 07:18:19 AM »
PS-sometimes Spellcheck is not your friend.

What you may write as ORDNANCE can turn into ORDINANCE if you are not wary of things like spellcheck, or whatever else may be causing the error.  The two words have quite different meanings.

Offline moose53

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Re: seacoast
« Reply #15 on: September 11, 2009, 07:55:09 AM »
I can second cannonmn's results with golf balls . I have tried them in my 40mm B/L and only got them to shoot straight with the most minimum velocity I could get  ::)

Offline cannonmn

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Re: seacoast
« Reply #16 on: September 11, 2009, 08:46:49 AM »
Quote
I have tried them in my 40mm B/L and only got them to shoot straight with the most minimum velocity I could get 

I think he has the key here, namely velocity.   When they exit the muzzle of the Hotchkiss with that much powder behind them, it is a good bet that they are supersonic.  Since the velocity of a relatively low mass-to-area sphere decays very quickly, I'm guessing the change in direction I saw may have occurred at the transition point from super to subsonic velocity, for lack of any better understanding of aerodynamics.  Maybe when the s/s shock wave passed the slowing ball, it kicked it to the side, who knows.

Offline seacoastartillery

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Re: seacoast
« Reply #17 on: September 11, 2009, 08:53:44 AM »
     It may be an impossible mission to get a GB to fly straight, but then again, that's what our families and shooting and hunting friends said about our little bench cannons too.  "You're going to do what?  Get 5 half-pound slugs into 3" at 100 yards, reliably, with a short, stubby,  bore of only 17" length ???  Are you guys nuts?"  Well no, we were not nuts.  AND yes, we did and continue to do exactly that!  So, after we get our 4 Brooke rifles delivered in March or April, we will try our GB idea with an open mind and a much slower twist than that Hotchkiss has.  That baby gets those bolts up to a terrific RPM with that very quick one turn in 29.83 cals. and 1,300 fps is way too fast.  We love a challenge, and look forward to building a test barrel with a chance of some success.  But, remember this, succeed or fail, we will continue to have more fun than working folks are supposed to have!

Regards,

Mike and Tracy
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline GGaskill

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Re: seacoast
« Reply #18 on: September 11, 2009, 09:14:01 AM »
Good golfers can get straight flight from golf balls.  Now I don't know what kind of velocity they are getting but it is non-trivial.  The spin they get is not axial but perpendicular to the line of flight.  Traditional rifling is not likely to be the answer.
GG
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Offline seacoastartillery

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Re: seacoast
« Reply #19 on: September 11, 2009, 09:42:12 AM »
     Who said anything about traditional rifling?  Sometimes inspiration can come from the strangest sources, like this carpet scrubber!

T&M


Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline carronader

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Re: seacoast
« Reply #20 on: September 11, 2009, 11:22:41 AM »
How come my 4 iron never gives me perpendicular spin..............must be incorrect theory.    Golf balls are for golf...............highly developed for mad people specifically to hit with sticks...............Enjoy cheap ammo..........and lower expectations..............will lead to better hair growth..........and more fun.
Scottish by birth and by heart.

Offline jeeper1

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Re: seacoast
« Reply #21 on: September 11, 2009, 12:41:55 PM »
A year or two ago when golf ball accuracy was being discussed I found this article
http://wings.avkids.com/Book/Sports/instructor/golf-01.html. In it was a section on lift. It also relates to accuracy.
Here it is.
    
 

How a Golf Ball Produces Lift

Lift is another aerodynamic force which affects the flight of a golf ball. This idea might sound a little odd, but given the proper spin a golf ball can produce lift. Originally, golfers thought that all spin was detrimental. However, in 1877, British scientist P.G. Tait learned that a ball, driven with a spin about a horizontal axis with the top of the ball coming toward the golfer produces a lifting force. This type of spin is know as a backspin.

The backspin increases the speed on the upper surface of the ball while decreasing the speed on the lower surface. From the Bernoulli principle, when the velocity increases the pressure decreases. Therefore, the pressure on the upper surface is less than the pressure on the lower surface of the ball. This pressure differential results in a finite lift being applied to the ball.
The dimples also help in the generation of lift. By keeping the flow attached, the dimples help promote an asymmetry of the flow in the wake. This asymmetry can be seen in Figure 5. In this figure, the smoke shows the flow pattern about a spinning golf ball. The flow is moving from left to right and the ball is spinning in the counter-clockwise direction. The wake is being deflected downwards. This downward deflection of the wake implies that a lifting force is being applied to the golf ball.

From reading it I concluded that to get a long straight and accurate shot There needs to be a narrow groove that goes straight up the bottom of the bore. Width and depth to be determined by trial and error.
I may not be completely sane, but at least I don't think I have the power to influence the weather.

Offline RocklockI

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Re: seacoast
« Reply #22 on: September 11, 2009, 01:05:23 PM »
jeeper1 thats a heck of a therory .....i think you are right ! i'd been thinking about this thread and after george said 'conventional rifling wouldnt work '.

i started thinking , but i think you are correct .

wouldnt it be a groove on top of the barrel though ? to create backspin ....
"I've seen too much not to stay in touch , With a world full of love and luck, I got a big suspicion 'bout ammunition I never forget to duck" J.B.

Offline KABAR2

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Re: seacoast
« Reply #23 on: September 11, 2009, 01:06:57 PM »

From reading it I concluded that to get a long straight and accurate shot There needs to be a narrow groove that goes straight up the bottom of the bore. Width and depth to be determined by trial and error.

Is this so you can split the barrel at the bottom? I think I'll stick with lead or zinc.......
Mr president I do not cling to either my gun or my Bible.... my gun is holstered on my side so I may carry my Bible and quote from it!

Sed tamen sal petrae LURO VOPO CAN UTRIET sulphuris; et sic facies tonituum et coruscationem si scias artficium

Offline jeeper1

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Re: seacoast
« Reply #24 on: September 11, 2009, 01:51:58 PM »
The groove could be an arc, not necessarily a slot. Ought not be much as the purpose is just to get the ball spinning on a horizontal axis with the top of the ball spinning towards the launcher.
I may not be completely sane, but at least I don't think I have the power to influence the weather.

Offline dan610324

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Re: seacoast
« Reply #25 on: September 11, 2009, 02:21:03 PM »
whats the minimum speed of the spin to have this work not only in theory ??
how many rotations per a specific distance ??
for example : how many rotations per one feet the ball travelling ??

when you bave this backspin , does the ball go straight then ?? or just straighter ??

last time we talked about this Magnus effect we came to the conclusion that it would maybe be good to have an adjustable screv going through the top of the barrel just a tiny bit from the muzzle
Dan Pettersson
a swedish cannon maniac
interested in early bronze guns

better safe than sorry

Offline RocklockI

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Re: seacoast
« Reply #26 on: September 11, 2009, 03:05:46 PM »
it would have to be a dedicated golfball backspinner only ....like kabar said that could be an issue .

OR redesign the tube to accomadate both .........

or if you turned a chalalie missile upside down , that might work ,if the dia. was right ........and if a four leaf clover in your pocket . upside down too , i spose ..

golfballs would be cheaper ..... ;D
"I've seen too much not to stay in touch , With a world full of love and luck, I got a big suspicion 'bout ammunition I never forget to duck" J.B.

Offline cannonmn

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Re: seacoast
« Reply #27 on: September 11, 2009, 04:14:57 PM »
For a barrel which will spin golf balls the way you want (top surface spins back toward shooter) you simply epoxy a strip of sandpaper to the top of the bore, probably covering about a 60 degree sector or less.  The proper grade of sandpaper would be determined by experiment, but start with a medium grit.  All other parts of the bore will be perfectly smooth.  The drag on the top of the ball caused by the sandpaper coating will spin the ball in the proper direction.  After the principle is demonstrated, a more permanent rough coating may be chosen and applied firmly to the top of the bore.

Or make a golf ball like a yoyo, in two halves with spindle on the axis of rotation.  Wind strong thin braided s/s wire cable around spindle, pull it through an access hole in the breech, and secure it to outside of breech with a clamp  provided for that purpose.  This is after loading powder of course.  When the gun is fired, the unwinding cable spins the yoyo ball in proper direction.  In this case providing straight grooves top and bottom mating with flange on yoyo ball will keep ball from cocking to any position other than vertical.

Have fun!

Offline Double D

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Re: seacoast
« Reply #28 on: September 11, 2009, 05:22:28 PM »
Make sure the material used inthe bore will not burn or smolder between shots.

Offline cannonmn

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Re: seacoast
« Reply #29 on: September 11, 2009, 05:51:45 PM »
Quote
Make sure the material used inthe bore will not burn or smolder between shots.

Wet sandpaper.