Calculating recoil and pressure on capsquares.

[Leatherneck]

In a few weeks I'll be an owner of one of Ed Hart's masterpieces, cant wait. 



The carriage is something I bought from an action figure company. The 1/6 scale detail would amaze you. Hardwood construction, some parts had to be epoxy-ed to stay on.
Capsquare bolts will have to be re-done completly. Probably by drilling 4 holes down the sides of the cheeks for 4 nuts and bolts to hold the capsquares down.



First question:
How much does a 14in x 3in (breech) barrel weigh? I may be way off but Ive seen everywhere from  12 to 20lbs on online weight calculators.
If that is so, the barrel weight itself should buffer the recoil on its own without transferring much more force/torque onto the capsquares and thus the carriage.


Other factors include powder charge weight, projectile weight, overall pressure created by the wad and so on.


Ive worked with lighter pieces in the past and Ive always seen the first signs of pressure on the capsquares, so I want to do it right this time.

I'll work up the charges/loads/pressures over time depending on what I see.
Any info on 1/6 scale guns would be helpful at this point.

[Doc Brown.]

Hi leatherneck. Are you sure the barrels going to fit in the carriage? That carriage in the picture looks kinda small for  a barrel with a 3" breach and the weight depends a lot on the bore size. That carriage is pretty and looks Ford tuff.

[GGaskill]

If the barrel were a 3" D x 14" cylinder, it would weigh about 30 lbs.  A 3" D breech - 2" D muzzle truncated cone would weigh about 21 lbs.  Both numbers would be less if the bore were subtracted but a 1" D x 12" bore would weigh only 1.65 lbs so it wouldn't make much difference.  Without more info, one cannot calculate better answers.

Refiguring with the new numbers, a 2 x 14 cylinder would weigh about 13.32 lbs; a 2, 1.5 x 14 truncated cone would weigh about 10.27 lbs, both solid.  The .5 x 12 bore would weigh about .71 lbs.

[Leatherneck]

My mistake on the breech.
Its 14.5in by 2in breech. Half inch bore.
I dont know how it can be heavier than a rifle barrel of similar specs. Or a rifle for that same matter.

[Cannoneer]

Leatherneck,

I first saw one of these models on eBay, where a crook was auctioning it off as a hand made one of a kind build (with a bronze functional barrel) for over three times the price they retail for.
Now, I don't know what the carriage is made of, or how well it's constructed, but I do know that it was never intended to hold a genuine firing barrel by the manufacturer. Are you sure this carriage is going to be able to withstand the forces that will be exerted upon it when firing a real black powder cannon?

[Leatherneck]

Cannoneer,
There are no differences in the way Dixie's 1/6 carriage was made when compared to mine.
Here is a firing version on the same carriage.
http://www.youtube.com/watch?v=dBe6TZLYSS4

Cheeks are about 1/2" in thickness. Main problem will be drilling the holes for capsquare bolts.

[GGaskill]

Main problem will be drilling the holes for capsquare bolts.

I hope you have both a drill press and an angle plate so you can clamp the cheek pieces vertically when you drill them.  If you do, it will be easy.  If you don't, make some tooling to imitate these pieces so you don't have to rely on eyeballing it.

[Cannoneer]

Leatherneck,

I've never had that model in my hands, and you have, so you should be a better judge of the carriage's sturdiness than I, but I don't think it's a good idea to use "yesnobub" as a yardstick by which to measure safety. I've seen many of this Frenchman's You Tube vids before, and that is a big part of what he's doing; he's building kits and buying models that were only intended for static dispay, and he's "modifying" them to fire projectiles.
His own words from the vid that you posted: "Thanks, I'm gunsmith and designer I make them or modify them by myself... If you want I send U a link of the French site where I put on sale them..."

The first vid I'm posting shows a model from a cheapie Spanish outfit called "Denix"; the barrels are made from some kind of zinc based potmetal alloy, and they're cast hollow, so he must be fixing some form of steel tube in the barrel (at least I hope it's steel and has a breech). The second vid shows another zinc barreled hollow cast piece of junk from Denix, and this time you can see the thin insert he put in the tube. The third video shows an Italian model companies version of an imagined American CW gun. I had one of these when I was a kid; the companies name was Aeropiccola, and the barrels they made were cast brass (hollow). Needless to say, none of these models were ever intended to be fired.

[Doc Brown.]

Heres a retro fit a guy I know did. He took a 10 to 12" .75 caliber stainless steel signal cannon barrel and put it on one of them little toy carriages. Notice how he had to flip the wheels around to get it to work. Im sure if this thing was loaded up good the cannon would do back flips.

[GLS]

Like In Cannoneer's post I just recently acquired one of the  Denix cannons as in his first video.  This Is the one that calls itself a Dahlgren 1861. Not.  I bought it cheap for the carriage since I thought I could take the lazy route in carriage construction.  This model is now selling for two to three times the price I paid for mine.  I have taken the measurements of the barrel, sent them in and have  commissioned Brooks to make me two golden barrels to fit this carriage, one napolean and one parrot.  Both barrels will be .30 cal as I plan for it to be a firecracker cannon.  I am in the process now of tearing bown the carriage, tighten things up and painting it in proper colors.  If this works out as planned I am sure Brooks can make more for those that have one of these carriages.

[armorer77]

Here is my version of this barrel
 

 
She is pretty . But the design is muzzle heavy .    Ed

[Double D]

Here is my version of this barrel
 

 
She is pretty . But the design is muzzle heavy .    Ed

So remove the two moldings in front of the  muzzle flare and cut the muzzle flare off saving the moulding between chase and swell. Turn a section of the barrel a cylinder.  Make the cut off flare a sleeve and put the flare on the cylinder section so it sticks beyond the flare to make new muzzle moldings

[GGaskill]

How muzzle heavy?