What do you guys think of this?

[FLYBYU]

Hi guys, I'm new here, I just introduced myself upstairs there. I'm currently taking a my pre-apprenticeship machinist course in college and I've finished all my school related projects, so the instructor gave me the okay to build a cannon. I've already fashioned the barrel and right now I'm installing the trunnions. The barrel is machined out of a piece of 2" 1018 round bar. It is 9.5" in length and I bored it out for 7". I drilled it to 27/64ths and then reamed it out to .500". For the trunnions I bored out a 2.750 piece of round bar to just under 2" and then heated it and shrunk it to the barrel. I threaded two 3" pieces of 5/8ths drill rod for .500" and tomorrow I will drill and tap two 5/8th holes in the ring and install the trunnions. I will also drill the fuse hole. I have no idea what diameter to drill the fuse hole to. Any ideas? Also does my setup sound safe to you guys? I will likely try shooting .490 round balls out of it, I will have to figure out a safe powder load when I get to that point. Any ideas that way would be appreciated as well. Thanks for any help.

[RocklockI]

sounds very good , with 2" dia.  and .50 bore there is plennty of wall thickness . i've been drilling fuse holes lately and i like .078" for the smaller standerdized fuse .
25 grains is my load in my .50 loverns cannon .

welcome aboard Gary

will the trunions screw though your shrunk piece and into the barrel ? I would do that .

[gulfcoastblackpowder]

Gary just beat me to it.  Yeah, the wall thickness should be fine.  Are you shaping the profile of the outside, or leaving the full 2"?  General rule of thumb for powder loads in small bores is a MAX load = bore, so 50gr for a .50 cal.  You should work your way up to the ideal load for it, though, since ideal loads aren't usually the max.  Starting around 25gr is a good idea.

Others will offer more (and likely better) advice.  Please post some pictures if you can!

[Double D]

American standard green fuse is 1/8 inch. Rule of thumb is 1 1/2 calibers for the vent hole.  So the vent should be .1875 or 3/16ths.   

[Cat Whisperer]

FLYBYU -

WELCOME to the board.

You're on a roll.

Fuse hole - small = less losses through it.  Suggest 1-1/2 times diameter of fuse; therefore find smallest fuse.

[Cat Whisperer]

American standard green fuse is 1/8 inch. Rule of thumb is 1 1/2 calibers for the vent hole.  So the vent should be .1875 or 3/16ths.   

There you have it - 2 recommedations of same size in a few seconds.

[lance]

Well, i like the 2mm fuse and use a 5/64 drill bit.

[Cat Whisperer]

Well, i like the 2mm fuse and use a 5/64 drill bit.

YUP.  As I learned from Lance - the little stuff also has the advantage of leaving nothing - it is consumed as it burns.  I think that's safer when it comes to reloading for the second shot.

[FLYBYU]

Gary just beat me to it.  Yeah, the wall thickness should be fine.  Are you shaping the profile of the outside, or leaving the full 2"?  General rule of thumb for powder loads in small bores is a MAX load = bore, so 50gr for a .50 cal.  You should work your way up to the ideal load for it, though, since ideal loads aren't usually the max.  Starting around 25gr is a good idea.

Others will offer more (and likely better) advice.  Please post some pictures if you can!

Thanks for all the info guys. I may just drill it to 1/8th to be on the safe side for now, I can always ream it out to a larger diameter at a later date if it's needed. It is 9.5" long and the first 4.5 is full diameter, after that I tapered it at a rate of .750"/ft towards the muzzle. I read somewhere online that your wall thickness should be at least the same thickness as the bore. My bore is .500" and my wall thickness is .750" so I should be set there. As for the trunnions, I'm drilling through the sleeve and into the barrel .100" just as an extra safety guard. I'll post some pics in the next couple of days when I'm finished, right now it's in the shop at school. I have all the parts finished I just have to throw it on the mill and drill and tap everything.

[Double D]

If you make a vent 1/8 inch then be sure you get fuse smaller than 1/8 inch.  Check with www.cannonfuse.com.  They havethe same fuses every one else does and they are cheaper.

[seacoastartillery]

Well, i like the 2mm fuse and use a 5/64 drill bit.

Well, i like the 2mm fuse and use a 5/64 drill bit.

YUP.  As I learned from Lance - the little stuff also has the advantage of leaving nothing - it is consumed as it burns.  I think that's safer when it comes to reloading for the second shot.

     Since 2mm fuse is .0787" and a 5/64" drill bit drills a hole close to .0781", how exactly do you fellows get the fuse down the vent?  Do you have a special wax, fuse lubricant or run it thru a fuse reducing die, or just white knuckle it down the hole?  No criticism here, just wondering, that's all.

Mike and Tracy

Mike here:
    I don't know what the 'BLANK' is going on on this post but I'm usually in the shop WORKING and not fooling around on this computer!
by the by, technically I do agree somewhat with the above post.
Mike

[GGaskill]

We tend to prefer welding the trunnions on guns with high recoil but your smallbore should be OK.  But, if they teach TIG welding, it would be useful to learn how to do that.

[armorer77]

A #29 drill gives a .136 dia fuse hole , good for most 1/8" fuse . Armorer77

[Zulu]

As for the trunnions, I'm drilling through the sleeve and into the barrel .100" just as an extra safety guard.
[/quote]

Some one help me here.  Is this how it should be done?  It seems to me that you shouldn't drill into the bore.  Am I reading this right?
Zulu

[little seacoast]

Zulu, I believe that he is stating that he will drill through the shrunken on sleeve and then into the body of the barrel 0.1" rather than all the way through the barrel and into the bore.   LS

[Double D]

1 1/2 calibers is recommend so the vent hole will not be too tight to slide the fuse in...fuse windage I guess...you want minimal resistance to the fuse sliding in  to assure the fuse goes all the way down into the powder charge.

Since we do have new folks here, the use of calibers here refers the diameter of the object, in this case fuse.  Standard American green cannon fuse is 1/8 in. So one caliber in this reference is 1/8 in inch (.125 in or  3.176 mm).  1 1/2  caliber would be 3/16 inch ( .1875 inch or 4.7625 mm.)

Some are concerned about loss of pressure with this size hole.  The loss is not significant. 

If you cannon is large and heavy enough to use friction caps, you will need a vent slightly larger .200.

A vent hole of 3/16  will also allow of quill.  We have a long discussion in this thread.   More: quill.  You will need a linstock to light a quill.

Here are some of the discussion threads we have had on quills and linstocks

Rolling your own paper quills
more: quill
Paper straws for quills
My Somewhat improved Linstock
Yet another linstock
Today's Project--Linstock
Slowmatch
Making NC Lacquer
KNO3
Lead acetate for Slow Match
How to use a linstock and make slow match

[FLYBYU]

Yes I'm drilling through my sleeve and into the side of the barrel .100" The sleeve will then be threaded and the trunnions will screw into the sleeve and extend into the side of the barrel .100" It is pretty much just a safeguard as the sleeve is shrink fit onto the barrel. I was just going to drill a 1/8th vent hole for now in the shop, just so I have a hole drilled as I don't have the equipment to do it at home. I can enlarge it later at home, but need it drilled beforehand.

[lance]

Well, i like the 2mm fuse and use a 5/64 drill bit.

Well, i like the 2mm fuse and use a 5/64 drill bit.

YUP.  As I learned from Lance - the little stuff also has the advantage of leaving nothing - it is consumed as it burns.  I think that's safer when it comes to reloading for the second shot.

     Since 2mm fuse is .0787" and a 5/64" drill bit drills a hole close to .0781", how exactly do you fellows get the fuse down the vent?  Do you have a special wax, fuse lubricant or run it thru a fuse reducing die, or just white knuckle it down the hole?  No criticism here, just wondering, that's all.

Mike and Tracy

Mike here:
    I don't know what the 'BLANK' is going on on this post but I'm usually in the shop WORKING and not fooling around on this computer!
by the by, technically I do agree somewhat with the above post.
Mike

Well, the 2mm fuse came from Pyrocreations, and it's marked 2mm, burns hot and clean, and it works perfect with a 5/64 drill bit hole, slides right in.

[Cat Whisperer]

Hard to argue with success. 

Drill it 1/8 if you wish. again, I like the really small fuse as it burns completely.

Not having glowing embers in the tube, as I've seen several minutes after firing, is a good thing.

[Cannoneer]

FLYBYU,
There's also another consideration, and that's the appearance/scale of the vent. This stainless naval gun is 10-inches long, .50 cal., and it has a 1/8" vent, which in my opinion looks oversized for the barrel. I've been using 3mm visco fuse with this gun, but I'd like its looks a lot better if it had a smaller diameter vent.

The brass gun shown is 16 1/2-inches long, .91 caliber, and it has a 5/64" diam. vent, which to me looks a lot more in scale with the barrel. I use 1.8mm fuse with this gun.

[FLYBYU]

Nice cannons Boom J, for some reason the 1/8 hole in your 50cal looks bigger then mine. I drilled it out yesterday and to me it looks okay. I'm still not sure where I can get fuse. I live in Canada and I think you need a blaster's ticket or something in order to buy it. I might just have to find someone with a blaster's ticket to buy me some.

[Double D]

Once you get a coat of paint on that stainless gun, the vent will look just fine.

[Cannoneer]

DD,
You know it amazes me that you've held your tongue for as long as you have about this barrel still being bright.   Believe it or not, this barrel will eventually be painted gloss black, and the carriage will be altered to look like W. Greene's plans of one of he carriages from the USS Cairo (that you were kind enough to provide me with).

[dan610324]

yeah DD you are probably correct there
btw , you didnt tell me how you are planning to attach the dolphins on your bronze barrel   

[Double D]

Dolphins? They serve a porpoise?  

[dan610324]

could be nice to have them to save your back when you need to lift that heavy barrel out of its carriage 

[irishman]

FLYBYU, You did a good job of nicely "overbuilding" your barrel. For a 50 cal barrel, I use 3/32 (.093) fuse hole with 2.2 mm/.0781 fuse. They also have 1.8 mm/.071 which some prefer with the .093 hole. I steer all Customers to WWW.cannonfuse.com. As much as I'd like to send fuse with my barrels, I don't have the required "permit". I am sure that they know how to legally ship to you.

I look forward to PICTURES.

                                   Michael

[FLYBYU]

Hi again guys, been super busy lately so sorry for no updates. I finished the cannon on Thursday, but just took pics of it now. I talked to my father-in-law last night, he used to have a big cannon, but sold it. He told me that I can buy cannon fuse for $1/foot at the sporting goods store. I know I can get blackpowder there to. He also gave me some good safety tips about swabbing the barrel out after each shot to get rid of any embers and other things.. Anyway here she is:

[Double D]

Trunnions should be one caliber long and one caliber in diameter. 

I have to admit even though this is not a traditional design and is a bit unusual, I like it.  How about some pictures with a powder can  for scale, even can of Pepsi will help.

 

[FLYBYU]

Trunnions are 5/8 Drill Rod and the bore .500".