Author Topic: Group buy-group pour, bronze 24 PDR Coehorn golf ball mortar (Read 27507 times)

RocklockI · « **Reply #60 on:** August 11, 2011, 02:47:52 PM »

Some updates of todays work and pics ......

But first I would like to go on record to say ,if it were me I would not now or ever buy one of these !
It is severly flawed in almost every way there is .....MULI DIMENSIONAL FLAWS at that !

It really does not resemble a 24lb cohorn in any real way .

Also it is only an inturpetation and all dims. were are are 'felxable'

If fact I scaled 90% if it , and god knows it shows . Verily screaming for advise, suggestions, and well meaning comments.
Lastly it is BLUE why hasn't any one suggested that I not make it BLUE ,.......I may be on the Pablo Piccasso side of cannon making ,but at least I know it should not be BLUE.

If one was to look very closly one may or may not be able to tell that the muzzle is not finished .

Also ,Tracy covered all the potty mouth jokes about it's physical apperance some that were funny and some that were not

,so I heard that too already .

So with out further comment here are the pics .no flash gaurd ,no tapered chamber , unfinished muzzle ....and BLUE
There are flaws you dont even see yet . So I have something to look foward to .

Guys this is and always has been a proto type mostly having to do with my idea of casting IN the bore and chamber . I don't know and noone else does either what the bore size will come out at .

I have arbitrarily chosen the bore size ,and now need to 'see' how it comes out and what it measures . NO I won't say what my target number is ...for oblivous reasons

.

THIS gun Is not going to be used a a mold master , things could change . Plus I want to see the casting these guys do B4 I 'throw in ' with them . Since my name will be on each one they must conform to some standard of quality ....with all known flaws intact .

In all honesty I do appericiate the comments . This has been a fun project .
Gary

GGaskill · « **Reply #61 on:** August 11, 2011, 03:09:59 PM »

Not to be too picky here but the breech end of a US Coehorn has a 6.5° taper, not a cylindrical section before the hemispherical part.

Double D · « **Reply #62 on:** August 11, 2011, 03:57:06 PM »

The Breech end is an outer wall that is parallel to the inner wall of the gomer chamber

seacoastartillery · « **Reply #63 on:** August 11, 2011, 06:01:42 PM »

Quote from: RocklockI on August 11, 2011, 02:47:52 PM

Some updates of todays work and pics ......

Also ,Tracy covered all the potty mouth jokes about it's physical apperance some that were funny and some that were not ,so I heard that too already .

Guys this is and always has been a proto type mostly having to do with my idea of casting IN the bore and chamber . I don't know and noone else does either what the bore size will come out at .

In all honesty I do appericiate the comments . This has been a fun project .
Gary

Gary, all I said was the shape of the prototype's end had the shape of a Bilboe which is a type of leg restraint used in the American colonies and elsewhere in the 1630s until the mid 1800s. He must have thought I said something else which sounded similar.

As far as suggestions which you said you would appreciate, I would change only outside appearance issues, nothing inside until the first proto is cast, so you can check out and adjust the wax's bore size if necessary and then get a second proto cast.

Tracy

Double D · « **Reply #64 on:** August 11, 2011, 07:40:16 PM »

Thisi what it suppose to look like.

keith44 · « **Reply #65 on:** August 11, 2011, 08:10:50 PM »

so for those of us who are accustomed to straight walls (powder chambers, muzzleloaders, and BP cartridges) what would be the advantage of such a powder chamber?

gunsonwheels · « **Reply #66 on:** August 11, 2011, 11:42:00 PM »

keith44:

Quote

...what would be the advantage of such a powder chamber?

I assume you mean 'other than just getting more powder in it'...??

Double D · « **Reply #67 on:** August 12, 2011, 03:42:25 AM »

A quote from Gibbons:

Quote

The Gomer chamber (after its inventor) consists of the frustrum of a cone connected with the
bore by a portion of the surface of a sphere. This kind of chamber is considered the most
.advantageous for mortars, and is used in most of ours. Being large at the mouth, it allows
the powder to act on an entire hemisphere of the projectile, and no risk is run of breaking it.
It, however, gives a less range than either of the others, but its capacity is greater.

Cannoneer · « **Reply #68 on:** August 12, 2011, 04:22:21 AM »

Quote from: keith44 on August 11, 2011, 08:10:50 PM

so for those of us who are accustomed to straight walls (powder chambers, muzzleloaders, and BP cartridges) what would be the advantage of such a powder chamber?

Keith,
Check out this thread; there are descriptions of gomer and cylindrical type powder chambers on page two.

http://www.gboreloaded.com/forums/index.php/topic,85639.0.html

keith44 · « **Reply #69 on:** August 12, 2011, 08:00:33 AM »

Ok that helped. Thanks for the sidebar.

RocklockI · « **Reply #70 on:** August 12, 2011, 03:10:22 PM »

More progress today

The trunions are long to accomadate the feed lines .

The lighting on the bottom picture makes it look like there is light shining thru there is not .

Gary

keith44 · « **Reply #71 on:** August 12, 2011, 08:12:03 PM »

so what pressure levels are expected when firing this mortar? will that blue prototype be fired to test the range capabilities of this wonder wax mortar?? Will the base also be made of this material?

keith44 · « **Reply #72 on:** August 12, 2011, 08:13:45 PM »

just kidding, I for one am hoping this works, it'd be interesting to see what could be "cast in"

RocklockI · « **Reply #73 on:** August 12, 2011, 08:28:42 PM »

"Eat the rock candy ? No, it's just for looking at

!"

The blue mortar will be be fired ....BIG time ,but it will be in a burn out oven ....

poor blue wax mortar .

But then a golden one will replace it .

keith44 · « **Reply #74 on:** August 12, 2011, 09:42:55 PM »

Quote from: RocklockI on August 12, 2011, 08:28:42 PM

"Eat the rock candy ?

I'll never tell

GGaskill · « **Reply #75 on:** August 13, 2011, 09:22:19 AM »

I know the current wax is an experiment but don't forget to put rimbases on the final one.

RocklockI · « **Reply #76 on:** August 13, 2011, 11:45:04 AM »

Todays update

She's looking good !

I made and attached the 'rimbases' . I called them gusets

Gary
Next will be the vent and vent 'relief'

GGaskill · « **Reply #77 on:** August 13, 2011, 07:08:03 PM »

Looking good.

RocklockI · « **Reply #78 on:** August 13, 2011, 11:33:24 PM »

Another hour or so and all is sealed up with disclosing wax . That is the white stuff ,it is a thin shoe polish like wax that is used to seal off any area that isnt perfect .

As you can see I need to go back and clean it up some more . The good news is that the picture is @ 4 times as big as the real thing . putting this wax in place is done with dental picks .

Just another day of bashing Tom .

Gary

RocklockI · « **Reply #79 on:** August 14, 2011, 01:25:00 PM »

It is done . Today was touch hole and shallow 'pan' (the tri angle shape around vent) .
Here you can see it's weight in wax , multiply by 9.1 for actual wieght it's right at 4.5 lbs .

The next pics are of the vent .

I really hope this can be a mold making piece, because I am very happy how it came out ...so far .

Gary

Zulu · « **Reply #80 on:** August 14, 2011, 01:48:10 PM »

Gary,
Is this lost to make a mould? Then your mould can be used many times?
Zulu

RocklockI · « **Reply #81 on:** August 14, 2011, 03:23:15 PM »

In my spare time today I made another mortar . This is is the 'crash test dummy' this bore is the same as the 24lber as is the outer ring . This one will be cast B4 the 24 lber hopefully the is will shrink to the correct number .

THEN the go ahead will be given for the 24lber mold to be made .

As it's an experiment ,I decided to add a dolfin which is a sea monster or shark .
I like dolfines

Zulu, If /when this is used to make a mold more than likly it would be destroyed . Maybe not as I am not sure how the mold will be made . I have used wax to make molds B4 , they get slit open and the wax gets scored when mold halves are seperated.

Spuddy · « **Reply #82 on:** August 14, 2011, 04:56:41 PM »

Great job Gary!

DaveSB · « **Reply #83 on:** August 14, 2011, 06:34:07 PM »

Nice work Gary! I like the progress... I am also a fan of dolphins (sp?), I'm very anxious to see bronze pouring on this project!

GGaskill · « **Reply #84 on:** August 14, 2011, 08:47:29 PM »

Once again, just to be helpful, there appears to be a small cavity in the corner between the left rimbase and breech in the following picture:

It may just be a color difference but I can't tell.

Cat Whisperer · « **Reply #85 on:** August 15, 2011, 01:33:51 AM »

Those were DENTAL pics that he used to put it in place - that dark spot might be left over from breakfast.

RocklockI · « **Reply #86 on:** August 15, 2011, 05:27:54 AM »

It is just a discoloration

. It is a bit of red wax ,and not breakfest

.

Gary

Cannoneer · « **Reply #87 on:** August 15, 2011, 06:40:23 AM »

Quote from: RocklockI on August 14, 2011, 01:25:00 PM

Rocklock,
In this photo, the surface plane of the left rimbase doesn't seem to be parallel wth the axis of the bore, it appears to be placed at an angle.

keith44 · « **Reply #88 on:** August 15, 2011, 08:44:18 AM »

Quote from: Cannoneer on August 15, 2011, 06:40:23 AM

Quote from: RocklockI on August 14, 2011, 01:25:00 PM

Rocklock,
In this photo, the surface plane of the left rimbase doesn't seem to be parallel wth the axis of the bore, it appears to be placed at an angle.

So? A bit of file work can straighten that out on the finished casting if needed.

GGaskill · « **Reply #89 on:** August 15, 2011, 09:16:18 AM »

A bit of file work can straighten that out on the finished casting if needed.

It's a lot easier to fix it once on the soft wax than fix every casting in hard metal.

Poll

I would buy...

Author Topic: Group buy-group pour, bronze 24 PDR Coehorn golf ball mortar (Read 27507 times)