Mortar Building Folly

[LivnDream]

Well being that i am now addicted to cannon's and mortars i decided to build myself a golfball coehorn  mortar
i thought to my self i know someone with a lathe ill buy some steel and make one.
so off i went i was on a mission hmmmm.
Well i got to Friends house  to begin turning a coehorn barrel.
turned out that his lathe is a southbend lathe built in 1943 a 9x36 with belt drive.
so to work i went,  everything was going good till it was time to start drilling the bore.
i drilled with a 1/2 drill first then to 1"  this lathe would not go as slow as it need to go to drill a 1" hole
so it was really slow going with all the chatter going on
finally i got the 1" hole drilled and realized we did not have a 1.75 drill bit and no bore bar
so i was stuck with a coehorn with a 1" bore
so i thought well at least its got plenty of wall thickness as it 4" round
so on to rounding off the back end took it out of the chuck
to turn it around and it fell on the bed ways and put a big dent in the muzzle end
so i went to work fixin that
now on to the rounding of the outer breach end
chuck would not tighten up to hold it
so it was not going to have a rounded end
now it was on to the base and the trunnion straps
which after all the trouble thus far went without a hitch

so here for your viewing pleasure is the result of my folly tryin to make myself a golfball coehorn
i guess it didn't turn out to bad for my first attempt at building a mortar

[jeeper1]

Do you think the walls are thick enough?
I've got the metal laying around here to build another mortar and I thought I'd do the same way as did only with smooth sides. 

[LivnDream]

so it looks like a mortar and sounds like a cannon best of both worlds

i have a cad file of the base sides if you need

[lance]

well for now you don't have to worry about buying golfballs. but in the future the day will come..........

[jeeper1]

I have neither a lathe nor a mill. I am saving up for the drill bit I'll need, $65 is a lot for one drill bit for just one hole. Then there is the cost of the hone.

[LivnDream]

as we speak i have a guy making me a soda can coehorn  on a cnc lathe
mite have another toy in a few weeks or less

[LivnDream]

the price kinda stoped me at 1" when i seen how much a 1.75 drill bit was
not to mention lathe wouldnt ever go slow enough to drill it

[Cannonball]

A 4" bar wit a 1" bore, this may be a blessing in disguise. My GB cannon is the same diameter of your mortar and the walls are too thin for a lead ball,(maybe with seriously reduced loads??)  I know that and you know that but the guy who borrows it off your son thirty years from now might not! Even a double charge with two balls probably won't burst her! Besides, she looks mean as hell! Nice work.

[GGaskill]

... not to mention lathe wouldnt ever go slow enough to drill it

I can't imagine you couldn't slow the spindle down for a large hole by putting the machine in back gear.

When starting a large hole, you will get chatter until the full diameter of the drill is in the hole and can be guided by the sides of the hole.

[LivnDream]

when i tried to put the lathe in back gear the motor wouldn't turn the spindle
would just stop the motor

[Cat Whisperer]

when i tried to put the lathe in back gear the motor wouldn't turn the spindle
would just stop the motor

Is there a locking pin that ties two gears together (for high speed) that needs to be disengaged for back gear speeds?

[m223]

Thanks for sharing your tale with us Livindream. I especially liked the part were the mortar fell onto the ways and dented up the muzzle. It is best to put a piece of wood under the chuck when dealing  with heavy hot metal. I feel your pain as I did the exact same thing. Live and learn. Sorry you didn't get the bore you wanted, but I think you did a great job making lemonade from lemons. Nice looking piece!