Cannon/mortar casting

[Musketeer]

I am totally new to this interesting hobby,  so I am looking for advice on building my first cannon or mortar.  I notice that most of the cannon or mortars made on this forum seem to be made on a lathe, which I do not have.  I am thinking of casting one out of scrap brass, about 10" long. The casting I think I can handle but how do I drill out the bore?  Will a drill press do ?  Do I need to be concerned about the metal used?

Any and all comments and advice will be greatly appreciated

[GGaskill]

Have you ever done any metal casting?  Check out this thread for some discussion of casting a half scale mountain howitzer.

[jeeper1]

Will a drill press do ?

Not really. Unless your DP has a really long spindle stroke (I've only seen one in my life) you will not be able to clear the chips without disturbing your setup often.
An alternative would be to use something like this which has an 8.5 inch spindle stroke.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=44991
That will also let you mill out where the trunnion(s) will go.

[longcaribiner]

A great many years ago, I helped cast a cannon barrel of iron.    We made a rather detailed wooden mock cannon (less bore) and packed it, I mean really packed it half deep in sand and then added the top frame of the "mold" and packed the other half.     The sand was made real sticky by adding molasses (really!)   we then cut sprue holes and took the halves apart and took out the wooden model.    I wasn't there for the pouring.   After the casting cooled, the barrel was x-rayed and then bored out on a jury rigged home made maching that spun the cannon barrel against the stationary cutter.  Then it was reamed by hand with a hand forged reamer. The the cast trunnions were trued up by hand with a brace and another hand forged cutter.    It was finally vented.     Finally x-rayed again and test fired.  The whole process took longer than I had patience for but it made for a great little cannon.  As I recall, the tube was 28 inches long, about 5 inches in diameter at the breech and 4 inches at the muzzle with a 1.5 inch bore.    We made a model for a thunder mug too, but I never saw that finished product.   

       

[entsminger]

    I really like the story about all the home made jury rigged stuff that allowed you to make a cannon! Shows that if you really want to do something you don't need all the fancy equipment. Sounds like the kind of way I would approach things since I don't have access to lathes and milling machines etc. I guess if you could make a mortar that way, you could really go to town with a  large lathe. I'm hoping to make a shootable mortar some day ( if I ever get a large enough lathe)  like a full scale 8 or 10 inch 1861 siege mortar but for now I have found an old piece of solid steel round about 3 inches in diameter and about 5 inches long and I am going to try and bore/drill it out on my junky drill press and weld on trunions etc etc.. to make a mini mortar.

  Scott Springston

[Rickk]

entsminger,

last week I drilled some 1 inch holes thru some 3/16 steel with my drill press, using a reduced shank drill. It really taxed the drill press alot.

Make sure you have the piece being drilled securely clamped in place with a really heavy vice. The torque of the big drill will want to make things vibrate. If it vibrates, the drill will constantly stick and drive you crazy. Keep the hole full of oil as well. If you see smoking oil, stop and have a cold one while you let things cool off or you will wreck your drill.

Rick

[Div Arty]

     Rickk
            You mentioned using oil while drilling or in fact any cutting.   In the past I think that I remember you saying an automotive oil.  I have done a lot of machine pipe threading and the Ridgid recommendation was to use a sulpher based cutting oil.  It dosn't lubricate as much as it lends itself to cutting.  Just a thought and I'm sure that GGaskill would be kind enough to correct me if I'm wrong.
          Div Arty

[Rickk]

My motivation for the oil is to keep things cool. I tend to use whatever is within arms reach. I usually have an old fashion oilcan full of 10w-30 hanging around. I have also used PB-Blaster and WD40. They all keep the bit cool.

I know there are cutting oils designed for cutting different kinds of metal, but my level of comprehension does not go that far. What the best oil is for steel or where to get it I have no idea.

I do know that if you overheat a cutting edge, it will get dull instantly and never hold an edge again... I learned that from cutting 10 cords of firewood a year with my chainsaw. When the oil starts to smoke, it is time to stop or the edge temper will be damaged. If the edge has tured blue from being overheated it will not hold an edge any longer.

Come to think of it, chainsaw oil may work good too... it is sticky and does not throw itself off quite as fast.

Rick