Drilling out a barrel or Shock and AWWWW,,

[john pike]

coming back from getting my carrage bolts from the hardware store,
i stopped at a local machinest, hes got some nice BIG machinery,

and asked him how much to drill out my 1018 for my 1/2 scale Howitzer,

i figure ill make up some kinda jig,  for my small lathe myself,

he wanted 350.00

i can get a finished cannon for that,

johnp

[GGaskill]

Unless he has a gundrilling machine or spade drills with high pressure coolant, that is not too excessive since deep hole drilling with ordinary tooling is slow.  

How big is your lathe?

[john pike]

Unless he has a gundrilling machine or spade drills with high pressure coolant, that is not too excessive since deep hole drilling with ordinary tooling is slow.  

How big is your lathe?

yr gonna be on the floor laughing,,,,,

9X20  a little bugger, used to have a 12X36 i miss it,

ive got a big mill, but no room,

johnp

[GGaskill]

I think drilling an 18" barrel (about 14" hole as I recall) will be virtually impossible on a short machine like that.  You should be able to do the outside but to use it for drilling, you'll have to make a bed extension that lets you move the tailstock off the end far enough to get the drills in place.  That is not impossible.

I did such a thing for my 17x54 when I had to turn 6' poles for a project.  It was easier in my case as the tailstock could be bolted in one position rather than having to slide down the bed, but you don't need to make the extension from cast iron since it won't be used very much.  You do need to get the V way on the extension accurately aligned with the one on the lathe bed or you will get an oversize hole from the misaligned drill.  Be sure to supply a foot under the extension so you aren't cantilevering the weight of the tailstock from the bed.  And provide a way to tie the extension to the bed so it isn't forced away by the drilling force.

[john pike]

I think drilling an 18" barrel (about 14" hole as I recall) will be virtually impossible on a short machine like that.  You should be able to do the outside but to use it for drilling, you'll have to make a bed extension that lets you move the tailstock off the end far enough to get the drills in place.  That is not impossible.

I did such a thing for my 17x54 when I had to turn 6' poles for a project.  It was easier in my case as the tailstock could be bolted in one position rather than having to slide down the bed, but you don't need to make the extension from cast iron since it won't be used very much.  You do need to get the V way on the extension accurately aligned with the one on the lathe bed or you will get an oversize hole from the misaligned drill.  Be sure to supply a foot under the extension so you aren't cantilevering the weight of the tailstock from the bed.  And provide a way to tie the extension to the bed so it isn't forced away by the drilling force.

i was thinging of taking off my tailstock, and moving the carrage down to the end,
making a mounting for the 4X18 round , removing the toolpost,
and mounting it,

putting the drill bits in the 3-jaw,  move into the drill,  back out,

probably only drill a few inches switch bitts, to a larger size, making room for extensions,
back and fourth, for ever,
then move the round forward, in the mounting, when needed,
also having a weight in front of the carrage to balance it,

im working on having someone else do it for me, if its a fair price,
just the drill bitts would cost me an arm and a leg and im shure the poor little lathe would take a beating,

johnp

[GGaskill]

The only problem I see here is keeping the hole centered in the bar.

[Cat Whisperer]

....
and asked him how much to drill out my 1018 for my 1/2 scale Howitzer,

he wanted 350.00
....
johnp

John -

I have a 5" diameter x 19" long piece of 4140 that cost me (including materials) $220 to be drilled/bored to 24oz soda pop caliber and a 1" diamber powder chamber too.

That is to say, I think he's counting the cost of buying/making a boring bar on your one job.

Shop around.

ALSO, look at CJ's thread on how she did her cannon - seems to me that she drilled and bored in on a relatively normal sized lathe.

There are quite a few things you can do by putting you mind to it and thinking through each process.  There may be some non-standard ways that can be made to do the job - and safely too.  

CJ bored her cannon tube to take a steel liner - and had it pressed in - see the thread.

[Cat Whisperer]

John -

Here it is: http://www.graybeardoutdoors.com/phpbb2/viewtopic.php?t=13760&postdays=0&postorder=asc&&start=0

It is well worth the reading to go through all 4 pages of posts - it covers the whole project day by day with design considerations (bronze with a steel liner) and shows pictures of the drilling/boring process.

[john pike]

....
and asked him how much to drill out my 1018 for my 1/2 scale Howitzer,

he wanted 350.00
....
johnp

John -

I have a 5" diameter x 19" long piece of 4140 that cost me (including materials) $220 to be drilled/bored to 24oz soda pop caliber and a 1" diamber powder chamber too.

That is to say, I think he's counting the cost of buying/making a boring bar on your one job.

Shop around.

NOPE, i had to supply the 4X18 1018, steel,

75.00 at my local yard,

i keep starin at my mill, im thinkin of twistin the head around to the back of it, away from the table, pouring a concrete saunatube table,
with bolts like a light-pole base,
makin up a steel plate, and leviling with the bolts,

then i can drill straight down,  ive got three inches of quill,
so id use some 3inch blocks, and keep blocking it up, and down,


another idea,,, dontcha love setting it all up,,,grin,,


johnp