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bigloudvtwin

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#1
I'm going to be chucking uo a piece of steel round stock 4" dia x 10" long. I want to bore into it approx. 8" deep. Final bore size to be 1.675 (golf ball interference fit). I don't have any drill bits this long to make a pilot hole for bar clearance.
Can I do the entire hole with a boring bar from a flush face to final cut?
I can either buy a bar or build a tool holder for a smaller bar. Just need the right angle on the cutting face. My experience with cutting angles is a trial and no chatter/galling error process.
Thanks
 

Richard King 2

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#2
What kind and size lathe do you own? What type of tool holder? Do you have a boring bar? What size taper in your tail stock ?

Have a steady rest? It's hard to help with out know these things..... Rich
 

RJSakowski

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#3
I'm going to be chucking uo a piece of steel round stock 4" dia x 10" long. I want to bore into it approx. 8" deep. Final bore size to be 1.675 (golf ball interference fit). I don't have any drill bits this long to make a pilot hole for bar clearance.
Can I do the entire hole with a boring bar from a flush face to final cut?
I can either buy a bar or build a tool holder for a smaller bar. Just need the right angle on the cutting face. My experience with cutting angles is a trial and no chatter/galling error process.
Thanks
When I need an extra long drill bit, I make them. Turn down the shank of the drill bit to around 2/3rds the diameter of the drill. Select a rod equal to or smaller than the diameter of the drill and bore a socket to fit the turned down shank. Insert the drill into the socket and fix by brazing, silver solder or Super Glue.

I would make the hole starting with a small diameter pilot and stepping up the size until it was convenient to bore with the boring bar.

You can bore a hole without a pilot with the right shaped bit. It is more tedious due to the zero radius cutting.
 

RJSakowski

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#4
BTW, welcome to the group!
 

Asm109

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#5
You need a 5 inch long drill. Drill from each end then use a boring bar from one end to clean up the hole and make it one size from end to end.
 

BtoVin83

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#6
IMHO trying to do it straight away with a boring bar will give you nothing but grief. Three choices come to mind, make a longer drill as RJ suggested (I always piloted them together and silver soldered), use tubing and make a breech plug, make/buy a spade drill. Spade drills work really well we had one 4 feet long.
 

chips&more

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#7
Making a golf ball cannon are you? To just make this a boring bar operation would be VERY challenging. I would pre-drill then bore to size…Dave
 

RJSakowski

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#8
You need a 5 inch long drill. Drill from each end then use a boring bar from one end to clean up the hole and make it one size from end to end.
I believe the OP stated that he wanted to bore a hole 8" deep in a 10" bar, the implication being that it is a blind hole.
If it were a through hole, I would definitely drill from either end.
 

rock_breaker

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#9
My 30 caliber canon made of 1.25" rebar (don't remember the number) was thru bored then plugged by a threaded plug. For added safety a cap was threaded over a 3/4" button that the plug is in. I misplaced the fuse hole to far forward which causes enough recoil to hit a target about 2 feet above the level barrel when fired about 1.5 feet away. It is a good noise maker but if I ever get serious about hitting targets the fuse hole will need to moved back almost to the rear of the bore,
If as conjectured earlier you are going to shoot golf balls compressed air is a lot more manageable than black powder.
Have a good day
Ray
 
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