Before turning a barrel question

Before turning a barrel question

Joined: April 25th, 2008, 12:25 am

March 8th, 2012, 8:03 pm #1

Do you drill the inlet port hole first on the blank and then turn it -
or turn the end and then drill the hole ?

what do you do and why ?
cheers
James
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Joined: November 15th, 2009, 8:24 pm

March 8th, 2012, 8:17 pm #2

Hi James,

It makes no difference at which order of operation you drill the hole as far as how the hole itself turns out. Indicate to find center and then use a spotting drill to start.

I think it does make a difference in your turning however if you drill the hole first. With the hole already in your work when the tool bit comes in contact with the drilled hole this interruption can cause some problems. Chatter of the bit is one. Another is if you are using carbide tooling it very well may chip the cutting edge of the tool off.

Good luck!
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Joined: October 21st, 2001, 3:36 am

March 8th, 2012, 9:45 pm #3

Do you drill the inlet port hole first on the blank and then turn it -
or turn the end and then drill the hole ?

what do you do and why ?
cheers
James
Is your shop ready?

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Joined: May 8th, 2001, 4:06 pm

March 8th, 2012, 11:24 pm #4

Do you drill the inlet port hole first on the blank and then turn it -
or turn the end and then drill the hole ?

what do you do and why ?
cheers
James
when you drill the hole, you often have to mill a flat, so can use the same setup just changing the drill to an end mill
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Joined: August 22nd, 2001, 3:27 pm

March 8th, 2012, 11:49 pm #5

Do you drill the inlet port hole first on the blank and then turn it -
or turn the end and then drill the hole ?

what do you do and why ?
cheers
James
transferport hole after you have made the lead in for the bolt, because weather you cut, ream or grind the lead in, the transferport hole will cause the lead in to be off center, due to a lack of material in that area. HTH.
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Joined: April 25th, 2008, 12:25 am

March 9th, 2012, 6:33 pm #6

Do you drill the inlet port hole first on the blank and then turn it -
or turn the end and then drill the hole ?

what do you do and why ?
cheers
James
might as well ask before I make a newbie mistake.
cheers
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Joined: February 1st, 2008, 3:28 am

March 10th, 2012, 3:02 am #7

Do you drill the inlet port hole first on the blank and then turn it -
or turn the end and then drill the hole ?

what do you do and why ?
cheers
James
once the diameter/o-ring groove/lead-in is configured, the barrel can be put in 5C collet blocks where the transfer port is drilled and faced. The barrel can then be turned over in the blocks to mill any flats, etc. as needed. It may be useful to practice this with some aluminum or drill rod before machining is done on the barrel.
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