Line boring help needed

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Naiveambition

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I'm getting setup for a line boring job and have some ?s about setup.

First being how do you measure the distance of the cutter head. My guess is half diam. of bar plus tool extent.

Can this be done on a 4 jaw setup, or with lathe dog/plate setup only. Most info I've read so far push torwards between center for accuracy, though if the 4 jaw is dialed in, how am I gaining?.

And, I have a big line boring bar from a freebie load, but is a little bent, if I true it up to a smaller diameter to take out the bend will it run true afterwards.
 
Have a look at kieth fenner youtube channel look for a series called because i can , he does a line boring job on an engine block . It doesn’t matter the size of the engine as the principles are the same .
You should be able to turn your bent bar between centres to true it up , depending on how bent it is of course ! Also look for between centres boring as that is what some also call it .
 
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If the boring bar is as crooked as dog leg it will still bore a perfect cylinder. Assuming is rigid and the way are parallel to the line between centers.
The cutting tip describes an immovable circle, the piece moves, is just a matter of geometry.
 
I make a boring for the job
If your boring is in lathe using center a bent bar will work

Dave


I'm getting setup for a line boring job and have some ?s about setup.

First being how do you measure the distance of the cutter head. My guess is half diam. of bar plus tool extent.

Can this be done on a 4 jaw setup, or with lathe dog/plate setup only. Most info I've read so far push torwards between center for accuracy, though if the 4 jaw is dialed in, how am I gaining?.

And, I have a big line boring bar from a freebie load, but is a little bent, if I true it up to a smaller diameter to take out the bend will it run true afterwards.
 

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