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Boring bar holder

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chips&more

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#2
Looks like a good project, go for it! And show us your pictures, we love pictures...Dave
 

mickri

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#3
I am in the middle of making a norman style qctp. So I probably won't make this exact holder. What caught my interest was mounting the holder on the compound in the position that the holder would be used and then drilling the hole for the boring bar with the drill held in a 3 jaw chuck. Doing this would have the boring bar centered with no need for shims. I thought that was a good idea.
 

mikey

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#4
What caught my interest was mounting the holder on the compound in the position that the holder would be used and then drilling the hole for the boring bar with the drill held in a 3 jaw chuck. Doing this would have the boring bar centered with no need for shims. I thought that was a good idea.
If the holder is a stand alone holder that bolts to the cross slide then drilling the bar hole this way is not ideal. Tangential forces will push the tip of the cutter down on contact, thereby reducing relief under the cutting edge and causing the tool to rub. You would then need to shim the holder up by 0.005" to 0.010" before using it.

If you make a holder for use with a QCTP then it might work.
 

Rooster

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#5
Greetings, the last tool post i made is very similar to the one your referring too. I drilled it the same way and with the flats on the boring bar it puts the cutting edge on dead center, works great. DSCN1352.JPG
 

mikey

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#6
Okay, I tried.
 
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