Hello all, got a question for you guys. I’m currently in the process of boring a hole to 1.3457. My initial hole measured .7695. So I touched off on my id and zeroed my dro, ran my cross slide out to .5762, then returned to the id to start my boring operation. My thinking is that as I feed out my cross slide, all I have to do is bore till I reach my diameter of zero on my dro. Am I correct or am I not doing the math right? Just not sure if I need to cut my measurement in half or what. Thanks in advance for any help you can offer.
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Need help with boring on the lathe
- Thread starter Pevehouse
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- Nov 25, 2015
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Why not take a cut, measure, then punch in your measurement?
That makes too much sense,lol. I took your advice and started boring and measuring and so on. Seems I would need to decide my number in half to hit my mark
Well, I hit the mark. It’s a slip fit. Just about perfect. Did not want a press fit due to the fact it’s going on my milling machine spindle. It’s a collar that slips around the spindle, where the collet alignment pin threads into the spindle. This will allow me to use the square Bridgeport style alignment pin that has a backup set screw that kind of jambs the alignment pin tight if you follow what I’m saying
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It doesn't need to be. But if you want your dials to be close to exact, then the BB has to be on the centerline axis. If you do bore above or below the CL axis, compensate when you dial in a depth-of-cut.
Just be sure that you aren't rubbing (burnishing) on the part. Burnishing will often give you a better finish.
Is your DRO set to radius mode (tool movement) or diameter mode (half of tool movement)? You do have to keep track of those for various operations...
I find that boring bars cut best when they're on or just above center. If you're getting better results below center, I wonder if you're rubbing a little, burnishing the surface so it "appears" like it's cutting better... Surface finish with a tool hung way out like that is always an issue to manage as you're going.
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you are not working off diameter on your DRO? Can't you set it that way. It makes your work much more accurate, no mistakes, just read what's on the dial.
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