# Boring on a G0602



## Transformer (Jul 21, 2014)

I am planning a project where I would take say 3" diameter stock 3" long and bore a 2.25" hole to a depth of 2.25".  How would I do this? This must be a job for a boring bar.  I have looked at utube and there are videos on the use of boring bars but they start with a big hole and then enlarge it.  If you have no hole to begin with how do you start? Also when you are not going through the stock how do you make the bottom of the hole flat?  My experience is still being measured in hours so I might try this in plastic before trying in metal.
Thanks, Transformer


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## zmotorsports (Jul 21, 2014)

Generally when boring a hole or through bore you start with a pilot hole just large enough to fit your boring bar into.  I have a 1/2", 5/8" and a  3/4" boring bar so depending on what size finished hole I need I will choose the correct boring bar.

Chuck it up in the lathe and use your tailstock mounted drill chuck to drill the holes.  Once you get to the size your boring bar fits, install the boring bar into the toolholder and touch off.  Making note of your size once you reset to zero then calculate how much you need to remove.  I generally go up to .010" of an inch with roughing cuts and then take the final .010" as a finish cut for a smooth consistent looking finish.

Also, when boring to a flat bottom hole, I run up against a softstop to again, within a few thousandths and then the final cut to proper depth.

Mike.


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## dave2176 (Jul 21, 2014)

Chuck the piece up and use a center drill to get a good center start. Mark a 1/4" drill so you don't go to deep. Step up to your biggest bit being careful not to to deep. Switch to your boring bar and complete the hole. A boring bar can also clean up the bottom.
 Dave

edit: Mike types faster, what he said. )


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## Transformer (Jul 22, 2014)

Thanks Mike and Dave: what is a soft stop?


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## Andre (Jul 22, 2014)

Transformer said:


> Thanks Mike and Dave: what is a soft stop?



A soft stop is an indicator on the ways, here is a Toms Techniques video on the subject (he is a fellow member here, although dismissed)

https://www.youtube.com/watch?v=Uyj3UO9s5Fw&list=UUqR9wRW2JYXOlpqiN8C0dIg


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## zmotorsports (Jul 22, 2014)

Andre is correct.  A softstop is merely a dial indicator that you run up to a predetermined reading.  Much different than a hardstop as you can power up to a  softstop, I do NOT recommend ever power feeding up to a hardstop.

Mike.


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## chuckorlando (Jul 22, 2014)

Is it not proper/acceptable practice to drill as large of a starter hole as you can? Heck of alot faster to drill out then to bore almost 2" at .010 at a time.


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## Fabrickator (Jul 22, 2014)

*"Is it not proper/acceptable practice to drill as large of a starter hole as you can? Heck of alot faster to drill out then to bore almost 2" at .010 at a time"*

My G0602 won't drive a drill that large w/o a lot of chatter and very large drills are very expensive.

Depending on what it's for and the desired wall thickness, I would take a look at getting some tubing that is closer to the inside dimension when possible, the outside dimension is easier to deal with.  It sounds like a cylinder to me.  McMaster-Carr sells ductile iron tubing in short lengths (12") that work great for a cylinder.


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## JimDawson (Jul 22, 2014)

chuckorlando said:


> Is it not proper/acceptable practice to drill as large of a starter hole as you can? Heck of alot faster to drill out then to bore almost 2" at .010 at a time.




I would say generally yes, that's the way I have always done it.  A blind hole requires cleanup in the the bottom if it needs to be flat, but I think that the time to clean up the bottom would be less than boring a little at a time.

I read somewhere that drilling is the most efficient method of metal removal.


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## chuckorlando (Jul 22, 2014)

Oh I dont mean drill a 2in hole. I just mean use as large as you can to start. This is how I try to do it even on my 9x20. I mean if you can step up from a center drill to a 3/4 or what ever, in steps, thats just less to bore. I'm asking more then stating.


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## zmotorsports (Jul 22, 2014)

That is what I have always done.  If for example I need a perfect 1" hole, I will bore to either just over 5/8" or 3/4" diameter (depending on OD of part as well) and then use either a 5/8" or 3/4" boring bar to take it to size.  

I generally don't use much over 7/8" drill bits anyways, I prefer to take out as much metal with drill bits up to around the 5/8"-7/8" and over that boring comes into play.

Mike.


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