Radius/diameter turning mode

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Scorn64

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I’m a novice machinists that just ordered a new lathe. I’m starting out by adding a DRO to the lathe. (TouchDRO)

What is everyone’s opinion on using radius vs. diameter mode? Because I’m just starting out I have the opportunity to get accustomed to either.

Is it better to view numbers as a finished amount or to just remember that the value is doubled? I know it’s six of half a dozen of another, but I just wanted the opinions of people who have used both.
 
I would set it the same as the handwheel increments. I have learned to love the diameter mode, which my new lathe came with.
 
I use diameter because that's how the drawings & my brain both work. I normally turn until a clean round, mic, then set the DRO so when I get to final it reads zero. Just before final I'll mic again just to be sure. If there are several diameters on one part I'll just set to diameter and put a cheat sheet where I can easily see it. Works better than my memory.
 
I use both. I have a lathe specific DRO display so it has a button to toggle back & forth. Some universal DRO displays do not have the radius/diameter mode button. I'm not familiar with the TouchDRO, if it doesn't have the toggle button, perhaps it's feature that may be hidden somewhere or could possibly be programmed in?

If I didn't have the toggle button, I personally would set it to radius mode. Higher resolution & it would be just like when I used my lathes before having a DRO. My current lathe has indirect dials & I prefer it that way.
 
I love diameter mode. Set so the cross slide movement toward center is the negative direction.

Take a cut, mic the diameter, the plug the measured diameter into the DRO for X. Then, the x value on the DRO is the diameter of your part. As you get close, you can still take measurements and light cuts to hit tighter tolerances.

If the tolerances aren't tight, just take cuts until the DRO displays the diameter you want to hit.
 
I’m getting a LMS 5100 so the dials will be off a little in imperial. The thought was it wouldn’t matter that the pitch of the lead screws was metric when using a DRO. The DRO does have a button to turn from one mode to the other.
 
It's entirely about what makes more sense to you. Personally I also suggest you turn it off for now and learn to use the dials. It gives me a much better feel for what's going on when I can see the dials smoothly turning rather than some abstract number on a display. It will also teach you to sneak up on a measurement instead of relying on the readout.

A lot of manual lathes have dials that read the diameter, and a lot have dials that read the radius. Mine reads the diameter, so it's what I'm used to.
 
I agree with regard to learning the dials first. I just got my first DRO a year ago. Used dials for a decade and a half. It's like stickshift vs Auto. Learn stickshift first and you'll be able to drive nearly anything.

My first lathe was all metric. .05mm handwheels. I spent my first 5 years converting everything inch into mm before taking cuts. Is your LMS5100 dials graduated in mm, inch or both?
 
I have a lathe with metric lead screws on the cross feed, the compound and the tailstock and (approximate) inch dials. I installed the TouchDRO which I use in inch mode and diameter readout. To set the x DRO, I turn a diameter and measure it with my mike and set the x axis to the measured value. Since I work to drawings or other specifications where diameters are called out, I am set to go as long as I am using the same tool. I will reset the DRO with each tool change.

I did most of my machining without the benefit of a DRO so machining consists of making a cut or several cuts and measuring to verify my cut(s). I still do this in spite of having a DRO when dimensions are critical.
 
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