Measuring cuts lengthwise?

[darkzero]

For sure! It is a lot easier to stop the carriage while watching the needle swing around the indicator than watching a bunch of flickering numbers. DRO's work for that job, but not as well for me. I can open the half nuts on a 20 TPI thread at 300 rpm within a few thousandths using a dial indicator, but I do not have any DROs so I have not learned the skills of using one.

IMO it's impossible trying to stop on or close to a number when the carriage is power feeding with a DRO. If there's people out there that do it, I have no idea how & give them 2 thumbs up. Full on DROs are awesome (not talking about the simple igaging units, nothing against them though) which I did not realize until having. So much more you can do with them, saves LOTS of time, and yes I will say it, it can make you a better machinist.

For the same reason, you won't see digital numbers for the tachometer on a race car. Even on supercars where an analog needle can't keep up with how fast their engines rev, they use a full digital display but the tach is still displayed as a needle on a dial.

 

[BGHansen]

I use a 2" travel dial indicator on my Clausing which doesn't have a DRO. Have a DRO on my Grizzly G0709. I also use a vernier caliper and/or a depth micrometer off the tail stock end of the stock. Set the caliper and/or mic to the depth, set the mic/caliper on the end of the stock, move the carriage until the tool bit touches the end of the mic/caliper.

Tom's Technique's (Google to find his site) has a nice project with a dial indicator mounted on the bed. There's also the micrometer stop option.

Bruce

 

[sanddan]

A 1" dial indicator with a magnetic back does the same job as the fancier solutions and is transferable to different machines and axes...

That's what I used before getting a DRO. I still like it as it's easier to see when you are close vs trying to watch the DRO screen. Both are useful additions to the lathe.

 

[Tony Wells]

I use my DRO to set my dial indicator when threading. All turning on the lathe that has a DRO is done using it. The other lathe I use an indicator only at the end point if it is longer than the travel. If it's a long distance, I set the indicator with a mic standard, in the same fashion as a jig bore, more or less.

 

[ch2co]

Dial indicators with magnetic backs. I have one of unknown manufacture that is ok (not OK), but when I tried to add a magnet
to the back of other dial indicators, they don't indicate in a linear manner. There must be magnetic susceptive parts inside. Just wiggling
a magnet around even one of my Starrett indicators changes readings when a magnet is attached to the back. Are there specific dial indicators
that don't react to magnets? Granted most of the magnets that I have are dang strong compared with those a couple of decades ago.

 

[Rustrp]

Since i'm a beginner here, maybe i'm missing this, but how does one judge a cut along the bed?

I've searched for the answer here, but haven't run across anything yet.

The cross slide and the compound slide both have graduations for cutting into the work, but how would I know how much i'm cutting along the work?

Begin with the precision rule with the hook on the end and then use the caliper and Mic to do your final. The DRO is always good until something trashy gets involved and you move your carriage 6" and the DRO only indicates 5.50". Measure twice and cut/drill once.

 

[Bob Korves]

Let's put this in perspective. Most of us, as hobby-machinists, rarely need to make a part with a truly accurate Z dimension. Sure, we can use our tenths indicating tools to make sure the cup holder we are making for our lawn chair is accurate enough in depth, but maybe that is a non critical dimension in the big picture, unless of course that is what makes you happy. Critical dimensions and whatever dimensions are often just the whim of whoever is drawing the part, how many digits they like to see beyond the decimal point as a tolerance. It is not very often that I need a Z measurement on a lathe that is required to be checked with more than a pocket rule, using the coarsest scale. Of course, I will try to hit my number anyway, because we are always practicing for the more difficult ones. Many times we force ourselves into tight boxes because we do not get the big picture in our heads before we start. Sure, I can use a stack of gage blocks wrung together to make a hole to the same depth as the length of the rod that goes into it, or I can just make it fit the rod, which is after all the master gauge for the job...

 

[JimDawson]

Since i'm a beginner here, maybe i'm missing this, but how does one judge a cut along the bed?

I've searched for the answer here, but haven't run across anything yet.

The cross slide and the compound slide both have graduations for cutting into the work, but how would I know how much i'm cutting along the work?

I normally use a tape measure or a scale, close enough for most work. If I really need to get accurate, I make the part long and face to length using the compound to set set the tool and using a caliper to measure.

 

[epanzella]

I use a 2 inch DTI as I often need more than 1 inch. I like the dial much more than digital readout as it's easier to anticipate the stopping point.

 

[Downunder Bob]

Not that good.

I did used to tell the young guys that I zeroed my rifle by firing a three round burst just for confirmation. And that the first thing I did when I got a new pencil was tear off the eraser and throw it away - never had any use for them.

I was told that a man who claims to have never made a mistake, quite likely never made anything.