# Measuring cuts lengthwise?



## Jmanb13 (Apr 5, 2017)

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?


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## David S (Apr 5, 2017)

As delivered I guess the short answer is that you don't.  However you can add a DRO to the X axis, or you can add a "travel dial" to work with short X axis cuts.

I do lots of accurate short length cuts and have added a 1" travel dial to the the ways.  It is adjustable so I can move it along the ways, and it has a built in travel stop, for repeat work.




David


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## Ed ke6bnl (Apr 5, 2017)

put a DTI digital test gauge on the travel and see if the readings are 1/2 the cut depth or is the actual amount of the depth of cut. on my lathe if I move the dial .010 it will take .010 off the diameter or a .005 depth in the cut. sorry I did not notice you meant along the bed length, I have used a 2" magnetic DTI on the ways to check distance moved.


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## Tozguy (Apr 5, 2017)

The carriage hand wheel on my lathe has a dial but it is .020'' per mark or .660'' per turn........too coarse for most purposes.
For more precise control, with the carriage locked and the compound set parallel to spindle axis, feeding with the compound will give .001'' increments.
Otherwise a dial indicator on the ways is good for up to 1'' movement.


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## British Steel (Apr 5, 2017)

I have a trav-a-dial on mine (if you haven't seen them, they're attached to the carriage and have a wheel that rides on the front shear, geared to a dial graduated in thou"), they can be a bit clunky on small lathe's and possibly lose some carriage movement, or I can use slip gauges or length rods in the tray on the front way cover in combination with the micrometer stop and stop rod if I want better than a thou".
Depending on the length of cut, people fit dial indicators on bed clamps against the carriage, you could do similar with a vernier / dial / digital caliper?

I did measure a rotation of the carriage handwheel and it's precisely 1.025", so if I could gear it 40:41 I *could* put a 1" dial on it, but I'd only get fussy and want a metric/imperial geared dual dial...

Dave H. (the other one)


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## Silverbullet (Apr 5, 2017)

We usually measure the cut has we do it a mark with a scale for quick measure then we Mic or vernier it to length. I have a long adjustable stop rod that I can use to set stops for doing lots of parts . Of course now everyone has electronics. But in my ancient youth that's the way we worked , print in hand.


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## Jmanb13 (Apr 5, 2017)

David S said:


> As delivered I guess the short answer is that you don't. However you can add a DRO to the X axis, or you can add a "travel dial" to work with short X axis cuts.
> 
> I do lots of accurate short length cuts and have added a 1" travel dial to the the ways. It is adjustable so I can move it along the ways, and it has a built in travel stop, for repeat work.


I'll look into DROs. However I think I remember glancing at them in the past and I remember them being rather expensive, especially for someone just getting started and tinkering in their garage.



Ed ke6bnl said:


> put a DTI digital test gauge on the travel and see if the readings are 1/2 the cut depth or is the actual amount of the depth of cut. on my lathe if I move the dial .010 it will take .010 off the diameter or a .005 depth in the cut. sorry I did not notice you meant along the bed length, I have used a 2" magnetic DTI on the ways to check distance moved.



Its funny you mentioned this. I actually was looking at the depth of cut yesterday on my cross feed and its measured in actual removed material. So if I move it 1 full turn (0.250), it moves .125" to remove a total of .250 of material. Good knowledge for using it.



Tozguy said:


> The carriage hand wheel on my lathe has a dial but it is .020'' per mark or .660'' per turn........too coarse for most purposes.
> For more precise control, with the carriage locked and the compound set parallel to spindle axis will give .001'' increments.
> Otherwise a dial indicator is best.



That is a good idea, If I need to be really precise it will definitely work.



British Steel said:


> I have a trav-a-dial on mine (if you haven't seen them, they're attached to the carriage and have a wheel that rides on the front shear, geared to a dial graduated in thou"), they can be a bit clunky on small lathe's and possibly lose some carriage movement, or I can use slip gauges or length rods in the tray on the front way cover in combination with the micrometer stop and stop rod if I want better than a thou".
> Depending on the length of cut, people fit dial indicators on bed clamps against the carriage, you could do similar with a vernier / dial / digital caliper?
> 
> I did measure a rotation of the carriage handwheel and it's precisely 1.025", so if I could gear it 40:41 I *could* put a 1" dial on it, but I'd only get fussy and want a metric/imperial geared dual dial...
> ...



I'll look into those trav-a-dials and carriage stops.



Silverbullet said:


> We usually measure the cut has we do it a mark with a scale for quick measure then we Mic or vernier it to length. I have a long adjustable stop rod that I can use to set stops for doing lots of parts . Of course now everyone has electronics. But in my ancient youth that's the way we worked , print in hand.



Thanks Silverbullet! I can understand cut and measure, repeat. However, how would you control the cut to a more precise movement than the carriage wheel? Would I do something like Tozguy said and just turn the compound parallel and use it for the final cuts?

Is there such a thing as a universal carriage stop? They look pretty basic in design, but since I don't have a mill yet, I don't think I would be able to fabricate one to fit over my V ways.


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## RJSakowski (Apr 5, 2017)

I have a carriage stop on my lathes and if I want to machine to a precise length as in distance to a shoulder, I will set the stop up with a spacer equal to the length I want to turn.  Then I face off the end and remove the spacer.  I can then turn to the stop knowing that I won't overshoot.  The spacer can be anything handy; drills work well for short distances.  I have some blocks of various thickness that can be stacked.  A simple adjustable spacer can be quickly assembled from hardware store parts.  Adjust the length with calipers and tighten the jam nut to lock.  Works great when making a bunch of identical parts


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## RJSakowski (Apr 5, 2017)

Jmanb13 said:


> I'll look into DROs. However I think I remember glancing at them in the past and I remember them being rather expensive, especially for someone just getting started and tinkering in their garage.


Take a look at the iGaging DRO's. They are reasonably priced and will measure to .001". A quick search brought this one up.  It's one of many vendors. http://www.micromark.com/iGaging-Easy-View-Digital-Remote-Readout?ounces=42


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## Bob Korves (Apr 5, 2017)

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


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## Wreck™Wreck (Apr 5, 2017)

Bob Korves said:


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


Have you never made a part longer then 1"?

For speed and ease of use a DRO is the way to go for the Z axis.
If one requires more Z accuracy the rod and micrometer head stop as used on jig bore machines is an excellent choice, fussy however and very few lathes are so equipped, choose wisely.
A very high end DRO will probably get you to where you need to be unless you are chasing tenths.


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## British Steel (Apr 6, 2017)

Jmanb13 said:


> Is there such a thing as a universal carriage stop? They look pretty basic in design, but since I don't have a mill yet, I don't think I would be able to fabricate one to fit over my V ways.



Hacksaw, file, care and attention can make most things a mill can make...

Dave H. (the other one)


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## Charles Spencer (Apr 6, 2017)

British Steel said:


> Hacksaw, file, care and attention can make most things a mill can make...



I made my first lathe stop for my South Bend by cutting the "v" with a horizontal band saw and finishing it by filing.  I tapped a hole and used a nut and bolt as RJ mentioned above.  Later I made one that held a 1" dial indicator.  For lengths longer than 1" I set it up using gauge blocks.


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## Jmanb13 (Apr 6, 2017)

British Steel said:


> Hacksaw, file, care and attention can make most things a mill can make...
> 
> Dave H. (the other one)





Charles Spencer said:


> I made my first lathe stop for my South Bend by cutting the "v" with a horizontal band saw and finishing it by filing.  I tapped a hole and used a nut and bolt as RJ mentioned above.  Later I made one that held a 1" dial indicator.  For lengths longer than 1" I set it up using gauge blocks.



I will probably try something like this, as I just ordered a 1/2 plate to mount on my harbor freight bandsaw in its vertical position. Should allow me to cut a decent V groove and then file it to fit perfectly.


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## Charles Spencer (Apr 6, 2017)

Just noticed - brain fart.  I meant vertical band saw.


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## Bob Korves (Apr 6, 2017)

Charles Spencer said:


> Just noticed - brain fart.  I meant vertical band saw.


You burst my bubble, Charles.  I was thinking, wow, this guy is REALLY good!  And you probably are...


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## Charles Spencer (Apr 6, 2017)

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.


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## darkzero (Apr 6, 2017)

Bob Korves said:


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





Wreck™Wreck said:


> Have you never made a part longer then 1"?



Before I had a DRO all I used was a 1" dial indicator with mag back mounted on the way. Of course I made parts longer than 1". I would zero the cutter, move 1" on the DI, reposition the DI to zero, move the carriage again, & repeat till I got to the length I needed. Slow process but it worked for me. I had a 2" DI but I liked using the 1" better.

I still use that 1" DI for threading though. Digital sucks when you have to stop at a reading instantly.


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## darkzero (Apr 6, 2017)

Stefan Gotteswinter made a pretty cool indicator mount for his lathe that uses a cam lock lever. Seen @ 20:38







And Randy Richard recently made an interesting mag mount digital scale for his lathe. If interested there's also a follow up video as well as one that he made for his tail stock.


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## Bob Korves (Apr 6, 2017)

darkzero said:


> I still use that 1" DI for threading though. Digital sucks when you have to stop at a reading instantly.


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.


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## darkzero (Apr 6, 2017)

Bob Korves said:


> 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.


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## BGHansen (Apr 7, 2017)

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


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## sanddan (Apr 7, 2017)

Bob Korves said:


> 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.


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## Tony Wells (Apr 7, 2017)

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.


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## ch2co (Apr 7, 2017)

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.


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## Rustrp (Apr 7, 2017)

Jmanb13 said:


> 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.


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## Bob Korves (Apr 7, 2017)

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...


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## JimDawson (Apr 7, 2017)

Jmanb13 said:


> 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.


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## epanzella (Apr 7, 2017)

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.


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## Downunder Bob (Apr 8, 2017)

Charles Spencer said:


> 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.


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## LarryJ (Apr 8, 2017)

Wreck™Wreck said:


> Have you never made a part longer then 1"?
> 
> For speed and ease of use a DRO is the way to go for the Z axis.
> If one requires more Z accuracy the rod and micrometer head stop as used on jig bore machines is an excellent choice, fussy however and very few lathes are so equipped, choose wisely.
> A very high end DRO will probably get you to where you need to be unless you are chasing tenths.



Cost wise, there is the mag-based dial indicator, a shop-made base for said indicator, or a thousand for a DRO.  Newbs like me generally go with the mag base DI for under $25 _first_.  To measure more than 1", set up, move he carriage, then reset the DI.  It takes maybe a minute per extra inch and saves $975, WreckWreck.  

Also, beginners are unlikely to have tight new machines capable of doing repetitive work in tenths, but could probably happily stumble upon it on occasion.  That's the way I've always done it.  <toothless grin>


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## LarryJ (Apr 8, 2017)

darkzero said:


> Stefan Gotteswinter made a pretty cool indicator mount for his lathe that uses a cam lock lever. Seen @ 20:38
> 
> 
> 
> ...



Wow, information density in Stefan's video was spectacular.  Great vid!


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## Bob Korves (Apr 8, 2017)

It is well worth subscribing to Stefan's channel.  It is one of the best.


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## marchyman (Apr 8, 2017)

I made a cam lock indicator holder for my previous lathe.  A cheap mag indicator holder works fine for my current mini-lathe.


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## Silverbullet (Apr 8, 2017)

My first lathe used to make money was an old Sheldon. I made a stop on my drill press for it. I used a 1" x  3" x  2". I drilled a 1/2" hole thru the 3" length about 1" from the edge. Stepping up from 1/8" to 1/2" three drilling total. Then I found where I could mount it on the head stock using existing threaded holes two are needed. Drilled those to clearance to mount the block . Using a 1/2" x 12" steel rod my stop was almost done a 1/4" -20 hole drilled thru the side into the 1/2" hole made my stop adjustment. At the end of the rod I drilled a 1/4" hole for a stud to mount dial indicator , or stop block. As long as you stop power feed and hand finish it will recut every time to the stop. No mill needed to make a usefull  stop.


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## Rustrp (Apr 8, 2017)

bobshobby said:


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


I'll add; I was told that a mistake was something that couldn't be fixed.   When the result turns out not being what I was attempting to achieve I save it for a later date when the application fits.


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## Wreck™Wreck (Apr 8, 2017)

LarryJ said:


> Cost wise, there is the mag-based dial indicator, a shop-made base for said indicator, or a thousand for a DRO.  Newbs like me generally go with the mag base DI for under $25 _first_.  To measure more than 1", set up, move he carriage, then reset the DI.  It takes maybe a minute per extra inch and saves $975, WreckWreck.
> 
> Also, beginners are unlikely to have tight new machines capable of doing repetitive work in tenths, but could probably happily stumble upon it on occasion.  That's the way I've always done it.  <toothless grin>


It was a joke, the thought of turning 50 inch long parts one inch at a time made me laugh a good deal, no offence intended, do what you have to do to make it work.


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## blu73 (Apr 9, 2017)

I just looked at most of the posts in this subject and it's possible I missed what I'm about to say, so please bear with me if I repeat what someone else has already said.

I just finished doing work that required me to make a lot of parts on a lathe where I needed to stop the cut at four inches in Z.  I had a lot of success with a one inch travel indicator mounted on a magnet and stuck to the bed near the head stock.  Once I established the four inch stopping point on the first part, I put the indicator on the bed and positioned it against the saddle with five turns of the travel used up on the dial.  I then moved to my starting point. got everything going, and engaged the feed lever.  All I had to do then was watch for the saddle to get close to the rod of the indicator and once it was contacted, just count five revolutions of the needle.  When it got to the fifth turn, I disengaged the half nut at zero and could do it within plus or minus .001 consistently.

Okay, with that being said, I feel I need to let everyone know that this is my first posting here and I don't really know the protocol, so I will sign off with my first name only.

Russ


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## brino (Apr 9, 2017)

blu73 said:


> Okay, with that being said, I feel I need to let everyone know that this is my first posting here and I don't really know the protocol, so I will sign off with my first name only.



Hi Russ,I'm glad to see you jumping into the discussions.
Welcome to the Hobby Machinist!
-brino


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