# Could I get a definition of Run-out?



## TellicoTurning (Feb 21, 2009)

I know I'm being a little dense, but you get that with bone heads and non-engineer types... 
I read all the comments about this and while I'm pretty sure I understand the concept, but would someone give me a precise definition of "Run-out"... how you determine the amount, measurements, etc... Thanks.


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## GoodTurns (Feb 21, 2009)

usually, if I run-out, the measure is a fifth :wink::biggrin:


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## GaryMadore (Feb 21, 2009)

How about this one: Mechanical Runout is a measure of the shaft’s deviation from a perfectly uniform radius as its circumference is traversed. This type of runout can be measured by a dial indicator.

And before some engineering geek beats me to it: Electrical Runout is a measure of a shaft’s electrical property variations as its circumference is traversed. (This type of runout cannot be measured by a dial indicator.)

Other definitions include that "radial runout" is how much a spindle "wobbles" at its end, while "axial runout" is how much "play" there is perpendicular to the axis of rotation.

If we're talking drill presses and lathes, and the associated bearings, we're talking axial. If we're talking bent shafts, we're talking radial.

Er, I think.

Cheers!

Gary


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## mrcook4570 (Feb 21, 2009)

(Usage 1) If I run out of beer in the fridge, then I 

(Usage 2) must run out to the store to get more.:biggrin:


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## TellicoTurning (Feb 21, 2009)

GaryMadore said:


> How about this one: Mechanical Runout is a measure of the shaft’s deviation from a perfectly uniform radius as its circumference is traversed. This type of runout can be measured by a dial indicator.
> 
> And before some engineering geek beats me to it: Electrical Runout is a measure of a shaft’s electrical property variations as its circumference is traversed. (This type of runout cannot be measured by a dial indicator.)
> 
> ...


  Okay, that clears it up as clear as mud.  :biggrin::biggrin::biggrin::biggrin::biggrin:
I told you I'm a bone head,  you gotta speak in red-neckeze or should that be Applachian American???.. :laugh::laugh::laugh::laugh:


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## GaryMadore (Feb 21, 2009)

ozmandus said:


> Okay, that clears it up as clear as mud.  :biggrin::biggrin::biggrin::biggrin::biggrin:
> I told you I'm a bone head,  you gotta speak in red-neckeze or should that be Applachian American???.. :laugh::laugh::laugh::laugh:



I just added to my original reply.

Mechanically speaking, there is "wobble" and there is "play"

Wobble is produced by bent shafts and is called "radial runout"

Play is produced by loose bearings and/or bushings, and is called "axial" runout.

Both are generally measured with dial indicators, although when I was drill press shopping I measured "axial runout" by extending the quill all the way, grabbing the chuck, and seeing if I could wiggle it. This measurement meant something to me, while a number (yeah, she's good for about 3 thou') would not have.

Cheers!

Gary


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## ed4copies (Feb 21, 2009)

*Simple definition*



ozmandus said:


> I know I'm being a little dense, but you get that with bone heads and non-engineer types...
> I read all the comments about this and while I'm pretty sure I understand the concept, but would someone give me a precise definition of "Run-out"... how you determine the amount, measurements, etc... Thanks.


 
Happy to, Chuck.

We don't eat dinner until about 10:45 PM while we watch Jay Leno.  AFTER dinner, every night, I enjoy a bowl of ice cream.  Unless I 
RUN-OUT!!  (Of ice cream) this is definition number one.

This leads, inexorably, to definition number two: I then RUN OUT to the car and RUN OUT to the gas station, which is, exactly .7 miles (3696 feet) down the road, where I can purchase ice cream at midnight. This leads to definition number 3:

When I return, and it is below zero, Dawn will proclaim, "What have all the brains RUN OUT of your head????  Going outside to get ice cream on a night like this is STUPID!!!  Of course, I'm a guy, I've learned to say, "Yes, dear" while I scoop out the evenings ice cream, sit down and enjoy, before going to bed under the electrically pre-heated covers.

HOPE THIS HELPS!!!


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## bad (Feb 21, 2009)

I'm a Canadian eh, so I don't necessarily speak Appalachian red neck but let me give it a try.

The easiest way for me to explain run out is to talk about a metal lathe. If you take a piece of metal, say aluminum, that is 10 inches long and 1/2 (.500) inches wide and mount it in your metal lathe and turn it down to say, 3/8 (.375) inches wide. If you then remove the piece from your lathe and measure it and find that it is .375 inches wide at one end and .365 inches wide at the other end you have a .010 inch run out over 10 inches. In other words your cutting tool isn't running exactly parallel to the work mounted in your lathe.


I hope this helps y'all.


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## skiprat (Feb 21, 2009)

Run out is a method of dismissal in the sport of cricket. It is governed by Law 38 of the Laws of cricket.

Hope this helps:biggrin:


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## holmqer (Feb 21, 2009)

A lot of folks have talked about what, I'll talk about how.

To measure the Total Indicated Runout TIR on the morse taper of your lather, you take a Dial Test Indicator which is a fancy measuring device that has a pin sticking out that can be pushed back and forth. You mount this gizmo on a stand such that the pin is parallel to the lathe bed, and the head of the pin is just inside the taper on your headstock, gently pressing against the inside of the taper.

You then turn the spindle by hand and observe the Dial.

Any wobble or out of roundless in the taper will make the needle swing.

The total range of that swing is the Total Indicated Runout of the taper.

Two common Dial Test Indicators are 0-4-0 or 0-15-0 which means they can measure +/- 0.004" or +/- 0.015". The 0-4-0 typically has an accuracy of 0.0001" while the 0-15-0 typically has an accuracy of 0.0005"

This TIR gives you some indication of the best accuracy you can possibly achieve with a taper mounted item in terms of wobble of the thing you are turning.

The problem with this measurement is that it does not tell you if the taper is crooked, which would make the accuracy of the taper even worse.

But for a dead center or spur center this is pretty irrelevant as the tip of the drive is so close to the taper that any error in the taper being crooked would have minimal impact.

For a taper mounted collet chuck, this would be relevent.

The other TIR measurement you can make is of the registration ring which is the metal ring that your chuck ends up pressed against when it is screwed onto the spindle.

You measure this with the pin perpendicular to the bed, touching the ring.

This measurement gives you an idea of the best case angular error when using a thread mounted chuck. It does not tell you how well centered your chuck will be on the threads, only how square it could possibly be.

This is important as you get away from the spindle. For example;

Assume 1 1/4" 8 TPI spindle thread.

The registration ring has a radius of around 7/8"

Lets assume the TIR of the registration ring is 0.0005"

So for every 7/8" away from the ring, you will get 0.0005" error plus whatever error you have in offset placement.

Assume you have a Talon Chuck which is 3" from registration ring to its jaws, and are holding a 5" long piece of wood. So the end of the wood is 8" away from the registration ring. The best you can hope for is that 0.0005 * 7/8" * 8" or 0.0035 wobble at the end.

In reality it would be worse than that because the error in the threads will always have the chuck somewhat offset from dead center adding to the above error.

This is partially why metal working lathes use 4 jaw chucks with each jaw independantly adjustable. You can correct for chuck mounting errors by tweaking the jaws to get the item perfectly centered relative to the spindle.


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## devowoodworking (Feb 21, 2009)

holmqer said:


> A lot of folks have talked about what, I'll talk about how.
> 
> To measure the Total Indicated Runout TIR on the morse taper of your lather, you take a Dial Test Indicator which is a fancy measuring device that has a pin sticking out that can be pushed back and forth. You mount this gizmo on a stand such that the pin is parallel to the lathe bed, and the head of the pin is just inside the taper on your headstock, gently pressing against the inside of the taper.
> 
> ...


 
Yeah that pretty much sums up 'RUN ON'...and on..and on...:biggrin:


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## leehljp (Feb 21, 2009)

And to sum up in different words:

"Run out" is precisely how much something wobbles off of "true". Most saw blades "wobble" a tad. "Run out" on a blade will increase the kerf width by how much run-out it has.

As an analogy: Some roads are 14 ft wide per lane, some 12 ft and some are 10 ft wide. A car is 8 ft wide. If the car goes down a straight road and "wanders" a 'tad' from side to side within its lane (instead of tracking perfectly in the center of its lane) that is kind of like the "run-out". *Run-out is the difference in how how much it SHOULD take versus how much it ACTUALLY takes to operate.*

On machinery, tolerances and "run out" are in miniscule amounts but the miniscule amounts are still "huge" when it comes to the finished product. 

A dial indicator (click here) measures how true or untrue something moves out of tolerance (or perfection), in my example these three cases:

Mandrel shaft - A mandrel shaft that has wobble or is not perfect will show up on the dial indicator as being off center as it rotates. Rotate the mandrel (on the lathe of course) with the dial indicator touching the mandrel. The dial indicator will show how much it is moving out of true center. This is Run-out.

Lathe Chuck - Do the same as with a mandrel shaft and find out how much the lathe chuck is moving out of center / off center as it rotates one revolution. This is run-out.

Table saw blade - Place the dial indicator so that it is very near the SIDE of the blade where there is metal all the way around, i.e. not at a gullet or open space; rotate the blade until the dial indicator tip and the blade are furtherest apart. Move the tip to barely touch the blade, reset the dial indicator to "0"; rotate the blade - and the dial indicator will tell you how much the blade is "running out" from true center.


The above explanation is over-simplified and is not perfect (it has some "run-out" :wink, but it is the gist of the meaning.


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## bad (Feb 21, 2009)

devowoodworking said:


> Yeah that pretty much sums up 'RUN ON'...and on..and on...:biggrin:



ROTFLMAO


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## tim self (Feb 21, 2009)

bad said:


> ROTFLMAO




Not me, I thought I knew what it was, now I'm more confused than ever.  Heads swimmin' like after a 12 pack.


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## TellicoTurning (Feb 22, 2009)

All of you guys are engineers (Except Ed) aren't you:biggrin:

In Redneckeze, if it wobbles you got run-out.... Huh??:hammer: but this will fix it.(Red-neck repair)


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## leehljp (Feb 22, 2009)

ozmandus said:


> All of you guys are engineers (Except Ed) aren't you:biggrin:
> 
> In Redneckeze, if it wobbles you got run-out.... Huh??:hammer: but this will fix it.(Red-neck repair)



OK Chuck - in a language you can understand: IN your past line of work, a person comes to you and wants to ship something from New York to Paris in the most direct way possible. You fix up the papers, dot the "i" and cross the "t". The package leaves New York, goes to Spain and then to Paris. That is the equivalent to "runout". :biggrin:


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## ed4copies (Feb 22, 2009)

leehljp said:


> OK Chuck - in a language you can understand: IN your past line of work, a person comes to you and wants to ship something from New York to Paris in the most direct way possible. You fix up the papers, dot the "i" and cross the "t". The package leaves New York, goes to Spain and then to Paris. That is the equivalent to "runout". :biggrin:


 

Watch your analogies, Hank.

In Tennessee, they call that "direct".  New York - Hawaii  - Paris  "Scenic".  And they NEVER RUN!!  So, it would be "wobble" to Southeasterners.  Or "mosey out".


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## Woodlvr (Feb 22, 2009)

Ozmandus,
    Thanks for asking the question now it is as clear as mud for me also.:redface::biggrin:


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## ed4copies (Feb 22, 2009)

Woodlvr said:


> Ozmandus,
> Thanks for asking the question now it is as clear as mud for me also.:redface::biggrin:



"Mosey out" would translate as an "evening stroll" in your part of the country, Mike.


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## Woodlvr (Feb 22, 2009)

ROTFL:biggrin:


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## amosfella (Feb 22, 2009)

I"m sorry, we ran out of definitions for run-out.  Please check back in a few days.  We don't have an e-mail when In stock option, so you have to continue looking.  But, please, feel free to look around for our other fine definitions.  Maybe you'll find another one you'll like.......


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## Chasper (Feb 22, 2009)

Thanks, I've been wanting to ask that question for quite some time, but I was afraid if I asked someone would either give me a wise guy answer, or a technical answer that I could not understand.  Now I know that my fears were not unfounded.  But the answers are pretty funny and I think I understand, almost.


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## AceMrFixIt (Feb 22, 2009)

In my book, run out means......slop.......


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## TellicoTurning (Feb 22, 2009)

leehljp said:


> OK Chuck - in a language you can understand: IN your past line of work, a person comes to you and wants to ship something from New York to Paris in the most direct way possible. You fix up the papers, dot the "i" and cross the "t". The package leaves New York, goes to Spain and then to Paris. That is the equivalent to "runout". :biggrin:




Oh No... That's normal Taxicab routing.. maximizing the routing for the bottom line.. S.O.P.......:biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin::biggrin:


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## bitshird (Feb 22, 2009)

Y'all jus ain't takin this hear mater ta hart caint a po apalachain amurikan ax a simpel quesion an get uh ez anser y'all ain't rat


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## GaryMadore (Feb 22, 2009)

Chasper said:


> Thanks, I've been wanting to ask that question for quite some time, but I was afraid if I asked someone would either give me a wise guy answer, or a technical answer that I could not understand.  Now I know that my fears were not unfounded.  But the answers are pretty funny and I think I understand, almost.



Is my answer, provided earlier and quoted below, really hard to understand?


"Mechanically speaking, there is "wobble" and there is "play."

Wobble is produced by bent shafts and is called "radial" runout.

Play is produced by loose bearings and/or bushings, and is called "axial" runout.

Both are generally measured with dial indicators, although when I was drill press shopping I measured "axial runout" by extending the quill all the way, grabbing the chuck, and seeing if I could wiggle it. This measurement meant something to me, while a number (yeah, she's good for about 3 thou') would not have."


Cheers!

Gary


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