t.i.r.?

[GoCreateParticipant @gocreate]

In his article MEW 175 ‘using collets in my lathe’ Mike Houghton refers to collet runout measurmrnt as t.i.r. i.e. o.oo5″ (t.i.r.)

 

What does t.i.r. stand for?

I am sure once someone tells me I will hang my head low in shame of not knowing.

 

Cheers

Nigel

[GoCreateParticipant @gocreate]

[Anonymous]

Total Indicated Runout, ie, what you actually measure. It doesn’t, on its own, tell you whether the runout is axial or radial, or a combination of both.

 

Regards,

 

Andrew

[DustyParticipant @dusty]

Hi

It stands for ‘total indicator reading’ The indicator being a clock,dial gauge or whatever you know it as. Total reading is twice the runout i.e if the reading is .002″ then your runout is .001″. We all come across these things from time to time when we do not know what the term really means. I was allways told if you don’t know ask, it is no good guessing.

[GoCreateParticipant @gocreate]

Oh, so obvious.

Thanks for a very quick answer

 

Nigel

[John OlsenParticipant @johnolsen79199]

Ok, let’s expand on things a little. The reason that it is “total” is that it is the runout due to eccentricity added to the runout due to the job not neccessarily being round. (For instance a piece of centreless ground bar may have a lobed shape rather than being a true circle.) The indicator will measure a amount that depends on all the errors. Practically, when the total indicator runout is minimised, the job is as close as you are going to get to being truly centred. The reading will only be twice the eccentricity in the case where the job is for practical purposes truly circular, which is often, but not always the case.

 

Andrew, whether or not you are measuring radial or axial runout is going to depend on how you have set up the indicator. Taking say a flywheel shape, if you set up the indicator to read against the outside cylindrical surface you will measure radial runout, while if you set it up against one side you will measure axial runout.

 

regards

John

 

 

[StovepipeParticipant @stovepipe]

Posted by tractionengine42 on 23/03/2011 17:15:04:

What does t.i.r. stand for?

I am sure once someone tells me I will hang my head low in shame of not knowing.

 

Cheers

Nigel

 

Rubbish (grin!). We all have to learn. The asking of the question proves that you want to learn, so there is NOTHING to be ashamed of.

 

Dennis

[Author]

Posts