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Mike Amick
01-12-2013, 01:51 AM
With all the tramming talk lately .. I have been trying lots of things. I seem to get really
conflicting results doing it different ways.

Just for giggles I tested the runout on my drill chuck and it was almost .003 . I figured
this can't be good so I ordered a brand new keyless chuck and shank. Well I got it today and
couldn't believe it when I measured .003 with the new one too.

So I am thinking ... ahhh ohhh .. spindle bearings or something horrible like that. So just to
make another check .. I threw a 1.25 shank endmill in and it measured 0.

any help

and because you guys like pics .. here is the two setups

http://www.mikeamick.com/misc/drill_chuck.jpghttp://www.mikeamick.com/misc/drill_chuck_end_mill.jpg

macona
01-12-2013, 01:55 AM
Measuring runout on the outside of the drill chuck is pointless. It has nothing to do with what is being held in the chuck itself.

Arcane
01-12-2013, 01:57 AM
What's the runout on a test piece in the jaws?

Mike Amick
01-12-2013, 03:03 AM
Just ran out and looked (fingers crossed) ... and I am getting almost .005

The drill chuck shank is 5/8 .. I have several collets that it appears to fit.

When I was getting a good reading on the 1.25 shank endmill ... it was with a new (for me) collet.

Maybe some of my older collets are buggered up.

They are monoset collets.

loply
01-12-2013, 05:13 AM
Drill chucks always have some run out, especially if they're not expensive.

Mike Amick
01-12-2013, 06:06 AM
cool .. I'll accept that (very happy actually)

So apparently the runout has no effect on tramming using a DTI or coaxial .. ? (in the drill chuck)

after thought ... how do you get a very round hole ... even with a reamer ? Do you have to put
the reamer in a collet ?

Black_Moons
01-12-2013, 06:13 AM
If your TDI had 0 runout, It would be measuring a hole the size of the ball on the end.

You basicly have massive runout any time you use a TDI to tram or center a hole.

Jaakko Fagerlund
01-12-2013, 06:27 AM
after thought ... how do you get a very round hole ... even with a reamer ? Do you have to put
the reamer in a collet ?
Yes, the best is to use a collet holder for reaming, unless you have a 400 EUR WTE precision drill chuck.

Richard King
01-12-2013, 10:00 AM
Take the collet out and get a mirror and flashlight and look inside the spindle hole. There might be trash or burrs up in there. Take the collet you never use, some odd ball size and rub some Dykem paste bluing on it and install it in the spindle , take out and look at it and see were the blue has rubbed off and also look with the mirror again. You might have to buy a round stone and get up there and stone off a burr Test that hole with your indicator. Troubleshoot it that way and let us know.

Mike Amick
01-12-2013, 02:42 PM
Thanks

I think I will do some checking .. just for sure.

But I did just do a search on Google for drill chuck runout .. and .. my results are
totally normal as some of you have suggested.

Surprising but noted

A.K. Boomer
01-12-2013, 03:00 PM
Drill chucks always have some run out, especially if they're not expensive.

I agree with this for the most part - and they are subject to change depending on what size piece your holding I.E. could be fine @ 1/4" and way off at 1/2"

danlb
01-12-2013, 03:59 PM
It's best to measure an end mill shank in the chuck jaws to measure TIR.

The body of the chuck does not need to be as accurate, so it's likely to have a high TIR.

Daniel

Rich Carlstedt
01-12-2013, 06:07 PM
......
So apparently the runout has no effect on tramming using a DTI or coaxial .. ? (in the drill chuck)?

Runout , spindle errors, collet quality (etc) have absolutely no affect of traming. Only loose bearings, or DTI error have impact on such a task
Rich

Bob Fisher
01-12-2013, 06:44 PM
Unless I misunderstood, you are tramming with a drill chuck.Why would you introduce another variable into the equation? Again, I may have misunderstood your question , if so, ignore my comments. Bob.

Black_Moons
01-12-2013, 06:52 PM
On a subnote, my glacern keyless chuck seems dead on when I quickly tested it with a 0.001" accuracy TDI.

And Rich is right. By using an offset holder for the TDI, You are effectivly introducing *inches* of runout to your TDI.
Another 0.01" is not going to matter. If you had no runout, you couldn't tram your mill (you would be rotating the ball on a single point)

Only thing that matters is the runout is consistant and not shifting. (Ie, Rotate the spindle, Don't rotate the TDI on its mounting point)

Paul Alciatore
01-12-2013, 07:21 PM
Unless I misunderstood, you are tramming with a drill chuck.Why would you introduce another variable into the equation? Again, I may have misunderstood your question , if so, ignore my comments. Bob.

If by "tramming" you are referring to checking to see if the spindle axis is perpendicular to the table, then it does not matter what you are holding the arm holding the DTI in. It must be held solidly in the chuck/collet/mill holder that you use to mount it, but any angular or radial error in that mount is totally and completely irrelevant to the tramming process. You are just sweeping the DTI in a circle around the table as determined by the spindle bearings and nothing else. So the world's worst drill chuck, as long as it mounts solidly to the spindle and grips the DTI arm solidly, will work just as well as the most precision collet you could possibly use. Absolutely no difference, what-so-ever.

The same argument holds equally well for locating a circular feature (hole or boss) under the spindle.

oldtiffie
01-12-2013, 07:22 PM
cool .. I'll accept that (very happy actually)

So apparently the runout has no effect on tramming using a DTI or coaxial .. ? (in the drill chuck)

after thought ... how do you get a very round hole ... even with a reamer ? Do you have to put
the reamer in a collet ?

Dead right.

The co-ax automatically aligns to the mill spindle axis.

The DTI does the same.

Mike Amick
01-12-2013, 07:33 PM
Unless I misunderstood, you are tramming with a drill chuck.Why would you introduce another variable into the equation? Again, I may have misunderstood your question , if so, ignore my comments. Bob.

ummm ... actually .. because of the tramming talks lately .. and my level of experience .. I have been
trying all kinds of tramming methods. Many youtube vids show people throwing an indicator into a
drill chuck for a quick tram. From the responses .. it seems that it should be ok.