PM30 spindle runout

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UMDJesse

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Has anybody measured runout on their PM30 spindle? I've attached a couple of videos of mine and trying to get a consensus, I seem to be getting about .0007 - .0010 wherever I measure and want to know from the experienced folks if this is acceptable or I should seek replacement.
 

Attachments

  • MVI_8075.MP4
    14.8 MB
  • MVI_8076.MP4
    12.7 MB
  • MVI_8078.MP4
    15.8 MB
  • MVI_8079.MP4
    5.7 MB
The runout on the spindle seems fine to me. The runout on the end mill is likely due to an accumulation of error from the collet, the collet nut and the end mill itself.
Using a gauge pin would be a better choice if one is available.
 
Yeah, I'm still accumulating tools, but have gauge pins on the list. I've tried some drill rod as well, but same result and don't know what the rods tolerance is. I'm mostly just curios what most folks here expect to see when they indicate on an endmill and indicate on the spindle taper.
Thanks for the input David
 
I would check the spindle on the inside, right on the taper. If that has no runout it should be ok. Even .0001 is acceptable. You will always find runout on collets when checking with gauge pins. The amount on most collets will be in the tenths range, from .0002 to .0005 depending on the quality of the collet. You will not find perfect in any sense with most machine tooling unless it is laboratory grade, even then it’s subjective. Most of the machine work done in general industry standards is in the tenths range, and most of us in the hobby shop, find we only work to 1/2 thou ! We don’t control the environment in order to work any closer than that.
 
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The spec on the R8 collets is around 0.0006" and you also can get some angular skew so the reading can get worse the further down the collet. You usually need to look at the interior mating surface of the spindle to R8 collet and your TIR is closer to 0.0006" and might have some unevenness on the measuring surface as the indicator jumps a bit. About what I would expect at that price level, but a bit on the high end of the range. On a knew knee mill, I can barely get my 0.0001" indicator to move measuring the R8 mating surface, but a poor R8 collet certainly much worse. When I need to setup my dial edge indicators to zero out the TIR, I use a high accuracy ER32 collet setup.
 
frankly2 said:
I would check the spindle on the inside, right on the taper. If that has no runout it should be ok. Even .0001 is acceptable. You will always find runout on collets when checking with gauge pins. The amount on most collets will be in the tenths range, from .0002 to .0005 depending on the quality of the collet. You will not find perfect in any sense with most machine tooling unless it is laboratory grade, even then it’s subjective. Most of the machine work done in general industry standards is in the tenths range, and most of us in the hobby shop, find we only work to 1/2 thou ! We don’t control the environment in order to work any closer than that.
Click to expand...
Hi frankly2, I'm measuring directly off the taper in two of the vids and getting that .0006-7ish reading
 
My G0704 has about 0.0003-4" of runout. Mostly in the taper grind. I can contribute maybe 0.0001" to the bearings I bought.
 
I didnt notice the runout spec published anywhere in the documentation, but was told that the limit was .0005. Does everyone concur that the video shows runout exceeding .0005?
 
UMDJesse said:
I didnt notice the runout spec published anywhere in the documentation, but was told that the limit was .0005. Does everyone concur that the video shows runout exceeding .0005?
Click to expand...
I'd say it's pretty much spot on .0005 based on the vids of the spindle nose measurement.
 
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