Looking for advice on tramming a small mill

[michiganbuck]

moonlight machine, sorry I thought the op's post must be a joke and added to it.

My bad I guess.

 

[CarbideBob]

,,,

Re: What could be causing this inconsistent reading?

Duh, this is normal. How many would do the extra revolutions and see it or wonder why?
So many do a one turn check and got it to zero. Go so far away from me.
The bearings do not to circulate in one rev.
Why do so many not understand this.? One rev can not check run-out. It is impossible if the system has bearings.
Air bearing fine, all others the cycle is different.
Can be two, five or the revs. It will repeat. Can be two and 3/4 reves dependent on bearings. It will repeat.
One also sees this in grinding spindles and surface finish.

 

[plastikdreams]

Post a picture of the surface your shell mill cut

 

[moonlight machine]

moonlight machine, sorry I thought the op's post must be a joke and added to it.

My bad I guess.

It is a joke, and I was just having fun with you!

 

[eKretz]

Duh, this is normal. How many would do the extra revolutions and see it or wonder why?
So many do a one turn check and got it to zero. Go so far away from me.
The bearings do not to circulate in one rev.
Why do so many not understand this.? One rev can not check run-out. It is impossible if the system has bearings.
Air bearing fine, all others the cycle is different.
Can be two, five or the revs. It will repeat. Can be two and 3/4 reves dependent on bearings. It will repeat.
One also sees this in grinding spindles and surface finish.

Yes this is generally true, but it's also generally not noticeable with a .0005" indicator (he is not using a "half .0001" graduations" indicator) on a good quality machine tool. In this instance, it could be something like a loose bearing fit in the spindle or a very subpar (there's that word again... B.S.O. anyone?) set of bearings.