Turntable speed accuracy

Purchased a Timeline last year after my Clearaudio strobe stopped working. The cost to replace the Clearaudio strobe was close to the price of a new Timeline.
Having used the CA since I bought my Verdier back in 2006, I found it easy to use and was able to set and forget about the speed. Enjoyed the music immensely on my table.
Since using the Timeline my perspective has changed.
At first I could not believe that the speed of my table was not accurate or stable at 33 1/3 rpm and the fact that it drifted all on it's own.
Then play some music and watch the Verdier slow down as the Timeline easily demonstrates. I use green painters tape, two pieces against the wall about 6 inches apart.
Quite frustrating. Did I worry about such a thing when I had the CA, clearly not. But now that I know that the speed is off, am always conscious of it. Obsessive no, but aware of it all the time. Do I enjoy music less on the Verdier, of course not but.
Have taken on the task to make a battery powered unit with a charging system like the "Callas unit" and will rewire the motor for the Verdier instead of using AC.
Hope that this will solve my speed issue on the Verdier.
My direct drive tables do not have this speed drift issue at all. Great video Halcro.
I think that Halcro nailed it in his post above.

"If you want to be happy.....use a strobe.
If you want the truth.....use the Timeline :^)"

My two cents, take care.

Accuracy or sensitivity of speed monitor device should be proportional to (1) distance of sensor from center of rotate (longer radius is better) and (2) stability of the strobe at 60 hz per second. Ergo in theory the kab strobe (battery powered and not subject to AC line frequency variations) should be superior to timeline (batt power but v short radius) and to allnic (worst, with AC line power AND short radius). Admittedly, the kab is least convenient.

Tonywinsc, you have used the term "runout" several times. I believe this is intended to relate to the accurate centering of the record. But in all my years in this hobby I've only heard the term runout applied to the area at the end of the recorded material where the stylus rides a continuous circle. Am I the only one not understanding this term?

Now back to the basic subject of this post. It seems to me the motor/bearing/platter have four tasks:
- providing a stable platform for the record,
- not introducing any noise which may be picked up by the stylus,
- rotating the record accurately at the desired speed (this might be considered the overall average speed), and
- maintaining that speed through the mili-seconds when interference might occur from imperfect motor rotation, power line fluctuation, stylus drag, etc.

If I am correct, it is the last of these tasks which may be the most difficult to achieve. I've never seen a Timeline, only a demo video. But I have two comments. First I agree with Lew that the distance to the sensor mark would be important. But secondly if the mili-second interference does not occur at the point when the sensor mark is reached the error may not be noticed. In other words the speed might have recovered by the time the sensor hits the mark. Does this make sense or am I misunderstanding something basic here?

Dear Lewm,
the Allnic SpeedNic is battery powered and not so bad as you think...
also it allows adjusting during play.
I am not selling this product :-)

Rugyboogie,
you are in very comfortable situation with one running turntable ;-)

best @ fun only

Rugyboogie, I meant with one belt drive TT, sorry!

best @ fun only