trackpoint "float"

[rebith75]

is it normal to have the trackpoint cursor sometimes stick where it will float across the screen slowly for a second or 2, not a real issue but it makes it feel a little "cheap" if you know what I mean, I downloaded another driver but it didnt help, if this is normal like I said no real biggy, I searched and found some x4X owners claiming this but my x61 is only 2 months old

[dj2005]

Just about all Thinkpads have this issue. The trackpoint is simply resetting its position so its movement stays precise. At least, that is what I've read.

[EOMtp]

The "float" happens because of the way you are using the trackpoint. You are holding your finger on the trackpoint while it is at rest, and the "natural" position of the trackpoint is other than the position in which you are holding it while your finger is resting on it.

If you keep your finger off the trackpoint when it is at rest, then there will be no "float".

[joester]

Not true on my T21. The pointer will float about an inch or two regardless of pressure on the trackpoint button, then it stops.

[GomJabbar]

Notes on TrackPoint Drift

A properly implemented TrackPoint will never drift when it is not in use. However, the user may defeat the drift control algorithms in two way:

1. The user may keep a finger on the stick for a long enough period that the zero-force signal drifts out of the dead band; how long this is depends on the rate of drift, e.g. the rate of temperature change. Then the cursor will be found to be drifting when the stick is finally released. The circuit will rezero and the cursor will stop in a few seconds. provided it is left alone; if the user keeps trying to hold the cursor still, it can go on indefinitely.
2. The user may be able to apply a very steady force (usually a very low force, as in slowly scanning down a list) for a long enough time to fool the TrackPoint into rezeroing improperly. The cursor stops, and when released moves in the opposite direction for a few seconds, as in the 'rubber band test'. Again, it recovers if left alone for the requisite three seconds.

Both of these cursor drift modes are part of the TrackPoint's normal function. They could be eliminated, but at the cost of occasionally reaching a state in which cursor drift occurs and does not spontaneously recover.

Another cause of drift is RF interference - for example from a nearby cell phone, or even worse a cell phone transmitter inside the same box. The problem comes from rectification of RF in the op amps, and can usually be cured by placing small bypass capacitors (50 - 100 pF) directly across the input pins of each op amp section.

[joester]

Bingo.

I am guilty of resting on the trackpointer, and have a cell phone with me always.

I'm doomed.

Joe

[draco2527]

Notes on TrackPoint Drift

A properly implemented TrackPoint will never drift when it is not in use. However, the user may defeat the drift control algorithms in two way:

1. The user may keep a finger on the stick for a long enough period that the zero-force signal drifts out of the dead band; how long this is depends on the rate of drift, e.g. the rate of temperature change. Then the cursor will be found to be drifting when the stick is finally released. The circuit will rezero and the cursor will stop in a few seconds. provided it is left alone; if the user keeps trying to hold the cursor still, it can go on indefinitely.
2. The user may be able to apply a very steady force (usually a very low force, as in slowly scanning down a list) for a long enough time to fool the TrackPoint into rezeroing improperly. The cursor stops, and when released moves in the opposite direction for a few seconds, as in the 'rubber band test'. Again, it recovers if left alone for the requisite three seconds.

Both of these cursor drift modes are part of the TrackPoint's normal function. They could be eliminated, but at the cost of occasionally reaching a state in which cursor drift occurs and does not spontaneously recover.

Another cause of drift is RF interference - for example from a nearby cell phone, or even worse a cell phone transmitter inside the same box. The problem comes from rectification of RF in the op amps, and can usually be cured by placing small bypass capacitors (50 - 100 pF) directly across the input pins of each op amp section.

I have also seen and had it happen were the trackpoint CAP goes "off-center" and can cause the cursor drift. Removing and "re-setting" the cap on the pointing stick seems to solve the problem...

[iamdmc]

Has happened with every thinkpad I ever owned, so long as I actually used the trackpoint. It also did so on my old Dell (except with the touchpad and only the trackpoint would stop the drift - oddly enough).

Not a huge deal. Doesn't last and it doesn't move so much. I still prefer this to any other version of a notebook mouse.