Thanks for the input, gentlemen.

I had already taken this new mount apart since it would not complete a single
azimuth rotation without hanging up, the clutch was too loose. But it seemed
clean inside, just a little string from a drip of the hot glue they use to
secure wiring which I removed.

But then I saw that overshoot about once every 4 or 5 slews. I normally power
from an older lab-type voltage and current regulated power supply, set to 13.5
volts.

I left the cellphone in the house and tried a fully charged 7 amp-hour gel cell
the other night, doing the "night's best" so it would slew a lot, and it never
overshot in an hour. If the clouds ever go away I will test more.

Frank


--- In MeadeDS@yahoogroups.com, "joe.ashley@..." <joe@...> wrote:
>
> I have both a teflon bearing DS2000 mount and a roller bearing DS2000
mount for a 2090AT telescope (the Teflon bearing mount is one with fried
electronics I purchased very cheap for spare parts). Other than the azimuth
axis thrust bearing, I can see no difference between the two mounts. The
electronic circuit boards appear identical.
>
> On several occasions, I've had my cell phone with me but have never noticed
any correlation with its use and mount performance. I'm not saying that there
is none but just that I have never observed any.
>
> The symptoms you describe are similar to what I experienced with my roller
bearing mount. The mount, when new, was very accurate but then started operating
in an erratic manor, e.g., occasionally my mount's movement was sort of jerky
resulting in an overshoot. The problem slowly got worse and eventually made the
mount's performance too uncertain to be usable.
>
> I opened up the mount and found a 1.5 to 2 cm long metal shaving wedged in the
thrust bearing along with a countless number of smaller metal particles. I
cleaned the bearing and re-assembled it but the mount is not now as accurate as
it was when it was new.
>
> The problem is tightening the azimuth axis bolt properly. Apparently there is
a narrow range of torque on the mounting bolt that will properly engage the
gears but not constrict movement. Too loose and lag time between motor signal
and movement is too long or, in the worse case, the mount can even wobble. Too
tight, and motor movement is restricted or locked in place. Through a tedious
iterative trial and error process, I am slowly improving my mount's accuracy and
have now got it to where an object is nearly always in view with a 40 mm
eyepiece and frequently in view of a 25mm eyepiece. Before the malfunction, an
object was nearly always within view of a 25 mm eyepiece.
>
> From this experience, I would strongly recommend not to open up a newer roller
bearing mount unless there is a very good reason to do so. If you can live with
your mount in its current state, do so.
>
> Good luck on finding your problem.
>
> Joe
>
>
>
>
>
> --- In MeadeDS@yahoogroups.com, Jerry <crazyj1251@> wrote:
> >
> > This sounds like a dirty or loose encoder. There is also the possibility
that the batteries are low. While the electronics in Meade scopes are not
shielded in any special way I don't think that most cellphones would have an
effect. Maybe a very powerful one with a low frequency or if you are operating
the scope under a tower, but not usually.
> > Jerry in Arizona