I'd prefer to attack the problem more directly. The problem wasn't a loss
of temper in the spring, it turned out to be a case of the pivot itself
needing lubrication. Once I addressed that, the drive engaged the teeth
properly and the whole thing ran smooth as silk. Using a stronger spring
would likely only be a case of masking the problem and possibly grinding the
gears together since the pivot in this case, would allow the drive motor
gearing to snap up against the fork gearing when the pivot came "unstuck".
You need the pivot to operate smoothly so that any case of excess force will
cause the drive motor to back out from the fork gearing under such
circumstances and walk back cleanly and completely in when the force is
relieved...

M.

> -----Original Message-----
> Sent: Friday, November 20, 1998 4:32 PM
> Subject: Re: [M]: 12"LX200 with T-Point
>
>
> I have had the same problem with my 12" - the teeth were not
> fully meshing and
> this introduced slop about the RA axis. My interim solution
> was to stretch the
> spring located on pivot. This seemed to engage the teeth a
> little better. What
> about using a spring with a little more compression to it.
> Would this harm the
> "system" in any way?
>
> Mike
>
> Richmann, Michael wrote:
>
> > I've run into a problem in the past which can give rise to
> the "slop" in the
> > RA drive problem you mentioned below. I was seeing jittering in my
> > guidestar images and finally tracked it to the RA drive.
> Pulling the
> > baseplate off and examining the RA drive revealed that the
> spring-loaded
> > pivot which keeps the motor drive gear firmly engaged to
> the gear on the
> > fork mount was sticking and thereby keeping the teeth from meshing
> > completely.
> >
> > Mike
> > http://www.concentric.net/~richmann/
> >
> > > -----Original Message-----
> > > Sent: Thursday, November 19, 1998 7:18 PM
> > > Subject: Re: [M]: 12"LX200 with T-Point
> > >
> > >
> > > Ric,
> > >
> > > Thanks for sending me a "checklist". Of the items that you
> > > mentioned, my
> > > drift alignment is "right on the money". My PEC training
> is suspect
> > > however.I have tried rocking the fork arms in RA and there is
> > > about 5mm of
> > > "play". Do you think it is a loose worm/drive wheel, or a
> > > loose locking
> > > mechanism, or has the lubrication worked itself from the
> gears or a
> > > combination of all three? Meade is asking $200 to fix it and
> > > another $200 to
> > > upgrade the drive to today's standards (new EPROM and HPP).
> > > As I said my
> > > LX200 was one of the originals and does not have HPP but I'm
> > > not certain I
> > > need it because I use TheSKY exclusively for pointing which
> > > essentially does
> > > the same thing as HPP by synching on a star when I slew
> to a different
> > > region of the sky near an object I'm trying to locate. I have
> > > heard from
> > > someone that some "older" EPROMS are not compatible with
> TheSKY. $200
> > > doesn't sound too bad to fix the problem (if they actually
> > > CAN fix it!) but
> > > I'm reluctant because I'm not convinced they will and I'm not
> > > too thrilled
> > > about being without a scope for weeks maybe months (from my
> > > experiences with
> > > Meade). I've followed MAPUG "threads" in the past about which
> > > grease to use
> > > and how to go about tightening up the RA drive train but it
> > > was some time
> > > ago. I remember you, Doc G, and others discussing this but
> > > can't remember
> > > the details. I suppose I could read the MAPUG "archives" or
> > > could you be a
> > > good samaritan and tell me how to get into the RA drive
> > > train, which screw
> > > to tweak, and what kind of grease to use and any other
> > > pertinent info I
> > > should look for? I would be forever grateful (not because I'm
> > > cheap, but
> > > because it might get fixed sooner).
> > >
> > > Thanks,
> > > Steve Stefanik
>

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