Advice/help please, drive/slow-motion control problem

[MahlerMoonMan]

Hi folks

I've been trying to attach an 'Orion TrueTrack Single-Axis DC motor drive' to the RA gear on my Qrion SkyView Pro EQ mount.  I've followed instruction to the best of my ability, several times now.  The good news is that the clock drive seems to work very well, as far as testing so far seems to show  .  The bad news though, for me at least, is that I don't seem to have manual slow motion control in RA any more .  The manual that came with the truetrack, AND my ED80 manual both state that to operate my RA slow motion control when the scope is being driven, that I must remember to dis-engage the manual clutch assembly, which I am certainly doing ....  But still no slow motion control/movement in RA that I can tell at all!  ....  Might anybody know what I may be doing wrong here?  I cannot see what difference whether or not the manual clutch 'thumbwheel' is either engaged or dis-engaged seems to make at all anyway, the slow motion wheel just will not turn, even though the drive gears are only just pressing together, just enough to turn smoothly when operating ...  Not too tight nor too loose, just as the manual describes.  I'm really flummoxed and frustrated with this  ....  I'm very keen to have the tracking capability to have a good at some astrophotography, but I should still have RA slow motion control according to my manuals ....  Cannot understand why I don't!  Any ideas?  What am I missing here?!

Greatly appreciate any help or advice given

Thanks,

Donaldo

[ronin]

Cannot help, apologies, but what you describe would mean that you have manual and motor drive options on the same mount. Usually the motor drive replaces the manual bit but uses some mechanical aspects of it.

So it sounds a bit strange, as at the final gear that rotates the mount you can have input from either the manual or the motor and that sounds like a mess waiting to fall on you.

[Cornelius Varley]

Cannot help, apologies, but what you describe would mean that you have manual and motor drive options on the same mount. Usually the motor drive replaces the manual bit but uses some mechanical aspects of it.

So it sounds a bit strange, as at the final gear that rotates the mount you can have input from either the manual or the motor and that sounds like a mess waiting to fall on you.

With the Skyview Pro / Skywatcher EQ5 it should be possible to use a RA drive and slo-mo control by the use of the clutch thumb wheel. Tightening it engages the RA drive and loosening it should allow the slo-mo cable to be be used with the motor disengaged.

[Bizibilder]

You should still have manual slow motion.  To disengage the drive you unscrew the brass locking knob (clutch - thumbwheel) which will release the brass gear on the RA axis the slow motion knob - on the other end of the axle) should turn and is still meshed with the worm gear, therefore it should work.  I suspect that the problem is that unscrewing the locking clutch (thumbwheel) does not actually release the brass gear - you may find that giving it a "pull" with your fingers will free it.  Once free the slow motion should work.  Once you have done this a few times the clutch should free itself - I suspect the new components will be a bit stiff to start with.

You have to remember that a worm and wheel gear is a one way system.  The worm can drive the wheel but the wheel can never drive the worm.  So you have to ensure that there is no mechanical connection where this is possible if you want the slow motion to work.

[MahlerMoonMan]

Thanks Ronin

I see where you're coming from, and I must admit it has crossed my mind more than once that with the drive in place that this may serve to replace [slow mo] manual control ....  This does seem reasonable.  However all the Orion info that I have at my finger-tips clearly indicates that I should still have the use of my RA slow motion wheel, although that I must dis-engage the drive clutch from the thumbwheel, or else I could damage the drive ....  My TrueTrack instructions say that when I require to move to another object I should:

unlock both Dec and RA,

move my scope to approximately where my new object should be,

lock both Dec and RA,

dis-engage the drive gear from the thumbwheel,

use both slow motions to centre the object in my field of view,

and then re-engage the drive and TrueTrack would continue to track ...!!! 

Puzzled

Donaldo

[MahlerMoonMan]

Thanks guys,

I shall continue to tinker, gently ....  Hopefully I'll get there!

Donaldo