how fragile is CG-5 GT mount ?

[resonator77]

During the night of observing, I accidentally dropped GT mount of my CG-5

Now it is making weird noise slewing from one object to another.

Does anyone have experience with anything similar?

How fragile is gt mount of CG-5?

[russ]

It could be you have knocked the gears slightly off and they are not meshing properly now. There really is nothing to these mounts when take off the motor housings. Just a Scaletrix motor with a cog on a spindle, which is meshed into a bigger cog connected to the mount. A single bolt holds the motors in place if it's like the standard CG5 motors and it wouldn't take that much of jolt to move them out of place. There maybe some instructions online which will show you how to dismantle the motor housings and what to adjust.

Russ

[resonator77]

Thanks Russ for the quick reply

do you think I have to resort to taking it apart?

Cant it be resolved with just greasing the cogs ?

[Cornelius Varley]

If the motors / gears have become misaligned then you have no alternative but to remove the motors and reinstall them. Regreasing misaligned gears will not work.

Peter

[resonator77]

Peter,

where can I find the manuals of how to do it?

I checked Celestron web site, they do not have repair manual for this mount:(

[Deneb]

Go here for CG5 stripping & improvements:

Astronomy Boy

Cheers

Nadeem.

[resonator77]

Thanks Nadeem

interesting info there.

[Cornelius Varley]

This is a link to the installion of the EQ5 dual axis motors, the removal will be the reverse. The CG5 GT mount is identical to the EQ5 so you should be able to work out how to remove the drives. dual axis motors

The DEC drive on the CG5GT is slightly more complicated to remove but you should be able to work out how the plastic housing is attached.

If you find that there is more damage than drive gears knocked out of alignment this site Astronomy Boy: CG-5 Mount Improvements will help.

Peter

[resonator77]

here is the video with the strange noise of dec axis of my CG-5 goto

can anyone advice as to how bad it is?

[Cornelius Varley]

The banging noises don't sound too good. Which drive are they coming from ?

Peter

[resonator77]

Peter,

Dec axis

It is tracking well and controlled well.

Maybe I shouldnt temper with it and leave it as it is ?.....

[Cornelius Varley]

It should be fairly easy to remove the DEC drive and check the alignment.

Peter

[resonator77]

Peter,

I heard that if you temper with and take apart goto CG-5 this knocks off its tracking. Which is bad if you think of it

[sxinias]

The "loping" noise is caused by a slight gear mis alignment. if it still works to your satisfaction, I'd leave it be. However, adjusting the gear alignment is rather simple. One trick to prevent binding gears is to simply place a tiny strip of paper between the gears as you adjust them.

[Cornelius Varley]

If the gears are misaligned then there is a chance of them wearing unevenly. Removing the DEC motor to check for misalignment should have no affect on the tracking accuracy and should only envolve remove a couple of bolts / screws at the most. Cigarette paper is ideal for setting the gap between the gears.

Peter

[resonator77]

Sxinias, Peter,

Thank you. It is a very good idea. I remember fixing my toy car when I was little with the piece of a tobacco roll paper

Do I have to take the Dec motor out or just removing the plastic housing will reveal the motor misalignment?

[russ]

Just take off the plastic housing and have a look. There is a single allen key bolt that holds the dec motor in place. You can slightly loosen off the bolt to make an adjustment to the alignment. Should be no more to it than that.

Regards

Russ

[resonator77]

Thanks Russ,

you ve encouraged me to dismantle it

[FLO]

If there are any internal bent bits it can be difficult (expensive) to repair but if it landed on grass/mud then it is most likely that the motor/worm/wheel isn't meshing properly, which you can probably fix yourself without difficulty. Otherwise it will be the cost of a motor plus the time required to re-seat everything (about 1 hour). If the RA is damaged the time and cost will be more.

Good luck

Steve

[Cornelius Varley]

Once you have removed the plastic cover and DEC axis motor you should be able to rotate the DEC axis shaft by hand and be able to tell if the shaft is bent.

Peter

[resonator77]

Steve,

if you could let me know the repair costs just in case would be great.

Do you sell by any chance just the mount of CG-5 GT (without a tripod) ?

Regards

Ramis