RA not tracking after flip

[traveller]

Hi all,
A quick question for the more experienced AP operators. I was imaging the Horsehead a couple of nights ago. The mount was behaving and I can get 5 mins subs without any problems.
However, after I flipped the scope (from pointing east to westside) the RA was playing up badly, 30 sec is about the max I can do. Dec stayed the same.
Is this a case of the gears not setting with the worm or some other mechanical issue with the mount?
Thanks
Bo
PS: I noticed when I was packing up that the RA freeplay was very smooth and rotated at will in clockwise direction, but is not as smooth in the anticlockwise direction. Maybe these two events are linked? :shrug::help::question:

[glend]

When you set the scope up did you leave some weight (ie not perfectly balanced) on the RA axis. If you make RA a little heavier on the counterweight side it will keep the gears meshed.

[traveller]

Thanks Glenn,
Yes, I left the setup bottom heavy (counterweight side) so the RA will push against the drive.
I have since adjusted the thruster bearings to the RA axis and will see if that make much difference.
Bo

[Peter.M]

If you make the counterweight side heavy, then the worm will be pressed up against the ring gear on one side of the mount and on the other side it will be moving away from the ring gear.

[traveller]

Thanks Peter,
I have adjusted the thruster bearings a bit on the RA axis and will see how it goes. I had to back off the pressure of the thruster bearings on the DEC axis and that made a difference.
Bo

[LewisM]

Scope east, counterweight least
Scope west, counterweight best

In otherwords, when the scope is on the east side of RA, let the scope side be slightly heavier (slide counterweight up a centimeter or so). When the scope is on the west side, make the counterweight side the heavier side (slide them down a little)

I had a small 500 gram stainless weight made just for this purpose. I set it so that perfect balance allows it a +/- 5 cm range. Seems to work fine.

[traveller]

Thanks Lewis,
Is this for the northern hemisphere or southern? I THOUHGT I made the setup bottom heavy when pointing East, but it would appear that I had the setup top heavy pointing East, and therefore should have eased the counterweights down a notch when pointing west.
Bo

[mill]

Bo Lewis means when the scope is east then the counterweights point west so the scope side should be heavier and vice versa.
So weights East, lower weights, weights West, put the counter weight up.

[traveller]

Yes Martin, that's how I had my setup.
I was imaging the horsehead in the early evening, so the scope was on the eastern side and the weights were pointed to the west. That was when I was able to get 5 mins of guided exposures.
Then I flipped the setup so the scope was pointed west and weights pointed east and that's when I was only able to get 30 sec exposure.
Bo

[LewisM]

But after the flip did you remember to alter the weight position to lower down the bar?

[alocky]

Did you flip the calibration on the autoguider or recalibrate it after the meridian flip?
Cheers,
Andrew

[traveller]

No, I didn't adjust the weights, so that needs to be done next time to see if it makes any difference.



Didn't do that either, looks like that's another thing to keep in mind.
Thanks again all.
Bo