just trying to improve my guiding with an AVX

Celestron Advanced VX Equatorial Mount Guiding
7 replies•251 views
Oscar H. avatar
Oscar H. avatar
Hello everyone, I simply want better guiding with my AVX, and I'm willing to "tear it apart" to change components whenever I need to.

I saw this video of a person changing the gears and adding a belt to get smoother motion (I think, and maybe better guiding as a result?) https://www.youtube.com/watch?v=NP9nf7pwXMg

But it's in Japanese or something, so I have no idea what he's talking about.

I don't want to try to remove backlash by putting the gears closer together, like this guy did https://www.youtube.com/watch?v=CARLY4Ji6DY

Google said that "if gears are too tight (i.e too close together), they can cause motor binding, premature gear wear, and inaccurate tracking."

So I want to try the belt option, for both RA and DEC

So can someone tell me what gears and belts I need for RA and DEC motors?

Also if you have any other suggestions for upgrades, let me know.

If this doesn't improve my guiding, then I need to learn about PEC stuff;

And if that doesn't improve my guiding, I'm selling my mount.
Engaging
Oscar H. avatar
Oscar H. avatar
My total guiding accuracy fluctuates between 0.7" and 2.0"

I know I have been calibrating guiding wrongly (I calibrated every time I slewed to another target)

But I would like to fix any mechanical issues first.
andrea tasselli avatar
andrea tasselli avatar
1. Show us the guiding log
2. What stepper do you have in the AVX (shaft diameter even better)
3. From that I can advise you on the next steps
Oscar H. avatar
Oscar H. avatar
andrea tasselli:
1. Show us the guiding log
2. What stepper do you have in the AVX (shaft diameter even better)
3. From that I can advise you on the next steps

1. Guiding log is gone; I usually delete it and everything else on the flash drive to get a clean start again (once I transfer the subs to the PC), which I know is a mistake, but I'm sort of careless, and I didn't think the logs were important.

2. Yeah, I'll take a whole bunch of measurements.

3. thank you

Sky is clear; I could take the scope outside tonight to get another guiding log, but can you tell me where I'm supposed to point the scope to do guiding calibration? I'm still not sure where I should point.

I have a direct view to the zenith, and north, northwest, north northwest, and some northeast

but south (sadly) is blocked by my big fat house, and south is where all the nicer galaxies are too.

but anyway, where should I point to do guiding calibration? what do you do?
andrea tasselli avatar
andrea tasselli avatar
Where to: As close to the celestial equator as you can go and as near to meridian as possible.
Oscar H. avatar
Oscar H. avatar
very sorry

I found out I accidentally stripped one of the tiny hex screws holding the gear on the DEC motor shaft.

So it's now unremovable, and no adjustments can be made for DEC.

So I can now forget about new gears and belts (sorry if someone was looking on this thread for answers to replacing gears on AVX mount)

But it's fine for me. I'll have to deal with what I have.

And I'm kinda demotivated now, so I give up on changing the RA motor gear; I don't want to strip the hex screw on that gear too.

but hey,

I was able to put a drop of SuperLube on RA and DEC gears after I cleaned some blubbery lube gunk that was on a RA motor gear (and the motors kind of sound smoother now, idk, might be my imagination)

and I now know how to correctly do guiding calibration smile

I'll report back, after the clouds go away, if my guiding improved.





Just one question:

do you approve my guiding settings, or should I change something?


Calibration step size = 218ms
Max RA duration = 2000ms
Max DEC duration = 2000ms
DEC mode: Auto
Guide exposure length = 1s
ASI174mm mini (guide cam) Gain = 400 (which is the max)


I have a 950mm newt with a 533 camera, and using an OAG with the 174.
Oscar H. avatar
Oscar H. avatar
Andrea, can you plz confirm I'm thinking about this correctly:

You said to point "as close to the celestial equator as you can go and as near to meridian as possible" to do guiding calibration

So this is what I imagine:

The white circle is the approximate best location to point for calibration

The green circle is the approximate location of the zenith (just for reference)




Am I correct?
andrea tasselli avatar
andrea tasselli avatar
Yes
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