Help. Mount RA Issues (AZEQ6)

[KemalOz]

16 hours ago, johnrt said:

Thank you for the comments; all greatly appreciated. I will look at your sugegstions.

I have been running the mount with my new EQDIR cable from FLO this evening as a test. The cable is a welcome replacement to my old Hitech astro one, which had seen better days. The new cable also required an entirely new driver, so I uninstalled the old, rebooted and installed the new software.

While I'm not entirely confident it is fixed, the mount guided quite happily for aout 3 hours. There was a couple of hiccups, but I was watching the very excellent Ken Burns Documentary on Vietnam at the time, there is quite a bit of low scattered cloud flying about so that could well have been the cause of the guiding issues.

More testing and cheking required!

 

USB cables transmit digital data. What I'm trying to say either they will work or they won't work, you might lose connection all together or nothing will happen. Quality of the connection won't change like analog transmission with different cables. So I doubt new cable will change anything. If the worm mesh has become too loose causing end play and that is the reason behind this maybe last night you have done your balance properly biased so you haven't noticed it. Or this problem could be on the worm gear itself so it happens in certain parts of sky and doesn't happen in other parts. Just check your worm mesh it is nothing to be afraid of mate. Here is the guide; http://www.astro-baby.com/EQ6 rebuild guide/EQ6 worm alignment.htm

[KemalOz]

19 hours ago, lux eterna said:

Do not rotate the cog wheels with the belt in place. The stepper motors will generate currents into the driver electronics.

Hmm I have never thought about this before. I turn them all the time in my DIY projects but most of the time they are disconnected from the motor driver. How much of a current do you think they can create by just moving by hand in low speeds? Have you measured it? Can it actually damage something have you experienced it or are you just guessing it?

[johnrt]

On 06/10/2017 at 15:41, doramason said:

USB cables transmit digital data. What I'm trying to say either they will work or they won't work, you might lose connection all together or nothing will happen. Quality of the connection won't change like analog transmission with different cables. So I doubt new cable will change anything. If the worm mesh has become too loose causing end play and that is the reason behind this maybe last night you have done your balance properly biased so you haven't noticed it. Or this problem could be on the worm gear itself so it happens in certain parts of sky and doesn't happen in other parts. Just check your worm mesh it is nothing to be afraid of mate. Here is the guide; http://www.astro-baby.com/EQ6 rebuild guide/EQ6 worm alignment.htm

The cable in question sn't a standard USB, but a USB -> Serial adapter, could this not make a difference?

In terms of play in the axis, I ave uploaded a video of me trying to move the RA. There is no visible play, I can feel just a touch when I move it in each direction, but not enough to see any movemoent in the axis. I don't think this is caused by a loose worm mesh.

Not sure how to insert a video so below is link to the vid on my flickr.

 

[Starlight 1]

Have you look at the PHD log with PEC Prep.

[johnrt]

17 minutes ago, Starlight 1 said:

Have you look at the PHD log with PEC Prep.

I have not got PEC Prep, what will that show me that the PHD viewer logs aren't showing me?

[Starlight 1]

go and look at the videos by Chris is the best way not easy to get your head round. that showing you the what going on in the mount  is the best way I can put it.

[lux eterna]

On 2017-10-06 at 16:47, doramason said:

Hmm I have never thought about this before. I turn them all the time in my DIY projects but most of the time they are disconnected from the motor driver. How much of a current do you think they can create by just moving by hand in low speeds? Have you measured it? Can it actually damage something have you experienced it or are you just guessing it?

I have read it, cant remember where. But it makes sense, moving magnets inside a few coils - that is a generator. If somethig gets hurt depends on two things, how fast you rotate and how "heavy duty" the elctronics are designed.

CS

Ragnar

[johnrt]

1 hour ago, Starlight 1 said:

go and look at the videos by Chris is the best way not easy to get your head round. that showing you the what going on in the mount  is the best way I can put it.

PECPrep is for measuring and correcting for periodic error I think, I don't think it's going to help me out. My error doesn't seem to be periodic, sometimes 5 mins or less apart, sometimes 10, sometimes hours.

[kens]

PEMPro Log Viewer is a useful diagnostic tool. http://www.siriusimaging.com/PEMProV3/PEMProLogViewer_Setup_1.4.0.0.exe

And it reads PHD2 log files better than PECprep. In additon it has an option to view the graph with the guide corrections restored - equivalent to an unguided graph.

All the EQ6 mounts are not easily corrected for PEC as the periods of the various gears are not harmonics of the worm so they produce a varying PE waveform. Its quite common to find that in addition to the 478 second worm period there is also a 122 second period. The belt drives help mitigate the latter.