Jump to content

Banner.jpg.b83b14cd4142fe10848741bb2a14c66b.jpg

Play in mount's axes

jambouk

By jambouk
in Discussions - Mounts

Recommended Posts

swag72

swag72

Posted
Posted

There seems to be two schools of thought on this - Some say to adjust it until there is no movement. And I believe that while it's nice not to have it, if it's not affecting you then leave it alone.

It is backlash, yes. I have an HEQ5 which has a little movement in the DEC, yet it will happily churn out 30 minute subs. So I think it's not worth fiddling when it does what I want.

There's a breakdown and rebuild guide on the astrobaby site http://www.astro-baby.com/astro_baby_telescope_help_and_advice.htm for stripping down and rebuilding the HEQ5 and the EQ6. But I see that you have a new AZ-EQ6 in your sig - I'd not want to be stripping down a new mount unless absolutely necessary as I'm sure it would affect the warranty. Have you spoken to your original retailer?

Link to comment
Share on other sites
jambouk

jambouk

Posted
  • Author
Posted

Thanks. I've not spoken to FLO about it. I just noticed it the other night, and then was reading a book about it last night and i just wondered how much is acceptable, and how to go about correcting it.

It's a shame there isn't just one screw to tighten to reduce it!

I'm going away for a dark week soon, so i'll give it a go and see how it affects my un guided attempts at astrophotography. I just worry though if the dec axes were to rotate over the celestial equator the scope would flop a bit so the goto would be out, and potentially the shift in declination might upset where the RA thinks it's all pointing and affect the tracking; the slack in the dec axis is worse than the RA.

I'm not sure the compensation mechanism in the handset takes into account the flop which occurs when the dec crosses the celestial equator or when the RA crosses the meridian.

I was never interested in engineering until i rekindled my interest in astronomy :)

Thanks for the help and words of wisdom.

James

Link to comment
Share on other sites
ronin

ronin

Posted
Posted

Ideally none that you can tell, but when these are assembled the people doing it will not be spending time in effect tuning each mount and the tolerances will be loose enough to make assembly easy and quick.

Problem is if the mount is new then if you take bits off to access the drive mechanism and then adjust it do you invalidate the warrenty? Usually obvious as everyone says remove and replace the stuff they call grease with something that is actually grease.

Your arguement is you are buying an EQ6 that is big enough and capable of driving a scope accurately for extended periods and if the drive chain is loose then it cannot do that.

It is not the fault, or I guess the responsibility, of the retailer. You will have received a new standard item that meets the manufacturers settings.

Link to comment
Share on other sites
jambouk

jambouk

Posted
  • Author
Posted

I asked the same question on the east midlands stargazers in the chat box and i disclosed I think the play is about an eighth of a degree in declination and a bit less in RA. It seems this is an acceptable amount so i'm worrying about nothing, and as always, i think i'm expecting too much from kit :)

The manual doesn't talk about how much play one should expect or tolerate.

James

Link to comment
Share on other sites
russ.will

russ.will

Posted
Posted

What I would do, is use it for a good few nights of observing with lots of impatient GOTOing to run the worms in, before bothering to adjust. It will save you doing the job twice and only adjust the play to zero at the tightest point in the worm's travel.

Russell

Link to comment
Share on other sites
jambouk

jambouk

Posted
  • Author
Posted

Impatient GOTOing.... have you seen me in action before :)

Thanks for the advice. I think the play I have is just what one should expect. It hasn't had any impact on my visual enjoyment yet. I'm hoping to get a go at refining polar alignment with that handset function on the latest firmware, and trying so unguided imaging, so I'll see if it causes any problems then (which I doubt it will).

Thanks again

James

Link to comment
Share on other sites
Purplehayze104

Purplehayze104

Posted
Posted

i was checking out my eq3-2 and theres a bit of wobble in it, but then it is the baby of the mounts almost, and also whilst going throu the synscan menus came across backlash compensation which you enter as degrees an minites was wondering if this would be of any use, not sure if i can measure the backlash, any ideas ??

Link to comment
Share on other sites
  • 2 weeks later...
jambouk

jambouk

Posted
  • Author
Posted

Update.

I had go at reducing the play in the axes of my azeq6, report below which i'd sent as a private message to an encouraging friend on the east midlands star gazers forum:

"Well, i did enjoy that. It has taken about two hours in all, but for a non engineer i had fun.

I took the side plate off the mount as i wanted to see the drive belts anyway. I videoed them, on my phone, running so i could record the sound.

I then followed the tutorial by astro baby on tightening the crucial bits (don't ask me names, i just followed instructions). A few things were in slightly different places on my azeq6 compared to the images and descriptions of the eq6, but it was pretty easy to work around.

I tightened the dec first, which was uneventful and it eliminated all the play in the dec axis, without changing the tone of the motors. I knew i was at about the right tension because much more and the motors did snag.

I then did the RA which again was largely straight forwards. I couldn't eliminate the play totally, as if i tightened it any more, the motors snagged. But i was happy there was much less play than before.

One thing which looks quite different between the azeq6 and the eq6 is the "worm end float adjusters"; the RA one looks more different than the dec one did, so i didn't adjust either of these at all.

Once i'd done that i checked the dec again and there was a bit of play i'd either not noticed before or which i'd somehow created when playing with the RA. So i re-did the dec and got the play again to zero. I thought i'd re-try he RA to see if i could make it zero also, but it still wouldn't.

Then i loaded the mount with my scope and counter weights, balanced it, and slew it in all directions a few times (RA over 360 degrees several times, and the dec nearly 360 degrees a few times (the dec seems to have slew limits set on it)). Again all moved nicely with no unpleasant motor noises or grinding. I had one last go at the RA whilst the mount was loaded, but again couldn't get it to zero play, but the play is minuscule, probably somewhere between one tenth and one twentieth of a degree on the RA setting circle.

Closed up the side panel and packed tools away.

Quite proud of myself.

Thanks for your input and inspiration.

James"

Link to comment
Share on other sites
  • 3 years later...
A40farinagolf

A40farinagolf

Posted
Posted

I need to adjust the RA backlash on my AZEQ6 however the link to the "Astrobaby" tutorial doesn't work - the error message below appears.

Does anyone else know where a suitable tutorial is located, thanks in advance Mark

HTTP Error 404.0 - Not Found

The resource you are looking for has been removed, had its name changed, or is temporarily unavailable.

 

Link to comment
Share on other sites
swag72

swag72

Posted
Posted
2 minutes ago, A40farinagolf said:

I need to adjust the RA backlash on my AZEQ6 however the link to the "Astrobaby" tutorial doesn't work - the error message below appears.

Does anyone else know where a suitable tutorial is located, thanks in advance Mark

HTTP Error 404.0 - Not Found

The resource you are looking for has been removed, had its name changed, or is temporarily unavailable.

 

Try this https://web.archive.org/web/20161116012518/http://www.astro-baby.com/astro_baby_telescope_help_and_advice.htm

Link to comment
Share on other sites
Starlight 1

Starlight 1

Posted
Posted
4 hours ago, A40farinagolf said:

I need to adjust the RA backlash on my AZEQ6 however the link to the "Astrobaby" tutorial doesn't work - the error message below appears.

Does anyone else know where a suitable tutorial is located, thanks in advance Mark

HTTP Error 404.0 - Not Found

The resource you are looking for has been removed, had its name changed, or is temporarily unavailable.

 

I have a very good link but not on this computer back in 5 mins

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.