Polarscope initial alignment hell

[Notty]

Ok, so I'm out of the traps and tripped up before the first metre. I'm really struggling with this. I've read lots on it, and printed out a very fine guide to "aligning the reticule" which is part of a mount setup guide someone here did. The trouble is, it doesn't seem to work for me. On first check on my target, it was a very small bit out on my target, so I set to work adjusting it. Man how I wish I'd left it, because it's way off now and I can't seem to find a way back. I understand the mechanics of what we're trying to achieve and it all seems perfectly logical, however.... what a horrible horrible procedure!

The problem started with the instructions of which screws to loosen/tighten depending on which way the target has moved. The guide suggested that if the target drifted to (eg) the SW of the crosshairs after 180 deg rotation, then you should loosen the screw nearest the NE and tighten the SW one. So I did that but that doubled the error and moved the target further to the SW, i.e. the wrong way! Am I moving the reticule, or the target?

So I tried it the other way and it moved ever so fractionally the correct way so I tried again. The trouble is now I cannot seem to get any further adjustments, as the screws I need to tighten won't turn against the one I loosen, I presume they must be hard against their stops, though I can't be sure of this as everyone says don't overtighten so I'm terrified of doing it some damage, there's lots of clicking and slipping of the allen key. Where on earth do I go from here? Should I remove all three screws, and try and re-install all equal turns and start again?

I saw a video of someone demo-ing the process and he had "modded" grip-screws you could turn simultaneously against each other instead of these hateful tiny allen head grub things. Does anyone know where I can get some for an HEQ5?

Any help would be greatly appreciated, I'm tearing what's left of may hair out here!

Andy

[Notty]

No help for the poor bumbling fool? ? I guess this procedure must be super easy for everyone else then!

[Andymac79]

Set the screws back so they all have equalish adjustment. Take a step back and have a brew.

Now get a distant bright object in view. Turn the RA axis through 180 degrees, however far the object has now moved, adjust the reticle so the object moves half way back to the original position on the same line. Thats really about it, you may need a few adjustments to get it bang on.

A bit time consuming but not hell for sure. Is this for visual or imaging?

[JamesF]

Now get a distant bright object in view. Turn the RA axis through 180 degrees, however far the object has now moved, adjust the reticle so the object moves half way back to the original position on the same line. Thats really about it, you may need a few adjustments to get it bang on.

That's pretty much what I was going to say. Forget which screws you need to move. Just look at where it is, where it needs to be, and move whatever screws are necessary in whichever direction is required to get it half way back. If you move one and it goes in the wrong direction, stop and put it back the way it was. Once you've done a couple of iterations you should get the hang of it.

James

[Photosbykev]

As above but DO NOT slacken any screw more than about 1/4-1/2 a turn at a time as it's possible for the reticle to dis-engage from the screws and then it becomes a pita to correct.

After the 180 turn you want to try to remove half the error and repeat as needed

[mapstar]

Hello Andy,

I too have the HEQ5 which hasn't even been aimed at a star in anger yet due to the cloudiest week for months!! I centred the reticule polar scope today using the Astronomy Shed video on you tube:-

He talks about a webcam first but its the second half of the video that you'll be watching but I found it useful.

Also is this write up from astro baby:-

http://www.astro-baby.com/HEQ5/HEQ5-1.htm

Hope this helps

Damian

[skir]

If the reticule has disengaged from the screw's it is pretty easy to put right as the polar scope unscrews into three parts. Then you can replace the reticle, lightly do the screw's up and screw the parts of the scope back together again.

Sent from my Nexus 7 using Tapatalk 2

[stem1989]

I had the exact same problem and almost ended up threading the tiny screws, so I walked away for a day or two and came back to it before I did damage and couldn't get it out all together.

At first I'd wished Id left it, I also had the problem making things worse as it where. But I sat down a few days later and it did take me around an hour to complete moving no more than an 1/8th turn each time. I think I was over moving the screws and also ran out of play. So I un-tightened them all as 'equally' as I could and started again and its still a tiny bit off but I try to use drift alignment (something Im still trying to get my head around fully) to compensate. But Im scared of going back to it and it happening all over again!

Those screws look like they would make the job a million times easier!

Good luck.

[nephilim]

I had the same problem the other day & had to take it apart & start again, if the reticule disengages its not a great deal to pop it back BUT if u overtighten u could damage it, it took me a while to get right but keep at it with just 1/8th turns at a time & you'll get there in the end. On the plus side, its a job that only really needs doing once.

Steve

[Notty]

Many thanks for the tips everyone, I've got it sort of centralised-ish now, which is where I'm going too leave it until I get to the stage it becomes a problem... which considering I haven't seen a star through this thing yet is going to be a while!

While I'm on the initial setup side of things, can anyone tell me about this business of setting "home position", and whether I need to worry about it at all at the moment with a SYNTREK (as opposed to GOTO) mount? I'm not planning on EQMOD type antics for a while, I just want to play with finding things in the sky on the scope manually and watching the scope track them. Is "home position" only a concern for GOTO equipment?

Thanks!

[Spanishfly]

Maybe equatorial mounts are not for everybody.

[nephilim]

Many thanks for the tips everyone, I've got it sort of centralised-ish now, which is where I'm going too leave it until I get to the stage it becomes a problem... which considering I haven't seen a star through this thing yet is going to be a while!

While I'm on the initial setup side of things, can anyone tell me about this business of setting "home position", and whether I need to worry about it at all at the moment with a SYNTREK (as opposed to GOTO) mount? I'm not planning on EQMOD type antics for a while, I just want to play with finding things in the sky on the scope manually and watching the scope track them. Is "home position" only a concern for GOTO equipment?

Thanks!

Although i'm not 100% sure, I think 'home position' is only needed for goto, u can track manually & follow objects but you'll need to be polar aligned to allow the scope to track although it neednt be bang on accurate if its just for visual, for AP thats a WHOLE different story

Steve

[Notty]

Maybe equatorial mounts are not for everybody.

Very helpful, thanks. We were all beginners once I think.

[Notty]

Although i'm not 100% sure, I think 'home position' is only needed for goto, u can track manually & follow objects but you'll need to be polar aligned to allow the scope to track although it neednt be bang on accurate if its just for visual, for AP thats a WHOLE different story

Steve

That sort of gels with my understanding, thanks for that Steve.

[themos]

Yes, don't bother with "home position" if you're finding things manually.