Polar alignment query on EQ5pro + Query on home position

[StargeezerTim]

Hi there,

I think I am almost understanding how to polar align now, having had my scope out a couple of nights.

I know how to find out the position of polaris using polar finder on my phone. The issue I have is using the polar finder. I have read that you turn the RA axis till the little locator circle on the polar finder approximates the position determined on polar finder. The trouble is that the RA axis doesnt turn enough to give a 360 degree coverage. The motor housings block  a 360 movement. Hence I am guesstimating the position and placing polaris at approximately the right position on the large circle.

Does this sound like I am doing it right? I assume that the motor housings prevent a 360 rotation so this is the best I can do, or am I missing something basic? 

Another problem I had the last time out was placing the telescope in the rings with the eyepiece and finder in the right positions. Last time out I set it up so it was Good viewing in the home position but when I slewed 180 to view Orion, the eyepiece was facing the floor! (I have a newtonian reflector) Does this happen normally, i.e. do you expect to rotate the telescope in the rings at different viewing positions or is there an easy to remember home position orientation that will allow good access to the eyepiece and finder when observing?

Its a steep learning curve this, but I have already got some nice pics. I look forward to your responses, even if it is just to say your on track!

Thanks. Tim. 

[Kropster]

I think rotating the scope in the rings to get the finder and eyepiece in a usable position is unavoidable.

I do it all the time.

It shouldn't affect polar alignment..... except maybe in supercritical astrophotography terms.

[bogdog]

watch these 2 cliips,explains it in easy terms ans maybe help you understand a bit better

https://www.youtube.com/watch?v=plx6XXDgf2E

https://www.youtube.com/watch?v=F7HVDKAZ6eM

[Oily]

To polar align,slacken the clutch off on the dec axis(OTA off) and rotate it until the polar scope is visible,then do your polar alignment.To get round the EP being in a 'funny position' people use a 'rotating ring'

This is a third tube ring clamped on the OTA which butts up to the top ring,so you leave the two rings clamped to the dovetail loose ish so you can easily rotate the OTA to any viewing angle.

DIY guide here for rotating rings:

http://www.astro-baby.com/articles/rotating%20rings/Rotating%20Rings%20Project.htm

[StargeezerTim]

Thank you folks,

I'm glad it's 'normal' to end up with the eyepiece gone AWOL, I thought I was doing something wrong!

Regarding the polar alignment with the polarscope, I'm still not sure if it is normal that you cant put the little 'target ring' for polaris anywhere on the 'clock'. As I said, the RA movement is limited by the motor housings.

I look forward to hearing if I am missing something here.

Tim. 

[Alien 13]

Thank you folks,

I'm glad it's 'normal' to end up with the eyepiece gone AWOL, I thought I was doing something wrong!

Regarding the polar alignment with the polarscope, I'm still not sure if it is normal that you cant put the little 'target ring' for polaris anywhere on the 'clock'. As I said, the RA movement is limited by the motor housings.

I look forward to hearing if I am missing something here.

Tim. 

That has allways puzzled me i have the EQ3-2 which will do a full 360 degrees with no obstruction so i too would be interested in the solution.

Alan

[jambouk]

If for whatever reason you can't manage to get the small polaris circle where you want it (have you tried going both directions), then just don't use the small polaris circle.

If polaris is meant to be at 6 o clock, but you can only get the polaris circle to say 5 or 7, then just position polaris on the larger circle line at the 6 o clock position, irrespective of where the small polaris circle is; if you do this, the north celestial pile will still be bang on in the middle of the cross hairs.

Problem solved.

Jd

[jambouk]

The other thing you could try, and i have no idea if this works, is rotate the dec axis by 180 degrees to see if that moves the motors out of the way and permits you doing a near 360 with the RA axis. It would mean the scope was pointing the wrong way, but that doesn't matter when polar aligning. I have never used one of these mounts so it may not help, but it was just an after thought.

Jd

[jambouk]

And one final thought, if you are just doing visual, polar alignment doesn't need to be highly accurate. Errors in your polar alignment will not influence the accuracy of your GOTO if you do a good star alignment.

Jd

[oldpink]

had similar problem as jambouk suggests turn the dec 180 deg so its pointing up
that solved the problem for me

[StargeezerTim]

Thanks folks,

Manages to polar align ok this evening, eventually! tried turning the dec, but still cant do 360 with polarscope. Never mind, as long as placing the star on the circle in the right place is OK, thats OK by me!

Tim. 

[oldpink]

whats stopping you turning it 360 deg, if the motor is out the way
can you post a picture of your mount in the home position

[StargeezerTim]

Hi Old Pink,

Done it! I was a bit flustered last night. I spent about 90 minutes trying to locate polaris in my polarscope. I put sticky markers on the floor the previous outing so it should have been there straight away. I only realised much later that the markers had moved. Anyway got it aligned eventually and have now worked out how to turn RA 360 deg. So all is well!

Tim. 

[oldpink]

good to here you got it sorted
I had a lot of similar issues to start with but slowly getting there

[jambouk]

Tim, how did you managed to get it to rotate 360, what was limiting it before?

[StargeezerTim]

I turned Dec the wrong way to open up the polarscope aperture. It just needed a 180 deg turn to free it up. Thicko I am! ha ha... I learn...slowly...

[Kropster]

I find that just doing an alignment of the tripod with Polaris by line of sight usually puts it in the polar scope field of view..... then just a case of nudging the tripod and final adjustment with the bolts/screws.

The alt adjustment is usually very close if you set up on the same surface each time.