eq6 Problems with EQ6 polarscope alignment

[Errol]

Hi everyone,

Over winter I purchased an EQ6 non GOTO mount. As it was dry today, I thought that I would have a go aligning the polar scope within the mount. It looks so easy on the eBay video's!

On the positive side I found that the cross-hairs kept steady on a distant television aerial when I rotated the Dec axis through 180 deg. What I didn't expect to find was that the TV aerial itself swung through an arc when I rotated the dec axis!

I took a not very good video of this rotation using my mobile,  which happened to be to hand but I think it is sufficient to see what happens. The video is below (hopefully).

First what is happening here - anyone had this problem?

Secondly, I took a photograph of the adjustments available to me near the polarscope. Which fasteners do I adjust? (image attached)

 

Any help would be greatly appreciated,

Errol

Video of rotation problems

 

 

[Darren Hill]

B should be the adjustment for the polarscope. There's three screws, be careful and adjust these in small increments, it's possible to go too far and drop the screw inside the mount. Some people change these screws out for ones that are adjustable by hand - but I did my polarscope once and haven't needed to touch it since. Also, as a note, you were rotating the mount in RA - not DEC.

 

 

 

 

[Errol]

23 hours ago, Darren Hill said:

B should be the adjustment for the polarscope. There's three screws, be careful and adjust these in small increments, it's possible to go too far and drop the screw inside the mount. Some people change these screws out for ones that are adjustable by hand - but I did my polarscope once and haven't needed to touch it since. Also, as a note, you were rotating the mount in RA - not DEC.

 

 

 

 

Thank you Darren. Yes of course I should have realised it was the RA axis!

Is it usual for the target itself (in this case the distant tv aerial) to rotate around an axis? I expected this to stay dead centre whilst rotating the RA axis but this is the first time I have tried to align a polarscope.

[Physopto]

4 minutes ago, Errol said:

Thank you Darren. Yes of course I should have realised it was the RA axis!

Is it usual for the target itself (in this case the distant tv aerial) to rotate around an axis? I expected this to stay dead centre whilst rotating the RA axis but this is the first time I have tried to align a polarscope.

The important bit was the aerial stayed in or on the craoss hairs. The movement is just mechanical error in the machining. You were spot on really, so no problems with your alignment at all.

Derek

[Errol]

2 minutes ago, Physopto said:

The important bit was the aerial stayed in or on the craoss hairs. The movement is just mechanical error in the machining. You were spot on really, so no problems with your alignment at all.

Derek

Phew! Thanks Derek.

[Darren Hill]

I thought you needed a very small adjustment - but like Derek says, if it is staying on the same part of the antenna you should be good!

 

[Errol]

14 hours ago, Darren Hill said:

I thought you needed a very small adjustment - but like Derek says, if it is staying on the same part of the antenna you should be good!

 

Yes, after looking at the video again I see what you mean. I stopped the calibration when I realised there was a rotation issue -  as I thought at the time. It's not critical at this stage as I am visual only at the moment but I am relieved that it is something that only has to be done once!. Earlier this week I made a right angle viewfinder for the polar scope following the instructions elsewhere on the Forum, so the next time I have to use the polar scope I won't have to perform contortions. :-)

[Uplooker]

On 30/01/2017 at 22:46, Darren Hill said:

B should be the adjustment for the polarscope.

I believe "E" are the correct screws to adjust the polar scope reticule orientation to the mount

[Errol]

3 minutes ago, Uplooker said:

I believe "E" are the correct screws to adjust the polar scope reticule orientation to the mount

Hi Ian, thank you for clarifying that - after all else failed I read the manual, which in itself is not really helpful, but it did indeed point to the 'E' screws being the one's to adjust.