Polar scope

[wookie1965]

Is there a easier way to calibrate a polar scope on a EQ5 than taking the motor off and the plate holding the front altitude bolt. 

Sent my mount off to a Astronomy shop to have it overhauled and paid a fair price. 

My polar scope has hairs and spots of dust in it how I have not got a clue it needs cleaning and I have to take it all out which means calibration thanks. 

[Seelive]

9 minutes ago, wookie1965 said:

Is there a easier way to calibrate a polar scope on a EQ5 than taking the motor off and the plate holding the front altitude bolt. 

Not sure why you would need to do either. OK, so I've got a EQ-35 but I'm sure they're not so different. My polar scope unscrews from the rear of the RA axis (if you really need remove it to clean it) so no need to remove anything. To calibrate I just raise the east and west tripod legs to the maximum leaving the north leg at minimum and then adjust the mount altitude until I can find a distant object in the polarscope near the horizon (obviously with the north leg pointing roughly towards the object!). That way you can comfortably sit down whilst aligning the polarscope.

[Jiggy 67]

Do you mean centering it on the axis or setting the clock face correctly (if it has one) or both. The first I would do on a distant object or Star, the second, I wouldn’t bother as you can turn the mount in RA so the clock is set correctly for PA. As for cleaning it, unless it’s un-viewable, again, I wouldn’t bother. The scope serves one purpose so as long as you can see Polaris you’re good to go

[fozzybear]

I know it is on another site but worth a look at as you then clean the actual reticule itself

[wookie1965]

1 hour ago, Seelive said:

Not sure why you would need to do either. OK, so I've got a EQ-35 but I'm sure they're not so different. My polar scope unscrews from the rear of the RA axis (if you really need remove it to clean it) so no need to remove anything. To calibrate I just raise the east and west tripod legs to the maximum leaving the north leg at minimum and then adjust the mount altitude until I can find a distant object in the polarscope near the horizon (obviously with the north leg pointing roughly towards the object!). That way you can comfortably sit down whilst aligning the polarscope.

Thanks no it's to calibrate the polar scope I have undone the focuser section but the dust and hairs are behind that as I have collimation knobs in instead of the Allen key bolts it is easier. I have tried the East and West trick but I still have nothing low enough to see I normally do it on an aerial accross the road it's just a faff. 

[wookie1965]

42 minutes ago, Jiggy 67 said:

Do you mean centering it on the axis or setting the clock face correctly (if it has one) or both. The first I would do on a distant object or Star, the second, I wouldn’t bother as you can turn the mount in RA so the clock is set correctly for PA. As for cleaning it, unless it’s un-viewable, again, I wouldn’t bother. The scope serves one purpose so as long as you can see Polaris you’re good to go

Setting it on axis I'm not bothered about orientation. I have had trouble seeing both the cross hairs and the aerial I use to calibrate it. 

[fozzybear]

just  unscrew  the whole assy  and clean as needed the reticle is held in place by the 3 grub or if modded thumb screws  the reticle should pop out ... 

[wookie1965]

17 minutes ago, fozzybear said:

just  unscrew  the whole assy  and clean as needed the reticle is held in place by the 3 grub or if modded thumb screws  the reticle should pop out ... 

But when I put it back I'm going have to calibrate it again with moving the grub screws. 

[fozzybear]

54 minutes ago, wookie1965 said:

But when I put it back I'm going have to calibrate it again with moving the grub screws. 

and is this going to be a problem

[fozzybear]

so to clean or not and let it be.. that is the question?

[Alien 13]

I will add my thoughts because I did a strip down and cleaned my reticule..

First of all get rid of the thumbscrews, they are always getting touched causing the reticule to move out of alignment, the grub screws are better in my view.

The inside of the polarscope barrel is full of grease, so if you can get the reticule out and back in without contaminating it you are a better man than me 😀 took me 3 tries.

Was it worth the hassle, definitely yes.

Alan

Edited June 7, 2021 by Alien 13

[wookie1965]

The problem is my view is somewhat distorted and second I paid £75 for the mount to be overhauled and set up. 

I can easily take the reticule out clean it and put it back and then calibrate it I've done that before. 

The one thing putting me off is taking the motor off then replacing it after, as good as it is now no backlash nothing. The hair goes right through the Cross hairs so needs something doing. 

I wanted to know if there was a way around it as it looks like there isn't I will just have to take the plunge tomorrow and go for it. 

Thank you all for your Imput much appreciated. 

[Alien 13]

Not sure why you would need to take the motor off, I know I have the EQ3 but the EQ5 is similar regarding the polar scope and it just unscrews..

Alan

[blameTECHIE]

I've an EQ5 (Pro) in the garage and had to go and check in case there was something strange with the motors (hadn't had need to take the PS out)
yep, just unscrews, feels a bit tight for initial release but a firm grip and rotate CCW

Hope the vid I've just taken helps

[blameTECHIE]

just realised that could come across as a dodgy link, so here's the youtube link directly

 

[wookie1965]

49 minutes ago, Alien 13 said:

Not sure why you would need to take the motor off, I know I have the EQ3 but the EQ5 is similar regarding the polar scope and it just unscrews..

Alan

You cannot rotate 360° with the motor on. It catches on the body. 

Edited June 7, 2021 by wookie1965

[wookie1965]

6 minutes ago, blameTECHIE said:

just realised that could come across as a dodgy link, so here's the youtube link directly

 

Yes I can do that but need to take the reticule out which means loosening the three grub screws or knobs like I have to aid calibration. 

Once you have done this you then need to do what astronomy shed shows or any number of video tutorials which involves taking the motor off. 

[blameTECHIE]

Have my EQ5 Pro with me at the desk now as I really want to help - checked and it rotates freely without hitting the body, the only issue is the DEC IN cable which is easily disconnected from either end.

clutch lever gets a bit close but does pass cleanly

Edited June 7, 2021 by blameTECHIE

[Stu]

@wookie1965 if the person that did the tuning up for you caused this, send it back and get them to sort it out. Don’t go messing with it and end up with it not being right.

[wookie1965]

13 minutes ago, Stu said:

@wookie1965 if the person that did the tuning up for you caused this, send it back and get them to sort it out. Don’t go messing with it and end up with it not being right.

No Stu it's my fault I've lost the polar cap so stuff falls down, a nice gentleman on here has 3d printed one and is sending it out to me. 

Paul 

[wookie1965]

21 minutes ago, blameTECHIE said:

Have my EQ5 Pro with me at the desk now as I really want to help - checked and it rotates freely without hitting the body, the only issue is the DEC IN cable which is easily disconnected from either end.

clutch lever gets a bit close but does pass cleanly

When you rotate the RA axis the motor catches on the body. 

[blameTECHIE]

Gotcha @wookie1965 and have repeated that here, yep the DEC motor hits the RA motor.

But the DEC axis rotates, so spin it 180° put the DEC motor at the front and it clears everything.

[wookie1965]

I apologise I have just checked if I start with the motor up it will rotate all the way around. 

I am a idiot only just noticed this. 

[blameTECHIE]

 this seems appropriate (or maybe it's just late on a school night for me, I've work in 6hrs)

 

 

Edited June 7, 2021 by blameTECHIE