ATIK EFW2 filter wheel grub screws...

[Hallingskies]

Just rotated my 460 camera on the back of my EFW2 filter wheel by slacking off the two grubs screws and retightening, as per instructions.  Easy-peasy, but then I noticed that on the telescope adaptor side, there are three little Allen screws on the filter wheel close to the adapter thread.  What do these do?   They are not mentioned in the manual but they show up on Atik’s drawing.  I could take it apart to find out I suppose, but I’d thought I’d ask here first.   Tilt adjustment maybe?

Edited October 20, 2018 by Hallingskies

[assouptro]

I am hoping to revive this thread as I have a tilt issue and would like to know if thee are any adjustments on the efw2 to compensate? 
cheers 

Bryan 

[Davey-T]

No tilt adjustment that I'm aware of, I had a problem with mine as one of the rotation grub screws was seized and I rounded out the head trying to remove it, had to drill it out and then replaced the grub screws with ordinary allen headed bolts.

Dave

[assouptro]

Thanks Dave, you’re always there with a quick reply! 
I truly appreciate the speedy response!

I have a ridiculously long imaging train atm!

 

 

 

it’s an Atik 460 hanging on the back of a Meade 8” sct with a self modified zeroshift microfocuser using a Pegasus Astro stepper Motor then the chunky reliable Celestron oag with a loadstar hanging on quite a few adapters guiding at f10 followed by a 6.3fr/ff, some spacers, then the Atik efw2 and finally the camera! 
I appear to be getting some eggy stars in one corner.

 

cloudy night testing....

 

Eggy stars top left....

Fairly round stars elsewhere...

It maybe that I am just getting some sort of sag, most likely from the zeroshift focuser? But I was hoping I could compensate without having to add any more distance to the sensor or my guide Camera could end up guiding from my neighbours garden! 
😊

I will have to try and work it out.

Thanks again for the input Dave!

cheers

Bryan

[Davey-T]

Here's mine on the 10" Meade SCT, Meade micro focuser, not quite as long as yours.

Dave

 

[assouptro]

Yeah, shorter camera, but the Main difference is the oag. 
I have several but find the Celestron the best due to the size of the pick off, also, I find the fr/ff can distort the stars for the oag and I have a a theory, if I’m guiding at f10, pre reducer then my guiding should be more accurate? 
I am gong to image straight up, taking gravity out of the equation and see where I go from there. 
cheers 

[Davey-T]

I get all sorts of funny shaped OAG stars but it doesn't seem to bother PHD.

Dave

[assouptro]

That’s true...

However I also had the problem of the oag being so chunky I struggled with spacing the fr/ff.
Maybe I need to rebuild, and try a different configuration using one of my slimmer oags? 
I will hopefully get chance to try over the next couple of weeks whilst the moon is about? 
or, I could just go back to my ed100 that seems to suit the 460 pixel to arc seconds ratio and get some wider field galaxy shots rather than the close up galaxy portraits I was hoping to achieve? 

Thanks 

Bryan 

[tooth_dr]

I think the three grub screws are for attaching the Atik OAG directly to the EFW2 base plate. 

[Hallingskies]

1 hour ago, tooth_dr said:

I think the three grub screws are for attaching the Atik OAG directly to the EFW2 base plate. 

Indeed they are, as I found out when I went down the OAG route!  Unlike Starlight Xpress cameras, I don’t think the ATIK range has any means of adjusting for off axis tilt.  You’d need an additional adjuster in line, like this one...

https://www.firstlightoptics.com/adapters/astro-essentials-m48-t-tilt-adjuster.html

Edited March 4, 2020 by Hallingskies

[assouptro]

2 hours ago, Hallingskies said:

Indeed they are, as I found out when I went down the OAG route!  Unlike Starlight Xpress cameras, I don’t think the ATIK range has any means of adjusting for off axis tilt.  You’d need an additional adjuster in line, like this one...

https://www.firstlightoptics.com/adapters/astro-essentials-m48-t-tilt-adjuster.html

Thanks for the input

I thought that would be the answer but I wasn’t keen on adding more spacers, although I could replace the existing spacers between the oag and the filter wheel with this tilt adjuster provided I can get to the adjustment screws when I’m situ and they’re not blocked by the filter wheel? Also I will have to make sure it’s not a gravity tilt as that will change as the telescope tracks? 
I will have to do some experimentation and see if the tilt stays the same whilst the scope is in different positions. 
I may buy one of these anyway as it will be a useful thing to have in my arsenal! 
thanks again 

Bryan

[assouptro]

Well, I ordered the adapter in the link, but failed to notice the t in the title! I thought it was M48 at both sides! 
I could adapt it for use but I would need more adapters or the adjustment screws would be inaccessible. 
Back to the drawing board! 

[Richie092]

On 04/03/2020 at 00:11, Davey-T said:

No tilt adjustment that I'm aware of, I had a problem with mine as one of the rotation grub screws was seized and I rounded out the head trying to remove it, had to drill it out and then replaced the grub screws with ordinary allen headed bolts.

Dave

Another thread revival here, @Davey-T could you give me a bit more info on how you drilled and threaded your filter wheel, I have just rounded off the head of one of the grub screws and now that rotating bit it is a tiny bit loose. Did you do it with a  hand drill or have you got special "stuff" what size thread bolt did you use?

Thanks in advance

Richie

[Davey-T]

On 20/04/2021 at 15:01, Richie092 said:

Another thread revival here, @Davey-T could you give me a bit more info on how you drilled and threaded your filter wheel, I have just rounded off the head of one of the grub screws and now that rotating bit it is a tiny bit loose. Did you do it with a  hand drill or have you got special "stuff" what size thread bolt did you use?

Thanks in advance

Richie

Used a pillar drill with it held in vice, 1.5 drill first I think, then 2mm and cleaned thread with 3mm tap.

Replaced both screws with 3mm bolts as pic'

Dave