Can’t get full focus for imaging no matter what I do

[AlanP_]

30 minutes ago, bottletopburly said:

Using an m48 T ring may give you a few mm needed as you may need more outfocus , just unscrew end out , see picture  

 

Thanks for the photo, much appreciated!

I just took the coma corrector off the t2 adapter, am I missing something or does mine not have that end piece like you unscrewed there?

[fozzybear]

that looks like a tapered fitting by the marks did you unscrew the T2 adaptor of some other means?

[AlanP_]

8 minutes ago, fozzybear said:

that looks like a tapered fitting by the marks did you unscrew the T2 adaptor of some other means?

Yeah, it was actually stuck on the t2 adapter the other day and I struggled to get it off, it was threaded on wrong. Fortunately, my brother in law showed me that I can use the grub screws on the t2 adapter to tighten the coma corrector on. It still fully flush when I tighten them.

[fozzybear]

this is mine

[bottletopburly]

oh dear  you really need to get that off imo

Edited April 23, 2021 by bottletopburly

[fozzybear]

5 minutes ago, AlanP_ said:

Yeah, it was actually stuck on the t2 adapter the other day and I struggled to get it off, it was threaded on wrong. Fortunately, my brother in law showed me that I can use the grub screws on the t2 adapter to tighten the coma corrector on. It still fully flush when I tighten them.

you could try and i say try 10 mins in freezer then with rubber gloves unscrew the adaptor  to shock the threads or try first in a shallow dish of warm water and again with rubber gloves as murder on the skin been there

 

[fozzybear]

7 minutes ago, bottletopburly said:

oh dear 

been there

[AlanP_]

3 minutes ago, fozzybear said:

you could try and i say try 10 mins in freezer then with rubber gloves unscrew the adaptor  to shock the threads or try first in a shallow dish of warm water and again with rubber gloves as murder on the skin been there

 

So can this bit that im pointing at come off? That is if the threads were still there 🤣

[fozzybear]

Just now, AlanP_ said:

So can this bit that im pointing at come off? That is if the threads were still there 🤣

on mime it does unscrew but it maybe an older version than yours 

[fozzybear]

here's mine

[AlanP_]

Wish me luck! 

[fozzybear]

Man with marigold's suit you Sir. Fingers crossed Remove the T2 first

Edited April 23, 2021 by fozzybear

[AlanP_]

Bingo! Your warm water idea did the trick, thanks a lot.
 

so is it the thin piece I’m removing? Btw, thats just some cloth fibre on the lens, not scratches! Has since been removed

Edited April 23, 2021 by AlanP_

[fozzybear]

I have an older version So I am with you blind leading the blind you could try without the ring but make sure you have the T2 adaptor attached otherwise the MPCC is going to drop onto the secondary as nothing holding it in place and chaos ensues . Part one completed detached the rest of the T2 adaptor that's a relief. 

[fozzybear]

I don't have the adaptor in the middle so don't know maybe @bottletopburly can shed some light

[AlanP_]

Ok so I dont think my problem is shaving off some spacing. I actually need more. When I put the extension tube in, I can get things closer to me focused 100%. However, its just a bit too long for infinite focus. When I remove the extension tube, its just a bit too short for full focus! Ahh, so frustrating. So im a couple mm off focus and I cant get it with or with the extension tube.

[bottletopburly]

The underside piece has two slots on a mk3 mpcc slot a dinner knife across and unscrew that becomes an m48 thread now all you need is a m48 TRing ,  using the m42 is known to cause vignetting something I didn’t realise until @alacantinformed me of it .

Edited April 23, 2021 by bottletopburly

[fozzybear]

5 minutes ago, bottletopburly said:

The underside piece has two slots

I take it this is the extra piece as not visible in the OP's photo

[bottletopburly]

7 minutes ago, fozzybear said:

I take it this is the extra piece as not visible in the OP's photo

if he flips the cc you can see it on underside they say a measurement of 55mm for m42 and 57mm for m48 apparently look for +1mm on those measurements ,on my nikon  T ring adapter i used the knurled ring as a spacer to give me an extra  2mm thickness on the tring m48 to make it 11.5 mm +46.5mm for nikon backfocus giving me 58mm 

Edited April 23, 2021 by bottletopburly

[alacant]

16 minutes ago, AlanP_ said:

I actually need more

The coma corrector is not at fault. Please see this article for details of how to connect.

The TS photon Newtonian reflectors (aka gso) come with a m54 extension ring on the focuser. Remove this and you'll be able to achieve focus easily.

Please post a shot of your focuser so we can see its components and we'll be able to guide you. Slightly different models have been used over the years.

Cheers

Edited April 23, 2021 by alacant

[bottletopburly]

3 hours ago, AlanP_ said:

My mistake, i misread your comment. Im not using the extension tube, the MPCC is directly inserted into the focuser. Here is a photo of the setup.

@alacant

[alacant]

The bodge of the Baader cc is still connected.

Firstly, if you haven't already, tighten one of the primary mirror springs -almost- fully and recollimate using only the other two.

Now remove BOTH Baader rings from the coma corrector.

Here the the link in full in case anyone missed it last time:

https://linuxcostablanca.blogspot.com/2021/04/baader-coma-corrector-spacing.html

 

Edited April 23, 2021 by alacant

[AlanP_]

So I got focused finally I think, although it’s a wee bit “hacky” for lack of a better word. It wouldn’t focus so I had to have half of the coma corrector in and then tighten it to the focused, so yeah not ideal, but I’m glad my scope is ok. I attached a few photos I took quickly as clouds were coming.

What’s the bodge of the cc? I’m not familiar with the terminology. Tomorrow I’ll remove  the two rings and try again. Should I still remove the m54 extension ring if I can on my scope?

 

appreciate everyone’s help.

[fozzybear]

getting there 

[alacant]

1 hour ago, AlanP_ said:

What’s the bodge

The M42 adapter and ring which causes tilt and vignetting. Remove it.

1 hour ago, AlanP_ said:

I had to have half of the coma corrector in and then tighten it to the focused,

Doesn't make sense. That's the same as if you push in the cc fully and wind the focuser outward to achieve the same camera position. The dslr focus position with the standard secondary is with the focuser wound outward about 10mm with the cc tight up against the neck of the focuser clamp.

Are you sure you are collimated?

Cheers.

Edited April 23, 2021 by alacant