newt v hacksaw

[Peter.M]

Hi guys, after getting my shiny new oag in the mail and trying to focus my qhy9 I realised that I would require a bit more backfocus. After a break while I decided what I wanted to do. With a small amount of backfocus still required I took the mirror cell out and began marking the tube. I was determined to get this system running the way I wanted it too. There is no going back now. Stay tuned for part 2 tonight where I get the guider working and post my first images.

[ballaratdragons]

Go for it Peter :thumbsup:

If the Hacksaw doesn't work, use an Angle Grinder :lol:
Looking forward to the results :)

[alistairsam]

Hi Peter, good luck with it but have you thought of the longer bolts and springs or a low profile focuser?
have you measured how much backfocus you need?

I have a GSO 8" F4, qhy8 and an mpcc and I get focus with the qhy8 and mpcc well out even with a stock bintel 10:1 focuser, and i'm not even using long bolts.

well, as they say, measure twice, cut once. potential for misalignment of the mirror may add to collimation issues, being F4 it'll be more pronounced.

[dannat]

I would go the longer bolts as alistair suggests! Or if you're desperate red rill the focuser/spider cane holes & move them

[asimov]

Yeah done this a few times before. An angle grinder is a lot quicker & cleaner. As long as the final result is a win I always say.

[Peter.M]

Longer bolts were a no go, I now have a ts giant oag mpcc filter wheel and qhy9 hanging off the tube.

[coldlegs]

Been there. Done that. Ugly,Ugly. Second time round I think would find a way to shift the mirror up the barrel. You'll have fun trying to file off the sharp edges. The barrel becomes very flexible. Good luck.
Cheers
Stephen