Hotech instructional video wrong ?

[Rusty2]

Howdy , I found something this afternoon , a problem with the Hotech instructional video .

If your secondary mirror isn't in the correct position to begin with then the whole process is flawed .

I've been trying to centre my secondary mirror for the last year and a half and could never quite get it there . I did it again this afternoon after inserting a field reducer into the focuser on the LX200 . Got to the same stage and still couldn't align the secondary mirror correctly .

I went through the entire process again and got to the part where LX200 users have to remove the corrector plate . I happened to glance up the tube and noticed that the laser cross hairs were way off centre of the internal tube . I thought that surely the laser cross hairs would have to be centred in the middle of the tube , right ?

I centred the cross hairs and the shadow of the tube , on the face of the Hotech plate , making sure that everything was aligned on the hotech .
I aligned the focuser and attached the corrector plate . Bingo , the secondary mirror now aligned perfectly .

Surely I can't be the only person who's noticed this , or am I wrong ?
Russell :question:

[Rusty2]

Nah , it was me , oops .
As it turns out I was aligning the scope to the internal (cropped) end of the laser line , not the external .
I got home this arvo and did it all over agin the correct way and still couldn't centre the secondary . I rotated the secondary 180 degrees and it finally worked .
Sorry for the kerfuffle : )

[evltoy]

Sounds like you are using the Hotech SCT collimation laser tool.. If so that is one bit of kit! where did you get it from?

Let me know what you think of the tool as I have been battling collimation on my 8" SCT for over 12 month with not much help from the forums. I'm now looking into the OCal collimation tool, its not as advance as the Hotech, but a lot cheaper, simple to use and with very good results.

[mldee]

I've had a Hotech kit for many years and found it to be quite useful for checking my C8 and RC8, although a bit fiddly to setup and maintain. It also takes up a fair amount of kitchen real estate when the whole kit and caboodle is in operation. Also needs a tripod for best convenience.

I got an OCAL last year and immediately found it to be far easier to setup and use, both with SCT, RC and Newt. Follow up with a star test and I suspect you'll be happy.

I posted about the OCAL on IIS late last year, but am only now getting around to doing some real imaging verification tests with the long FL scopes, as I have been busy with rain and wide field toys.

Cheers,

[evltoy]

Thanks for pointing out your Thread on the Ocal. They do look very promising.