VintageBigBlue.org

 

PEC.....ALIGN GEAR BOX


Sep 9, 2006

 


----------------------------

#30775 Sep 9, 2006

Hey Dudes,



It was suggested long ago to try this so I gave it a shot. The first

thing I noticed is that I no longer hear the gearbox whirling and

whinning during slews. What did I do? I just aligned the gearbox

with the center point of the worm gear. All I did was oblong the

gearbox mounting holes alittle so I could adjust it. I was surprised

how far off the stock alignment was.



Peace,

Russ

Cool Observatory

www.stargazing.net\coolastronut



--- In Losmandy_users@yahoogroups.com, "Ladislav Nemec" nemecl@...>

wrote: >

> Thanks, I hope to succeed similarly. After my first attempt to

align the > stuff 'systematically' we got a rain here. Murphy's law?

>

> Clear skies will come, eventually.

>

>

>

> Regards, LN

>

>

>

> -----Original Message-----

> From: Losmandy_users@yahoogroups.com

[mailto:Losmandy_users@yahoogroups.com] > On Behalf Of Teri Smoot

> Sent: Wednesday, September 06, 2006 8:10 PM

> To: Losmandy_users@yahoogroups.com

> Subject: Re: [Losmandy_users] PEC

>

>

>

> Ladislav,

>

> Couple of comments on this issue (and from a point somewhere in the

middle > of the thread...).

>

> I've used my G11 for over two years now for unguided imaging (at

1000 mm > focal length and with a 1.3 arc sec/pixel Canon 20D). It has worked

well > BUT I did spend a fair amount of time in the beginning adjusting

the worm > block (though making no changes to the stock block). After getting

it > right, I haven't needed to do anything more. [Maybe I was lucky

though?] >

> The second thing to mention is that if you use something like

ImagePlus to > do your stacking, you don't run into memory issues. I regularily

stack 30 > full size RAW images (converted to FITS) with my 500 Mb memory

computer. > Its no harder to stack 30 images than 5 images (though it does take

a bit > more processing time).

>

> FWIW,

>

> Teri

>

> ----- Original Message -----

> From: "Ladislav Nemec" nemecl@earthlink. mailto:nemecl%

40earthlink.net> > net>

> To: Losmandy_users@ mailto:Losmandy_users%40yahoogroups.com>

> yahoogroups.com>

> Sent: Wednesday, September 06, 2006 10:52 AM

> Subject: RE: [Losmandy_users] PEC

>

> >I calmed down somewhat this morning. You are absolutely correct

about > > 'catching flies.'. You are possibly correct about virtually

perfect > > original

> > alignment of my new (I purchased it September 27, 2005 at

Woodland Camera > > in

> > LA) G11. Earlier tests indicated quite low PE specially compared

to my > > previous Celestron CG-5 that one has some 90 arcsecs of PE and NO

PEC. > >

> >

> >

> > I have to disagree with your comments about 'guiding out' the PE

error. I > > have been doing this for some time now and it, indeed, works very

well > > (most

> > of the time). I have to completely disagree with your statement

that G11 > > is

> > a 'wrong mount' to do unguided astrophotography. I do not think

that Scott > > would agree with that and experience of many amateurs is not

consistent > > with

> > that statement.

> >

> >

> >

> > It is VERY simple. Part of the specifications (that decided my

purchase of > > the mount) is its PEC function, even with the G11 minus Gemini and

> > especially WITH Gemini L4. That functionality is completely

absent on my > > mount. It would be counter-productive to put it THIS way to Scott

> > although,

> > legally, it is undeniably the proper approach. This may be

actually a nice > > case for Judge Judy.

> >

> >

> >

> > The reason why I need fairly good tracking unguided is this: I

just > > purchased advanced digital color SLR that has no ability to guide

the > > scope

> > as my other cameras (ST7, ST8) have. I have now two alternatives:

to make > > the PEC (with or without Pempro) work adequately or add a

guidescope to my > > OTA possibly exceeding the load capacity of the G11. At this

point I am > > pursuing the first alternative but if it fails, I'll have no

choice but to > > add a guidescope. I actually tried that but I really did not like

the > > situation when the mount could NOT be properly balanced along the

DEC > > axis.

> > This may not be too important since the motion in DEC is minimal

during > > the

> > guiding and limited number of results indicated that this could

be done. > >

> >

> >

> > I have always looked for a SIMPLER solutions if one was at least

> > theoretically possible. I'll pursue this by all available means

taking > > into

> > account the good reputation Scott Losmandy has in helping his

customers. I > > hope I have not antagonized his already but sometimes this cannot

be > > helped.

> > This should have no effect on resolution of the problem.

> >

> >

> >

> > As for unguided imaging, it is possible now for shorter

exposures. > > Actually,

> > it seems to be related to the 77 s periodic error (1 or 2 minute

exposures > > are mostly adequate). It is really an issue of stacking. DSLR

color (raw) > > images are huge with a 8 MP chip. It is feasible to stack some 5 -

10 of > > them, more difficult to do it for 50 or something. That is a

software > > issue

> > I will handle only after the hardware is optimized.

> >

> >

> >

> > Thanks for your friendly advice although I cannot agree with all

what you > > wrote.

> >

> >

> >

> > Best regards, Ladislav

>

>

>

>

>

> [Non-text portions of this message have been removed]

>







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