From: Milton Aupperle <milton@outcastsoft.com>

Date: September 13, 2010 6:43:39 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] new guiding log... [1 Attachment]


Mark;


It's not much better than the last one, as you can tell from reading the 10th to 16th  line into the file (which I explained the last 2 times too).


CalibX4: R Dist 321.48 X1: 1204.78 Y1: 487.89

CalibX5: L Dist 368.46 X2: 1501.97 Y2: 705.71

CalibX6: R Dist 166.42 X1: 1383.21 Y1: 589.12

CalibX7: L Dist 509.31 X2: 911.26 Y2: 397.65

CalibX8: R Dist 494.75 X1: 1336.64 Y1 650.29

CalibX9: L Dist 196.94 X2: 1259.86 Y2: 468.94


One time its 166 pixels, the next time it's 509. That's grossly out of whack and you much have at least 40 arc seconds of slop on the mount in the RA. As I said before, when I do my guiding at 1150 mm focal lengths, my R and L distances for the calibration are < 1% different (i.e. L and R distances are 40 +/-2 pixels / arc seconds for all passes).


The Dec did not complete reliably either and had to re-try multiple times, which also tells me your Dec is not really good either.


If you have a grinding noise, then your gear position or tension needs adjustment. Not only will it track like crap (as evidenced above and in your log with jumps of +/- 60 pixels), it will also not do star alignment reliably either. Slewing back and forth between a few targets (i.e M42 to M46 to M42 to M46 to M42) and see if it's still centered on the last change. You might need to give it a bigger range, but if the targets are not' centered between runs then you have slop in the mount.


So you still have the same mechanical issues I mentioned last time and have not resolved them yet so it simply will never track well.


I would not even bother putting a DSLR camera on until you sort out the Mechanical issues and get some decent calibrations.


Milton Aupperle


On 13-Sep-10, at 5:37 PM, Mark Gaffney wrote:




Milton,

I got out & attempted to image M 42 early this morning (4 am) but rain

closed me down before I took any shots with the DSLR..

M 42 was just above the tall trees I have at the new site in the north-

east.

Above is the guiding log for the brief session..I hope it`s improved

over previous excursions?

I`ve realised I`d do better in future using my f6.3 reducer with the

Nikon D5000 & C9.25 but the above is with my Kwiq guidescope (9 x 50

mm) & Scorpion camera guiding the complete 2350 mm FL of the scope.

I`ve set the autoguide rate on the mount at 75 % of sidereal (Azm &

Dec) & loosened my tightening of the knob below the tripod a little so

there`s less of a binding noise..The rocking of the mount on the

tripod is still virtually non existent..

The backlash settings should be still all at noughts- I haven`t

touched them since the re-set. ( mentioned below)

My Precise Go To (nearby star Altinak) is much better since I did a

factory reset of the mount (due to somebody running over my leads with

a car & causing an intermittant connection which led to erroneous

slews with with my new 240 volt- 12 volt power adapter..) I thought at

first there was something wrong with it..!

I appear to be actually seeing the nebula in the FOV of my 25 mm EP at

least.

I did a 2 star, 1 star callibration alignment & All Star PA earlier in

the night,  this time using my 12 mm illuminated reticle EP for all

alignments & got the "Display Align" (which is the measure of PA

accuracy available after doing an All Star PA) down to Azm : 00* 00'

01" & Alt : 00* 00' 01"

The Up & Right direction buttons were used for finalising the earlier

alignments as usual..


Mark.