really struggling with the 2 star drrft alignment method

[cal1985]

hi all , i tried for 6 hours last night to align my scope using the drift alignment method.

the first star in the south about 10deg above horizon, i then took a image of the star for 1 min and looked for up/down drift then adjustd the mount head left or right depending if up or down drift..

once all drift up/down was absent, moved to the second star in the west, again took a exposure of 1 min and looked for movement up and down and adjusted the altitude of the mount (latitude) once that drift was absent went back to the star in the south and checked there was no movement. then adjusted the motor gears to keep the star tracking central.

perfect !! at least i though it was ! the problem i have is once i move the scope to a new region say' M13 the tracking is terrible. im lucky if i can get a 15sec exposure without trails. im also finding that i have to adjust the speed of the motor to keep the stars tracking.

i thought once the alignment was set and the motor moving at the correct speed that was it ?? but just seems that i have to constantly adjust the speed of the motor to each and every object.

what am i doing wrong, i have searched the forums and internet and cant find any solutions.

sorry for the essay !!

[michael8554]

I think one clue is your statement "then adjusted the motor gears to keep the star tracking central".

Sounds like your RA drive has a knob to adjust the speed?

If so this isn't accurate enough, fine for visual, but for imaging the RA drive speed needs to be fixed and accurate, and only modified temporarly, usually by East and West buttons on the controller.

Also when you move to M13 the load on the motor probably changes, particularly with a 300D hanging off to one side, and it sounds like the speed is changing as a result.

However, a 300D on a 900mm isn't that high a magnification, so 15secs should be possible even with this basic mount?

Cheers

Michael

[cal1985]

the camera is also attached to a barlow as with the skywatcher 130/900 you cannot acheive enough inward focus without the use of a barlow.

yes that sounds exactly right, regarding the gears, there are no buttons to adjust only a knob, i have swapped to wide field imaging piggy backed until i can afford a better mount and motor. the wide field images are coming out ok but still so so much to learn!