Here is a simple way I
use to Train my drives. I know, if the tube was 45 degrees pointed up, it
may be a better sampling, but, I can perform this indoors, and with Dick Seymour's
Patch Kit in the software, I can access the Train Drives numbers for RA and
Dec. Currently, 26 and 30 after realigning the gears etc.
I use a better laser now,
but we start by taping the unit to "On" and then tape it to the
finderscope mount. Alignment to the central axis of the OTA is not that important.
I like to use a front
surfaced mirror placed as far away as possible. This will reflect the beam
back to my end of the house and make it easier to see when things are Happy.
The total distance from scope to mirror to door is about 75 ft. Were this
a lesser distance, I would use another mirror or two. I did the math and 75
ft will give about 20 arcseconds for 1/10th inches.
75ft x 3.14159 = 471.23
471.23 ft x 12 in = 5654
5654 / 360 = 15.7"
15.7" / 60 = .262"
1/10" = approx 20
Arcseconds (1/3 of .262)
This is way beyond the
tolerance of the GoTos etc where 2 ArcMinutes is the normal tolerance.
This is from the mirror
Darkened a bit.
Every laser has some scatter.
I marked the chart to take advantage of the fingerprint. Makes knowing when
it is centered easier.
Where we start out. Also,
it is important at this time to slew into the center from the same direction
the first movement will go towards. ie: If the alignment in Dec moves the
beam to the right per the arrow, center the beam from the left, to the right
then start the training.
When the beam slews out
and comes back, about here, slow the slew to Speed #1 or 2. This makes it
alot easier to center the beam. This adjustment will not harm the procedure
The new laser. A really
nice spot compared to the other one.
I repeat the same process
for the Dec and then, repeat the whole thing at least 5x per axis. Read the
numbers out each time and average them for your values to rekey back in. This
will also allow you to note if the numbers are consistent.