Quick Polar Alignment
The fastest way to align a Paramount ME is to skip the alignment step!]
My environment in Florida is nightly equipment moves to the end of the
driveway from the garage. That is, I must move equipment, re-setup and re-align
every night. Supporting my
is a Monolith Portable Pier which rides on JMI Wheely Bars.
A working Procedure:
My biggest frustration with the
was my inability to rapidly setup and achieve a good polar alignment
each night. Using the Takahashi NJP
mount with its internal polar alignment scope I am usually able to accomplish
these tasks in 10-15 minutes. With the
ME it was taking 90 or more minutes every night. To be fair the ME is carrying much more
weight which the NJP would not support. Also the focal length of the Takahashi FRC-300 atop the ME is 2348mm vs. 1000mm
for the TOA-130 on the NJP. This makes the nightly
ME alignment process relatively much more difficult. However, this procedure has worked well on focal length telesocpes of over 3500mm.
After months of unsuccessful trial and error, I have finally
found a setup procedure for the ME that gets the setup done in less time than the
NJP. Here is my procedure:
is to do a good, full setup of the
mount. (this now means on top of Pier-Paws, see
below) First, permanently fix the heights of all 3 wheely-bar height
adjusters and then lift the mount onto Pier Paws. This includes physically locating the
tripod supports (height adjusters) on the JMI wheely-bar in a fixed spot
on the driveway. I then accurately
in all directions. I establish a very good polar alignment
using the Quick-setup procedure from Software Bisque. After this I make 2 or even 3 T-Point
model runs of 20+ points. After
each run I refine the polar alignment and start over. After I have a good polar alignment
(usually under 120 seconds of error) I do a T-Point run of over 100
points. This model is saved for
future use on subsequent nights. This entire procedure normally takes me 90-120 minutes. On subsequent nights no changes are made
to any of the ME ’s physical positioning mechanisms, and I can then do the following procedures:
What did not work
very well for me?
Comment: Positioning the equipment while sounding simple can be a bit esoteric. There are two major alternatives: First, permanently fix the heights of all 3 wheely-bar height adjusters and then lift the mount each night onto supports (ie. Something like vibration dampeners). Or secondly, use 1 or more fix positions on the driveway and adjust the wheely-bar’s height adjusters into the fixed driveway positions each night. Option 1 may not result in the exact same position each night (since you have lifted the tripod off the ground it may not rest precisely over each mark on the driveway); Option 2 may not be at the same level position on the driveway each night (since you must adjust one or more of the wheely-bars height adjusters).
- Driveway Markings: This was my first approach, and it is essentially what I had been
using with the Takahashi NJP platform. I had made black magic-marker marks on the surface of the
driveway. Each night I would
position over these marks as precisely as I could and I would re-level the
mount. After I “homed” the ME
however, the first slewing star would not be visible on the imager
chip. So I would either re-sync and
begin a short model run or start all over with new ME alignment. Over time, I became less and less
satisfied with short runs, as the pointing accuracy was not as good as I
wanted it to be. This option was not resulting in either the same physical
position or the same level position each night.
- Driveway Shallow Hole: To position the tripod in exactly in the
same physical position as the prior night, I drilled a shallow hole in the
driveway-pavers where one of the Wheely-bar height adjusters was placed. To accomplish a precise position, the
other two legs are positioned over driveway markings. I would re-level each night using bubble
levels. This option was not
resulting in the exact same physical position or the same level position
each night, and the results were equally unsatisfactory for me.
- Adding two Lifting Blocks: To reduce the need for as much
re-leveling I fix just one wheel position into the driveway shallow hole
and positioned vibration dampeners over driveway marks for the other two
wheels. This meant that each night
I only need to make leveling adjustments on one of the three wheels, and I
was anchored into the exact spot at one point. I also marked the exact screw position
on the wheely-bar’s height adjuster and I used 7 bubble levels. While things began to improve, the
procedure was still far inferior to what I could achieve with the polar
alignment telescope of the NJP in 10-15 minutes. There was often the need to re-sync and
often a need to do a short model run.
A Fast Procedure that works
While moving equipment each night, I am now able to position the equipment so
precisely that its performance characteristics seem to be on a fixed pier.
This means I only need to move the equipment into position, and there is no
need for any leveling, polar alignments, position adjusting, or T-Point short runs; I can just
begin imaging. I have invented and produced a proto-type, home-made product “Pier-Paws”
for making this work. Click on this link and you can see the design specifications for my Pier-Paws.
After many nights of testing and now use: It
works. No leveling, no syncing, no polar aligning, no
adjusting, no T-Point short runs, just a home and go. [All targets are not
always perfectly dead center, but nor was my original polar alignment perfect
from the first night. All targets are, however, well on the FLI Proline09000’s imaging
chip even with a focal length of 2348mm... Wow!!!]
- Use two Driveway Shallow Holes: This fixes the position precisely, with
no possible deviation.
- Use three Lifting Blocks (Pier Paws): which
eliminates any need to re-level. (Perform Step-0 using Pier Paws. Then firmly fix the position of
all Wheely-Bar height adjusters, as they will no longer need to be
moved.) The height-adjusters are
fixed high enough to be very solid and high enough to be out of the way
and thereby allow for easy movement of the platform every night. The lifting bocks are placed into the
same position and orientation each night.
- Fit two pegged Pier-Paws into the driveway holes at
two wheel points (thus fixing the position), while using a non-pegged
Pier-Paw for the 3rd wheel. This simplifies the driveway hole making (as a 3rd and
final hole does not have to be precisely drilled) and still eliminates the
need for re-leveling and position adjustments.
- Fit all Wheely Bar height adjusters into the tops of
the 3 Pier-Paws. Since my platform
exceeds 300lbs, I use a car jack to lift the mount each night on and off
The end result is very fast movement
and setup. Each night I am able to
simple roll out from the garage and position the wheely-bar on top of the 3
Pier Paws, connect my cables and I can begin imaging. For me this is a vast improvement over my
earlier setup times, and it is even faster than what I can do with my TAK NJP
which still requires nightly re-polar alignments.
See my full astronomy website at: http://SchickWorld.com/Astronomy/Index/AstroIndex-Main3.shtm
Mel Schick, June 2007