Planewave Ascension 200HR Pointing

Great progress so far. This mount is great. Last night was PointXP night. I tried the instructions in the manual for calculating the 6 point model so it would provide the differences from polar alignment. It involves initially using the Scitech exe, chart menu option then selecting a star and doing and initial align (one button click). My scope pointed miles away from the selected star, perhaps it was the Southern Hemisphere thing. So I manually slewed to the star did an initial align and then all the subsequent stars appeared on the image (which is about 20′x 15′). Most were within 5 arcmin or so of center. The stars got closer to the center as I went, by number 3 it was pretty close every time. Not bad at all.

I do however have lots of trees around so not all the stars displayed on the chart menu were visible. Naturally the Sitech chart can’t display everything. So I gave up. I wanted to get the magic number of turns the pointXP displays so you can align your mount more accurately. So I gave up on the 6 point model and just went for the complete pointing option. I did an initial star alignment, followed the instructions for making a script for a PointXP model and let it do it’s thing. Initially I tried a 30 point model and the code crashed, twice. I reduced this to 27 points and it worked really well. I increased the exposure time to 6 seconds as the default of 3 seconds did not work for Sydney skies. The modelling took about 30 minutes to run, and about 6 of the points where failures because of trees. The results indicated that my polar alignment was out by about 2 arc minutes in both axes (where a 10 minute run in PemPro indicated about 20 arcsec, why?).

The end game was pointing and tracking. Pointing is within a 10 arcsec everytime. Tracking errors as reported by MaxiumDL are not bad either. Peak to peak is about .2, and I have yet to balance my scope!!!!

Watching the PointXP do it’s thing is a pleasure to behold with a hit within 1 or 2 seconds everytime you can get an image of stars.

Great job guys. Most impressed.

Ascension 200HR Southern Hemisphere configuration

The mount is installed and Polar aligned. The alignment was done initially with a laser pointer (toward sigma Octans) and then using PemPro polar align. It took a while to get there, but the mount is brilliant.

The documentation that came with the mount was a collection of A4 pages which although a little amateurish are actually pretty good. There is nothing in the documentation about Southern Hemisphere alignment. The Sitech documentation on Dan Gray’s site is however comprehensive. It looks like the software that comes with the Planewave has slightly diverged from Dan’s.

The Yahoo Group was very helpful.

When I started on my configuration the instructions are to perform a “Initialise Scope Using Homing Switches”, which with the default configuration sends the scope pointing directly at the North celestial pole. So to get it basically working there needs to be 2 changes. See screens below.

Change 1. This is based on the SciTech manuals. Essentially this configuration change works out (for Sydney Latitudes at least) like this: Using the ServoConfig.exe, “Edit Parameters” menu option then “Get Configuration from Controller” tick the invert motor encoder direction, invert motor direction and invert scope encoder, in both RA and DEC. See screen shot (from v 1.2 of ServoConfig).


Update the Flash Ram from ServoConfig (Edit then Misc and Action) and all should be well. With this change the scope will track, undergo a PointXP model etc.

The home page of ServoConfig should now look like this:


Change 2. From the Planewave support guys. To get the controller to “Initialise Scope Using Homing Switches” in the Southern Hemisphere, successfully you need to untick the two check boxes see highlighted below.

As soon as you do it all just works.

Installation of the Planewave Ascension 200HR mount

After 11 months of patience my Planewave mount turned up. The idea was to replace my G11 temporarily so I could get used to working it then put a 20″ scope on it and host it at a dark site. I’ve brought a FLI Proline 16803 etc to go with the new scope as well.

First impressions where BIG! It’s a monster compared to the G11. It’s heavy as well the crate was almost 200kgs. Physical setup was a breeze but it was so big I replaced my pier, with a 10″ wide with 3/8″ wall thickness pipe. Thank goodness the concrete block beneath was huge to start with.

Pictures below




The father in law and creator of the pier, oh, and also the engineer who made the mount plates etc.