Micro Guider 5

Dave Ek has released a firmware upgrade for his DSC encoder interface You can either purchase a new PIC through the link on his site or I can reprogram the PIC for you. Cost is $5 to cover return postage and handling. Contact me at: bill(at)beevo.com

Having tired somewhat of getting the Magellan II to work to my expectations I have decided to try a purely PC Based DSO/Planetarium setup. Nova Astronomics markets the Planetarium program Earth Centered Universe (ECU) and the Micro Guider 5 telescope interface. I am now in the process of installing the system into the LX50. I am installing it as (for the time being) a redundant system. I am leaving the Magellan II installed and will continue to use it stand alone and with the two planetarium programs I currently have in my possession.

		Fastening the encoders to the required a 10-32 screw with a 1/4" socket on the top. I used a 1/4" ID steel set screw collar brazed to the head of a 10-32 x 3/4" machine screw. Alignment of the parts is very important as the encoder can not tolerate any side load on its shaft. Side loads can cause inaccuracy in the encoder signals. I used a nut and a machinist's vice to hold the parts together while brazing. Next summer I have got to get a new lathe!!
		Here is the completed bolt. Here is the bolt installed on top of the RA encoder drive gear for the Magellan II. The Magellan II encoder is under the white nylon gear.
		Here is a shot of the RA encoder connected to the RA shaft. Not wanting to cut up the factory cover plate, I am building one from 3/16 acrylic sheet. The notch is to access the set screw in the adapter.
		Here is the detail of the RA encoder bracket. The bracket is formed from 1" brass strip.
		The finished RA Encoder installation. I use the NGF-S and it will fit through without the diagonal attached even when the f 6.3 focal reducer is attached ahead of the NGF-S. ECU allows 0 ° to be used in addition to 90 ° Declination during the alignment process.
		Shown here is the 1/4" -20 coupling nut during modification. The threads were drilled out all but 3/8" of the way. The threaded end is fitted with a short piece of threaded rod and a small set screw hole is made in the smooth end. The length of the threaded rod is the same as the original fixing bolt plus 3/8". The threaded rod is secured to the coupling nut using red LocTite.
		Left image shows the encoder fastened to the adapter. I elected to use the setting circle and aluminum hubcap to preserve the look of the scope. Right side shows the bracket that was fabricated from thick brass strips and silver soldered together.
		Another view of the encoder. Final installation of the DEC encoder and bracket. While this is not my preferred mounting choice for the encoder until the Magellan II encoder vacates the housing the encoder will have to stay here. :o)
		I elected to use a PC ribbon cable type connector at the telescope end of the encoder cable that runs to the interface located near the PC. This connector is bolted to the acrylic cover plate that the RA encoder is bolted to. The locking arms have been removed to prevent damage to the cable if it is snagged by someone walking around the scope. Better to have it unplug and have to re align than to tear the cable apart and still have to re align.
		Finished cable ends, hooked up to the scope. Right image is the MicroGuider 5 interface, it's about the size of a pack of cigarettes.

For those of you interested in the S2 encoders I used, here's a link to the US Digital site's S1/S2 data page.

2/12/02 I managed to test the entire set up. The MG5 showed up at 5:30 and I had the whole system up and running by dark. The unit works as advertised and I was able to find all sorts of things that I couldn't see because of the Phoenix light pollution!! :o)

The sky was incredibly steady and clear this night, I shot a whole roll of slide film on Jupiter and Saturn. It was the best viewing of the planets I have seen in many months.

I am currently using both the ECU (written by the maker of the MG5) and The Sky.

2/19/02 Another fine, though slightly breezy night to observe. Second run with the MG5 and the two programs netted some pretty startling results. I am tending to favor The Sky mostly because of it's closer similarity to Sky Map Pro which is the software I have been using the longest. Unfortunately Sky Map Pro won't work with encoder based systems. Pointing accuracy is very very good with either program, I have not refined the alignment process well enough to see differences in the programs. I truly enjoy being able to sync on anything I can see, instead of a list of 250 stars plus the objects in the database. A full out test in the sticks is planned for the weekend of March 16th. Report to follow.....

3/11/02 Well, it's not the weekend of the 16th but I spent two nights out at a dark site in western AZ with the new set up. In a word,

I got set up late friday evening and managed an excellent polar alignment. Synced on Regulas and Castor. Fiddled around in the area between these two stars as well as looking around Orion. Then decided to look at M81 and M82, set the find function in The Sky and had M81 in the middle 50% of the FOV with a 24.5 Meade SWA @ f10. Everything I went looking for was in the middle section of the FOV all night long!! I really can't say anything bad about this setup after using it for as many nights as I have, even while learning to use it.

3/29/02 Ken Sikes and I got together and decided to hook the MG5 to the stock Magellan II encoders. The wiring of the encoders is the same for both the US Digital and HP (Argent) encoders with one exception, the pins are reversed in order. Simply flipping over the cables I have already made just before plugging them into the HP encoders is all that is needed. Because of the gearing the following settings are used:

RA (azimuth) 7022 counts per revolution (4096 encoder counts * 1.7143 gear ratio= 7021.77280)