Posts Made By: Jim Moscheck

Hi,
First post in this forum. I was driving to my usual dark sky observing site last Saturday afternoon and I stopped to take a few shots with my new camera. This is the first time I've been out shooting in years. Hope you find them interesting.

In a recent thread we were talking about how we store EPs while observing. My friend Doug Scobel made the case that rides on the front of the rocker box.

See post:
http://www.astromart.com/forums/viewpost.asp?forum_post_id=512467&poll_id=&news_id=&page=4

This two part question is for Doug and Floyd or anyone else that might be able to help. I really like the idea of the battery riding on board while in use, but this would add to the weight of the scope on the azimuth bearing. I assume adding this weight would change the size teflon pads needed. Correct?

Also, I have a 17ah battery. I know this is enough to run fans, argo navis, and dew control for a couple of nights. Would this still be enough power if I add a Servo-Cat in the future or will I need more amp hours?

I've never center spotted a mirror before and I'm to the point in my telescope where I have to do it. My XT10 came with it's reinforcement ring installed.

I just got back from Staples and they didn't have the old paper style rings you had to lick, but new ones made of plastic with self adhesive on the back. Are these OK to use on a mirrors surface? I tested one on my car window and it was very difficult to remove so the adhesive is pretty strong.

What kind of adhesive do the Jim Fly center targets use? Maybe I should just order one from him. :S

I cut down my truss pole tonight and had first light, sort of. What a great feeling of accomplishment seeing it all work and worked nicely it did. I was a little worried about balance as I had to move the mirror cell up an inch because of the large collimation knobs on the cell. I didn't take them into account when I designed the mirror box or the rocker. :S After cutting the poles down 1 1/2" total I was able to focus all my EPs but not by much. I'll
still need to trim about a 1/2" off of them after I mount the mirror for good. Interestingly, I was able to collimate the scope really well with my HG laser and without the center spot on the mirror no less. I collimated the focuser earlier so I set the scope up and put the laser in and projected it onto the mirror box lid and adjusted the secondary till the beam hit the center of the knob. Took off the cover, centered the mirror best I could by eyeball and the return beam was close and adjusted the collimation knobs. I thought it would be really rough collimation, but surprisingly it was pretty close.

Anyway, I got to look at the Moon which was exciting for a change. 8) Needed those sunglasses, too. Very bright, but it was a nice image although it had a lot of scattered light.

The best part was after taking the picture I tested the balance by loading up the UTA with everything I plan to use: Paracorr, 26Nagler, telrad, and finderscope. I was afraid the finder would put me over, but it balanced like a champ first try. And the motions were as smooth as any telescope I've ever used. Absolutely no striction or backlash. I moved it easily and it stayed put. Who ever said you'll never need to use the algebra you learned in High School never built a telescope. The math in Kriege and Berry's book was right on the mark. I also had a lot of help from my friends Eric Webster and Dave Lacko, who both got me through some of the tricky parts.

Except for putting foam on the truss poles and getting the Argo Navis up and running it is finished. I have a shroud on order from Floyd Blue which should help with the scattered light and a star party storm cover coming from astro systems.

First light under dark skies will be in two weeks at a star party in Georgia. I can't wait! 8)

Here's a quick little add on I made from a piece of scrap plywood, an extra split block, a scrap piece of aluminum pole, and some extra hardware I had on hand. I utilized a threaded insert used by the wheel barrel handles to attach it to the rocker box. This is one that happened fast, just an afternoon from idea to spraying with finish.

I was traveling back home from a star party in Georgia this past Saturday afternoon and decided to take a detour on the BRP and then through Smokey Mt. National Park. These are some of the clouds which became the nor'easter that pummeled the east coast Sunday. Not much traffic up there this time of year and it was kind of spooky, although I only experienced rain after reaching the highest part of the parkway with no lightning or high wind.

Here she is all done and ready for photons.

Stevens 14.5" f/4.3
Protostar 2.6" secondary
Webster Telescopes mirror cell
Argo Navis DSC and 10,000 tic encoders

14.5" f/4.3 Truss Dobsonian with Stevens primary mirror

April 12, 2007
Location: Deerlick Astronomy Village near Sharon, Georgia.
Skies: Clear and DARK with average seeing.

I recently returned from an observing trip down south to my friend Daves place at the Deerlick Astronomy Village. The purpose of the trip was to help Dave build a cabin on his lot but it was a good and memorable opportunity for first light. I guess the new scope curse is a myth as I had two real good clear nights observing. I had the scope out in the backyard a few times during testing and tweaking before the trip and while the collimation wasn't perfect it did give some pretty good views of Saturn.

My first task was assembling and collimating the telescope. Assembly is real quick as I’ve had lots of practice during construction. It is for all intents and purposes a pretty close clone of a 15” Obsession, but with an optical twist by using a mirror and focal length similar to a Starmaster. Ed Stevens, who had previously worked for Carl Zambuto, has made me a pretty darn good mirror. I really don’t want to get into too much detail on the performance of the mirror as I still don’t have cooling fans installed and I want some more experience viewing with it, but I did do a test which surprised me. I had planned all along to use a Paracorr with the fast mirror, but I took it out and gave it a try using only the EP. Not much coma at all in my Nagler EPs, just a slight little bit at the very edge of the field. With the Paracorr stars were pinpoint to the very edge of the field. I hesitate to state the strel ratio of the mirror as it’s pretty high along with the other specs, at least higher than any primary mirror I’ve had the opportunity to use. I plan to do a more comprehensive review of the mirror after I’ve used it for a year or so.

I had collimated the focuser before the trip and all I really had to do was use my HG laser and BLUG to get it real close. I was given a lesson on how to use a Catseye auto collimator by one of the members of the DAV and the combination of the barlowed laser and auto collimator was all I needed to get the scope perfectly collimated. The seeing wasn’t good enough to do a star test and I stayed under 200X with most of the time only using a 17T4 yielding 107.1x and 26T5 at 70x.

While it was getting dark the first photons caught were of Saturn, which showed up in all its glory. Crisp Cassini division and multiple bands of clouds on the planet and little pinpoint moons. I went back to Saturn a few times as the night progressed and the later images were even better as the mirror was probably better acclimated to temperature.

Next up was M42 in the WSW and as it was getting darker more and more detail jumped out. Saw E and F stars of the trapezium easily. Next up was to M46 and M47 in Canis Major as they were getting low in the west also. M47 is one of my favorites with the little planetary nebula in the cluster. Sad to see these objects go for another year, but the springtime sky of the Virgo Cluster, Leo, and Ursa Major were calling. First up was M51 and I could see spiral structure in it for the first time in one of my telescopes! Next I checked out M81 and M82 together in my 26T5. With the dark sky background they really jumped out at you with lots of detail I had never seen before. I bumped the power up and saw the dust lanes in M82. I took quick looks at M108 and M109 which I’ve never been able to see well in my 10” dob. Wow, galaxies! I never spent much time with them except for the brighter ones, but obviously I can go a little bit deeper with this aperture. I next moved into Leo and first up was the triplet. Again, lots more detail than I was used to. These weren’t just smudges anymore due to the good contrast and resolution of the mirror. Took a look at the M64 the Blackeye Galaxy, again with great contrast on the dust lanes. I’m liking this mirror a lot.

I spent the rest of the night wandering around in Virgo with a couple of exceptions. When M13 rose high enough I took a look, but only for a sense of scale. I then slewed the scope to Omega Centauri. While it was only 10º above the southern horizon I was amazed at how big it was compared to most globulars. It practically filled up my Nagler 26T5 (70x) and was resolved to the core. It was pretty low and I was sitting on the ground, but it’s an experience I’ll never forget, and on first light no less!

At this point the summer sky was rising in the east and I looked at a few early summer objects including M57 and M92 before I called it a night about 2:30 am. I had a very successful first night with my telescope, and look forward to many more. I did have a few glitches that were easy to fix. The azimuth encoder popped off the pivot bolt which is the reason I couldn’t get a good warp with the Argo Navis. I pushed it back on and it then worked fine. I also need to tweak the bearings a bit as it’s a bit too stiff for my liking. I didn’t use any car wax on the ebony star and this will probably smooth things out a little. I might also put teflon around the pivot bolt like the old milk jug washer trick as the mirror box is heavier than I would have liked. I need to do something because tracking at high powers is difficult as things fly through the EP pretty fast. I might make an EQ platform, but more likely I will probably go with a stellarcat system. All in all a very enjoyable night galaxy hunting, I can’t wait for the summer nebulae and more globular clusters.

Here's a shot waiting for it to get dark at the Deerlick Astronomy Village. The large telescope across the street is a 32" dob which on a good night will eat my scope for dinner, but on the average seeing conditions we had I feel my scope did pretty well concidering it less than half it's size. I compared M51 in each scope and the 32" was definitely much brighter, but the resolution was held down due to the seeing. The image in my 14.5" was just as pleasing but dimmer.

I just received this email:

"We are excited to announce that the April issue of Astronomy Technology
Today is printed and is on its way to you! It was mailed early last
week and if you have not already received your copy you should be
receiving it soon."

Cool! 8)

That's the way I understand it. I've listed lots of items at a time in different ads and also in the same ad with multiple items. Of course when I did sell a lot of expensive stuff I also became a supporter so AM got a cut.