The First Cut is the Deepest!

I measured and marked out the central area for the azimuth motor and I took a hand saw to the rocker and cut out the notch for the Tech 2000 Dob Driver II's Hurst stepper motor and gear assembly.



I then test fit the motor in the slot. It seems to fit well. I may need to notch out the slot a bit so that the motor sits flush with the board rather than proud of it. I want to be sure that the diamond patterned wheel makes solid and balanced contact with the base board. There are two roller assemblies which need to be mounted underneath the rocker and replace the Teflon pads that are there now.



This is the view of the stepper motor from the front of the rocker box. I may need to paint the stainless steel plate to help make it blend in more with the rocker box.


Next up is to cut out the large circular area for the 18" altitude bearing I picked up from Bailey Ceramic Supply!
http://www.baileypottery.com/potterywheels/throwingbats.htm

Ambrose Liao

Moon, Jupiter and Venus conjunction

My wife, Cynthia, called me on the way back home from work last night and told me that I had a present waiting for me when I came out of the subway. A gorgeous moon with two sparkling diamonds floating by her. I couldn't wait!

When I did come out, I had to walk out of the busy downtown Bethesda high rise area to see it and I was floored!

The photo above doesn't show how sparkling Venus and Jupiter were in the night sky. If you zoom in to Jupiter (the one on the left), you can see one of it's moons!

Taken with a Canon 30D with a 18-85mm IS lens handheld.

Ambrose

Third Upgrade of the Coulter Odyssey 1 - The Drive System

The basic Alt-Az mount for a Dobsonian is a very basic, yet fully functional way to point your scope at the stars. However, when you're using a high powered eyepiece, objects that you locate move out of the field of view very quickly. The time can be as short as 30 seconds. This isn't enough time to get a really good view of a star or the moon. The next upgraded needs to address this.

I originally heard about a device called an equatorial platform. This device rotates the scope essentially in harmony with the rotation of the planets around the earth (sidereal rate). It's quite ingenious, but pricey. The least expensive one I could find new was around $500-800!

http://roundtableplatforms.com/

There is also the option of building one yourself, if you have the woodworking and electronic skills necessary to do the job.

http://tech.groups.yahoo.com/group/eqplatforms

Since my hobbies are woodworking and electronics, I thought it was an ideal project to take on next! However, as fate would have it, I came across a used Tech 2000 Dob Driver II Rim system for sale for $100 on Astromart.com. The two motors used in the Dob Driver II are more expensive than $100. The red handheld unit where all of the "smarts" of the system are, is where all of the costs are located!

http://picasaweb.google.com/ambroseliao/Tech2000DobDriverIIRIM#

The Tech 2000 Dob Driver II system is also quite ingenious and much simpler in implementation. Instead of mimicking the rotation of the earth, it simply adjusts the alt-az mount to track the object you're observing. It contains two powerful stepper motors (one drives the rotation of the scope and the other drives the altitude of the scope) and with just a few seconds of training, will track an object without tedious polar alignment or telescope levelling which are critical for an equatorial platform.

http://www.tech2000astronomy.com/

New, their models sell for around $750 to around $1150! I was able to find a NOS (new old stock) Rim drive system for only $100 on Astromart.com. This is almost as good a deal as my Big Dobsonian was!

More photos of the Dob Driver II here:

http://picasaweb.google.com/ambroseliao/Tech2000DobDriverIIRIM#

I've got all the parts I need for upgrading the system, now all I need to do is to mount the drives and install the altitude bearings to have it work with my Coulter.

I've already notched out the baseboard for the azimuch motor:

http://picasaweb.google.com/ambroseliao/DobDriverIIOnCoulterOdyssey131DobsonianTelescope#

Next, I need to cut out a circular area out of the rocker box so that I can add an 18" altitude bearing to the right side for the Rim drive motor.

Ambrose

Second upgrade for my Coulter - Focuser

I still have the spider to upgrade on my Coulter, but a more urgent needs was to upgrade the focuser. The original focuser was a fairly straightforward rack and pinion 1.25" focuser which worked well, but was limiting in that I couldn't get my dSLR (Canon 30D) to focus. The Canon needed about 2 or 3" more inward travel. I decided to go for a low-cost 2" low-profile focuser. The ones I found on the popular telescope stores were kind of pricey at around $160. This Orion one looked good, but was out of my price range.

I was fortunate in finding the same focuser from Astromart.com. It was only $100 used. It didn't have the exact same coloring as the Orion focuser, but it functioned and looked identical.

The focuser allowed me to achieve enough in-focus to use my dSLR! I was very happy.

What is even more spectular is that with my dSLR and the scope combination giving me 2,400 mm, the moon fills up the frame of the dSLR almost perfectly. This is a full-frame (1.6x crop factor) shot of the moon.

Next up: the drive system!

Ambrose

First upgrade of the Coulter - The Cell

After reading up on the Coulter on Cloudynights.com and on Kirk Mona's excellent Coulter Odyssey web page (http://www.silverbugstudio.com/kirk/coulter/index.html), I decided to upgrade the primary mirror cell and focuser first.

The cell came from JStar which is a one-person operation based in California. The cell is fairly heavy duty, but very easy to adjust and to install. 

All of the photos of the cell and spider are here:

http://picasaweb.google.com/ambroseliao/JStarCellAndSpider42408953AM#

After the installation of the cell, the scope looks like this:

Because of the dramatic reduction in the weight of the scope's cell, the balance was changed so I needed to add a couple of hand weights to the scope to rebalance it.

The new cell dramatically improves the cool down times of the scope. I can start observing less then half an hour after taking the scope outside. Whereas before, I would have to wait 2 hours or so before observing.

All of the photos of the scope with cell are here:

http://picasaweb.google.com/ambroseliao/JStarCellAndCoulter131PrimaryMirrorInstallation#

Ambrose

Updating the Coulter Odyssey 1 13.1" Dobsonian Telescope

Back in March of this year, I was fortunate to be able to purchase from Craigslist.org, a used Coulter Odyssey 1 13.1" Dobsonian telescope in essentially pristine condition. It's about 5'5" tall and weighs around 90 lbs. It came with 2 Televue eyepieces, a 7.4mm and a 32mm Plossl. It also came with a 2.5x Televue barlow and a Telrad Finder. All for $175! I was very happy. The original 8x50mm finder scope was pretty much worthless, so I removed it and sold it.

The telescope is a 1,500mm (59") focal length and a f4.5 focal ratio. Very powerful and very fast, too!

Here's how it looked when I first picked it up:

Here's the whole batch of photos that I took of it when I first got it home.

http://picasaweb.google.com/ambroseliao/CoulterOdyssey1DobsonianTelescope030308#

Ambrose

Upgrading my Coulter Odyssey 1 13.1" Dobsonian telescope

I haven't really mentioned this much before, but I thought I'd start entering some info on my upgrading of my Coulter Odyssey 13.1" Dobsonian telescope. I originally bought this back in March of this year and love the views from it, however, found out fairly quickly that it's a bear to set up and to use (bump, nudge, bump, etc...)

Shortly after that, I decided to update it and improve it as much as I could do inexpensively. The key word is "Inexpensively!". It's very easy to spend big $$$ on upgrades. I hope to do this with a minimal amount of money and more sweat equity.