Posts Made By: P. Lee Stock

See a use for these?

http://www.rockler.com/ecom7/product_details.cfm?sku=10602&filter=58244

Not too bad at $6/each if you don't have machining capability.

After an almost compulsive multi-year stretch learning to make telescopes and refining my woodworking skills, I am taking a sabbatical of sorts as I change headings and pursue new horizons. I know that this is going to mean less time here on the forum. Besides the usual career and family pressures, I am developing new interests building on my love of instrument making outside of telescopes and have also decided 2003 is to be a year of rapid progress in some as of yet unexplored territories in my life.

That said, I do still have 3 telescopes I plan to finish this year or next-- a 6" f/5 briefcase travel scope I've had on the back burner for a few months now, an 11" f/5.5 of the design aesthetic I developed and refined, and another 8" f/6 I am almost finished with. I'll be sure to post photos as I finish these.

Rather than just slip away quietly, I wanted to give a heart-felt and sincere thank you to the friends I have made on this forum--most of whom I have never met and may never meet. Among them, Chuck Fellows, Jerry Loethen, Sam Greenlaw, Eugene Artemyeff, Herbert Highstone, John Zeigler, Rob O'Toole, Floyd Blue, Chuck Jackson, Michael Zammit, Bill Burghardt, Tim Lemmon, Walter Hamler, Ed Taychert, Mitch Alsup, and so many others. Thank you for the stimulating ideas, enjoyable discussion, and of course, the photos of your awesome telescope work.

I thought I'd flame out with photos of a few of the telescopes and astro projects I've completed the past few years. Some of these I've already posted here, so if you've seen them before, my apologies.

If you ever feel like dropping me a line, please do so at [email protected]. I'd sure love to hear from you.

In friendship,

Lee

P.S. I'll start with my most recent completion, an 8" f/6 Zambuto in antique cherry finish...

That Meade will only keep the fire going for 1/2 hour. I hope they brought more.

I need some inspiration. How about some of you with projects underway post some photos of your work.

Come on, what say ye?

;^)

Lee

P.S. I'm bogged down in an ATM project--a 10" hybrid truss dob with a rotating upper ring, parallel trusses with tensioning cables, etc. Nothing to show yet except wooden parts drying on the counter. Picked up Rob O'Toole's free-floating Zambuto mirror a couple weeks ago and am trying to give it a decent home.

P.P.S. In particular, I'd like to see some of Herbert Highstone's work--he sparks enough intelligent conversation, you'd think he at least has a piece of polished glass or half-finished sonotube lying around somewhere ;^).

We had that recent thread on how to position the focal plane relative to your focuser travel, so I thought I'd post this.

I made this tool to help with the problem of determining the ideal primary mirror/cell location in a tube. Most modern newtonian focusers are low profile and have drawtubes with a travel range somewhere between 1-1/4" to 1-5/8" or so, which means you really only have 1/4" or so of room for error when positioning the focal plane relative to the focuser/drawtube travel or many eyepieces out there won't come to focus within the range of your focuser.

When assembling the components of a tube, I first install the focuser and then the secondary mirror assembly. Then, after leaving the tube intentionally long, I insert this into the back, flush with the end. With my trusty TV plossl (I bought one just for this purpose), I take the telescope out under the stars and advance the primary mirror using the extremely long screws until stars come to focus. This tells me exactly where to position the cell.

When I mess up and get the primary too close to the secondary, I get to make a brand new tube since my cells attach to a back plate that attaches to an end ring, Richard Berry style. I hate that. When others get it wrong, they either have to drill new holes for the mirror cell, or new holes for the focuser and spider, or make a riser block for the focuser. Why guess?

The reason for using a TV eyepiece for this function is explained here:

http://astromart.com/messages.asp?message_id=180100&page=

This one is for 10" mirrors. I suppose I could have made one that adjusts for 8", 10" and 12.5", but I went the separate tools method instead. Note that it has very long travel. There are nails set into the wedge blocks that grab the tube wall for peace of mind. I wouldn't trust friction alone.

If you are making just one scope, then this is overkill. But if you are planning to make a few in your life, this is far better than guessing where the focal plane will wind up and being completely wrong, or having your son peek through your Nagler while you sit on the ground with a mirror in one hand and a measuring tape or pencil in the other asking "are they points yet?" That got tired.

Cloudy Skies!! (TM'ing weather)

Lee

I have always wondered how reliable and repeatable Astrosystems upper cage clamp mechanism is. In my mind, I imagined the clamp could pivot around the pin. A current ad posted by Gary Siegelman shows what I believe to be a homemade variant of Astrosystems' clamps, and the problem I always suspected might occur is clearly seen in his ad photo.

Does this actually occur with Astrosystems'... er, system? If so, I wonder if they ever considered using a second pin below the clamp pin that slides into the slot and prevents this racking motion? Clearly, to me, this would cause at least mild collimation issues. And how could you ensure you got it exactly the same each time? I suppose this doesn't mark the end of the world, but I am a stickler for rigid assemblies and also hate to fuss with assembly inaccuracy and collimation problems.

Lee

I have a relatively small shop about the size of a 1.5 car garage. I measured it at 19' x 15' the other day, or 285 SF.

One thing you need if you want to cut plywood sheets on a table saw is space. Not having much, I had to come up with an alternative method: the circular saw panel miter station.

I've seen designs for small versions meant to replace a 10" or 12" miter saw, and I've seen vertical panel saws that can cut at 90-degree angles, but I have never seen the miter station I made anywhere else, shown below. It's sort of a cross between the panel saw, miter saw, and radial arm saw. It is extremely accurate after you make some test cuts to set it up before the first use--getting perfect 90-degree (perpendicular) cuts is a piece of cake.

It can crosscut plywood 48" wide or cut 36" widths at a 45-degree angle. You could make it larger, but this is about as far as you can reach across comfortably (and it helps to walk down the left side while cutting if the sheet you are cutting doesn't hang out too far, getting in the way).

Compared to a cheap table saw, this is MUCH better. And if you work exclusively with plywood, this may be all you ever need (once you make a 10-foot rip guide for your circular saw for lengthwise and diagonal cuts on 8-foot sheets). It fits perfectly over my double router table when I want to use it, and stores neatly against my shop wall.

Why the drawing instead of an actual photo? I accidentally destroyed mine with water (particle board became swollen and buckled) and I also accidentally cut off the some of the angle gauge section with my sabre saw... oops. I definitely will make another one.

If this is too complicated, or you simply want a way to make 90-degree/perpendicular crosscuts with a circular saw, you can use this principle to make a circular saw T-square. Most plywood or panel cuts are either parallel or perpendicular to a factory edge, and a T-square cutting guide takes up almost no space.

Try it--you'll like it!

Lee

Self-explanatory. I also made a zero-clearance plate for the bottom of my circular saw to minimize tearout. Works great if you have a circular saw, limited space and/or are on a budget.

My favorite new astronomy program is only $9.99 - Galaxy Explorer. It is by Space.com Software, same people that make Starry Nights.

The program maps 28,000 of the nearest galaxies by position, orientation, and type. In spaceship mode, you can fly (in variable multiples x the speed of light) to visit all of them.

Even more amazing is starting at the edge of the mapped universe, or even the known universe, and trying to hunt down the Milky Way, then our own sun, and finally the earth or another planet or moon. Objects are beautifully rendered.

No astro program I've ever used gives such an incredible sense how vast our universe is and how fortunate our tiny patch of planetary surface is. It is absolutely worth the $10 price of admission. My kids use it almost every day, and probably not more than a couple days go by before I hear it calling my name.

From what I can tell, Galaxy Explorer is Space.com's $19.99 Deep Space Explorer, stripped of its multimedia content and Find functions.

http://www.buytelescopes.com/product_list.asp?m=73

Here are some screenshots for you. First off, the Virgo Cluster in non-spaceship mode. Dragging your mouse around, the cluster pans to show you the various galaxies. If you click "spaceship", you find yourself flying toward one of the galaxies at this zoom level.

Anyone else like this as much as I do?

http://astromart.com/viewad.asp?cid=259376

(also: he's selling it too cheap ;^)