Posts Made By: P. Lee Stock

Download "Newt.exe". It is easy to use and will give you all the dimensions you need to make good design decisions.

http://home.att.net/~dale.keller/atm/newtonians/newtsoft/newtsoft.htm

Lee

Charlie Wicks made a nice one. You can see it here:

http://home.earthlink.net/~cwicks1/index.html

Borg's commercial line of refractors break down into separate components you can stick your socks and underwear in to save space in your carry-in luggage. Here's a nice review:

http://www.cloudynights.com/reviews/borg76ed.htm

Probably the most recommended optician that actively advertises testing and refiguring services is Steve Swayze of Swayze Optical. Never heard anything but raves about his work.

I think Bob Royce--RF Royce Precision Optical Components can be coaxed into refiguring also. I'd also contact Mark Harry (Astromart sponsor) or Mike Spooner. Google will easily find them all for you.

Good luck,

Lee

It says: "never mounted" but nothing about "never looked through". Of course I can't know, but it sounds like he bought two and is keeping the one he prefers. Simply put: you might be paying a $28 premium for the scope that lost the comparison.

Why doesn't he just return it? No, that would represent a loss in shipping charges, much less the $28 premium.

I'll take the one he prefers more, after he mounts it and looks through it, of course. If you get a lemmon, you bought it second hand and, as far as I know, have no return privileges. Why would I pay $28 extra for that? AP, TMB, etc. don't ship lemmons, but Orion and the 80ED have no such track record.

P.S. And the reason for shipping: "...bought two, one to keep and one extra." Why would you buy "one extra" except to compare and keep the better of the two?

Nice review. Nice photos. Nice choice of finish.

If your scope has a freely rotating tube, the eyepiece can be easily accessed at all times from one, seated height. It's all in the design.

Here's a 10" f/5.5 I made for a friend. He tells me it is a joy to use.

Clear skies,

Lee

SCTs seem to lose a large percentage of their value more quickly compared with other types of scopes. Comparing them to new automobiles is probably fairly accurate--new ones are readily available, in great supply, price based on latest body style and features, and there are numerous similar models and/or substitutes. Used ones are also in huge supply.

I think Astromart keeping an archive of listings has something to do with it too--being able to look up what the lowest amount something listed for can set a new low unless it is seen as an anomoly. (Anomoly: I once saw a Zambuto Starsplitter list here for something like $500 or $600--the mirror alone was worth almost twice that). But once a lower price happens a couple times or more, as long as supply of similar used scopes is large, the price will tend to hover near that while all us price-conscious buyers wait for the next "deal" to come along, refusing to jump on your "that's $200 off the price of a new one" ad.

I've followed Astromart for years and I believe the situation for SCT owners wasn't always so acute. I remember some Celestron C5+ ads awhile back--often first offered at $1,200, then after a series of price drops, reluctantly and ultimately below $600 before the listing(s) finally stopped appearing. That was well below 1/2 the new price for LNIB.

You mean that big tube dob with the white mount in the background is a 22"? That thing is huge. Looks like it's made out of 2x4's.

John Dobson would be proud.

Lee

It must've been off/wrong to begin with, but how would you know since it was a commercial scope?

See if the mirror cell can be modified to drop the mirror 1/2" or better. My second choice would be to move the entire mirror cell. I wouldn't personally move the focuser--too ugly.

I never trust Newt.exe or even the FL written written on the mirror back--it's too easy to make a mistake and you only have about .25" of room for error with low profile focusers that have ~1.25" of travel if you want the majority of eyepieces out there to work. So I always leave the tube a couple inches longer than I think it needs to be and test for where the actual focal plane lies using the actual mirror in the actual tube (a lot of "actual" going on there... ;^). Then, after I know for certain, I mount the cell in place.

You ought to be able to get 3/4" without having to play with the focuser, but if you can't, then you might also consider making a focuser mounting block to raise it a little, in conjunction with one of the other methods described. However, I like to optimize the secondary size as much as possible and raising the focuser works against that. Add to that, those old scopes already had tall focusers, so you probably don't want to make it any taller.

Good luck.

P.S. I had the same problem once after getting a new mirror to put in an old tube--I had no back end left to drop the mirror cell and I refused to move the focuser and make a new hole, so I made extension blocks and hung the cell out of the back of the tube, as shown below.

Hey Walter,

Nice rig! Someday I'm going to buy one of those old SCTs, wrap the tube in a fine wood veneer and have the cast parts powder coated to some never-before-seen color :-).

Lee