Hi, I went to my first star party - the 2002 Mid-South Star Gaze in April. I had a really great time looking through the telescopes there and want to thank all...
3350
mharveyww1@...
mharveyww1
Jun 18, 2002 10:46 pm
Hi Alan... You're right about it being "the combination" of the 16 inches and the binocular viewer. The old adage that there is "no substitute for aperture" is...
3351
jim_nadeau_101
Jun 18, 2002 11:56 pm
... there ... in ... one. ... Hi Alan, That was David Stokes' 16" f/4.5 NightSky Scope with Meade optics. It was my Binoviewer and my EQ platform it was riding...
3352
Stathis Kafalis
dobsonstathis
Jun 19, 2002 6:42 am
... Of course not! The more light rasp, the more spiral arms you see. ... At deepsky objects aperture can be replaced by even more aperture only. Some people...
3353
richmaher
Jun 19, 2002 4:46 pm
The prices of all the Photon Micro light products have dropped from 15% to 30% at www.photonmicro.com. Photons are great for travel, safety, emergencies,...
3355
buskila57
Jun 20, 2002 1:48 pm
Given the choice between 1.6" and 2" thickness for a 22" diameter mirror, what is the better choice (considering, for example, cool down time,flexture, and...
3356
Hugues.Laroche@...
Jun 20, 2002 2:06 pm
Hi Ken, ... Well, I guess the main disadvantage of a thin mirror that you buy is flexure, if you know it and the supporting cell are of good quality. I would...
3357
buskila57
Jun 20, 2002 2:16 pm
p.s. perhaps I should also mention that the 1.6" mirror (from Pegasus, apparently in-stock) happens to have an f/4 focal ratio. The 2" thickness could be...
3358
etaychert
Jun 20, 2002 6:00 pm
Or to look at it another way: There may be a small, second _advantage_ with a thin mirror: the higher center of gravity will mean that your Alt bearing don't...
3359
Stathis Kafalis
dobsonstathis
Jun 21, 2002 9:02 am
I made a 24" f/4.1 mirror myself by hand with a 1.6" thick blank. I had no problems with bending and astigmatism during fabrication, so I would go that thin...
3360
compq2955@...
ionheavens
Jun 21, 2002 11:13 pm
In a message dated 6/21/2002 6:23:50 AM Mountain Standard Time, ... I have a 22" f/5 mirror from Nova's Steve Dodds. It is a 2" thick mirror. I am pleased with...
3361
Eric Ng
eric5hk
Jun 23, 2002 12:40 pm
Hi all, I have read Dave's book and he recommends to use 1.5inch aluminium pole for the 25" F5 dob. Unfortunately I cant get the 1.5" aluminium pole in Hong...
3362
jpcrombie
Jun 23, 2002 3:36 pm
... pole for the 25" F5 dob. Unfortunately I cant get the 1.5" aluminium pole in Hong Kong. Do you guys think that 1.25" is too weak? Someone suggests me to...
3363
garyk9rx
Jun 23, 2002 5:03 pm
Unfortunately I would have to say yes - it will make a difference. And the issue is mostly diameter and not material or thickness. The problem is expansion and...
3364
Neal Galt
nealgalt
Jun 23, 2002 5:26 pm
Gary...did you run into truss pole sag? (Very slowly the front end drops...probably not noticeable to the eye, but certainly noticeable in collimation, as...
3365
garyk9rx
Jun 23, 2002 8:32 pm
According to the calculations I would have been more than the 1/4 wave Raliegh limit out. I believe the limit calculation for my scope was 0.011" and I...
3366
Eric Ng
eric5hk
Jun 24, 2002 10:42 am
Hi, Thanks for the response to my problem in truss tube materials. I have one more question, can I use the 5 layers plywood instead of 9 layers or even...
3367
Bob Bunge
bungerob
Jun 24, 2002 11:52 am
Eric, The number of plys/layers in plywood has very little to do with it's strength or stiffness. The appendix on selecting plywood in the Kriege/Berry book...
3368
Eric Ng
eric5hk
Jun 24, 2002 1:33 pm
Hi Bob, OIC. So you mean even if I use 5 layers plywood should be OK for the 25"? That is really a good news to me. Thanks! BTW, thanks for the information....
3369
James P Crombie
jpcrombie
Jun 24, 2002 7:58 pm
I am guessing here, but I think that flex in the mirror cage will have more effect on collimation than tension or compression in the truss tubes. In a lot of...
3370
at making
atmaking
Jun 25, 2002 11:18 am
Hi, Their is a new page on our web site. It's a 26" altaz scope with a astatic chrysocal mirror cell and a mirror made by John Lightholder : ...
3371
Thomas A Simmons
rumybro2
Jun 26, 2002 8:33 pm
James, Where did you get the tube ends, or are these home made? Not sure from the picture, but it appears the ends are screwed in place >and< welded? Snipped...
3372
James P Crombie
jpcrombie
Jun 26, 2002 11:52 pm
Tom The ends are shrunk fit and held with a small screw to prevent rotation. I machined the tubing to length and bored the inside to just under the size of...
3373
Thomas A Simmons
rumybro2
Jun 27, 2002 2:03 pm
James, Thanks for the answer, those have got to be among the best ends I've seen. Don't quit your day job ;-))))) Very interesting approach you used, Hope you...
3374
john_the_telescope_man
john_the_tel...
Jun 27, 2002 2:43 pm
where does one get the marine mahogny plywood? John ... have ... of ... there ... in my ... material ... the ... the...
3375
szsherm
Jun 27, 2002 8:24 pm
... good ... Levin, ... The thin mirror will cool down faster. You will most likely experience astigmatism below a 50 degree or so tilt if you use a sling. You...
3376
starsplitterbill
starsplitter...
Jun 28, 2002 12:21 am
Hi Does anyone have a Starsplitter Compact IV telescope? These have only 4 truss poles and come in 10" f/6 or 12.5" f/4.8. They seem pretty lightweight but...
3377
djops
Jun 28, 2002 3:24 am
In my 10" with a LOMO(s-t) BINO, planetary viewing is very pleasureable, sometimes fantastic. The combo I have however, only works well on the Moon, Jupiter...
3378
James P Crombie
jpcrombie
Jun 28, 2002 3:42 am
John I ordered the plywood through a local hardware store. I believe it came from Montreal. But check any specialty wood store or boat repair shop. It is...
3379
mconleyngc
Jun 29, 2002 4:00 am
I know it's been awhile for this post but when I ran across this add I had to throw it out here for all to see. Harbor Freight does have some good deals from...
