[phpBB Debug] PHP Notice: in file /viewtopic.php on line 988: date(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected the timezone 'UTC' for now, but please set date.timezone to select your timezone.
[phpBB Debug] PHP Notice: in file /viewtopic.php on line 988: getdate(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected the timezone 'UTC' for now, but please set date.timezone to select your timezone.
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4284: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4286: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4287: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4288: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
Webster Telescopes Forum • View topic - D14 side bearing size
Register    Login    Forum    Members    FAQ

Board index » D Series




Post new topic Reply to topic  [ 2 posts ] 
Author Message
 Post subject: D14 side bearing size
 Post Posted: Sun Nov 28, 2010 3:41 pm 
Offline

Joined: Sat Jul 04, 2009 1:50 am
Posts: 12
Location: NM
Jim,

On the Cloudynights website there is a discussion about the size of your side bearings on the D14. The OP seems to imply that the bearings are "way too big" and that makes the mirror box deeper than another telescope brand.

I know you guys have your own forum, but did you at least read it? People want you to answer them on CN.


Top 
 Profile Send private message  
 
 Post subject: Re: D14 side bearing size
 Post Posted: Sun Nov 28, 2010 6:01 pm 
Offline

Joined: Thu Jul 02, 2009 11:48 am
Posts: 80
Location: Detroit Michigan
Honestly, we don't have the time to read all of the forums on the web, and even if we did, we probably would not want to respond.

Why? Because when a manufacturer is seen posting on a public forum they often appear to be either defensive or promotional; and either one comes off as rather desperate to us.

We are a professional telescope manufacturer. This is not a sideline, secondary or hobby business for us. We do not need to promote ourselves on the internet forums (or even buy ad space in magazines) as we have enough orders to keep our shop running 12-14 hours a day.

If anyone wants to know the details behind the design decisions we make, we would encourage them to post here (as you did) or just call us. We answer our phone lines 12 hours a day, every day.


But off of my soapbox and on to your questions...

The larger the ALT bearings, the more a telescope is immune to imbalance problems. Huge ALT bearings give much better "staying power" to a telescope, regardless of eyepiece size.

You have certainly seen older 14" telescope designs that require a different counterweight to be installed every time the owner changes eyepieces. Or even a sliding dumbbell weight that needs to be constantly adjusted. That is not the kind of telescope we build.

Many of our older 14" scopes had smaller 19" ALT bearings on them (we still have the mold forms if anyone needs smaller aluminum bearings for a 12" scope). But at some point we changed to the larger bearings and found them vastly superior. It may cost a little more to cast the larger bearings, but it sure is worth it not to fool with counterweights all night long.

On the subject of mirror box depth, it is simply a balance equation. Other brands may use a 2" thick mirror on their 14" scope. We use a 1.4" thick Zambuto mirror. Of course it is much harder to figure a thin mirror over a thicker one, but Zambuto is certainly up to the task. Because our mirror is so much lighter, we make the mirror box a little deeper so the scope is perfectly balanced. It is the same as a teeter-tater; put the skinny kid on the long end, the big kid on the short end.

Practically speaking, the ALT bearings have no real influence on the mirror box size. In fact, on our 32 through 40" telescopes, the ALT bearing diameters exceed the bottom of the mirror box. We have no problem breaking the rules of convention when it results in a better performing scope.

Like always, you are welcome to copy this response (or anything else on our forum or website) to other forums.

_________________
Eric Webster
http://www.WebsterTelescopes.com


Top 
 Profile Send private message  
 
Display posts from previous:  Sort by  
 
Post new topic Reply to topic  [ 2 posts ] 

Board index » D Series


Who is online

Users browsing this forum: No registered users and 1 guest

 
 

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
cron