14" OTAs - weight

Hi Dave,

Regarding the 'over engineered' statement, I was just quoting John Murphy's earler post. That being said, there is obviously some reason why the Meade optical tube weighs more than the Celestron.

A difference of 15 pounds between two (mostly) identical OTA's would seem to indicate a rather different approach to engineering, I would think. The only additional mechanics that I can see in the Meade is the progressive mirror lock, and I wouldn't think it would account for that much additional weight.

Speaking of, the mirror lock is quite nice to have while focusing with an ST-9. That and the (slightly) faster optical system is (in my opinion) an advantage over the Celestron. Using the Meade 3.3 focal reducer without any spacer equates to about F/5.8. A tad bit of vignetting, but not real noticeable.

Those are incredible pics Dave. Love the M13!

Hi Pat,
I'd love to know what causes the weight differance, from an engineering point of view.
I totally agree with you on the mirror lock, the 12" here is pre mirror lock era and I did find the scope lost focus when slung from one end of the sky and back again, but fortunately it comes with a mirror locking bolt for transportation, so I now use this for locking the mirror, it does a surprisingly good job and I always use it, especially when imaging.

Would the celestron mirror flop around just like the meade, or are its manufacturing contraints more tight and prevents this from been a problem?

Hi Dave,

Unfortunately, Celestron's SCT's seem to be just as guilty as Meade's when it comes to mirror flop - at least prior to the release of the CPC series. Their ads state that this new fork mounted series doesn't suffer from mirror flop. Perhaps so, but I've never seen a CPC so I can't really say.

To the best of my knowledge, the mirror flop issue becomes progressively worse as the size/mass of the primary increases. I've been told that if all the C-14's in the world crossed the meridian at the same time, the total amount of mirror flop could substantially alter the Earth's orbit.

Seriously though, for the most part larger SCT's seem to be more effected by this than their smaller siblings. Before I acquired the 14" LX200 I had an 8" Classic and never had much of an issue with flop. One of the things I did with the 8" was to go slightly past focus in the clockwise direction and then 'back up' against the mirror, so to speak, in an anti-clockwise direction. This puts just a little bit of tension against the mirror and seems to help with the flop issue.

Please understand that I am in no way, any sort of expert on the subject of SCT's and imaging. What I know is only what I have experienced in playing with these over the years. I feel much more comfortable discussing truss tube Dobsonians ... I've built a number of them.

Thanks for that response Pat,
I guess the greater size of the bigger SCT mirrors feel gravity more so they move around more, a fair assumption.

I have to jump in here. I have the Meade LX200GPS 14" and have been told and can verify that the Meade's extra weight comes from the primary mirror being thicker then the Clestron. The primary mirror on my 14"er is almost the same weight as the whole Clestron OTA. The actual tubes of the OTA's are basically the same weight unless you have a carbon fibre tube from Celestron.