View Full Version here: : Question regarding Meade LX90 + Antares Focal reducer.
sharkbite
22-12-2015, 11:49 AM
Hi folks....
Wondering if someone can help.
I recently picked up a pretty schmick pre-loved LX90 which i think i will never sell.
In the box of bits, there was an ANTARES SCT Reducer (part number = "#SCTFR" )
this fits ok onto the visual back - threads are a bit tight but seems to go on ok.
the meade eyepiece adaptor however, is too large for the thread on the reducer. (seems like the thread on the front of it is different to the back)
Can anyone shed some light on what is going on here?
Do i need another piece to attach eyepieces?
Any help would be most appreciated.
cheers,
iborg
22-12-2015, 12:22 PM
Hi
I was curious myself as I think I will get something similar sooner or later.
Googling came up this
A few people have reported issues with the male SCT thread diameter on this item being a bit larger than necessary. We have tested our current batch and it works with Meade, Celestron, and Baader SCT accessories. However, it will not thread into William Optics accessories, and with GSO it is a hit or miss.
http://agenaastro.com/antares-f-6-3-focal-reducer-schmidt-cassegrain-telescope.html
Could be the problem you are having.
Philip
sharkbite
22-12-2015, 12:36 PM
Thanks Philip...
To be clear - on mine the male thread diameter is too small.
cheers,
julianh72
22-12-2015, 02:22 PM
I'm not sure if this is the specific issue, but there are two similar but not quite identical thread sizes that you find on the backs of various small SCTs (depending on make and age).
The "standard" SCT thread is 1.375" * 24 TPI (1.375" = 34.925 mm; TPI = Threads per Inch). The original Celestron C90 also has these threads on the rear port, and I think this is also the thread size used on the larger Meade SCTs.
The Meade ETX90 rear port is slightly different, but close at M35-1 (i.e. 35 mm diameter, 1.0 mm pitch).
ETX accessories (with the slightly larger metric female thread) will thread on to the slightly smaller C90 male thread, but bind after a few turns. You generally can't get the slightly smaller "standard" accessories onto the Meade ETX metric male thread.
sharkbite
22-12-2015, 03:10 PM
thanks Julian - Mine must be 2" fittings - they are around 50mm size.
jenchris
23-12-2015, 12:13 PM
I have an antares 6.3 that fits on my lx90.
My only problem is my lx90 is the acf version which means that the result is over corrected for field flatness. The stars are elongated axially.
sharkbite
23-12-2015, 12:21 PM
Thanks Jenchris...
Can you tell me how you attach your eyepieces/camera to the reducer?
(my meade eyepiece adaptor is too big)
cheers,
jenchris
23-12-2015, 12:23 PM
I'll check it out exactly and post the result
jenchris
23-12-2015, 01:03 PM
Sorry to be the bearer of sad news.
My Antares has the right thread back and front.
Does your visual back on the OTA have a external thread diameter of 50.00mm?
My adapter and all the other compatible visual back items (2" 1.25" Adapters) threads are 50mm OD.
And fit together like toast and butter.
jenchris
23-12-2015, 01:04 PM
Where are you?
STATE?
TOWN?
sharkbite
23-12-2015, 10:35 PM
Thanks jenchris...
Apart from the bit where my eyepiece adaptor doesn't fit,
This is almost identical to what I have.
having a closer look - it seems your eyepiece adaptor nut is a bit longer than mine....
and there's my problem right there....
the reducer threads are actually the correct diameter etc, but since the nut is too short, they never come in to contact.
If i remove the t-piece it screws up just fine....
looks like i need a different eyepiece adaptor to make this work.
Thanks again for posting these pics.
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