I have a Vixen Sphinx SXW mount which I use with a Skywatcher 127mm Maksutov. I'm considering purchasing either a Stellarvue 125mm f7.8 or an Explore Scientific 127mm f7.5 refractor. I understand the mount has been rated to carry 20 pounds. Does anyone have experience with this mount carrying a payload of 16 to 18 lbs. and will be necessary to purchase a pier extension to avoid the optical tube coming in contact with the tripod legs?
Vixen Sphinx Payload
Posted 11 January 2019 - 03:04 PM
I use a Vixen Sphinx SXW mount with a C9.25, approx 20 lbs weight. The mount does makes more noise with the C9.25 than with the little Vixen A62SS, but reduce the slew rate if that worries you. However the C9.25 being a SCT it is a lot shorter that your scopes, so cant help you there.
Posted 11 January 2019 - 09:05 PM
Back in the day, my SXW carried my long 5in f/8 refractor [8kg] without problems for visual.
Load rating is over 15kg.
Do recommend Half-Pier to avoid hitting tube on tripod if you are looking toward zenith.
Edited by waso29, 11 January 2019 - 09:10 PM.
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Posted 12 January 2019 - 08:40 AM
Thanks for the information. Back in the day you certainly had a great looking setup. Do you know if anyone other than Vixen sells a pier for this mount?
Posted 14 January 2019 - 04:48 PM
I have a Vixen SXW and it has a pier but mostly for getting the tripod through the door. I mostly use a Vixen ED 103 refractor that is f/7.7 so pretty long and have used that set up without the pier and never saw close calls of a collision and no issues reaching the zenith. The heaviest scope I've had on the mount is a SV 115t that was at least 17 pounds with diagonal, finder and eyepiece and never felt like the mount was struggling. Vixen rates the mount for 26 pounds actually and it is generally believed that Vixen is conservative with payload ratings.
Posted 14 January 2019 - 08:09 PM
The two scopes I'm considering are just over 33", I believe that the Vixen scope that you use is just under 32". I keep my mount in an enclosure outdoors so I don't need to go through a doorway. So I can leave the legs extended. Do you think I would be able to mount either the SV 125 Access ( 33.5") or the ES 127 ( 33.25") without using a pier and still be able to reach the zenith?
Posted 14 January 2019 - 09:31 PM
you should be able to determine if you would need add pier.
1st position the mount as if pointing scope to zenith.
measure the distance from the dovetail saddle to the top of nearest tripod leg.
if this is more than half the length of scope, you are ok.
remember to take account the accessories: diagonal/ barlow/ etc.
Posted 15 January 2019 - 08:42 AM
I don't think the lenght of the 125 access is an issue but it's balance point might be. My Vixen 103 is tail heavy so it does not extent far back from the dovetail clamp. The SV115t I had was nose heavy and I can't remember if I used it without the half pier. I think pier wise the one made by Vixen is the only one that will work. Piers and tripods made by Synta were copies and interchangeable with Vixen GP systems but all Sphinx mounts are the newer SX system. In other words there are no cheap half pier alternatives I'm aware of.
Posted 16 January 2019 - 06:07 PM
I've pushed my SXW to it's loading limits with both a C11 and a Lunt 152ED (Not at the same time of course). I have used it using the standard tripod with the tripod plate and the Half Pier which is still available from Vixen.
Below is picture of my setup on a portable pier, but as I've said before I have used it with the standard tripod and it works. A bit of the shakes when focusing or if it's windy, but doable.
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Posted 16 January 2019 - 09:25 PM
That portable pier sure looks solid. I see your using that you changed to the Nex SXW control. Do you know if it is still available, and what do you find are the advantages over the star book?
Posted 17 January 2019 - 02:36 AM
Unfortunately the NexSXW is no longer available, the person who made them Maite sort of disappeared. Not entirely sure what happened, but it's a great product. The replacement controller took care of the Dec Drift that some experienced, though I don't remember having them myself. I do like that I'm able to do the All Star Polar Alignment with it though.
Anyway, here's a picture of my setup with the C11.
Edited by sctchun, 17 January 2019 - 02:45 AM.