sturdyness of a mount

Jingguo · Post by **Jingguo** » Sat Sep 18, 2004 12:06 am

Hi guys. i would like to ask experience astrophotographer which of the three mount is suitable for astrophotography. 1) GP mount 2) GPD mount 3) Sphinx mount. Are the mount with better gear grip, accuracy and sturdyness better for astrophotograpghy? thanks lot

MooEy · Post by **MooEy** » Sat Sep 18, 2004 5:41 am

i think the sphinx is much better designed than the gp series. it comes with hal 110 legs, same as the gp-dx.

the half pillar in the sx mount is well executed, instead of 3 pathetic small screws to hold the head(the threads will eventually wear out and the half pillar will never be able to hold the head properly), it comes with 1 large knob to screw from below and 2 more side adjustment screws for azimuth setting. u have to see it urself, quite hard to explain.

the overall weight of the sx is lighter than the gp-dx due to the motors countering the weight of the scope. the counterweight shaft can be kept inside the mount when not in use.

wormgear are suppose to be better, but no idea abt the pe of the mount. the mount seems to slew with very little whining. there's only 2 cable to the mount, starbook and 12vdc. less messy and lesser stuff for the mount to chew on.

as much as i like the sphinx mount, i cannot really recommend it yet due to it's lack of support at the moment. it comes with goto and have an autoguider port, but the software doesn't support autoguiding and pec yet. in fact i dun even know how to get it to track.

the gp and gpd doesn't have goto nor autoguiding, unless upgraded with the skysensor 2000. a complete gpd rig with dual axis motors and manual clutch are already in the 3k range, getting the skysensor would boost it to 4k.

so one of ur consideration would be whether u will ever need the autoguider, if u don't a gp/gp-dx rig with the motors will do fine.

if u ask me which i would get, gp-dx or sx, i would get the sx and slowly wait for future patches. other options include the tak p2z which cost abt the same price as a gp-dx rig but has a working autoguider port.

~MooEy~

ariefm71 · Post by **ariefm71** » Sat Sep 18, 2004 9:56 am

if money is no object, i'll get a tak em200

Post by Q » Sat Sep 18, 2004 3:29 pm

em200 is with the wooden legs izzit?
is wood good? I always have the idea that wood is not durable...

MooEy · Post by **MooEy** » Sat Sep 18, 2004 3:52 pm

hmm..my mistake, p2z doesn't take autoguider, em10 does. anyway there's a new mount from tak.

http://www.pbase.com/gesc/image/29900714

now stop drooling and start saving up.

~MooEy~

gwenyi · Post by **gwenyi** » Sat Sep 18, 2004 4:29 pm

yeah... wood is damn stable.. but it's very heavy as well.

dew · Post by **dew** » Sun Sep 19, 2004 2:04 am

about the sphinx i would advise, if you have the time, to wait. vixen has made many promises but has yet to deliver anything useful in the form of patches especially regarding autoguiding. also they apparently have no plans to support PEC or to upgrade the goto software either. the goto was also pretty dissapointing to me but other then that its all pretty good. for its capacity its very light and i can put a 80mm refractor on it without any counterweights!

eu-wen

Post by **Airconvent** » Sun Sep 19, 2004 2:57 am

dew wrote:about the sphinx i would advise, if you have the time, to wait. vixen has made many promises but has yet to deliver anything useful in the form of patches especially regarding autoguiding. also they apparently have no plans to support PEC or to upgrade the goto software either. the goto was also pretty dissapointing to me but other then that its all pretty good. for its capacity its very light and i can put a 80mm refractor on it without any counterweights!

Hi EuWen
Can you elaborate on the goto portion? Why is it a disappointment?
How does this compare with the autostar?
cheers

eu-wen

Post by **rcj** » Wed Sep 22, 2004 12:01 am

software autoguider support for the sphinx is ready. but you will need to pay extra (VISA payment) for the autoguider firmware upgrade, which was greeted with dismay from the sphinx users as Vixen once claimed that the autoguider support was free. Let's hope they will do something about this issue. Otherwise, my advise is to go for the time-tested GPD mount which has generally lower PE than even the stock Losmandy mounts, but of course you will be limited to three slew speeds and no autoguider correction facility assuming the DD1 usage. The SS2K option is still available but is limited in quantity from Japan.
GPD is extremely popular when it comes to low-cost but good option for wide-field portable imaging AS COMPARED to other premium brands.
Incidentally, the Takahashi EM11 is out with better bearing system, and slated to replace the older EM10. I have one used if anyone is interested, shipped directly from Japan with Temma GOTO retrofitting.

dew · Post by **dew** » Thu Sep 23, 2004 4:15 pm

hi rich, havent seen you in a long time. yeah my dissapointment with the sphinx's go-to is because of my experience with my ETX. with the ETX all you need is a rough alignment to the north, 2 alignment stars and thats it. most of you go-tos should be within your eps FOV (anything less than 80X mag usually.) but with the sphinx you need a really good north alignment + 8-12 alignment stars to get anywhere near a good go-to performance. when i tried only using 2-4 alignment stars, the moon was a few degrees off! ok, i have not had enough experience or practice with this mount to say anything conclusively but a few degrees is abit much.
but as i said before, hardware wise it is very attractive to me mostly because of low weight for its class.

eu-wen