GEM for equator area

ariefm71 · Post by **ariefm71** » Tue Jul 18, 2006 6:39 pm

just get a full pier.

river · Post by **river** » Tue Jul 18, 2006 6:40 pm

you use GEM for bird watching!?

any advantage doing so?

river · Post by **river** » Tue Jul 18, 2006 6:55 pm

just get a full pier.

Yes, full pier is the way to go! But where can we get a good full pier?

wucheeyiun · Post by **wucheeyiun** » Tue Jul 18, 2006 6:58 pm

Not GEM, but the position of the tripod legs...the single leg pointed to north( it will prop up refractors better in polaris) ...i use a Manfrotto 475b for birding and once i slew the scope to the middle 2 legs position, the scope almost topple over.
If it is a GEM, i would advice to do the same.

mrngbss · Post by **mrngbss** » Tue Jul 18, 2006 9:51 pm

wucheeyiun wrote:
If it is a cassigrain, ie like Mewlons, it is less likely to happen as the thick mirror cell is at the rear of the Telescope. ( like the picture above and the em500 looks really good )

Wow, that's the EM500?! I saw the 400 and I tot that was cool.. The 500 is even cooler! Yes, it does look very good. I'm sure it works even better too! What was the big cannon beside the Vixen (not seen in pict?)?

river · Post by **river** » Wed Jul 19, 2006 9:16 am

should be Takahashi EM200.

Post by **weixing** » Wed Jul 19, 2006 11:24 am

Hi,

Not GEM, but the position of the tripod legs...the single leg pointed to north( it will prop up refractors better in polaris) ...i use a Manfrotto 475b for birding and once i slew the scope to the middle 2 legs position, the scope almost topple over.
If it is a GEM, i would advice to do the same.

Which refractor are you using and how heavy is the refractor??? FLT-110??

Have a nice day.

wucheeyiun · Post by **wucheeyiun** » Wed Jul 19, 2006 1:18 pm

Yes, it a flt-110. The weight is about 7kg, the the front triplet is about 3 kg...and i just got it change to latest lightweight dual speed crawford focuser on the rear.
So it is really heavy on the front.
Balancing about 2/3 to front.

Post by **weixing** » Wed Jul 19, 2006 8:19 pm

Hi,

Yes, it a flt-110. The weight is about 7kg, the the front triplet is about 3 kg...and i just got it change to latest lightweight dual speed crawford focuser on the rear.
So it is really heavy on the front.
Balancing about 2/3 to front.

I think your case may be because your Manfrotto 475b is too light compare to the front of your FLT-110. The Manfrotto 475b tripod is only around 4.3kg, but your refractor front is already around 3kg... so I think your refractor front itself can easily lift your tripod rear leg up with a little external force.

I think it'll be quite difficult for this to happen on a GEM... the Vixen GP mount head is already 4.4kg and a AL-150 tripod is at 4.2kg... total will be around 8.6kg. Also, although the counter-weight is between the leg, it is very close to the mount, so the heaviest point will be very near the centre of gravity. As a result, I don't not think it'll topple as easily as your Manfrotto 475b tripod.

Anyway, I'll remember to test it next time when I setup my scope.

Have a nice day.