Author Topic: Skywatcher AZ-GTi mount  (Read 336 times)

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RobertM

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Skywatcher AZ-GTi mount
« on: Nov 10, 2018, 11:34:54 »
As some of you are aware I’ve been using a Star Adventurer for a while now and the results have been very good.  Having had a few of these portable mounts I generally consider the SA the best I’ve used so far.  One thing has been outstanding on my list of “wants” from a tracking mount and that is the option to auto guide (and by definition the option to dither); it’s been on my mind for a while but since I’d not seen any portable alternatives I was beginning to feel that this was a lost cause.

Enter the Skywatcher AZ-GTi...  a cheap lightweight tracking mount with a 5kg load capacity and port for a Skywatcher handset ala. HEQ5 etc. This also opens up the possibility of using an EQDirect cable to auto guide and GoTo.  Now I hear you say “but it’s altaz” and yes you are right but SW have also introduced firmware that allows it to be used in equatorial mode as well using a suitable wedge (think Star Adventurer).

From what I’ve read the auto guided performance is quite reasonable up to about 200-300mm f/l.  It also has a built in WiFi hub which would allow connection to planetarium programs, encoders, a snap port (which is what I use on the SA) for triggering the Sony A7S (thinking N.I.N.A. here)  and can run off internal or external batteries.

I’m sure there are going to be some negatives but I’ve just ordered one so will find out soon.

Fingers crossed it doesn’t affect too many clear nights !

Robert

Carole

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Re: Skywatcher AZ-GTi mount
« Reply #1 on: Nov 10, 2018, 13:43:46 »
Interesting report Robert. Will bear this in mind and watch your progress.

Carole

RobertM

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Re: Skywatcher AZ-GTi mount
« Reply #2 on: Nov 17, 2018, 19:32:09 »
Ahhh - had to reorder as they were OOS, rare as hens teeth but managed to track one down.


RobertM

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Re: Skywatcher AZ-GTi mount
« Reply #3 on: Nov 20, 2018, 20:50:50 »
Quick update...

It's arrived and looks promising...

70mm aluminium axis wheels on both axes
Brass worms and gears with spring loaded tensioning to both axes (both locked down too tightly) but cant tell if they are as big as the one on the StarAdventurer (though I don't think so).
All metal die cast chassis
No discernable backlash (but one of the gears is a tad loose)
Sounds like a coffee grinder on speeds > 7
Can't see much sign of grease or lubricant
The drive from each motor is through a single gear to the one on each worm wheel
It has a screw thread that a counterweight bar could be attached to

To do's before first light
1) Unlock the tight drive mesh to each wheel
2) Add a tiny amount of lubriplate grease
3) Tighten up the loose gear

For later
4) Make up an EQDirect Cable
5) Try triggering the A7S with a computer from the snap port - cant see why that won't work as it should be the same as the SA which does.
6) Download the Equatorial mode firmware
7) Try autoguiding and 'snapping'
8) If I get this far then a very light polluted image followed by keep or bin decision time.

Robert

RobertM

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Re: Skywatcher AZ-GTi mount
« Reply #4 on: Jan 10, 2019, 22:13:44 »
It been a while now but some progress with the coffee grinder...

Have made an eqdirect cable and tested connectivity to TheSky astronomy program; got it wrong to start with (Tx-Tx and Rx-Rx), schoolboy error really but easily changed.

I can now slew around under planetarium control from a PC using the cable.  This also means that I can auto guide though how well needs to be quantified.  If I can get this to within a few arcsec then it may end up being a great portable widefield rig.  I can also release the clutches and move the mount whilst seeing TheSky crosshairs move on the screen, quite impressive for a cheap mount.

I’ve also got a counterweight bar that I can use with the Star Adventurer counterweight but I need either a bit more weight or a longer bar to balance my camera/lens.

That’s it for now.

Robert

RafalK

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Re: Skywatcher AZ-GTi mount
« Reply #5 on: Jan 11, 2019, 20:04:04 »
I can help with stripping, greasing and putting it back together if needed. I've just been through all the kerfuffle with my EQ-5. I installed new ball bearings, teflon shims and Geoptic grease (two types: one for bearings and other for worms) and it's smooth like a baby's bottom.  8)  :lol:

The Thing

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Re: Skywatcher AZ-GTi mount
« Reply #6 on: Jan 11, 2019, 20:30:44 »
A kind offer, but I Roberts had plenty of experience with babies bottoms sorting out dodgy mounts, even ££££ ones. Poor Robert!

RobertM

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Re: Skywatcher AZ-GTi mount
« Reply #7 on: Jan 11, 2019, 21:48:30 »
A kind offer, but I Roberts had plenty of experience with babies bottoms sorting out dodgy mounts, even ££££ ones. Poor Robert!

Yes Duncan, even babies bottoms (yuk) !  I’m wondering whether I’ve set my sights a bit too high but then again I only ever wanted something that worked; perhaps that’s too much to ask for ?  Even the MX has had new worm block and motherboard though fortunately at no cost to me.  Strikes me that someone could do a roaring trade selling something that worked out of the box !

Robert

The Thing

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Re: Skywatcher AZ-GTi mount
« Reply #8 on: Jan 11, 2019, 22:28:22 »
I'm out in the obsy tinkering, the cloud has just rolled in this minute but at least i have verified my latest collimation efforts. And the mount has peformed just as I would hope after all the hours I've spent with grease, bits of hardware and soldering irons, maybe I should paint it baby bottom pink! That should be the colour scheme for your new line of mounts that actually work properly out of the box.

Carole

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Re: Skywatcher AZ-GTi mount
« Reply #9 on: Jan 11, 2019, 22:54:07 »
Sounds like a few of us have been doing tinkering. 

Carole