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Old 01-01-2017, 09:20 AM
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EQ8 mount quality?

Hi Guys,
Here's an interesting video that I just found.

I just had a look at this 1080 pixel video on Youtube:
https://www.youtube.com/watch?v=wLbiok7WJjE

Take a look at 24:10 - all the swarf.

Take a look at 28:16 - threads damaged by grub screws.

I'm still not sure if the EQ8 has a belt drive for both RA & DEC?
Does anyone have a link for a mechanical exploded view of the EQ8?

Any thoughts on the quality of the EQ8?
Is there a newer better version coming out?

cheers
Allan
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  #2  
Old 01-01-2017, 10:10 AM
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Ray (Shiraz) is getting excellent results with his EQ8. Not sure if he has done anything in the way of modifications to his or other issue but it seems to be doing him well.
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Old 01-01-2017, 11:11 AM
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Quote:
Originally Posted by Atmos View Post
Ray (Shiraz) is getting excellent results with his EQ8. Not sure if he has done anything in the way of modifications to his or other issue but it seems to be doing him well.
Yes - they seem to be giving good results.
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Old 01-01-2017, 11:18 AM
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Quote:
Originally Posted by glend View Post
Belt drive terminology, as used by the big manufacturers, usually refers to a belt from the motor to the worm sprocket, not to a belt driving the ring (RA or DEC rotation). The Avalon Linear does use total belt drive i believe.
The EQ8 would be belt driving the worm on both RA and DEC.
There are adjustments internally to belt alignment, clearance, etc that can affect performance. Out of the box, quality control can vary. There is no substitute for knowing how to tune your mount for optimal performance; and this includes worm end bearing play, ring and worm meshing, etc.
Do you need the EQ8 capacity? Perhaps compare to the Celestron GGE Pro that is currently on sale at Bintel for much less than an EQ8.

Thanks Glend,
I am doing some long term research.
I will have to change my job location within 1 year from now &
I'm just wondering about buying a larger mount to
suit a much larger telescope than I have now.
The site I'm thinking about is near Lara 3212 in Victoria
but I don't even know what the seeing conditions are like yet.
However I do know that it's a dark site & you can easily see the Milky way at night.
I'll need to check that out with my 10" f4 carbon fiber Newt.
on my modified EQ6 mount at some stage.

cheers
Allan
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Old 01-01-2017, 01:48 PM
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Actually there's only a belt on the RA axis. The DEC is direct stepper driven.
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Old 01-01-2017, 02:15 PM
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Quote:
Originally Posted by peter_4059 View Post
Actually there's only a belt on the RA axis. The DEC is direct stepper driven.
Thanks Peter i corrected my post. That was nit mentioned in the Skywatcher spec page i checked before i wrote it, sorry.
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Old 01-01-2017, 02:47 PM
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Quote:
Originally Posted by glend View Post
Thanks Peter i corrected my post. That was not mentioned in the Skywatcher spec page i checked before i wrote it, sorry.

Thanks - there seems to be very little information.
There is a .pdf of the handbook but no exploded view of the assembly.
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Old 01-01-2017, 03:22 PM
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There's plenty of info on the Yahoo SkywatcherEQ8 group including instructions on how to adjust the worm mesh that shows pictures of each axis.

https://groups.yahoo.com/neo/groups/SkywatcherEQ8/files
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Old 01-01-2017, 04:05 PM
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Quote:
Originally Posted by peter_4059 View Post
There's plenty of info on the Yahoo SkywatcherEQ8 group including instructions on how to adjust the worm mesh that shows pictures of each axis.

https://groups.yahoo.com/neo/groups/SkywatcherEQ8/files
Thanks but it's only for members.
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Old 01-01-2017, 04:31 PM
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Free to join though
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Old 01-01-2017, 04:37 PM
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oh and there's this coming...

https://sway.com/HkJZWSxZVdLDAtbR
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Old 01-01-2017, 04:59 PM
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Quote:
Originally Posted by peter_4059 View Post
oh and there's this coming...

https://sway.com/HkJZWSxZVdLDAtbR

That looks interesting.
It sounds like the original mount has many shortcomings.
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Old 01-01-2017, 05:19 PM
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not really - the spring loaded worms are the most significant upgrade being discussed. if you searched for the word problem in the equipment forum you'd find most mounts mentioned for one reason or another including the high end ones.
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Old 01-01-2017, 08:23 PM
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that looks interesting Peter - thanks for posting.

Allan, the EQ8 suffers from some penny pinching decisions in the manufacturing stages and one basic design fault as outlined in the article that Peter linked. However, it is worth noting that it costs about 1/2 - 1/3 as much as a 40kg "name" brand and can deliver the goods if you work around the backlash issues. Spring loaded worms will fix the backlash/runout and if anyone can put together an upgrade set that works (without introducing a whole new set of problems), it will be up there with some very good mounts, since the basic design PE seems to be about 7 arcsec p-p.

the stripdown video shows swarf - mine regularly ends the night with a layer of damp dust all over/in it, so a bit of swarf is actually quite minor by comparison - shouldn't happen, but not a game changer. Additionally, using grub screws to lock threads is fairly standard - eg the EQ6 - it isn't pretty if you pull it down, but it works fine. The rust is also annoying, but it has no effect on performance. Overall, if you care about finesse and beauty, don't go there - if all you care about is quite robust functionality, the EQ8 is worth a good look.

Last edited by Shiraz; 01-01-2017 at 09:07 PM.
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Old 01-01-2017, 09:12 PM
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Al,

Here's the guide history for my EQ8 for info

http://www.iceinspace.com.au/forum/s...3&postcount=10
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Old 02-01-2017, 08:29 AM
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Quote:
Originally Posted by Shiraz View Post
that looks interesting Peter - thanks for posting.

Allan, the EQ8 suffers from some penny pinching decisions in the manufacturing stages and one basic design fault as outlined in the article that Peter linked. However, it is worth noting that it costs about 1/2 - 1/3 as much as a 40kg "name" brand and can deliver the goods if you work around the backlash issues. Spring loaded worms will fix the backlash/runout and if anyone can put together an upgrade set that works (without introducing a whole new set of problems), it will be up there with some very good mounts, since the basic design PE seems to be about 7 arcsec p-p.

the stripdown video shows swarf - mine regularly ends the night with a layer of damp dust all over/in it, so a bit of swarf is actually quite minor by comparison - shouldn't happen, but not a game changer. Additionally, using grub screws to lock threads is fairly standard - eg the EQ6 - it isn't pretty if you pull it down, but it works fine. The rust is also annoying, but it has no effect on performance. Overall, if you care about finesse and beauty, don't go there - if all you care about is quite robust functionality, the EQ8 is worth a good look.

Thanks Ray for the info.
Looks like it's not worth buying until Skywatcher fixes up those problems
or a kit is available to modify it.
I am only in the planning stages so there is no urgency.
I know that with my EQ6 I had to change the counterweight shaft
to get it to work to my satisfaction:
https://www.flickr.com/photos/247194...in/photostream

cheers
Allan
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Old 02-01-2017, 08:32 AM
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Quote:
Originally Posted by peter_4059 View Post
Al,

Here's the guide history for my EQ8 for info

http://www.iceinspace.com.au/forum/s...3&postcount=10

Thanks Peter,
I am normally get a bit better than your graph with my EQ6.
I watch the guide graph & if it goes more than 1.5"
I cancel the picture & start again.
I lose about 1 in every 20 pictures.

cheers
Allan
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Old 02-01-2017, 09:16 AM
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Maybe but I bet you don't have 25+kgs worth of Schmidt Newt scope sitting on your EQ6. Are you dithering?
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Old 02-01-2017, 09:23 AM
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Quote:
Originally Posted by peter_4059 View Post
Maybe but I bet you don't have 25+kgs worth of Schmidt Newt scope sitting on your EQ6. Are you dithering?
Yes - of course I use dithering.
I have only a bit over 12 kgs on my EQ6 but your graph
was for an EQ8 with 25 kgs?
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Old 02-01-2017, 10:03 AM
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Bare SN10
Stiffening plate for focuser
QSI683ws8
Parallax rings
Mini Borg+rings and clamps
ZWO120MM
ADM Plates x2
Moonlite + Stepper
Dew Controller
Dew shield

2x10kg counterweights!
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