EQ8 Pros and cons?

[reddoss]

I am going to by an EQ8 head and put it on a tripod which is some what lighter than the on it comes with (but is capable of taking the load).  I do not want to buy the polar scope as the consensus seems too be that the auto polar alignment  is fine. I  heard that you can not balance the mount without it, I don't think this can be true but would like to hear people views.

Also, what other pros and cons should I be aware of before I buy one.

            

[Velvet]

some but a small counterbalance on it to compensate for the out of balance caused by all the weight being to one side on the 8,  i am sure someone will post a pic of it.

I have seen one used to great effect.  It is quite difficult to handle without this.  Stephen (moderator on here) uses one.  nifty little device 

Velvet

[Zakalwe]

I don't have a polarscope on mine and yes, it's slightly out of balance in RA. I can't say that it has ever caused me a real problem. Certainly, when imaging Jupiter it can keep the image on a tiny DMK21 sensor for ages. And that's at 8 metres focal length. And it was good enough to do 2 minute unguided subs at 1.7metres focal length (that was in a quick experiement that I did with the mount very poorly balanced. I really need to try imaging with my C11 properly). I always balance the mount very slightly heavy on the East to keep the gears meshed.

Advantages of the EQ8?

• Lots of bang per buck.
• It guides beautifully with a guide trace thats damn near perfect. And thats with the aggressiveness and hysteresis turned right down.
• It has a huge payload.
• Fully EQMOD compatible.
• Extremely well made. Everything bar the stepper motor covers is made of beautifully machined ally. The altitude and azimuth adjusters are buttery smooth and a million miles away from the EQ6.
• Its dead easy to mount on a pier. There's no pier adapter required.
• The Synscan polar alignment routine is excellent. I haven't drift aligned as I guide, but it got the PA pretty damn close.

Disadvantages?

• It's a heavy old beast and you wouldn't want to drop it on your toe. I've heard of peeps using them in a portable setup. Best get down to the gym if you are thinking of doing this.
• The saddle locking knobs are hard to tighten fully by hand. A 22mm socket on a ratchet is an easy fix.
• It comes in a massive roadie-style case on wheels. Forget about storing that in the attic. Mine is currently cluttering up my obsy.
• The handset cord is stupidly short. I use EQMOD though, so after polar aligning my handset is gathering dust somewhere.

[ollypenrice]

My experience was different. Mine came with excessive backlash in RA (possibly adjustable) and a non-adjustable problem with backlash in Dec. On one side of the wheel mesh was tight and on the other other it was slack, meaning a lot of Dec backlash on one side and a risk of binding on the other. Surf the net and you'll find that this is not unknown but nor is it by any means universal to the mount. There are plenty of happy owners but a small number who have seen the same issues. In my opinion Skywatcher need to come clean on this and talk about it. I'm sure they can find a solution.

I'd stop some way short of 'beautifully made.' You don't blank off drilled holes with headless grubscrews when you make things beautifully. The metals are marginal. But, with the issues resolved, bang for buck would be in the SW area of expertise and very good indeed. Had I received Zakalwe's mount I most probably would have been delighted. As it is I have gone for a second hand Mesu and a new Avalon Linear Fast Reverse which should be arriving soon. I'll comment on that when I've had some time with it.

Olly

[Zakalwe]

Olly, yes you had a wrong 'un. No mass produced item is ever perfect, 100% of the time.

I'm interested in the bit about the "The metals are marginal" piece. Which bits are you referring to?

[ollypenrice]

Olly, yes you had a wrong 'un. No mass produced item is ever perfect, 100% of the time.

I'm interested in the bit about the "The metals are marginal" piece. Which bits are you referring to?

Had mine been the only one with the assymetry in mesh I'd have put it down to 'a wrong 'un' as you suggest, but there is a small but perceptible trend to be found out there on the net.

Metals? Well, the outer casings with that crackle finish didn't strike me as being as good as the finish on the EQ5 and 6 and the wheels, visible through the covers, had the rust potential of a 1970s Fiat, as it seemed to me. There is no comparison with the machined stainless of the Mesu or the CNC work on the Avalons. However, there is a price difference. I'm happy to accept that, but I'd substitute 'beautifully made' for 'cost effective' or 'very cost effective.'

Olly

[Zakalwe]

Had mine been the only one with the assymetry in mesh I'd have put it down to 'a wrong 'un' as you suggest, but there is a small but perceptible trend to be found out there on the net.

Metals? Well, the outer casings with that crackle finish didn't strike me as being as good as the finish on the EQ5 and 6 and the wheels, visible through the covers, had the rust potential of a 1970s Fiat, as it seemed to me. There is no comparison with the machined stainless of the Mesu or the CNC work on the Avalons. However, there is a price difference. I'm happy to accept that, but I'd substitute 'beautifully made' for 'cost effective' or 'very cost effective.'

Olly

Olly, the wheels are aluminium, so I'd be amazed if they ever rust!   And the "trend" of which you speak is, as far as I can see, made up of a very, very, small number of people that are very, very vocal.

And the Mesu isn't perfect either. And it's twice the price of the EQ8 (if you include the £150 transport case, assuming that you opt for it)

All in, the EQ8 is a bit of a game-changer and offers amazing value for money. All IMHO, of course.

[libraryman]

Interesting comments, i found that my EQ8 appeared to have the out of round Worm wheel when i used the recommended method to test for it, however; i found that this method was unreliable and adjusted the DEC backlash with great success, i have very very little back lash now and pleased with the mount.

RA balance is not an issue, however i have mitigated it by using the mount as a platform for several pieces of my equipment i.e. usb hub, dew heater hub etc, and put them on the side to counter the weight.

It's a shame that Olly appeared to have a duff mount, however;  i fear had an attempt to adjust the dec axis been made it "may" have been found that it was in fact o.k.

One has to respect the decision to return it though.

Ray

[ollypenrice]

Olly, the wheels are aluminium, so I'd be amazed if they ever rust!   And the "trend" of which you speak is, as far as I can see, made up of a very, very, small number of people that are very, very vocal.

And the Mesu isn't perfect either. And it's twice the price of the EQ8 (if you include the £150 transport case, assuming that you opt for it)

All in, the EQ8 is a bit of a game-changer and offers amazing value for money. All IMHO, of course.

My mistake on the wheels, then. Point recinded and my apologies. I still don't like the crackle finish but don't care much about it either.

The Mesu is perfect (well, hey, not really but very nearly!!  ) but the Sitech control system is difficult. I have the ArgoNavis/Stellarcat version and that is still available - and cheaper. For those who cannot leave their PC screens then they need to lock antlers with the Sitech. I like going outside and am delighted to get away from the PC so I like the Argonavis. All I mean by 'perfect' is that I haven't dropped a sub to guiding erros once in 2.5 years, including 2 years at 0.6 arcsecs per pixel. That is, let's be fair, kind of perfect!

As for being vocal, well yes. I spent three and a half grand on a mount which was chucked out of the factory in an unworkable state with perfect and total cycnicism on their part. The person adjusting the Dec mesh had got it right according to what his mentors were saying. Do what you can on the tight side and let the slack side do what it must. Send it out. I dismantled an observatory, unpacked and built up an EQ8, loaded it up, found that it was unworkable, dismantled it, repacked it and then rebuilt the observatory as was. So much for my Christmas holiday. Vocal? Darned right!! Mount manufacturers need to live with this (and yes, Lucas needs to live with people like Simon being fed up with the Sitech. He has a right to be fed up and to say so.)

Olly

Edit, Ray, your post came in as I was writing. I don't know how you adjusted your Dec mesh. I followed in theory the method I think SW suggested without actually touching anything because their point was to set the tightest point first, and this had no backlash in my case. In fact I considered it too tight. I therefore concluded that there was nothing to be done for the slack side. Is this incorrect? Dark Matter's experiences are what I would have expected mine to turn into had I decided to get involved in trying to sort it out.

[libraryman]

Hi Olly, always great to converse with you.

The Skywatcher method was to use the saddle to check the back lash! i found this unreliable so i removed the motor cover and turned the motor drive coupling with my finger and thumb (not a lot of room) 

This gave me very good feedback on the backlash and tightness, i was able to reduce the play to barely perceptible with out binding.

In my case, i wondered if the factory took a cautious approach to adjustment and tended to leave them a little slack??

Ray 

[Zakalwe]

Everything that is man-made has pros and cons. And very, very rarely will it be perfect 100% of the time. To expect so is to set yourself up for disappointment.

Sara (and others) love the Avalons, yet there is talk of the spring-loaded belt-drive system "bouncing" with long OTAs in a breeze.

Many love their iOptron mounts, but I've heard issues with their spring-loaded worm drives.

The 10Micron mounts are hugely expensive. per loves his pair of GMs, yet there are a number of people having major issues with a reported firmware bug in guiding.

Paramount mounts are highly regarded, but I know of one user that couldn't get a control board to work even after following advice from the Bisque brothers.

Mesu mounts are also highly regarded, yet they have been supplied with duff encoders which needed replacement. Plus the control systems are either basic (no PC integration) or if you want PC integration, unbelievably complicated to set up (Scitech controllers).

No matter what the device is, if you go looking for issues then you will find them. And you'll also find people that swear by them.

[libraryman]

Very true, but don't the manufactures do you head in when they promise virtual perfection??

Ray

[Zakalwe]

Very true, but don't the manufactures do you head in when they promise virtual perfection??

Ray

Only if you believe them. I'm far too much of a miserable, cynical git to believe any marketing spiel.   I fall firmly on the side on the Bill Hicks view of marketeers and advertisers!

[ollypenrice]

Very true. Mounts seem to be hard to make, given that no one make has ever acheived a perfect reputation.

Olly

[Zakalwe]

Very true. Mounts seem to be hard to make, given that no one make has ever acheived a perfect reputation.

Olly

The Astro-Physics come close. Serious money though.

[tony210]

Hi - my small contribution as an on going user of the EQ8 - great with EQMOD!- an absolute must for me with remote operation and still locked into Cartes du Ciel - good guiding with 30 minute subs once Dec backlash mastered (which is not difficult)  - an enormous payload option for little money( and I could not go to £4k+)- still impressed but will feed back next season - Tony

[tony210]

Hi -sorry also way back - forget the polar scope I bought one and don't use it! - any imbalance is effectively irrelevant in the performance and the Synscan routine is great - Tony 

[ollypenrice]

The Astro-Physics come close. Serious money though.

I have seen bad behaviour from an AP mount here. Not just once, either, but it is from one mount.

Olly

[reddoss]

Many thanks for all the comments guys.

Much appreciated.

[teleskopjo]

So to get back to the initial post can one simply ignore the polarscope weight offset and just have it slightly unbalanced? 

[stephen_usher]

So to get back to the initial post can one simply ignore the polarscope weight offset and just have it slightly unbalanced? 

It's so close to the pivot point and such a relatively small amount relative to the capability of the mount's drive system  and the overall mass of the mount that it's unlikely to matter at all.

[Zakalwe]

It's so close to the pivot point and such a relatively small amount relative to the capability of the mount's drive system  and the overall mass of the mount that it's unlikely to matter at all.

I've seen some people mounting weights on a bar that's then bolted to where the polarscope mounts. I keep meaning to try that, but have yet to get round to it.

[reddoss]

As I have to set up in the field I have now bought a polar scope for the EQ8, it just makes things easier. I can honestly say that I can not  detect any real difference to the RA balance now it's attached. 

Setting up an EQ8 in the field is not much more involved than setting up an EQ6 in my opinion. Mind you I do have the Altar Astro Starbase tripod pier (it is actually the prototype - the one in the promotional pictures on their website) which is much easier to handle weighing in at 17Kg than the 32 Kg base that SW supply. I must admit that I can not fit the mounts flight case into my car, so I protect the mount  in heavy duty bubble wrap and it sits in the passenger seat.