EQ3 EQ5

[alanwestlake]

Hi,

First post - so I hope I'm putting this in the right place. I wonder if anyone can help? I've got an EQ3 synscan mount which sits on top of a concrete pillar. Despite the Rigid Pillar and good Polar alignment I get terrible Goto's and Tracking. I wonder if upgrading to an EQ5 might solve some of the problems. It seems, from the reviews, to be a much more accurate mechanism. But if I did that is there any way I could buy the basic EQ5 and use my current EQ3 Synscan motors/handset with it. Buying the whole EQ5 with synscan is horribly expensive, and having already got the synscan unit would seem a waste. 

  

[Cosmic Geoff]

I have a Celesrtron Nexstar SLT GoTo, and I get quite good goto with the budget GoTo mount set on a  wobbly aluminium tripod. It will track for hours. I doubt that upgrading to a EQ5 will solve your problems. I think you need to analyse why you are getting poor results. It could be anything, from your procedures to the power supply to the polar alignment.

I think you will find that you can use the same handset, but not the motors or power board. Essentially you will need to buy the complete EQ5 Synscan set and sell off the EQ3. What telescope(s) are you putting on it? That might be relevant information. 

[Alien 13]

As far as I am aware the EQ3 and EQ5 are identical apart from scope capacity, what do you use for polar alignment? this could be an issue.

Alan 

[Cornelius Varley]

30 minutes ago, Alien 13 said:

As far as I am aware the EQ3 and EQ5 are identical apart from scope capacity, what do you use for polar alignment? this could be an issue.

Alan 

The two mounts are totally different and have no common parts.

[Alien 13]

3 minutes ago, Cornelius Varley said:

The two mounts are totally different and have no common parts.

My bad, what I meant was they are the same in engineering terms and the motor drives are based on an identical controller albeit with different firmware.

Alan

[ronin]

With a fixed pillar and so fixed location etc I cannot see why the goto is bad. The complainrts of the EQ3-2 are that the tripod is not great, the actual head unit seems fine.  It is one of the options that I am thinking of for a small goto.

What scope are you putting on it ? Have you used a location of London or set you own custom location into it all. How accurate is the pillar - is it actually pointed True North and at the correct angle? Ask as on an equitorial and with the right scope if the pillar is correct then I know of one place that does not do goto alignment as the real algnment has already been done by the positioning and accurate setup of the pier.

Basically you cannot swap the bits over except for the handset. And if you buy an EQ5 goto you get a handset anyway.

From what you have said I would question the data that is in the handset - at this time of year is DST set to On. Is the Long and Lat that is in the handset correct (London is too close to 0.00 for my liking). THen I would check out the pillar that the EQ3-2 is sitting on. Should be True North, not magnetic (compass) North, and see about a inclimometer to check the angle it is set at.

[Astro Imp]

One of the common problems with inaccurate GOTO is not using a good enough power supply. What's yours?

[alanwestlake]

Thanks for the many replies. Here's some detail that I should have given before.

Weight wise I'm putting a 150mm SkyWatcher Newtonian on the mount, so not too heavy i guess, but when you add the weight of all the counter balances and a DSLR I was wondering if that was too much! At first I kept getting lockups which i finally traced to the power supply. So I got an awesome Maplin's power supply that seems very stable and i think would power a whole space station. Best thing I ever brought

For Polar alignment i was using the polar scope along with Jason Dale's PolarFinder, but Just recently I've started using Alignmaster as I'd heard that it gives really excellent alignment.

For the location (I live in Surbiton, so I've used my own data )  Long 0,16',41"  Lat 51,23',36". 

For the time I use the Laptops' clock (which is synchronised) and at the moment I set DST to Yes.

I normally do a 3 star alignment and try to always finish each star with the same paddles (always the left and the up paddles)

So having done all the above I'm ready to roll. I'll slew to something big...lets say the moon!! But it will miss. It will be close, but i have to go and stare through the finder and mess around with the paddles to get it right. That's fine with a big bright object like the moon, but if you now want something faint, lets say M81,  you got no chance -  you can't even see it in the finder. Perhaps I'm expecting levels of accuracy that are unrealistic?

 

[YKSE]

What is the eyepiece(s) you use for alignment?

I use Baader zoom for C8 on EQ3, its 24mm - 8mm settings covers 0.48° to 0.33° TFOV. mostly only 2-star alignment for the meridian I plan to observe. Alignment finishes with the two stars dead-centerred in 8mm with errors around 10' both in DEC and RA. Slewing to known targets in the same meridian with 24mm, it'll be at worst very close to the edge. Viewing with EPs showing 1°TFOV, the targets are mostly near center. When the battery works, i.e.

[Cornelius Varley]

34 minutes ago, alanwestlake said:

Thanks for the many replies. Here's some detail that I should have given before.

Weight wise I'm putting a 150mm SkyWatcher Newtonian on the mount, so not too heavy i guess, but when you add the weight of all the counter balances and a DSLR I was wondering if that was too much! At first I kept getting lockups which i finally traced to the power supply. So I got an awesome Maplin's power supply that seems very stable and i think would power a whole space station. Best thing I ever brought

For Polar alignment i was using the polar scope along with Jason Dale's PolarFinder, but Just recently I've started using Alignmaster as I'd heard that it gives really excellent alignment.

For the location (I live in Surbiton, so I've used my own data )  Long 0,16',41"  Lat 51,23',36". 

For the time I use the Laptops' clock (which is synchronised) and at the moment I set DST to Yes.

I normally do a 3 star alignment and try to always finish each star with the same paddles (always the left and the up paddles)

So having done all the above I'm ready to roll. I'll slew to something big...lets say the moon!! But it will miss. It will be close, but i have to go and stare through the finder and mess around with the paddles to get it right. That's fine with a big bright object like the moon, but if you now want something faint, lets say M81,  you got no chance -  you can't even see it in the finder. Perhaps I'm expecting levels of accuracy that are unrealistic?

 

What do you enter for your coordinates ? The numbers should be entered as 000 17 W, 51 24 N.

[alanwestlake]

Peter,

I was entering 000 16 W. Next time I'll enter 17 and see if that helps a bit. Also noticed the mount was making a strange clicking noise as it tracked, so I've been stripping it down and cleaning it. It's all nicely greased up and put back together now and sounds so much better!

Looking forward to a chance to try it out now.

Thanks everyone for all the advice.

[alanwestlake]

On 6/23/2017 at 15:54, YKSE said:

What is the eyepiece(s) you use for alignment?

I use Baader zoom for C8 on EQ3, its 24mm - 8mm settings covers 0.48° to 0.33° TFOV. mostly only 2-star alignment for the meridian I plan to observe. Alignment finishes with the two stars dead-centerred in 8mm with errors around 10' both in DEC and RA. Slewing to known targets in the same meridian with 24mm, it'll be at worst very close to the edge. Viewing with EPs showing 1°TFOV, the targets are mostly near center. When the battery works, i.e.

Thanks for that interesting post. I was just looking at Stellarium, specifically at Jupiter. Don't know if you can see this screen grab. If you can it would appear that an accuracy of 10' would put you anywhere between  +14 degrees 55' and 14 degrees 45' on the vertical axis (azimuth grid). So you could end up looking at empty space rather than Jupiter. I guess that's what I get! So maybe i was expecting too much from the Goto mount? Actually Stellarium says the apparent size is only 37" at the moment, so you would need an accuracy of more like 10" rather than 10' to get spot on Jupiter.

Looking at M81, which I referred to earlier, that apparent diameter looks to be much bigger at  around 15'. I guess that means your mount would find that fairly easily.

 

[YKSE]

sorry for the typo, what I meant was 10"

[alanwestlake]

Wow that is accurate then!

[YKSE]

45 minutes ago, YKSE said:

sorry for the typo, what I meant was 10"

Sorry again for tha hasty reply. it was meant 10'. The correction just made more confusion. 

 

Yes, if you keep using the high power EP, it might be pointing at empty space,therefore I usually start with EP showing at least 0.5○ TFOV. a zoom is very handy and time-saving in this aspect

[skywatcher58gb]

One thing you could try is doing a one star alignment, then a two star alignment as well as the three star. i have found that the three star alignment usually involves a meridian flip which causes problems in itself. I now usually do two star alignment and it seems to work.