FenSkies

I'm in Cambridgeshire and get the same impression. And even nights forecast as clear often have a cover of haze that takes the contrast out of the sky. There definitely seem to be fewer crystal clear, frosty winter nights during this last two or three years.

2 hours ago, Bugdozer said:

The difference between magnetic/geographic north shouldn't give you an 8 degree error. It sounds like the scale is not lined up right. It may be adjustable? Then once you have the pole in sight you can manually calibrate it?

2 hours ago, Elp said:

Considering how small such scales are and likely not made to any sort of accuracy tolerance I wouldn't take much notice in it. The number however maybe close to a target, I've noticed some altitude scales are printed "backwards" so they're not set at the number one would expect but 90 minus though yours is no where near.

Yep, I think the scale must be way out. With the mount set to 52 on the scale, the inclinometer app on the phone (placed on the bar the scope rings are fixed to) reads 47 degrees.

12 minutes ago, Cornelius Varley said:

True north not magnetic north. The tripod doesn't need to be absolutely level, near to level is sufficient. Probably best to ignore the latitude scale and just use it as an approximate guide. 

Thanks Peter. Yes, magnetic North was just a starting point to rotate from.

I take it I can assume the altitude scale is nowhere near accurate then?

I've installed an inclinometer app on my phone now, so I'll sit the phone on the bar between the scope rings to roughly set the altitude.

I need a sanity check.

Just how inaccurate can I expect the latitude scale on the Skywatcher EQ 2 mount to be?

With the altitude set correctly, the mount levelled pointing to magnetic North, and the scope in the home (top) position, my understanding is that rotating the mount a little should bring Polaris into the field of view.

I am in Cambridge UK at latitude 52 and a bit, but I'm having to wind the mount to 60 degrees, according to the scale, to get Polaris in the FOV.

Am I doing something stupid, or is the altitude scale hopelessly out? The tripod was levelled using a circular bubble level before fitting the mount.

Help! Thanks.

3 hours ago, SwiMatt said:

I guess the main point of my question (which has been answered now) was whether a beginner in typical city location with limited aperture (say anywhere between 90 and 150 mm) is limited to see the moon, the planets and 3-4 smudges, or whether the number of (averted) visible smudges was in the tenths or even hundreds. Whenever I read "you can see the moon, the planets and the bright DSOs" it sounded like the former, but it seems like lots more can be done even under polluted skies. And I expected lots of subjectivity, but the general answer seems to be "you can see lots of stuff, with time, experience and a bit of luck".

My very much beginner experience with a basic 90mm/910mm achromat, is that the smudges are at least in the tens under my variable (apparently Bortle 5) skies. M1, The Crab Nebula, is just about visible with direct vision (once found) under crystal clear conditions with a 90mm but I have only found it three or four times in as many years. M81 and M82 are easy, as are the main globular clusters and many open clusters. M103 can be a little jewel box on a good night. The Leo triplet of galaxies are not  difficult with direct vision. M57 is easy and shows a little colour at 90mm. Owl nebula, surfboard galaxy, star clusters in Auriga etc.

6 hours ago, SteveNickolls said:

Thanks for posting I hope you are able to resolve the issue you are having. I've had the same unit for focusing my StarTravel 102 for a number of years now and while basic does the job fine. When you get the unit back working you might check this replacement controller unit and wi-fi unit to replacec the stock SW brand item.

https://www.firstlightoptics.com/skywatcher-focusers/4tronix-focusrf-remote-control-for-dc-focus-motors.html

It actually has an on/off switch and a better build, no more removing battery between uses. The wi-fi unit allows control over a greater distance if that brings more to the table.

Hope you get the problem fixed.

Regards,

Steve

I've just taken a look on the FLO website. Looks like an excellent solution if, as is probable, I can't fix my unit 🙂

1 hour ago, Tomatobro said:

from your description it seems like you have the DC version. Between the motor and the output shaft there is a gearbox which has a high reduction ratio so with the motor removed from the focuser with just the output shaft with the flat on it its not possible to stop this shaft from rotating with your fingers when powered from the handset.

Yep, that's the one I have. Identical to the photograph. Unfortunately I am able to stop the motor with my fingers, so it's not looking like a simple bad connection or cable problem. Time to take a closer look at the PCB methinks. There is a possibility that I damaged something when changing the battery, which is a very tight fit. I'm keeping my fingers crossed that it is something fixable.

Thanks for the info on the expected turn rate too. Very much appreciated. I'll report back when I've either fixed or killed it.

I'm hoping someone can advise. I bought the Skywatcher variable speed autofocuser (really just a focus motor) a couple of years ago. It worked perfectly with my EV90 for several months, but then I got an 8" Dob and didn't use the refractor for a year.

Coming to use the EV90 again, the motor struggled to turn the focus spindle. I have tired several fresh batteries, taken all the tension out of the rack and pinion short of making it sloppy, and still the motor struggles. It runs in both directions when removed from the scope.

Does anyone know the cable connections between the motor and control box, and whether it is a stepper motor or DC? If it's a stepper then I'm hoping that the connection to one phase has come adrift.

Any advice or thoughts welcome.

Jumping in on this as I have just refitted one of these to my scope after a year of disuse. I found that the motor now does not have the torque to turn the focus mechanism unless I take out so much tension that there is backlash.

Has anyone taken the actual motor/gearbox unit apart and service it. I suspect there is a slip-clutch of some sort to prevent the motor from burning out under load, as i can hear the motor turning feebly, but the shaft that connects to the scope remains stationary.

Any advice or knowledge on this will be very welcome 🙂

I am in the strange position of my eyes being so different that, at astronomical focusing distances, there is not enough adjustment in binoculars to compensate. So, easy decision for me 😀