Help needed with skywatcher telescope

[astrohabby]

Hi guys,

I'm new to this astro viewing so go easy on me. I have a question about a problem with a telescope that I recently purchased second-hand and wonder if anyone can help. The device in question is a Skywatcher Autotracking P13065.

The problem seems to be with the motor/mechanism not working in the way I think it should.

This telescope has a motorised movement that is controlled via a small hand device, power is supplied via a battery pack containing 8 AA batteries. The problem is that when it is all connected it doesn't move. I took the side off the mount and it worked perfectly and when I put the side back on it stopped working again. In experimenting with it, I discovered that it seems to be light sensitive in some way (the side blocking out the light and making it stop). You can even stop it when the side is removed by placing a hand over certain parts of the mechanism.

I don't really want to leave the side off to make it work and wondered if anyone had any experience of this problem and/or solutions as to how to fix it (that is if it needs fixing as it may be me that is doing something wrong).

Hope someone can help

regards

[Capricorn]

Hi, you seem to have black text on a black background.

I could only read it by selecting the whole message which then changes the colour of the text.

Yes, have heard about similar.

There is a light sensitive something close to the motors. This registers the movement and feeds back to the computer bit sans so the system knows how much it has moved. So in theory knew where it was, how much it has moved and so where it now is.

The odd thing is your description says you have to have the side off for it to do anything. The ones I read said that the light coming in was creeping round and so they had to block off the light in order for the drives to work.

Will go search for the other mention of this but don't expect an answer/information rapidly.

Were you trying the scope out during the day?

If you were then try covering the arm with a dark cloth and see what happens. Especially where the sections meet and around the area where the drive unit is.

Think that SW switched to a cheaper material and this was unexpected.

Forget the text colour, it is all there now bright and clear. My browser I expect. Sorry

[Capricorn]

Have a read of this. If it sounds the same then visit the thread and read it all, then post a question to the person that identified it. Basically get all the information you can.

RE: Synscan AZ slew rate prob please help!!

This was the post when they found the cause:

#############################

I've found out exactly what the problem is!!!

Long story short, it's sunlight shining through the silver casing on the mount arm. Inside the arm there are light sensors on the stepper motors which, when bright sunlight shines through the case, get confused and don't know what they're reading, sending the tracking off at random speeds depending how bright the light is.

There are two solutions than I can see;

1/ Cover the arm with something to block the light. I hooked the hood of my jacket over the arm and it went fine.

2/ Take the cover off and spray the inside of it with black paint. Which I'm gonna do now.

Both these solutions will solve the problem. The painting option being a more permanent one.

I noticed that when the suns intensity was reduced by a cloud, the problem was reduced, and when the sun was totally blocked, it went totally fine. When the sun came out again I stood in front of the scope and slowly stepped sideways and noticed it only happened when the arm was in the sunlight. So I took the scope indoors, took the cover off and used a torch to reproduce the problem, but more accurately, noticing that it was the sensors on the stepper motors that were being affected.

I'm going to contact SkyWatcher in the hope that they will ask the manufacturers to modify future mounts and inform suppliers of the problem.

What you describe sounds similar, and hopefully the same.

Although the problem described was using the scope during the day, which was something I ask earlier.

If you have the problem at night, in the dark, then it could be something else but the a similar general cause - the sensors.

[Mikea]

It would appear that the LED in your optical encoder is not illuminating the sensor. That's why it only works with the cover off. Are both motors misbehaving?