GeorgeCarey

Hello Christer, I have never understood this message. I just ignore it and carry on and everything seems to work. George

I have got the Roddier sofware running. Now to get some images to put through it. This is a test run:

Reflection off the edges of the secondary could be a cause. I painted mine with matt black paint as seen here:

How about indoor testing with an artificial star? I suppose the most important part of the system is the primary mirror. You could rotate that 90 degrees and keep everything else the same. If that seems OK then rotate the corrector. If that is OK then it must be the secondary.

If the defect rotated when you moved the camera then that rules out a defect in the camera. Is it possible to rotate the Wynn corrector and keep the camera fixed? Thanks for mentioning the Roddier software. I had never heard of it and it sounds just like the sort of Geeky stuff that I like!

Hello Pavel, I had a similar problem with my Netonian scope when I replaced the secondary mirror with a larger one. This webpage describes what I encountered http://geoastro.co.uk/february2011.htm In the end it turned out to be a faulty secondary. A replacement cured the problem. Does your defect stay at 5 o'clock inside and outside focus, or does it shift over to 11 o'clock? George

Autoslew would see a rapid rise in motor current and switch off the motors. However, it is probably best to set the slew limits so that this will never happen. George

I suspect this is normal. Maybe it is due to the cabling that goes through the mount? If I balance with the counterweight bar horizontal and East and then slew to the West, it is not balanced. This is with the scope horizontal, so offset filter wheels and so on should not make a difference. However, I get good performance from the mount, with no position errors, so this slight imbalance is not a problem.

Note that the instructions say 'move the counterweights along the counterweight shaft back and forth until both the top and bottom red bars are perpendicular to each other'. Perhaps, 'in line with each other' or 'level with each other' would be better. (Sorry, being pedantic, I know).

Neat solution! Are you getting smooth movement in dec now?

Hi Josch, I also managed an image of SN 2013ej on 2013-08-13 00:30:51 UT My magnitude (V filter) at the time was 12.57

Motors on, after homefind, magnetic angle etc.

It sounds like it might be a USB problem. Occasionally I lose connection between Maxim and Autoslew and guiding does not work, but this never happens in the middle of a run. It tends to happen right at the start when I am setting up. Solution is to disconnect and reconnect Maxim.

Good to see that you are getting somewhere. My system is difficult to balance because moving the scope a millimetre in the tube rings is sometimes too much. I have invented a magnetic balance weight which makes the balancing process very easy and accurate. I have taped a magnetic stainless steel plate to the side of the scope, and made a lead counterweight. Eight small neodymium magnets are glued into the counterweight and a layer of thin felt applied. The counterweight slides easily up and down the steel plate, but the magnets hold it firmly in place. I have the steel strip over to one side, to balance the offset weight of the camera and guide lodestar.

There seems to be a readint16 read error right at the start. I have no idea what this means but it looks suspicious. Have you ever tried a manual home find? The magnetic angle is stored in the registration key and is used automatically when you do a manual home find.

It might be useful to turn on the logging feature. I can't recall exactly where it is in the menu system. Mount... servos I think. That will enable you to read the log and see what the current consumption is. Often before an error the current rises.

Which axis oscillates? I have never seen this on my ddm60, and would be surprised if this was 'normal' on a ddm85. I assume you used the auto tuning in Autoslew. Perhaps it needs fine tuning because an oscillation usually implies that the I value is not perfect.

Yes, I am eager to know what it will do. I have never tried Sequence until last night. I made a 57 star autogrid. 48 images were solved in the first run. Very easy to use. The only hard part was rotating the observatory dome!

I got my connecters from RS-online http://uk.rs-online.com/web/p/products/6121614/?cm_mmc=EmailUK-_-2012-_-PRODACC-_-6121614

Hello Ian, Is that with the telescope loaded on the mount? The DEC axis always seems a bit stiff in places when the mount is unloaded. My mount has just come back fron ASA after a bearing problem. Even with new DEC bearings there is still some stiffness unloaded, but with my scope which weighs 20 kg in place it seems very smooth. Maybe ASA can give a comment as to what we should expect? George

Very nice image, Thomas! It just shows that you don't need an expensive CCD camera to take good images.

Thanks Antonio. When you switch on the power to the mount I assume that Autoslew then does a magnetic angle find? I suspect that his problem may be that if a good magnetic angle is not found then he has difficulty getting the mount near the homefind position. There was a rumour that ASA were going to have a new startup procedure that did not need a magnetic angle find - anyone know any more about this? George

I spoke to someone at an astronomy show recently who was trying to set up a DDM85 remotely in Spain (we are in the UK). He was having such difficulty that he was considering selling the DDM and getting an alternative. His biggest problem was in doing the Homefind at the start of the session. Nearly always it failed and needed someone to manually move the scope. Can someone familiar with remote operation give a description of the startup sequence? Do you leave the mount powered up all the time? A manual homefind is obviously not practical - how do you do the homefind? George

My DDM60 is going on holiday in Austria. To make it easier to Polar align when it comes back I have stuck a piece of paper on the dome and marked where the laser shines. I can now put the mount back on the dome in daylight, and not have to wait for a clear sky.

Great image! What I like is that you give the sky quality. Sometimes I see fantastic images and have no way of knowing if I could get something similar. My SQM varies from 19.4 to 20.0 so I have similar sky to you.