Jay

Hi Wojtek and Happy New Year, It looks like you might have a problem with plate solving. I assume you’re using Sequence ? If the plate solve fails (e.g. pointing is too far off from the target) Autoslew cannot create a pointing file. The best way to check if plate solving is ok is to make a test plate solve (in Sequence under plate solve settings). After that test is fine, do a synch and "set new Homeposition" Jay P.S.... if synch fails you should not try to set a new Homeposition because it will most likely be way off. P.P.S...and before turning off Autoslew remember to save all new settings ! P.P.P.S...GPS/Autoslew can have signal problems sometime, don't really know why. However, you can always input coordinates manually if needed.

I've had similar problems with the corrupted Homeposition coordinates lately. Only 2 times so far but the latest almost made the scope to hit the pier.... not good. I had to set the Homeposition again and now everything is working fine. The problem is of course that using automated Homing (after the photo session) is not fully reliable anymore... Jay

Hi Wojtek, I have similar issues with the homefind. Every now and then the homefind fails without any obvious reason. Especially the RA homefind used to fail almost every time when doing the procedure for the first time. After 2-3 tries it usually went through. The trick that seem to work with my mount is starting the homefind into a "wrong direction". When the homefind slew returns and finds the reference mark, everything is fine. I'm glad that this trick works but am quite pissed that have to do this kind of things to make the mount functioning properly. In addition the DE homefind still fails sometime. So I can't fully rely the homefind procedure working everytime, which is really frustrating because I'm operating a remote observatory. Jay

Hi Josch, I've had quite a lot of problems with my DDM60 Pro ...never found out what caused the problems but after the service everything is working quite ok, however not perfectly. E.g after switching to Win10 the first "home find" fails every-freaking-time. When turning off Autoslew and trying it again, no problems what so ever. Changing the serial key: http://forum.astrosysteme.com/index.php?/topic/766-new-serial-key-autoslew/ Regards, Jay P.S. Pointing accuracy problems might have something to do with the old sky model. I've never had problems with pointing accuracy, on the contrary, pointing has always been VERY accurate

Hi Daniel, Don't know if this helps any but I've had my share of problems with the Windows 10, especially with COM / USB ports when installing drivers. Sometimes installing different drivers doesn't seem to help because the "old" drivers should be have been deleted first ? I also used to have "USB error" issues but with good cables and better USB hub, they have mostly disappeared. After quite a lot of work I finally have everything running again (with the new laptop and Win 10), except can't still get the AAG Cloud sensor connected for some reason. So the problem might not be with the Autoslew drivers... Jay

I usually take 20 min exposures, so a little drift every 100 minutes would mean that I have every 5th image with double dithering Best regards, Jay

Mike, The USB port/hub in the DDM60 mount is just a hub...and is connected to your computer via the USB cable. It doesn't matter where you put your GPS receiver...same result. Jay

Thanks Bernard, and I agree with you that the GPS can't produce sub-millisecond time references. I was just wondering if the Autoslew only checks the time from GPS before every slew and not in between. Tracking one object without a slew can take several hours...

Hi Lukas, And congratulations for your new scope. It's a wonderful piece of equipment ...I know because have owned one for couple of years now Mine is not the AT model, so there is a need to do refocusing every now and then but no complains. It's a quite fast scope and the focusing a bit critical but I've been using the "Lunatico" stepper motor, Seletek and FocusMax, and have never had problems with the focusing. The focuser itself is the original from OS. I'm using a similar combination (stepper motor, Seletek, FocusMax) with my 300 mm Canon (F 2.8) and no focusing problems there either. Jay

Hi Mark, I think the end result depends very much on what kind of (and how much) flexure your setup contains... If the system would have 0 flex (which is impossible) the unguided system would be as good as the tracking accuracy. However, there will always be more or less flexure depending what kind of setup you have. That doesn't mean that an unguided imaging setup wouldn't be able to produce wonderful results if built rigid. Guiding with a separate guider will have similar flexure issues and they have to be dealt also before achieving good results. However, guiding with an OAG will automatically eliminate most of the flexure problems and should be able to produce good results quite easily. Jay

Is this a fact or an assumption ? ...very important thing. I only know that if the GPS signal is not found when starting Autoslew, it will try connecting to the GPS module every couple of minutes. It would be odd if that procedure would stop after finding the GPS signal once ...or only before every slew. Why would Autoslew be design in that way, especially when the time component is so critical ? Jay

Hi Thomas, I'm pretty sure the GPS time is synchronized every time when starting the Autoslew. As Ian said, you'll get an error notification right away if the GPS is not working, and then it keeps checking the module every couple of minutes... What comes to different GPS modules, I've always been using the basic GPS module without any problems ( http://usglobalsat.com/p-688-bu-353-s4.aspx#images/product/large/688.jpg).Can't comment about the accuracy because have never compared it to anything else... Jay

Just to let everybody know that inputting the serial key properly is VERY important... For some reason the system will accept wrong serial keys also and e.g. last two digits have something to do with the DE axis values. I managed to input them the wrong way around and had some unstable behavior. The mount worked well most of the time so the problem was difficult to locate.

Hi Daniel, I do Polar alignment and pointing model only once when the season starts in September (ends in April)....if using the same scope all the time. If switching scopes then I'll do the alignment and model again. Jay P.S. I have a permanent observatory

Hi Waldemar, Yes got the mount finally back. Unfortunately they've also changed some cabling (have the DDM60 Pro model) so have to do quite a lot of extra work in my observatory to disassemble and reorganize the power input to the camera and heaters. New cables were included though.. Haven't been able to make proper tests yet but there is some worrying noise coming from the DE axis and USB cable problems (something I didn't have before). Lets hope that all this goes away after careful balancing and using the mount for a while. Best regards, Jay

Thanks a lot Mark Jay

Can somebody remember how to install a new serial key to Autoslew after mount service ?. Have done it once but can't remember anymore. Jay

OK, but that news has been there for a while already...

Lukas, could you be a bit more specific. All I found was old news...

No problem Daniel The total length of the MLPT is the value you input to the "total exposure time" box (e.g. 120 min) And it's the same time you need/use for the shooting session for that specific target. The number of exposures will just tell Sequence how many MLPT points (plate solves) you want Sequence to use when calculating that 120 min session MLPT curve (e.g. 6 exposures). That curve will be then sent to Autoslew. P.S. your MLPT exposure settings are the same than plate solve settings (e.g. 5 seconds, lum filter, bin 3x3). No additional input needed. P.P.S. your exposure setting for that session (e.g. 10 x 20 min subs) are not related to the MLPT curve other than you'd need a 200 min MLPT curve (or 220 to be safe) to perform that session using the MLPT function. P.P.P.S Maybe it helps if you think that the MLPT is just a super accurate pointing (tracking) file created for one specific target. When the general autopointing file covers the whole sky

Daniel, you really should read the manual one more time You will always "send" MLPT to Autoslew. Autoslew will use it after that. Sequence is only a tool used when creating the MLPT curve. You can see when MLPT is active when the button turns orange in the Autoslew... "Once you send the data to Autoslew the LPT button will be painted orange and Autoslew will start following the orange curve. If you want to deactivate the LPT you can click on the same button. If the button is activated the LPT will be used as long as you observe at the same hour angle you followed during the measurement. LPT is not saved, if you restart Autoslew you have to send it again from Sequence." Sub exposure time has nothing to do with the MLPT duration/number of exposures. A good starting point is to use the 5 exposures /100 min duration (suggested by the Sequence). E.g. 300 min duration (5 h session) would need 15 exposures. P.S. One iteration should always be enough

Thanks Lukas...

Look at the Sequence manual pages 24 - 28. Very simple thing to do...

That would be great !

I always use the planetarium software when slewing to an object, and Autoslew (arrow keys) only sometime when framing the object if not satisfied how it has been originally positioned. The bad news is that the pointing shouldn't be that much off after only 6 days. However, I'm sure there is just some small thing you're doing differently that causes the problem. Have you checked that the computer time is accurate and the same time is used with Autoslew and Sequence ? I'm using a GPS module and a small software in the laptop to have the time always correct. Edit: And have you set a new homing position after you've done any changes to the setup...e.g. polar align ?