robertp

Hi Christian, one addition: you can do what I described above indoors by starting Sequence, clicking Connect and then tell autoslew to start in simulator mode. Robert

Hi Christian, that's very strange. First of all, I'm surprised that doing the MLPT you got a max RA error of only 6 arcsec and a max DE error of only 44,2 arcsec. My max-errors with similar polar misalignment are always way higher (I just checked the last session, max RA error war 9 arcmin, max DE error 2,5 arcmin). For me that would indicate that you have a very stiff setup. Did you measure flex and hysteresis with your setup? I would expect that with such perfect max errors, you should get perfect tracking. I have no clue why using a sequence file at the same region, you suddenly got good tracking. Could you please do the following: When you open Sequence an go to the MLPT-screen, there's a button labeled "Load and Draw LPT File". When you click that, you can choose a directory starting with LPTxxxx and Sequence will redisplay the fitting curve. Could you do that for the two sessions from yesterday and compare the fitting-curves of the MLPT run and the run with the sequence file? I guess you might have stoppped the first run after a while and started the run with the sequence file so that portions of both fitting curves might overlap? Do they look similar? Have you tried to contact Philipp Keller with your problem? Best regards, Robert

Hi Christian, Maybe you could try the dedicated MLPT-function to rule out some weird issue coming from the additional functionality of the automation processes. I would expect that the algorithms are identical but for a quick test the dedicated function is quicker anyway as you don't have to select a target etc. Please tell your wife that your tests are of great value for the community and that we, the community, really appreciate her patience ;-) Good luck, Robert

Hi Christian, hm, interesting. So you also see worse tracking for the first few images. Philipp thinks that it might be that the scope needs more time to settle after the MLPT-calculation with the various slews finished. One thing that I want to try is to slew to the imaging target, slew e.g. 2 degrees further east of the target in RA, do the MLPT calculation there, send it to autoslew, slew "forward" to the imaging target and start to image. If the tracking is then perfect right from the beginning, it might indicate a problem with the first portion of the fitting curve. I still can't understand why you do not get decent tracking at least after a few minutes. I'm not sure whether you tried the following: * clear the configuration, so that no pointing model is in use * sync with Sequence * do the three star polar alignment procedure with Sequence and check whether polar misalignment is smaller than 1 arcminute. * slew to the imaging target (might be a little off center as you have no pointing model in use), synch with Sequence, slew to the image target again (it should be dead center now) * do an MLPT with e.g. 6 points and 1 hour imaging time * start to image e.g. 5 minute exposures So basically you do an MLPT without any pointing model with an appropriate polar alignment. This is under the assumption that you have the fixed encoders and do not have to do an encoder calibration. One thing that is vital is that you have a working GPS connection. To be on the safe side even thought it should not matter make sure that before you start with the MLPT the computer time is as accurate as possible (sync it via the internet). Maybe you can do some screenshots on the way, e.g. showing your polar alignment results and the fitting curve in Sequence. Good luck, Robert

Hi, I can't help on Cristians issue, but one question to Markus with regard to his original problem: Markus, when you experienced the elongated stars with MLPT, did you check the first image in a session or did you also see the problem after several images of a session? The reason I ask is that in the past, I basically always experienced the problem, that the first and last images of an MLPT run had elongated stars, while the images inbetween were perfect. I did some tests and had an email exchange with Philipp about that issue. My guess was, that maybe the starting and end-points of the fitting curve had a problem leading to not so perfect tracking. Philipp is quite sure that there is no problem with the calculation of the fitting curve. At that time, he fixed the problem with doing a MLPT across the meridian and that issue is gone, but I'm not sure whether the other issue still exists. It's not too big a problem for me, but I usually loose two images of a session. Could you please check whether your stars get perfect after a while? Best regards, Robert

Hi Markus, very strange indeed When you do an MLPT, how does the graph look like that interpolates the dots that represent the errors in RA and DEC? Are these smooth curves (no s-shaped curves)? After the MLPT-calculation run, did you press "send to autoslew" and did you check whether in autoslew the LPT-icon is orange? Do you have a gps installed and connected? Autoslew relies on a very accurate timestamp. Best regards, Robert

Just to check: Are you sure that you connected the power supply to the correct cable and the correct pins? I have a DDM60 Pro and there are several inputs for power. One that actually powers the mount and its electronics, one that provides 12 V to the plug at the mount head and one that you can use to provide 0-48V (I think) to the mount head. Please double check whether you connected the correct pins. Good Luck, Robert

Hi George, congratulations to the beautiful image. Did you use comet tracking in autoslew or did you use sidereal speed and stack the images on the comets head? Best regards from very foggy Ulm, Robert

Hi Kazuo, I just tested the beta release of Sequence (version version 2.0.1) together with autoslew 5.2.0.2 and can confirm that doing an MLPT through the meridian now works great! So I would recommend that you register as beta tester to be able to use these versions, best regards from Ulm, Robert

Hi Michael, I'm already beta tester of Sequence2.0 and provided my feedback back to the support email. I'm in contact with Philip with regards to bugs and improvement recommendations. Can you please add me to the bug report board? Best regards from Ulm, Robert

Hello Kazuo, I can confirm that there is a problem with MLPT in case you record a local pointing file starting east of the meridian and ending west of the meridian. I reported that back to ASA quite a while ago and again two days ago as a first feedback with regards to the beta version of Sequence 2.0. I got a reply from Philip Keller who was not aware that this problem exists and I try to support him in resolving the issue by providing further information. So I guess at the moment, you will have to wait until the new version is available. You might consider to volunteer as a beta tester for the new sequence, hoping that there will be a fix in a new beta version available soon. Best regards and clear skies, Robert

Hi, I hardly ever disconnect sequence without experiencing any problems, so I guess that if there ever was a problem, it's resolved. I can remember that in sequence 7 there was an advice to disconnect but even than I never experienced a problem. Best regards to Norderstedt from Ulm, Robert

Hi Cristina, I tried to find the description in the old autoslew manuals but did not find them. So here's how I use the balance feature: I start with putting the telescope horizontal as well as the counterweight shaft horizontal. Then I start the balance feature for the dec-axis. The dec-axis swings back and forth (about 15 degrees if I remember correctly) and the two bar-graphs indicate the amount of current required to swing the axis. One graph indicates the forward motion, the other one the backward motion. While the axis swings, I try to remember the maximum position of both graphs. The idea is that once both graphs show the same maxima, balance is perfect as it takes the same current to swing the axis in both directions. If the maximums are not identical, move the telescope forward or back until the graphs are symmetrical. With a heavy scope, you will see quite a difference if you move the scope by few millimeters. For an optimum balance, it's important that the scope is in the configuration that you intend to use (including CCD and filterwheel, dew cap, dew heater) and that the focuser is in the focus position. Once the telescope is balanced in the dec-axis, you do the same thing with the RA-axis. This usually is easier as you can easily move one of the counterwheights until you achieve optimum balance. If you want, you can check the balance in other positions as well. It might be difficult to achieve optimum balance in all positions if you e.g. have a heavy finder scope off-axis or if your filterwheel is asymetrical ... Hope this helps, Robert

Hi Nigel, I just checked it at the mount to be sure how I did it: I connected both FLI pairs together to one Galv supply and use that to power my ML8300 together with the filterwheel. I use the other Galv supply to power my motor focus controller (that sits at the mount head) and a small power distribution box that provides 3 additional 12V plugs at the mount head for e.g. dew heaters, flat-box, fans, ... I hope this helps and that you also get your pointing errors sorted out, Robert

Hi Nigel, I power my Microline since more than two years using the Galv power without any problems, but I'm not sure how or whether the power adaptor is different to the Proline ones. The power adaptor delivered with my ML8300 is branded "Power Solve", Model PSG120-12-01 (120Watts). Clear skies, Robert

Hi Matts, I use the same configuration and never had the issue you described. I bring up autoslew first, then start TheSky 6. In the Sky 6, within the telescope setup, I have selected "Telescope API" and under "settings" I use the "Poth Hub" but I guess "Astrooptik Server Telescope" works as well (I think I used that in the past). When I click on the "establish link" icon (the second from left in the telescope toolbar, the link gets established and I'm ready to go. Very strange that you get the display setting window. best regards, Robert

Hello Antonio, congratulations to that wonderful image! Phantastic rendition of a rather unknown region with beautiful star colors - I love it! clear skies, Robert

Hi Bob, it's a good idea to ask ASA. The forth port of the hub is not in use as it points to the opposite direction compared to the three ports you can use. The connection to the hub is done via the mini or micro-usb port of the hub. If you would like to have a look at the configuration and check how much room there would be for a replacement: You have to remove the saddle plate from the mount head. Then you will see 4 hex screws. If you unscrew them, you can lift off the upper part of the mount head. The usb-hub sits inside this part fixed with some glue which can easily be removed. Robert

Hi Bob, as you have the DDM60 Pro with the older encoders, I guess you also do have the version with the unpowered usb-hub? I had that version as well a while back. The hub in my older DDM60 Pro was actually a usb 2.0 4-port hub identical to this one: http://www.conrad.com/ce/en/product/980580/4-Port-USB-20-Hub-Style (I had to replace it once). Only three of the 4 ports are accessible and the hub could be powered, but there was no room in the mount head to power it. To my understanding, the plug at the base of the DDM60 was directly connected to the hub and therefore completely isolated from the mount controller. So in theory, you should be able to just replace the existing hub with a usb-3.0 version. The problem here would certainly be to find one that would fit into the rather small pocket in the mount head where the original one sits. Another option that I tried successfully would be to install another usb-hub at the mount head. I did that for a while by taking a new usb-3.0 hub, cutting the usb-cable in half, solder two 8-pin DIN plug to each of the 4 wires and plug them into the data port. You can e.g. use velcro to attach the new hub near the mount head. It's not as neat as the original version, but it works very well without doing any alterations to the mount. Robert

Hi Erik and Bernard, the connectors are not that hard to find. Try a google search for "din connector 8 pin" or similar. In Europe, you can e.g. get them at conrad.com, e.g. here http://www.conrad.com/ce/en/product/733425/Lumberg-WSV-80-DIN-Cable-Connector-Angled-Number-of-pins-8 I have bought several of them to build custom cables for my DDM60 Pro. In the following document http://www.produktinfo.conrad.com/datenblaetter/725000-749999/733425-da-01-ml-DIN_STECKER_8POLIG_GEW_WSV80_de_en_fr.pdf there's a reference to the different versions (pin-numbers and pin-layouts) at the bottom of the first page. Please be aware that there might be different types for the same pin-numbers (e.g. for the 8-pin-connector), so make sure that you order the right ones. With regards to the maximum current allowed: I think that the 8-pin-connector (data-port) officially is only rated for a few hundred mA per cable (can't find the information at the moment). According to the handbook, the 8 cables running through the mount are shielded and 0,2mm diameter. That should be good for something like 2 up to 5 Amp of current per cable but I would really check back with ASA to prevent any damage. The galv cable is intended to power e.g. CCDs, filterwheels and stuff. At the DDM60, the cable supports 12V 2amp and 1-48 V 5 amps. Not sure whether that's true for the DDM85, too. To be sure, I would contact ASA, but I'm sure you can find a solution to power all your equipment using the internal cabling. Best regards from Ulm, Robert