RamaSpaceShip

My understanding of MLPT is that it creates a pointing model with points along the path followed by the imaged target. This target-specific pointing model is then used during the imaging session in place of the existing pointing model. The better is the existing pointing model, the closer from the best trajectory are the points found by MLPT, the best accuracy is got for the tracking. Hope this helps your understanding. Bernard

Hi Jay, A GPS device needs to have the trajectory information of the GPS satellites to be able to compute its position. It stores this information in its own memory, but they are only valid for a short period of time. When they are obsolete, it needs to download an update, which may take some time (20 minutes is not rare) because it is done at low speed. That's why the position calculation may be very quick or quite long. Best regards. Bernard

Hi Robert, I just got MaximDL and started to use it. It crashed quite often and I had to restart it. At the end of the session, Autoslew reported several pending Ascom connectiions, but I think that they were from the crashed MaximDL runs, and were not cleaned after each crash. Did you have some crashes of Ascom connected applications?

Hi John, It's unfortunately just a fact. They already did it, and nothing is indicating that they would behave differently. Probably, they don't have any answer yet, and it may take them some time in this holiday period to get anything to tell us. Regards. Bernard

Hi John, The first and only comment from ASA occurred about 3 weeks after the start of this thread. So we cannot expect reasonably anything before the end of this month. Sorry to break a dream. Regards. Bernard

Hello, John, you may think that re-doing the mount documentation is crazy. It is probably. But we are too dependant from ASA and this is a way to recover a part of our freedom. I cannot wait for things to happen while I can do them by myself. In France, we have a proverb: "God helps those who help themselves", and, as I don't care of God(s), you see which possibilities remains to me. Lukas, I am an IT professional in real-time systems since 35 years, so I have no trouble to work on the Autoslew code in the case where it would be made open source by ASA, or at least, the communication protocol with the mount (and I would love to make a Linux version as this is the operating system I use every day). And Nigel, I agree with you that even an NDA would be profitable to provide some safety in case of a failure of the developer of ASA mounts software. I hope that ASA will understand that opening the knowledge will be profitable to them, and I expect that Michael's presentation will present them this opportunity. Best regards. Bernard

Guys, ASA has demonstrated very clearly that they have no interest in really improving the documentation to make it usable, either by beginners or more experienced users. But I agree with Lukas, this is something we can fix by ourselves, and a wiki is very appropriate. On our proposal to ASA to set one up, other users joined, this triggered some activity to make some choices, but eventually nothing was done. So Lukas, please go on, set this wiki page, and I am sure that other users will participate as I will do. Regards. Bernard

Hi Prefetch, I have never seen any difference on the tracking accuracy, but I must say I didn't look carefully at the figures, only at the very begining when I was discovering the mount. On my own experience of the DDM85, the tracking accuracy is influenced by: - appropriate balancing - rigid mechanical setup (all screws correctly tightened so nothing is "moving"), else you quickly get a false pointing model - precise polar alignment - good pointing model. Once the above steps are done, I never had tracking issues, and, as far as I can see on this forum, it is the same for other DDM owners. The only other cause of tracking issues I have seen on this forum was a broken mount. Best regards. Bernard

Hi Prefetch, This diagram represent the magnetic angle autofind for each motor. The motor magnetic angle knowledge is mandatory to efficiently and precisely control and command the motor. Don't touch anything here, it is now fully automated (in previous Autoslew versions, you had to fiddle here). Best regards. Bernard

Hi Prefetch, You can. From Salt Lake City, go south! I heard that there are some dry areas not that far away in Utah. You can also ask some native american great wizard to do the appropriate dance. Best regards. Bernard

I also use the Logitech F710 permanently connected to my Windows 7 PC. It took me a while before configuring it properly, mainly to control the focuser. But now, it works like a charm, I just have to press one button to wake it up from time to time as it goes to sleep quite quickly. At the beginning, I had some turn-on sequence troubles like Mark has, but they disappeared when I changed my PC: I first used a notebook, now I use a desktop. Probably the issue was due to the USB and the low level of current available on notebooks USB plugs, to be shared at start-up. Mark, do you use a notebook? You have to take care of the configured mode. In one mode, the mount movements are controlled by the D-pad, and the mini-sticks do nothing. In the other mode, this is the other way round, the left mini-stick control the mount movements and the D-pad does nothing. You can switch the mode by pressing the mode button on the joystick. Be aware that the mount movements are slow (around the sidereal speed) if no accelerator button is pressed, so you won't see any movement, unless you look at the RA and Dec values in Autoslew. Best regards. Bernard

May-be this diagram will be clearer Turning the green knob causes the threaded bar to push or pull the dovetail. Best regards. Bernard

Hi Wojtek, My joystick is a Logitech wireless gamepad F710. Regards. Bernard

Hi all, I would like to share with you the mean I use to easily adjust the balance on the Dec axis. I have made a modification to the dovetail so that I just have to turn a knob to precisely adjust the balance. I needed to use a PTFE spray so that the dovetail slides without effort. The image of this system is attached here: This is not patented and I strongly invite ASA to improve this design and add this very useful feature. Regards. Bernard

Of course, I use my joystick all the time when I use my telescope with an eyepiece. My wireless joystick is very helpful to adjust the focusing when looking through the eypiece, or when "walking on the moon". I use Autoslew Version 5.1.1.6 with ACC. You need to have ACC installed (you can get it on the ASA web site-> Downloads-> focuser), and to fully configure it before activating it in Autoslew. If you use the joystick to control the mount, this means that your joystick is recognised by MS-Windows. From the picture you showed when creating this topic, the joystick icon has a red cross on it, meaning that Autoslew didn't see the joystick yet. I was not sure that your joystick driver was working for other applications. Regards. Bernard

This is a limitation of the DDM60. OK3Z does work with joystick on the DDM85. Regards. Bernard

Ok, I translated with Google. From the picture of Autoslew you show, the joystick is not recognized by Autoslew, as if it is not active for MS_Windows. First make your joystick work with MS-Windows. Then check that Autoslew recognises it. Then make it work for controlling the mount. Then you can expect to make it work for the focuser. Regards. Bernard

Hi Lukas, You can remove pieces from the imaging train to keep only the minimum to make a picture, and check if the circles still appear. If you have easy access to another camera, it would be helful to do the switch. This will allow you to identify where the issue comes from, and where it doesn't. You can also check if you can see the circles with an eyepiece only. I got once a single circle on a picture. It was due to a drop on the edge of the corrector, created by accumulated dew, Regards Bernard

I use my joystick to control my OK3Z without any trouble. It was not obvious to setup, but I eventually succeeded. But I can only help you if you describe your issue in english (or in french). My polish is limited to "Niech żyje Polska". Regards. Bernard

Hi Chocolate Elephant, A power failure can only be a problem if it occurs when you do a fast slew. As nothing will brake the mount, it will hit the mechanical stops violently, and this may cause some dammage. To protect against this, there is a simple solution: use an UPS, for the PC and for the mount. You also need to take care when you change your equipment as the balance is then broken and this may cause a quite fast movement, with the same result. It is wise to set a lock in such a situation, in particular for RA.axis. Of course a pier which avoids the meridian flip reduces the number of mechanical stops to those of the mount itself. Best regards. Bernard

Hi, You can avoid the need to rebalance if you put additional weight to balance the focuser and the camera on the OTA itself. Then rotating the OTA does not change the position of its centre of gravity and so no rebalance is needed. But this means more weight and then you may reach the weight limit of the DDM60. It may add also some flexure. Regards. Bernard

Hi Paulo, I can understand your concern and it is not my intention to explain Asa stategy. They will do it if they want. But, to use an Asa mount to do astrophotography, this makes no sense not to have: - a PC with MS-Windows, as Autoslew is the only way to control the mount - an OTA, you easily imagine why - a camera, same as above - MaximDL and Pinpoint in order to use Sequence and MLPT None of those is provided for free with the mount. You complain for the last item, which is generally the cheapest if you want some performance, but not for the others. I wonder why. As there is no efficient alternative to Sequence, and as this implies MaximDL and Pinpoint, I think that Asa should propose a reasonable price for this additional software, as its mount customers are prisonners of this software choice. This would be fair. You ask much more than that, and I don't see it as fair. Best regards. Bernard

Hi Ralph, It is not evidently contradictory. The move may occur when the mount is under the control of Sequence, due to some movements that only Sequence do. Or the move is due to a vibration that occurs because the link between your two OTAs is too soft and Sequence leaves not enough time for the vibration to cease. It is difficult to answer your question without the knowledge of what is moving. As I already told you, you need first to verify each screw, including the pier screws, the tube rings screws, the OTA screws, and the refractor link screws. Once you are absolutely sure that nothing can do a move because you have carefully verified everything, then you can start looking at another issue. Nothing else can be done before. You can also remove the refractor and check if you still have the problem. Regards. Bernard

Hi, My little experience with the DDM85 tells me that if a pointing file is good one day and bad another, this often means that something is moving in the mechanical setup. In my case it was the dovetail screws which were not tightened enough. But it can be anything else in the OTA. You need first to verify every screw or similar. Check also your pier if there is any chance for it to cause the move. Don't be lazy, even if it appears very surprising, the evil hides there. Good luck and happy new year. Bernard

Hi Luke, If you put a plastic ceiling to your roof, then you cannot hit when opening as the scope is already below the ceiling and can only slide along this ceiling, and the plastic will not do any dammage. Then the only risk is the edge of the roof when closing. You can put an electric switch on this edge which cuts the power of the roof motor when hit. You can also use a camera to monitor this critical phase. In addition, you can extend the plastic ceiling outside to guide the scope below it, as in case of wrong position, the scope should not be that far and the plastic can have the appropriate shape to put back the scope in the correct place. If the position is too wrong, the plastic will fold without dammage, and this leaves time for the other security mechanisms to activate. I agree with Nigel that I wouldn't leave the motors on. In case of a problem, they create a too big resistance which can lead to dammage. When the motors are off, the scope can move freely and be pushed away in most cases.