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Pages: 1 | 2 | 3 | 4 | (show all) engchris super member Reged: 05/17/12 Loc: Florida Re: Frustrated 8 SEer [Re: hamdul]       #5377094 - 08/20/12 07:43 AM Edit   Reply   Quote Quick Reply   Quote: Bob, and all others trying to help, You and several others have mentioed setting the "Anti-Backlash" That's all well and good but it scares the be jeepers out of me. When this is advised I think of that old adage, "If'n it ain't broke don't fix it" I say this because to this untrained eye the scope appears too move fine. There's no jerkiness, on command the scope starts to move steadily and I say to myself "What's to fix" If i go to Anti backlash settings what do I do? do I increase the number or decrease the number? If the instruction gave some indication to fix a problem (Like if the scope shakes 3 time and coughs decrease the backlash setting until the symptom sissappears.)I could understand that but as I said to me the scope moves fine. My new question is, what do I look for and which way do I go to correct it??? Although I lost my sky in Mass. When I left on a good night if I could see 3rd magnitude stars that was a good night. Thing are a little better hear in NH but not much. The Manchester airport put out quite a dome of light to my North. Anyway, thanks for the congrats. Fred Something else you might try to make sure your GOTO is working properly is use "Calibrate GOTO" in the Utilities menus. I use it almost every time I finish A2SA. It's probably not necessary to do it everytime but it makes me feel better. It's like a good luck charm and seems to work for me To use it, go ahead and do your A2SA. Once your HC says "Alignment Successful" go to the Utilites menu and find "Calibrate GOTO" and press enter. The scope will start to move and if your GOTO is properly calibrated one of the stars you used for alignment should show up in the center of your eyepiece. If you've never done this before it might be a good idea to try it out and see if everything is working properly. As far as backlash goes, I believe these mounts are all slightly different. I've never needed to adjust mine and have had good success after using the proper approach and alignment procedures. Mine definitely has some backlash, just not to the extent that it has been so bad as to need adjusting. Other mounts seem to have more of a problem. Best of luck! Post Extras:       hamdul super member Reged: 06/23/09 Loc: Litchfield NH, USA Re: Frustrated 8 SEer [Re: Tel]       #5378168 - 08/20/12 06:52 PM Edit   Reply   Quote Quick Reply   Tel, I bit the bullet and attempted to do the backlash thing. I first did the scope setup thing. After that I selected Solar System Alignment then I entered all the required data (Time, Date, location etc.) and then selected Saturn since Venus was not available. I pressed Enter and Align and the HC said alignment successful. But when I pressed the arrow buttons to move the scope it would not move. At that time the HC screen said Nexstar 8SE and in the right corner was the numeral 6. I shut the scope down and repeated the process 3 times all with the same results. It's a good thing I'v got that British stuborness. Fred Post Extras:       Mariner@sg super member Reged: 06/28/12 Loc: Little Red Dot Re: Frustrated 8 SEer [Re: hamdul]       #5378442 - 08/20/12 09:49 PM Edit   Reply   Quote Quick Reply   Quote: Tel, I bit the bullet and attempted to do the backlash thing. I first did the scope setup thing. After that I selected Solar System Alignment then I entered all the required data (Time, Date, location etc.) and then selected Saturn since Venus was not available. I pressed Enter and Align and the HC said alignment successful. But when I pressed the arrow buttons to move the scope it would not move. At that time the HC screen said Nexstar 8SE and in the right corner was the numeral 6. I shut the scope down and repeated the process 3 times all with the same results. It's a good thing I'v got that British stuborness. Fred Hi Fred. Seems like you somehow set your slew rate to 6 which will not be very apparent. Also, you might like to try using other alignment stars other than Polaris and see if that solves the issue? Post Extras:       Tel Postmaster Reged: 03/31/06 Loc: Wallingford England Re: Frustrated 8 SEer [Re: Mariner@sg]       #5378801 - 08/21/12 05:02 AM Edit   Reply   Quote Quick Reply   Hi Fred, Having sat down with my own Nexstar mount and aligned on Saturn in, I presume, exactly the same way as you had, I think I may have I've figured out why things are going awry. Going by your description, you say you did just that: aligned on Saturn and obtained a successful alignment. So did I with a little time cheating this morning. BUT (again from your description). you don't say that you selected some star or object to which to make a "GoTo" slew but that you (apparently) only pressed (one ?) of the direction buttons, receiving no perceptable motion and the number 6 (upper right corner of the screen). This, I also found,... (I say "found" because it's not usual practice to do this), is just what happens. The 'scope IS moving, (if you put your hand on it you'll detect the motion), but only at slew rate 6 ! Now perhaps I'm trying to teach my grandmother to suck eggs here, but to make a "GoTo" slew, you must select an object and press "Enter". Pressing the direction buttons will NOT produce a "GoTo" slew. They are only generally employed when the automatically governed "GoTo" slew has reached its target but perhaps needs centralising in your eyepiece. Does this make any sense and perhaps explain why you're getting no response ? Best regards from your stubborn Brit, Winston Churchill Post Extras:       Midnight Dan Postmaster Reged: 01/23/08 Loc: Hilton, NY, Yellow Zone (Bortl... Re: Frustrated 8 SEer [Re: Tel]       #5378865 - 08/21/12 07:06 AM Edit   Reply   Quote Quick Reply   Hi Hamdul: I think Tel has got it. To do a high speed slew, one that you can detect without looking through the eyepiece, you need to change to speed 9 after alignment. When you look through the eyepiece to adjust backlash, change back to a slower speed - I usually use speed 4 or 5. -Dan Post Extras:       hamdul super member Reged: 06/23/09 Loc: Litchfield NH, USA Re: Frustrated 8 SEer [Re: Midnight Dan]       #5379064 - 08/21/12 10:02 AM Edit   Reply   Quote Quick Reply   Tel, Yes what you said makes sense. According to my weather bar the sky tonight is supposed to be moderately clear so we'll give it another shot. Will let you know how things go. By the way, I don't consider you a Stubborn Brit, More like the patience of Job. Fred Post Extras:       Tel Postmaster Reged: 03/31/06 Loc: Wallingford England Re: Frustrated 8 SEer [Re: hamdul]       #5380576 - 08/22/12 07:11 AM Edit   Reply   Quote Quick Reply   Incidentally, Fred, another thought has just occured to me. If you're not using an "Auto Two Star Align" or the manual, "Two Star Align", (and I still recommend you to do so for the sake of accuracy), be sure to level your mount. It's not critical when performing an ATSA or TSA, but has a significant effect on accuracy with "One Star Align" and "Solar System Align". Good luck and best regards, Tel Post Extras:       Doug Michel sage Reged: 09/18/11 Loc: Lincoln, NE Re: Frustrated 8 SEer [Re: Tel]       #5381928 - 08/22/12 10:47 PM Edit   Reply   Quote Quick Reply   Just to throw my 2 cents in here, a member of my astronomy club that has the 9.25 inch celestron says that he uses Polaris as the 2nd star in the alignment process and not the first as I had always done, and he says this generally gets a little crisper alignment, so you might also try that method and see if that improves. Post Extras:       hamdul super member Reged: 06/23/09 Loc: Litchfield NH, USA Re: Frustrated 8 SEer [Re: Tel]       #5385519 - 08/24/12 11:39 PM Edit   Reply   Quote Quick Reply   continuing my saga. Tonight while still daylight I decided to tackle the antibacklash. As I said before the scope seemed to move O.K. It started its motion when I pressed the Arrow key, Moved smoothly. and stopped when I released the arrow key. But to get back to tonights adventure I went to "Scope set up" and toggled to "Antibacklash". Got Azm. Positive and pressed enter. the figure 00 was showing on the screen. I changed it to 10 and when I sweeped the scope from side to side It seemed to have a very slight hesitation before the scope moved. I bumped it up to 20 and nothing seemed to change so I then set it at 70 and wow when I pressed the arrow key it fairly jumped forward came to a screeching halt and then proceeded with a smooth horiz. motion. When I started back in the opposite direction the same thing happened, A quick jerk of a start and then went to the sready motion. I then changed the setting to 50 with the same results. I continued to decrease the numbers by increments of 10 but nothing seemed to change, it continued to have that jerky start untill it got back to 00. so I left it there .. And Oh yes, during the preceeding I did lower the slew rate to 4. I now went to Alt. Negative and it to showwed a figure 00 so I bumped it up in increments of 10. Again as in Azm. mode the sope started off with no delay when I pressed the arrow button, it moved verticaly smoothly and when I released the arrow button it stopped. Nothing seemed to change untill I got to 40. Then the scope started off right away when I pressed the arrow button but then seemed to chatter when rising and decending When I changed the setting to 50 the chatering was more noticable. The scope always stopped when I released the arrow button. Oops!!! as I write this and refer to Tel's instruction I see that I was supposed to do bothe Azm. and Alt. in both positive and negative modes and I only did the Azm. in positive and the Alt. in negative. Oh well, tomorrow I go thru the instructions again. Fred Post Extras:       Tel Postmaster Reged: 03/31/06 Loc: Wallingford England Re: Frustrated 8 SEer [Re: hamdul]       #5385780 - 08/25/12 04:11 AM Edit   Reply   Quote Quick Reply   Hi Fred, If you're satisfied that at, let's say, Slew Rate 3 or 4, your 'scope moves smoothly in all directions, takes no more than a few seconds for the drive to take up the movement in any direction and stops when you take your finger of the button, I woouldn't worry too unduly about backlash settings any more. if this is the case, it would indicate that they are about right and should stand you in good stead to move on to an alignment test. Best regards, Tel Post Extras:       Midnight Dan Postmaster Reged: 01/23/08 Loc: Hilton, NY, Yellow Zone (Bortl... Re: Frustrated 8 SEer [Re: Tel]       #5386042 - 08/25/12 10:21 AM Edit   Reply   Quote Quick Reply   Hi Fred: One more thing about the anti-backlash settings. Not sure if anyone mentioned it already, but you need to adjust the settings AFTER the scope has been aligned. It behaves differently before hand. If you're setting anti-backlash during the day, you can just do a mock alignment. -Dan Post Extras:       hamdul super member Reged: 06/23/09 Loc: Litchfield NH, USA Re: Frustrated 8 SEer [Re: Tel]       #5388782 - 08/26/12 09:31 PM Edit   Reply   Quote Quick Reply   Tel & All Took the scope out tonight with your instructions in hand. SUCCESS!!! Well mostly, at least good enough to give me confidence that with more practice the "Go To" will get better. After alignment I went to M-13 and there it was just barely in the field of view in the upper right quadrant. Them I went to Saturn with much better results. it was also in the upper right quadrant but about half way from the edge to the center of the field. Next M-5 and that was just inside and at the top of the field of view. Next Albireo Ooops! Not in the field of view but it was in the finder and finally I went back to Polaris and that came in almost smack in the center of FOV. All in all I was truly pleased BUT, (Isn't there always a BUT) Unless I get Really good, and I mean really good at getting targets closer to the center of the field I'm afraid it will not do for me what I got this scope for and that is to get Variable Star fields. All of the work tonight was with a 25mm eyepiece, and the moon is just pass first quarter so it was bothersome and that's why I packed it in early Joyfully Fred Post Extras:       WarmWeatherGuy professor emeritus Reged: 08/27/11 Loc: Orlando, FL 28° N, 81° W Re: Frustrated 8 SEer [Re: hamdul]       #5388792 - 08/26/12 09:36 PM Edit   Reply   Quote Quick Reply   Have you tried Precise Goto? http://youtu.be/qjoQdruBkGc With Precise Goto you can get your object of interest to be much closer to the center of the eyepiece. Post Extras:       Tel Postmaster Reged: 03/31/06 Loc: Wallingford England Re: Frustrated 8 SEer [Re: WarmWeatherGuy]       #5389174 - 08/27/12 04:43 AM Edit   Reply   Quote Quick Reply   Hi Fred, I'm glad to hear that you are at last getting some success with your 8SE although it sounds as if it could still do with a "tweak" or two ! As WWG (above) advises, you could certainly apply the "Precise GoTo" feature and probably to improved effect but that is, at least to my mind, a "bandage" rather than a "cure". These 'scope ARE capable of placing objects well within the field of view of a 25mm EP and not just at random, although the tuning of yours to do so, may take a little more time and effort. So what to do ? Well for a start I would now be inclined try giving the OTA a little rear end heaviness by sliding it further back along the dovetail and then shift the Altitude GoTo Approach from a Negative to a Positive one. Keep the Azimuth setting Poasitive though ! Then, moving your alignment stars, this time from the top left quadrant of your EP (rather than the bottom left), to the right and DOWN to centralise, carry out a comparative test to try to establish whether one "Approach" is more accurate than the other. Be careful though in moving the 'scope rearwards for fear of the diagonal/EP assembly striking the base. Try therefore to maintain some clearance at least for the purpose of the test. The main issue is this time to provide a small rear end weight bias rather than the fore-end bias first suggested and such should go hand in hand with the Altititude GoTo Approach setting. Hoping this may prove even more successful. Meantime, I'll keep thinking ! best regards, Tel BTW: I gather you chose Polaris as your first alignment star but, just out of interest, what star did you choose for your second ? Post Extras:       hamdul super member Reged: 06/23/09 Loc: Litchfield NH, USA Re: Frustrated 8 SEer [Re: Tel]       #5389444 - 08/27/12 09:56 AM Edit   Reply   Quote Quick Reply   Tel. I think that you may have hit on something. A little history. A little while back I added a dew shield to the configuration. When I moved the scope up I sensed a strange noise so I took the scope off the mount to find the balance point. When I was sarisfied I put the tube back on the mount and all seemed well. The other night when I had the scope out it was rising close to zenith and I noticed the diag.would contact the base if it continued. It stopped short of the meeting at that timr but the next morning I moved the scope forward a skooch After reading your post I thought that maybe the "altitude go to approach" should have been positive all along. Will try that the next time out. To satisfy your curiosity - It was not quite dark so I used Arcturus for my 1st alignment star since it was visible, and thern went to Polaris. Again, Thanks for all your help Fred Post Extras:       Tel Postmaster Reged: 03/31/06 Loc: Wallingford England Re: Frustrated 8 SEer [Re: hamdul]       #5389856 - 08/27/12 02:18 PM Edit   Reply   Quote Quick Reply   Hi Fred, Traditionally, (according to Mike Swanson's "The Nexstar Users's Guide"), it was recommended that the older Nexstar 8i, with which Bob G., Rickster and I started out, was set to have a POSITIVE Altitude GoTo Approach to take advantage of its backend heaviness. These 'scopes' OTAs were however fixed to the mount arm : (i.e. there was no dovetail rail and no possibilty, without tools, of removing them let alone sliding them backwards or forwards)! Now, despite both Bob, Rickster and I obtaining a "Ray's Bracket" for our N8is by which we are able to place our OTAs anywhere we care to in relationship to the mount arm, we have retained a POSITIVE Altitude GoTo Approach based, certainly in my case, on that original, POSITIVE recommendation. But, when the Nexstar 8SE arrived on the scene , to my recollection, the Altitude GoTo Approach was set, by "Default", to NEGATIVE. Time has however passed and it now seems that with more and varied accessories available etc. to vary the weight distribution, things are perhaps not so "clear cut" as they were. My own thinking is that with the introduction of the Vixen rail to the SE series, which gave manoverabilty to the OTA on the arm, the OTA was logically slid forward of the mount arm in order for the diagonal and EP to clear the base of the mount with ease, a feature not possible on the older, fixed model. Thus, in moving the OTA forwards by means of the rail, weight distribution now made the OTA fore-end heavy on the 8SE and thus invoked the change (from POSITIVE to NEGATIVE) with regard to the Altitude GoTo Approach. So much for the explanation. But what this really says is that the Altitude GoTo Approach settings are there to be experimented with nowadays. Be guided by "Fore-end weight bias: NEGATIVE, "Rear end weight bias: POSITIVE but be aware that these maxims are no longer to be regarded as inscribed in tablets of stone. Hoping this helps, and remember to keep the Azimuth setting POSITIVE at all times. I hope you'll continue to keep us all posted. Best regards, Tel Post Extras:       hamdul super member Reged: 06/23/09 Loc: Litchfield NH, USA Re: Frustrated 8 SEer [Re: Tel]       #5395012 - 08/30/12 02:15 PM Edit   Reply   Quote Quick Reply   I'm not sure if I damaged my cable connecting my Power Pack to the 8 SE. The other night I was out doing the things in Tel's instruction. After alignment every thing was working mostly fine (See previous post) I was doing a go to and I noticed the scope started to make a strange noise and was struggling in azm. motion. Whooops! the cord was wrapped around the tripod leg and was restraining the scope motion. I shut off the power and undid the cord and decided to call it a night. Tonight I went out and while setting up I noticed that the plug the connects to the mount felt a little bit flopsy. I plugged the cord into the mount, turned on the scope and every thing appeared normal. That shows you how appearances can be deceiving. I did the Auto 2 star and I know I was on both stars but it told me the alignment failed. I did this 2 times, same result. On the third try the HC lost everything and reverted back to the start up screen. I selected 2 star auto and reenterd the required data then selected Polaris. Got polaris in the finder and in the scope so pressed enter. Centered Polaris and pressed align. Then I selected Arcturus as my 2nd star prssed enter and the scope started to go to the star. It traveled about 10 or 15 degrees in azm. and stopped. I manually went the rest of the way and got Arcturus in the finder, looked in the scope , it was there so I presed enter. Centered the star and pressed align and again I got alignment failed. Had to start all over again. Selected 2 star auto, entered all the data and the screen said to select the 1st star. When the list came up I started to scroll to Polaris and I noticed the list was way bigger than what I recalled. Anyway I selected Polaris got it centered and pressed align and I was asked to select the 2nd star. I selected Arcturus and pressed enter and the scope didn't move. Thats when I realized I was not in the 2 Star Auto but the in the 2 Star. Again went manually to Arcturus, Cetered it in the scope, pressed Align and got Alignment Failed..Again Started all over again bur this time I decided to use "Sky Align" Once more entered all the data selectd and aligned the stars and finally got Alignment successful. WHEW!!! Picked out a few objects to go to with no success. I noticed the HC sort of blinking and dimming. I immedietly suspected a low battery in the Power Pack so I shut things down and started to charge the Power Pack. The red light came on indicating it was charging so I went back to securing the scope. THat job probably took me no more that 5 minutes and when I was going into the house I noticed that the green ligt was on indicating the Pack was fully charged. Based on all the foregoing my assumption is my cable is defective. What say you???? Post Extras:       Tel Postmaster Reged: 03/31/06 Loc: Wallingford England Re: Frustrated 8 SEer [Re: hamdul]       #5395166 - 08/30/12 03:55 PM Edit   Reply   Quote Quick Reply   Hi Fred, If you have no instrumental means of telling whether the cable is at fault, (e.g. you have no continuity meter), then merely place some fresh AAs,(not rechargeable AAs), in the mount and operate the 'scope solely from them. I'm not sure that this is the answer to your problem but if your 'scope works with the AAs, it throws suspicion on either your external power supply or indeed the cable, or possibly its connections to power supply and/or mount. Depending therefore on the result you receive from testing as of above, we'll take it from there. Hoping this helps, Best regards, Tel Post Extras:       Tel Postmaster Reged: 03/31/06 Loc: Wallingford England Re: Frustrated 8 SEer [Re: Tel]       #5395189 - 08/30/12 04:07 PM Edit   Reply   Quote Quick Reply   An additional thought, Fred,: After having placed the AAs in the mount, just check that it will rotate a full 360 degrees in Azimuth just to ensure that no damage has been caused to the drive as a result of that unfortunate cord wrap. Best regards, Tel Post Extras:       hamdul super member Reged: 06/23/09 Loc: Litchfield NH, USA Re: Frustrated 8 SEer [Re: Tel]       #5395644 - 08/30/12 09:01 PM Edit   Reply   Quote Quick Reply   Whew!!! I got a request from some little folks in the neighborhood to look at the moon tonight. I told them that because it was full it would not be a good moon to observe and besides that it would be so bright it would be stressful on their eyes, but they insisted so out the scope went. Since all I thought I would do was show them the moon I used "Solar System Alignment" and everything went like clockwork. After they all had their look, on a lark I tried to show them Saturn, so I plugged it in and low and behold the scope was off and stopped on Saturn. Not quite in the field but at least it showed me that my problems last night were over. Incidently I think the source of the problem was The connector to the battery was not in all the way. I realized that tomight when I was setting up. I'll wait a few nights when the moon will be less of a problem and give it another go round. Fred Post Extras:       Pages: 1 | 2 | 3 | 4 | (show all)

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