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Lonestar70

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Everything posted by Lonestar70

  1. Hi Wyldkatt, Welcome to SGL. Now that's what I call getting hooked... wish my other half would get a bit more interested. Best regards and clear skies. Sandy.
  2. Lonestar70

    hello

    Hi Sandy, Welcome to the club from another Sandy... that will confuse the sassenachs!!! I am a wee bit further up the west coast than you near Lochgilphead. Enjoy your time here and ask any questions you like, there is always someone who can answer them. Best regards. The other Sandy. :grin:
  3. On reflection, I think I should have posted my last entry in the DIY section but wanted to keep it along with the previous posts on this subject. If the modorators feel the entire subject should be moved to the DIY section then please do so. My appologies if it is in the wrong place. Best Regards. Sandy.
  4. Hi Skyscanner, As Astro_Baby has mentioned above, using the dials is quite easy once you get the hang of them so it is worth getting them set up correctly. Polar finder will show you where polaris should be at any given time... the trick is rotating your RA axis to get it exactly in the right place... easy when it's at 12oclock, 3 oclock, 6 oclock and 9oclock... but not so easy when in between. I don't actually use the dials (or the handset) since I have my HEQ5 mount connected to a laptop and control it using Ascom and EQMOD. This has the advantage of having a built in polar alignment facility which locates the correct position for polaris (it auto rotates the RA for you) and it also gets the time from the laptop and remembers your Latitude and Longitude settings, which the SW handset doesn't. Polar alignment using polaris only will be good enough for observation work and for picture capture of up to around 60 seconds MAX. depending upon how carefull you are with the setting. For longer exposures you will need to refine your polar alignment using DRIFT Alignment. Again, Ascom has a suitable solution in the form of EQalign... but there are several other programmes available for this function. Hope this helps a bit more. Best regards. Sandy.
  5. Hi All, Having done some more work on this subject and having rejected the long dovetail idea, since I think it could introduce unwanted flexture from the single point mounting... the following is the result of my playing around with a sliding weight balancer attachment. I first needed to establish the approx weights required for different set-ups Using the standard SW 210mm heavy-duty dovetail bar, and the scope pushed as far forward in the scope rings as possible, the scope is mounted on the HEQ5 at the back of the dovetail... Right under the focuser. With my Nikon D90 DLSR (quite a heavy lump), SW FR/FF and stepper motor focuser drive attached and with the focuser at normal focus position it was established that the counterweight necessary to balance the assembly in DEC was as follows: - 900gm (approx 2lb) at the front of the dovetail bar. 450gm (approx 1lb) at the front of the dew shield. To simulate a set-up similar to Gina’s with SW FR/FF + powered filter wheel + Atik CCD camera and the necessary extensions I fitted an additional 80mm long x 2” dia extension and racked the focuser all the way out. In this configuration the required balance weights were: - 1587gm (approx 3½ lb) at the front of the dovetail bar. 680gm (approx 1.5lb) at the front of the dew shield. From this it was clear that a sliding weight of around 800gm (approx 1.75lb) would satisfy both requirements. The standard heavy duty SW dovetail bar supplied with the ED80 pro had 2 convenient tapped holes (albeit one was ¼” UNC and the other was M6) available towards the front end, so these were used as the mounting points for the balancer assembly. The main T shaped mounting block was made from aluminium and was tapped 5/16” BSF on one vertical face to accommodate the slide bar. The slide bar is made from 5/16” dia stainless steel and is 270mm (10.625” long) including the threaded section which screws into the T mount block… thus it extends outward to almost the end of the dew shield. The outer end of the slide bar is drilled and tapped M5 to accommodate a safety stop. Originally I made a single sliding weight of some 880gm from a convenient piece of 1 3/4” dia brass bar that I had in my stock drawer (I did not see the point of cutting off an odd 3/8” or so as to make it exactly 800gm) This was drilled and tapped in 2 places M6 for the locking screws. The locking screws for the weight, and the stop screw for the end of the slide bar were made from stock 9/16” brass bar and knurled for easy tightening. The first photo shows all the original component parts. When first attached to the scope I found that the single weight was a little tricky to position easily, so I cut it in half in the lathe leaving me with 2 weights of 430gm (0.92lb) each. These proved far easier to set. These last 2 photos show the final assembly with the 2 weights fitted. In reality, I only need to use 1 weight for my DSLR set-up, when taking the weight of the slide bar, end stop and mounting block into consideration, since the original weights established would have been inclusive of this weight. I will keep the second one for later, when I go for a full CCD set-up. I can now easily balance the scope in DEC; whatever I choose to fit at the focuser end and I am very pleased with the outcome. I accept that this method does add a little extra weight, however, it is well within the capabilies of the HEQ5 and it overcomes the possibility of flexture when using an overhung long dovetail bar. I hope this gives some of you an idea of how to go about such a balancing act. Best Regards and clear skies to all. Sandy
  6. Lonestar70

    Balancer 2

    From the album: Lonestar70 Scope bits

    ED80 DEC balancer fitted and showing revised double weights.

    © A F Campbell

  7. Lonestar70

    Balancer 1

    From the album: Lonestar70 Scope bits

    ED80 DEC balancer showing component parts and original single weight.

    © A F Campbell

  8. Lonestar70

    Balancer 3

    From the album: Lonestar70 Scope bits

    ED80 DEC balancer close up showing attachment to dovetail bar.

    © A F Campbell

  9. Hi, The statement 'A fully 'Stabilised' mount' in my last post should have read 'A fully 'Stabilised power supply'. Sorry for the typo error... too many thumbs!!! Best regards. Sandy.
  10. Hi DeeRoy, Most modern mounts run from a NOMINAL 12v DC. A lot of people use a rechargeable 12v battery which, when fully charged will output 13.8v... this is quite normal. The mount electronics can take any voltage between 11v and 15v ( skywatcher/celestron ) without any problems. I would strongly suggest that you choose a good 'Stabilised' power supply, such as the one I listed or a similar quality one. I would steer away from the plugtop types, since the majority are not 'Stabilised' and their output voltage can vary quite a lot with load variations, or input voltage variations, meaning that you could quite easily apply too low a voltage (less than the minimum 11v) which would cause eratic behaviour of your mount or, worse still, too much voltage (more than the 15v max) which could damage your mounts electronics. (expensive repair job). A fully 'Stabilised' mount will provide a constant 13.8v at any current up to the maximum output current of the power supply. Your mount should not draw much more than 2 amps and the suggested power supply can provide 4 amps, leaving a fair margin for you to use the same supply for other items, such as a dew heater or camera. I hope this puts your mind at rest. Best Regards. Sandy.
  11. Hi SkyScanner, Polaris transits once every 24hrs approx but the exact time may differ for different locations. You can find the exact times for any day using the following FREE software. http://www.myastroimages.com/Polar_FinderScope_by_Jason_Dale/ it will also show you where the little polaris circle should be positioned (in your polarscope) at any given time on any given day. remember... your polarscope will show an inverted image so 0hrs/2400hrs will be with the small circle at the bottom when viewed through the polarscope for any of the daily polaris transit times. Hope this helps. Best regards. Sandy.
  12. Hi DeeRoy, This would do what you require: - http://www.rapidonline.com/electrical-power/fixed-out-13-8v-4-6a-cigar-socket-psu-85-1714 It is the same power supply as sold by several telescope suppliers but at a much lower price. Hope this helps. best regards. sandy.
  13. Hi Mike, How about using some 25mm aluminium electrolytic capacitor clamps (vertical) http://www.audiocap.co.uk/accessories-67-c.asp The second ones down should do the job. Hope this helps. Best Regards. Sandy.
  14. Hi Martin, Yes, I agree... cigarette connectors are very unreliable. I second the use of the 3pin (or more) XLR connectors... I use them for most of my power and data cables. As Chris has stated... the Anderson Powerpole connectors are also a great option and can be stacked to form multipole connectors if required... they are used a great deal for Radio controlled models (electric flight etc) and also for amateur radio. They are readily available in the Uk from the following: - http://www.mardave.co.uk http://www.northern-connectors.co.uk http://www.amazon.co.uk/Power-Pole-Connector-Black-Anderson-Sermos/... http://www.torberry.co.uk/powerpoles.php They are also available from various ebay suppliers. Hope this helps. Best regards. Sandy.
  15. Hi Riggy, I also use a Nikon DSLR and have found that mirror vibration is, for all intents and purposes, not a problem. As with most modern DSLR's the mirror mechanism is a very gentle affair... so don't worry about it. As for a dew shield... if you already have the standard Nikon flower petal type lens hood fitted then all you need is a cardboard tube (preferably black on the inside) that fits snuggly over the shield... make it so that it extends about 1 1/2" - 2" past the outer end of the lens hood. It does not really need to be insulated, but it would do no harm to cover the outside of it with some dark material (thin foam or velvet cloth). A couple of other points: - Shoot your frames in RAW mode... JPG is far too lossy and can also introduce conversion noise. Turn OFF in camera long exposure noise reduction. If you are using a high ISO (above 800) then also turn OFF high ISO noise reduction. Take some DARK exposures at exactly the same settings, and focus, as for your LIGHTs... and use them when you stack your images to eliminate/remove any noise. DISABLE the on camera flash. Cover the viewfinder (use the small black viewfinder cover supplied with the camera to prevent any light entering through it). After you have focused... Turn OFF Live view... and, as has already been stated, the auto preview of the pictures. These features will (a) cause the sensor to heat up and ( will use up battery capacity. I will second the recommendation for using a programmable electronic timer release... it certainly makes life a lot easier, and will ensure that all your exposures are exactly the same length... not always so easy with a manual release. One of the important things to remember is... leaving a delay between each exposure (a. to let the sensor cool down) and (b. to allow sufficient time for the transfer of the taken image to the memory card)... the programmable timer release can accomodate this very easily. I think that about covers most things you need to know... so HAPPY SHOOTING and let us know how you get on. Best regards. Sandy.
  16. Welcome to SGL Alan, There are a few clubs in Essex which you could look at, I am sure one, or more, would be within striking distance. Perhaps the members at one of them would help you with your scope and suggest how to get the best from it... it may only require a better eyepiece to improve your viewing. Castle Point Astronomy Club Clacton & District Astronomical Association Havering Astronomical Society Loughton Astronomical Society North Essex Astronomical Society (NEAS) Thurrock Astronomical Society I hope you find a suitable one from this list. Best regards and clear skies.
  17. Hi guy's, Not sure I totally agree with your last statements Neil. volatile long NoOfSteps = 1000; //required number of steps to make volatile long Position = 0; //used to keep track of the current motorposition volatile long MaxStep = 200000; //define maximum no. of steps, max travel volatile int SPEED = 500; Surely these 4 Variables can be changed outside the programme by e.g. the stand alone focuser test interface. And, presumably, any other interface using the ASCOM driver. Whilst the values assigned by the above declarations are a good basic starting point, not all focussers would use the same values. (mine certainly does not) The whole point of declaring them as volotile prevents the compiler from optimising them out or doing some other dastardly thing with them (as they often do) just to make the code more compact. I agree that the others could be made non-volatile since they are only ever assigned a final value by the programme once. Please correct me if I am wrong in this thinking. Best regards.
  18. Strictly speaking... the 2 scopes you show links to are not the same OD The first one is an 8" scope and the second is a 6" scope which will have markedly different tube OD's. Both sizes of scope are available on either type of mount so yes, in order to mount the DOB version of each size on an EQ mount then your last assumption regarding the correct tube ring size is correct... you would also need a suitable Dovetail bar. Best regards
  19. I forgot to add that the other advantage of using the FLO nosepiece is that you can easily rotate your camera for framing... not so easy with the FF/FR directly screwed in place. Best regards. Sandy.
  20. Hi Amajed, Yes it screws directly to the focusser tube when you unscrew the standard 2" eyepiece holder, however this makes using any additional filters tricky (other than the clip in versions for canon camera's. What I do is leave the standard 2" eyepiece holder (standard fitting on the draw tube) attached, and use a 2" nose piece (available from FLO for use with this FF/FR) which has the facility for screw in 2" filters. The whole FF/FR + t-ring and camera then become a single assembly... just like a normal 2" eyepiece. Best regards.
  21. Hi Amajed, The correct FF/FR for your scope would be the SW 0.85... it has been optimised for that scope. The SW 0.85 FF/FR and the corect M48 - T adaptor for your camera are currently available from http://www.harrisontelescopes.co.uk/acatalog/Focal_Reducers.html Both are showing as in stock and just as FLO they are a trusted company to deal with. You will not require any additional extenders for this combination. Hope this is of help. Best regards. Sandy.
  22. Hi Sam, Ok, that explains a lot... I have just been looking at the manual for your scope and it would appear that the 2" extension is required to achieve focus when using standard eyepieces... so you may find you have to re-fit it when you dont use the barlow. It also appears that the focuser is a low profile unit which is good for achieving focus (prime) with a DSLR camera. It clearly states that the extension should be removed and the t-ring directly attached to the focusser tube. The Meade #140 barlow,Quite a long looking afair, is also shown in the manual, and seems to have the extension built in so again the normal extension would need to be removed. Seems a very strange way of arranging the optics though... but Meade tend to do strange things at times. Anyway, you have got it sorted for the time being. That just leaves the tube rotation to sort out and you will be away and running. Have fun. Best regards.
  23. Hi Sam, A barlow lens will/should make the focal point further out from the focusser so would require greater OUTWARD travel to bring an eyepiece, or camera, to focus. Have you tried focussing over the full range of focusser travel?... go slowly, as it's quite easy to miss the correct position. As for modifying your tube to allow front end rotation... NOT a good idea as it would certainly play havoc with collimation. The normal course would be to slacken both the tube rings and rotate the whole OTA to bring the eyepiece to a more suitable position for viewing, then tighten the rings again. A third ring fitted to the OTA just above and just touching the top ring but not attached to the dovetail bar will prevent the whole OTA slipping down when adjusting the orientation. Do a search for "rotation ring" on the forum... there have been several posts showing how these can be easily made and fitted. Hope this helps. Best Regards.
  24. Hi Whistlebare, Don't fret about it... a lot of us (including me) made the same mistakes when we first started. I find it a lot easier to polar align the mount without the scope attached... the mount can get into some very wierd positions sometimes in order to get the polar circle in the right place and this would often mean the scope would hit the mount if it were attached... I have to set up every time, since I don't have a fixed pier... once polar aligned I return the mount to the Home position and fit the scope and balance it... returning to the home position again before starting star alignment. You have the luxury of a fixed pier so once you have got it polar aligned you would only need to check it from time to time. (nice pier by the way). Anyway, glad you got it sorted. I am a good bit further up the west coast to you... near Lochgilphead.... lovely dark skies though... WHEN IT STOPS RAINING that is... Keep happy. Best regards.
  25. Hi, You need to return the scope and mount to the Home position (weights down and scope pointing towards polaris) before you attempt star alignment. The mount makes the assumption that this is the position it is starting from before slewing to the first alignment star. If, as it would seem you are doing, you leave the scope and mount in the position you had it for Polar alignment then the mount just assumes it is in the Home position and you end up with it slewing into the mount. Hope this helps. Best regards.
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