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TwoPi

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About TwoPi

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  1. Cheers, but the goal was to be able to focus all the EPs with and without the ext tube present. This is so I can have a filter screwed into the ext tube and quickly swap the tube in or out, regardless of which EP I'm viewing through.
  2. Hi again everyone. I've finally found some time to do some rough measurements and the table below summarises the situation. All measurements are from an arbitrary point on the focuser, at the base of the focus tube. Having thought about the figures, they don't quite add up (my focus range seems to vary by 2-3mm in some situations - I'm putting that down to dodgy tape measuring in the dark!). But hopefully the figures are good enough for you to get the drift. As you can see, without the extension tube I have to pull out the Ethos 13mm (in 2" mode), the Delos 8mm and Nagler zoom ever so slightly. No big deal. However, with the 1.5" extension tube in place, the Ethos 21mm and 13mm (in 1.25" mode) can't be brought to focus; they would need to be about 5mm and 12mm further in respectively. From this data, buying a 35mm extension tube isn't going to resolve the issue (and presumably the Ethos 21mm EP will lip out even further). Two other points: my MoonLite 2" to 1.25" adapter when added to the extension tube actually lips out slightly too, adding a further 2mm to the minimum focus length. And finally, as I said in an earlier post I can remove a 13mm spacer in the focuser, effectively adding 13mm to the focus distance required for each EP in my table above. As you can see, that solves the problem when the extension tube is in but without the tube, I can't pull 3 of the EPs out far enough to focus them. So in summary I think I'm wasting my time with this (and yours ) and probably just need to accept screwing/unscrewing the filters as a fact of life. Unless I'm missing something? Thanks as always for wading through all of this!
  3. Hi all, thanks as always for all the helpful replies. Steve, I think 35mm is still too long - my existing extension tube is 38mm (1.5") and although the 3mm of additional inwards travel might make the difference, I'm guessing it's not going to be enough. Robin, Steve is right, I meant a focus extender rather than a barrel extender, although I'm intrigued how this would affect things. Am I right in thinking these would change the focal length of my eyepieces (and that presumably they would only fit certain models of eyepiece)? I'm not trying to change the focal length, just gain enough inward and outward travel to reach focus across the range, with and without the extension tube. Or have I misunderstood? Danny, assuming that I've understood what the click-lock does, 47mm is definitely going to be too long. John, my ideal goal would to be able to focus my 21mm Ethos EP (2" as you know), 13mm Ethos (in both 2" and 1.25" fittings), 8mm Delos (1.25") and 3-6mm Nagler (1.25") EPs both with and without the extension tube in - so I can quickly swap between a filtered and unfiltered view. If I keep both base plates in the CR2 focuser (as designed) then I can achieve focus with everything bar the Nagler zoom, which I have to pull out of the focuser by a small amount due to lack of outward travel (no big deal as the MoonLite 2" to 1.25" adapter can sit slightly proud from the 2" EP holder if necessary or I can just not insert the Nagler in all of the way). One thing to note is that the MoonLite 2" to 1.25" adapter doesn't add more than 1-2mm to the length of the focuser - it sits fairly flush against 2" EP holder. If I then put the 1.5" extension tube in, I don't have enough inward travel - I need to recheck to remember exact which EP and barrel size combinations didn't work but I think it was the 13mm I was struggling with. I tried taking out one of the CR2 spacers (the smallest - approx. 12mm) but then I was struggling with outward travel without the extender in quite a few combinations - so I don't think this is the answer and I've put the spacer back in... So as to not waste everyone's time, I think the best thing for me to do would be to recheck and create a little chart so I can give you a clear description of what works and doesn't and whether more inward or outward travel is required in the various combinations. Thanks again for replies.
  4. Great replies as ever - thanks all. I'll take a closer look at the socket and circuit board and decide whether to continue to bodge the solution or sort it out once and for all! Cheers.
  5. Thanks for the replies chaps. I've found a few other threads mentioning this in passing but couldn't find a thread describing what was done in any detail. Is it obvious once you take the cover off or did you follow any particular instructions? I have a soldering iron but wouldn't consider myself an electronics expert. Ta once again.
  6. Hi. Just wondered if anyone else experiences the same problem that I do with the power supply jack plug of the SynScan GOTO AZ mount? The slightest rotation or knocking of the jack at the telescope mount end of the power cable results in a temporary power interruption to the handset, which then resets. Quite annoying midway though an observing session if you've carefully gained alignment and have to repeat the setup procedure. I've taped it in place which largely seems to do the trick, although I do still occasionally knock it in the dark when replacing the handset in the holder on the side of the mount. Some swearing usually follows. Seems pretty poor - wondering if I've been unlucky or if this is a fault anyone else has experienced? Cheers.
  7. Hi folks. I've got a 1.5" focus extension tube (this one) but I find that when it's in use with my 50mm travel MoonLite CR2 focuser, I can't achieve focus with some of my eyepieces (which of course seem to have wildly different focus points across models and mixtures of 1.25" and 2" EPs). I've tried taking the thinnest spacer out of the CR2 but then struggle to achieve focus when the extension tube isn't in place... basically the 1.5" extension tube I have is too long. The reason for all of this faffing around is that I thought it would be great to have a short extension tube for use with 2" filters that I could quickly swap in and out across my whole EP range (i.e. be able to focus my EPs with and without the extension tube and also with and without the standard MoonLite 2" to 1.25" adapter - the latter doesn't really alter the length of the focus tube at all because of the design). I'm beginning to think I should just give up and accept that I'll be screwing / unscrewing filters as required - it's not like I use them all the time so it's not the end of the world. However... my goal might still be achievable if I can find an extension tube between say 0.5" and 1" long? Obviously it needs to have a 2" filter thread, and it would also be great if it was a compression ring design too, so as to not mark the EP barrels. Anyone know of anything like this? Thanks as always.
  8. Fabulous site Ian, not seen that one before & very handy being able to select the altitude. Usefulness aside, I found the graphics quite mesmerising!
  9. Personally I think it's a marvellous EP, hope you enjoy yours as much!
  10. FLO is an online business so guess they process orders in the order they receive them. However, according to http://www.firstlightoptics.com/contact.html their office hours are M-F 9.30am-4.30pm
  11. This is also a handy site for seeing available darkness hours & whether the moon will interfere: http://www.dreistein.nl/dark.aspx (You need to enter your location & timezone first).
  12. Fab report as ever, sounds like a great night. I always find that you give me some new ideas; either things I'd forgotten about or things I never knew about! Thanks for taking the time to share it.
  13. You might also want to take a look at SatelliteTracker if you have a laptop. In theory this should do what you want it to do, but I'm struggling a bit in practice!
  14. Good to hear others are giving it a go - good luck folks As a follow up to my original post, I discovered that changing the telescope protocol setting in SatelliteTracker from NexStarGPS Continuous Tracking to Celestron CGE Continuous Tracking was better (the scope went to the right place and started tracking at the right point), but still failed after a short while with the same error message "Cannot get Celestron CGE Current Position!". Not tried it with ISS yet but will persevere and see if I can get it to work by fiddling with the settings a little more. Will report back if I succeed. Have fun everyone!
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