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Fellside

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    75
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About Fellside

  • Rank
    Nebula

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  • Gender
    Male
  • Interests
    Astronomy, Fly fishing
  • Location
    South Lakes
  1. Hi I`m looking for a Howie Glatter Single-Beam 2-inch Laser. You may have one sitting in a draw and is never used. Regards Graham
  2. Fellside

    RC10c Summer refit

    John Does the RC8 Tilt adapter isolate the image train from the Mirror cell or does it screw onto the mirror cell thread. Make sure your laser is collimated. Ideally the laser should be screwed into the focuser but not many can do that. Hotech SCA laser Collimator comes with a automatically centering device which may help get accurate alignment. https://www.firstlightoptics.com/hotech-collimation-tools/hotech-sca-laser-collimator.html With the laser in place it should only take a few minutes using the push/pull screws to get the red dot in the center of the secondary donut marker. As many others have said the donut is probably marking the mechanical center of the secondary mirror and not he optical center. But it will probably be close. Graham
  3. Fellside

    RC10c Summer refit

    John I have the the same manual for the RC10. My secondary mirror was not removed. From what you say it is as well that i did not remove it. There is a small amount of dust on the secondary but nothing like the amount I had on the primary mirror. Graham
  4. Fellside

    RC10c Summer refit

    Neil 1% and 2020 does sound much more like a manufacturing tolerance. I think that is a good place to start. Thanks John I have not seen any published dimensions for the the distance between mirrors. I may be wrong. I should think it is fairly hard to measure the distance with the mirrors installed in the tube anyway. I will go with setting the focal length and see what sort of images I can get. Graham
  5. Fellside

    RC10c Summer refit

    John Before the refit I had a plate solved image that showed the Focal length as 2191mm. The further you are from the true Focal length the harder it is the setup a good collimation. I will take Plate solved images and depending on what I get I will try to move the primary mirror towards the secondary or away from it and keep it collimated. I sure I have read somewhere that the figured FL is written on the primary mirror. Apart from the hand written text on the edge of the mirror, see the first post on this thread. On the back of the mirror etched into the glass was Y202. Does that mean plus 202 so that's 2202. That seems a long way from the advertised 2000 FL. Not sure. When I am happy with images I will stop. At that point I will fit the CCDT67 reducer. Graham
  6. Fellside

    RC10c Summer refit

    I tested the Secondary dew heater this afternoon and it is showing 11Watts at 0.8Amps on the Powerbox software. On full it was to hot to touch. So there is plenty of head room for those subzero nights in mid winter. Thanks for reading Graham
  7. Fellside

    RC10c Summer refit

    All the equipment installed and ready to go. Just need a clear night or two to get the collimation finished. Normally the weather will break at this point. RC owners seem to be very much in the minority but I hope one or two of you found this useful. The fear of collimation has given these great scopes a bad name. Other opinions may differ.
  8. Fellside

    RC10c Summer refit

    The whole back plate and mirror assemble is lowered back into its original position and all screws fitted loosely before a final tighten. In the picture below you can see the 2 pin GX12/GX16 socket for connection to the dew heater. These are very nice plug/socket combination and I would have fitted a 4 pin version if I had fitted the primary dew heater. I left the original plug socket arrangement for the fan motor supply in place as it works ok at the moment. I will see how things go over the next winter as to if there is another refit next year. This will be for Primary dew heater, some sort of DIY Snap Flap. Another thing I have thought about is shortening the top and bottom Losmandy rails and fitting a tube ring maybe half way along the tube. When fitted to the mount the scope is always fitted as far forward as possible so this would not cause a problem. But on the other hand automatic temperature compensation on the focuser may be able to take care of any supposed movement in the tube. All finished and ready to fit back on the mount. Here we are safely back on the mount. One 25mm extension ring had to be removed to allow the correct back focus. I now have the Tilt ring plus one 25mm extension ring fitted and focus is around half focuser travel. This will change when a reducer is fitted. Focuser has been changed to a TS-Optics 3 Inch Rack and Pinion focuser TSFOCR30S. I`m very impressed with this focuser and its good value compared to others of this size and load carrying capacity. There are a number of thread size combinations. It is possible to fit a reducer internally and have an all threaded image train. The 2"/1.25" unit show is to allow the fitting of a laser for collimation. I would like to have a threaded fitting for the laser but you have to stop somewhere and after all these things only get you close to collimation. Its a star test that counts.
  9. Fellside

    RC10c Summer refit

    The thing I had been putting off until last. Cleaning the mirror. Once the mirror cell was removed from the back plate I could see the probable cause of the triangular stars in the test images I had taken. Pinched optics. The mirror was sitting in the cell on three cork pads bur at three locations a fairly rigid black silicon product had been injected through holes to glue the mirror in place. It all seemed quite tight. A slight surprise was that there were no mirror safety clips screwed to the edge of the cell. Other RC10 I had see on the web had the clips in place. Removing the baffle tube is just a matter of unscrewing it. The mirror locking ring has two small grubscrews that lock the ring in place on the protruding mirror cell thread. These do not need the be removed completely just wound out a couple of turns. The locking ring is then removed. You cant forget that you are working above the mirror surface and you do not want to touch it. The next part was the most time consuming. That was cutting through the three silicon pads as I had decided to remove the mirror from the cell. It would be possible to clean the mirror with it still fixed in the cell. The three mirror supporting cork pads and the three that centralize the cell in the back plate. These were trimmed of with a Stanley knife blade and the remaining sticky mess cleaned off with a mentholated spirit soaked cloth. Springs that surround the collimation pull screws were fixed in place with a blob of silicon adhesive and left over night to set. This I hoped would stop a lot of frustration and hair pulling when refitting the back plate to the mirror cell. Another idea from the web. I did a few tests with these velcro pads before I started. The adhesive was strong as long and the surface was smooth and clean. when to two parts (hooks and loops) were pushed together they were about the same thickness as the cork strip they were replacing. So the mirror cell was thoroughly cleaned with mentholated spirit and the pads were stuck in place. Half size pad were used at the edge. There is a raise area on the casting that was the location for the three cork pads. I sited the velcro to miss these raised locations. Leave the top protective paper layer in place for now. In the picture above you can see the remains of the silicon mirror holding pads. I had to improvise for the new safety clips as it was Sunday afternoon and the shops were shut. I found an old transistor heatsink. With a bit of cutting and filing three clips were manufactured. Not as pretty as I wanted but they are hidden inside the scope. The were made to have the smallest mirror overlap. Three holes were drilled and tapped in the side of the cell to hold the clips in place. The clips are a bit of overkill really as the mirror is going nowhere with the central retaining nut keeping things in place. Three remaining pieces of cork strip were placed in the cell to help with mirror alignment. These were removed after the mirror was reinstalled in the cell. I wont go into the detail of mirror cleaning as there are plenty of tutorials to read up on. Like a lot of people say the best advice is to not clean your optics. But if you have to its at you risk. get everything you think you may need ready and do it on a quiet day when you can concentrate on your own and do not rush. Nobody can hear you when it all goes wrong My mirror was in a sink of warm water with a touch of soap. Sloshing it about I noticed a blooming pattern from part of the edge and all round the central hole was appearing. At this point don't panic I had a spray Baader Planetarium's Optical Wonder Fluid just for such emergency. Spray with the Baader fluid and left for a minute not allowing it to dry out. Back in fresh warmer water and using a microfiber lens cloth to gently waft over the mirror surface under the water. All the blooming disappeared and did not return after the mirror was dryer using a hair dryer. I have know idea what the blooming was. It may have been a residue already on the surface or the type of soap I used. once it was dry I was very please with the result. When the mirror was dry the back was cleaned with a small amount of Meths and it was gently lowered back into the cell taking care to install it in the same position as it originally was. I carefully wound on the central mirror retaining ring. This was tighten more than necessary to compress the velcro strips and allow the adhesive to create a strong bond. After a cup of tea the ring was retighten to a point where the lower "O" ring is just pressing in the mirror surface. The two grubscews were then wound in to lock the ring in place. Baffle tube screwed back in place and all is complete. Ready for fitting back in the tube.
  10. Fellside

    RC10c Summer refit

    Next job is the fit the Secondary mirror dew heater. View with the tube sitting on end. Secondary baffle at the bottom and all those Molded plastic baffles. I have see a couple of sites that say the baffles serve no purpose and may even cause turbulence in the air currents percent in the tube. I decided to leave them in for now. Flocking the inside of the tube is an option for the future, The baffles are a snug fit in the tube only and are not attached with any type of glue. The baffles have a very convenient channel molded into them. I assume this is to allow clearance on the seam that is present inside the steel tube version. All the baffles are removed and slipped back in feeding the dew heater supply wire in as you go. The dew heater kit came from Telescope Services as nobody else seem to stock them in the UK. As usual it arrive very quickly. As always from TS. The "C" shape heater has to be glued in position with a silicon adhesive. I cut the out going wire to size before installation, it easier out of the scope. Self adhesive copper strip from Ebay is used to carry the current across the spider arm. It keeps everything nice and thin. The copper is really easy to work with and a like a few things on this refit it is another great idea picked up on the web. I was slightly concerned that the copper tape would lift when the heat of soldering was applied. But I suppose that is what this tape is deigned for. I once made a Terrarium out of glass, this same tape and solder. Anyway both ends soldered and everything kept out of the light path. The wire cores at the back plate end were fitted with some simple crimp on bullet type connectors to allow easier assembly when the time came, The wire and tape were given a coat of flat back paint and that was another job complete.
  11. Fellside

    RC10c Summer refit

    The main reason for the refit was to fit Moonlite tilt adapter plate. This is surprisingly easy once the scope is in pieces. Here is the kit contents. Two piece Aluminum ring, "O" ring and a bag of Imperial screws. Some of the screws seam to have nothing to do with the fitting of the ring. Instruction sheet quotes drill sizes in 64ths. I selected a suitable metric equivalent. The "O" ring is used as an alignment tool and fits over the thread protruding from the mirror cell. The lower part of the plate is a tight fit onto the "O" ring. The top tilt plate has to be removed to allow the next part of the process. The lower ring is positioned so that it is clear of the fans and using a drill the position of the mounting holes is marked. My plate only had three screws/holes to mount it to the back plate but I am sure I have seen other versions with six screws, Three are adequate. Remove the plate and "O" ring (no longer Required). Remove the mirror cell by removing the Collimation screws. Complete the drilling of the holes through the back plate. Using nuts, spacers and washers (loctite) fit the rear plate in position. All that's left is to fit the tilt plate and the main part of the job is complete. When complete the mirror cell is no longer connected to the image train.
  12. Fellside

    RC10c Summer refit

    The reasons for the refit were. Fit a Moonlite tilt adapter plate. This also removes the link between the image train and the mirror cell. Fit Secondary dew heater with concealed wiring. Fit primary dew heater. I was not sure what I was up against with this as far as what sort/size of heater was required. This in the end was not fitted. But If the scope is ever in pieces again I will know what is required. Clean the primary mirror. With this my thoughts were while the scope was in pieced I might as well take the opportunity to clean the mirror. I thought a few pictures might help other GSO RC owners out there so here goes The wife was away for the weekend so the kitchen table became an operating table for the RC. Ok ready to start. Thread protruding from the Mirror cell has cork packing to keep it central with the back plate. This wont be required soon. The whole end plate assembly with mirror cell and baffle tube lifts out easily. It is surprisingly heavy. Collimation push pull screws removed. Count the turns on the way out. I don't know what was going on with this scope one screw was three turn different to the other two. Baffle tube removed and the mirror put away safely to be cleaned when the scope is ready for reassembly. Mirror surface was dusty and worryingly there were a couple of small smears on the surface.
  13. Hi I got this scope secondhand last year had planed to strip it down and carry out a few mods. When I got it home the mirror was loose and once I got it setup images confirmed the collimation was way out. Images had oval and triangular stars. I used Prism 10`s optic analysis tools which confirmed there was a lot of tilt in the images. Anyway the scope it now stripped. To confirm the tilt diagnosis one of the push grub screws was wound back three turns from the position of the other two. The mirror has some text hand written on the edge. I have seen this mentioned on another site but I cart find it now. I assume it is the actual focal length of this mirror. They don't always come out bang on the stated 2000 focal length every time. Anybody could come up with a idea what it say`s would be most appreciated. I will post more on the refit when I have finished.
  14. Fellside

    Fellside OB is water tight

    James By coincidence I spoted the pin sticking out of the rear wall on Sara's build as well. What a good idear The other end of my ROR will have a piece of steel plate on the moving part and right angle piece on the fixed part. Moving plate passes under fixed part and is trapped and cannot rise up. I will post some pictures when its done. You have a lathe at home. I wished I had a lathe Why are you thinking of buying anything I have work now for two weeks so everything stops. Graham
  15. Fellside

    Fellside OB is water tight

    Newstargazer01 Here are a few more pictures of the ROR. I am just working out how to stop the roof lifting off if the roof closes and the clamps are not on. Prism decides its to windy to continue imaging and closes the roof. Wind gets stronger. No clams and I in bed I friend is making up some parts. Hopefully they will be fitted before the winter. ROR is a fairly simple structure using 50 x 100 Tantalized timber and plenty of screws. The corrugated steel sheet adds a lot of strength and rigidity to the structure when it is screwed on. The whole structure is rap`d in a breathable membrane fabric to help with condensation and as a finale defense against wind/drafts and water leaks. There is a small slope to the ROR roof so that water runs off onto the fixed roof and then into the end gutter. If you live in a very wind spot just add more longer screws to hold the sheets on. V rails and 6 wheels from FH Brundle http://www.fhbrundle.co.uk/groups/13C__Sliding_Gate http://www.fhbrundle.co.uk/products/0515096__T_Wheel_120x16mm_With_Internal_Support_Max_300_Kgs_V_Groove http://www.fhbrundle.co.uk/products/0587604000__3_metre_Track_for_V_Grooved_Wheels_in_galvanised_steel
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